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Bruce Momjian authoredBruce Momjian authored
postgres.c 111.84 KiB
/*-------------------------------------------------------------------------
*
* postgres.c
* POSTGRES C Backend Interface
*
* Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/tcop/postgres.c
*
* NOTES
* this is the "main" module of the postgres backend and
* hence the main module of the "traffic cop".
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <fcntl.h>
#include <limits.h>
#include <signal.h>
#include <time.h>
#include <unistd.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#ifdef HAVE_SYS_RESOURCE_H
#include <sys/time.h>
#include <sys/resource.h>
#endif
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#ifndef HAVE_GETRUSAGE
#include "rusagestub.h"
#endif
#include "access/printtup.h"
#include "access/xact.h"
#include "catalog/pg_type.h"
#include "commands/async.h"
#include "commands/prepare.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "nodes/print.h"
#include "optimizer/planner.h"
#include "pgstat.h"
#include "pg_trace.h"
#include "parser/analyze.h"
#include "parser/parser.h"
#include "postmaster/autovacuum.h"
#include "postmaster/postmaster.h"
#include "replication/walsender.h"
#include "rewrite/rewriteHandler.h"
#include "storage/bufmgr.h"
#include "storage/ipc.h"
#include "storage/proc.h"
#include "storage/procsignal.h"
#include "storage/sinval.h"
#include "tcop/fastpath.h"
#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
#include "tcop/utility.h"#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "utils/snapmgr.h"
#include "mb/pg_wchar.h"
extern char *optarg;
extern int optind;
#ifdef HAVE_INT_OPTRESET
extern int optreset; /* might not be declared by system headers */
#endif
/* ----------------
* global variables
* ----------------
*/
const char *debug_query_string; /* client-supplied query string */
/* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
CommandDest whereToSendOutput = DestDebug;
/* flag for logging end of session */
bool Log_disconnections = false;
int log_statement = LOGSTMT_NONE;
/* GUC variable for maximum stack depth (measured in kilobytes) */
int max_stack_depth = 100;
/* wait N seconds to allow attach from a debugger */
int PostAuthDelay = 0;
/* ----------------
* private variables
* ----------------
*/
/* max_stack_depth converted to bytes for speed of checking */
static long max_stack_depth_bytes = 100 * 1024L;
/*
* Stack base pointer -- initialized by PostgresMain. This is not static
* so that PL/Java can modify it.
*/
char *stack_base_ptr = NULL;
/*
* On IA64 we also have to remember the register stack base.
*/
#if defined(__ia64__) || defined(__ia64)
char *register_stack_base_ptr = NULL;
#endif
/*
* Flag to mark SIGHUP. Whenever the main loop comes around it
* will reread the configuration file. (Better than doing the
* reading in the signal handler, ey?)
*/
static volatile sig_atomic_t got_SIGHUP = false;
/*
* Flag to keep track of whether we have started a transaction.
* For extended query protocol this has to be remembered across messages.
*/
static bool xact_started = false;
/*
* Flag to indicate that we are doing the outer loop's read-from-client,
* as opposed to any random read from client that might happen within
* commands like COPY FROM STDIN.
*/
static bool DoingCommandRead = false;
/*
* Flags to implement skip-till-Sync-after-error behavior for messages of
* the extended query protocol.
*/
static bool doing_extended_query_message = false;
static bool ignore_till_sync = false;
/*
* If an unnamed prepared statement exists, it's stored here.
* We keep it separate from the hashtable kept by commands/prepare.c
* in order to reduce overhead for short-lived queries.
*/
static CachedPlanSource *unnamed_stmt_psrc = NULL;
/* workspace for building a new unnamed statement in */
static MemoryContext unnamed_stmt_context = NULL;
/* assorted command-line switches */
static const char *userDoption = NULL; /* -D switch */
static bool EchoQuery = false; /* -E switch */
/*
* people who want to use EOF should #define DONTUSENEWLINE in
* tcop/tcopdebug.h
*/
#ifndef TCOP_DONTUSENEWLINE
static int UseNewLine = 1; /* Use newlines query delimiters (the default) */
#else
static int UseNewLine = 0; /* Use EOF as query delimiters */
#endif /* TCOP_DONTUSENEWLINE */
/* whether or not, and why, we were cancelled by conflict with recovery */
static bool RecoveryConflictPending = false;
static bool RecoveryConflictRetryable = true;
static ProcSignalReason RecoveryConflictReason;
/* ----------------------------------------------------------------
* decls for routines only used in this file
* ----------------------------------------------------------------
*/
static int InteractiveBackend(StringInfo inBuf);
static int interactive_getc(void);
static int SocketBackend(StringInfo inBuf);
static int ReadCommand(StringInfo inBuf);
static List *pg_rewrite_query(Query *query);
static bool check_log_statement(List *stmt_list);
static int errdetail_execute(List *raw_parsetree_list);
static int errdetail_params(ParamListInfo params);
static int errdetail_abort(void);
static int errdetail_recovery_conflict(void);
static void start_xact_command(void);
static void finish_xact_command(void);
static bool IsTransactionExitStmt(Node *parsetree);
static bool IsTransactionExitStmtList(List *parseTrees);
static bool IsTransactionStmtList(List *parseTrees);
static void drop_unnamed_stmt(void);
static void SigHupHandler(SIGNAL_ARGS);
static void log_disconnections(int code, Datum arg);
/* ----------------------------------------------------------------
* routines to obtain user input
* ----------------------------------------------------------------
*/
/* ----------------
* InteractiveBackend() is called for user interactive connections
*
* the string entered by the user is placed in its parameter inBuf,
* and we act like a Q message was received.
*
* EOF is returned if end-of-file input is seen; time to shut down.
* ----------------
*/
static int
InteractiveBackend(StringInfo inBuf)
{
int c; /* character read from getc() */
bool end = false; /* end-of-input flag */
bool backslashSeen = false; /* have we seen a \ ? */
/*
* display a prompt and obtain input from the user
*/
printf("backend> ");
fflush(stdout);
resetStringInfo(inBuf);
if (UseNewLine)
{
/*
* if we are using \n as a delimiter, then read characters until the
* \n.
*/
while ((c = interactive_getc()) != EOF)
{
if (c == '\n')
{
if (backslashSeen)
{
/* discard backslash from inBuf */
inBuf->data[--inBuf->len] = '\0';
backslashSeen = false;
continue;
}
else
{
/* keep the newline character */
appendStringInfoChar(inBuf, '\n');
break;
}
}
else if (c == '\\')
backslashSeen = true;
else
backslashSeen = false;
appendStringInfoChar(inBuf, (char) c);
}
if (c == EOF)
end = true;
}
else
{
/*
* otherwise read characters until EOF.
*/ while ((c = interactive_getc()) != EOF)
appendStringInfoChar(inBuf, (char) c);
/* No input before EOF signal means time to quit. */
if (inBuf->len == 0)
end = true;
}
if (end)
return EOF;
/*
* otherwise we have a user query so process it.
*/
/* Add '\0' to make it look the same as message case. */
appendStringInfoChar(inBuf, (char) '\0');
/*
* if the query echo flag was given, print the query..
*/
if (EchoQuery)
printf("statement: %s\n", inBuf->data);
fflush(stdout);
return 'Q';
}
/*
* interactive_getc -- collect one character from stdin
*
* Even though we are not reading from a "client" process, we still want to
* respond to signals, particularly SIGTERM/SIGQUIT. Hence we must use
* prepare_for_client_read and client_read_ended.
*/
static int
interactive_getc(void)
{
int c;
prepare_for_client_read();
c = getc(stdin);
client_read_ended();
return c;
}
/* ----------------
* SocketBackend() Is called for frontend-backend connections
*
* Returns the message type code, and loads message body data into inBuf.
*
* EOF is returned if the connection is lost.
* ----------------
*/
static int
SocketBackend(StringInfo inBuf)
{
int qtype;
/*
* Get message type code from the frontend.
*/
qtype = pq_getbyte();
if (qtype == EOF) /* frontend disconnected */
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected EOF on client connection")));
return qtype; }
/*
* Validate message type code before trying to read body; if we have lost
* sync, better to say "command unknown" than to run out of memory because
* we used garbage as a length word.
*
* This also gives us a place to set the doing_extended_query_message flag
* as soon as possible.
*/
switch (qtype)
{
case 'Q': /* simple query */
doing_extended_query_message = false;
if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
{
/* old style without length word; convert */
if (pq_getstring(inBuf))
{
ereport(COMMERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("unexpected EOF on client connection")));
return EOF;
}
}
break;
case 'F': /* fastpath function call */
/* we let fastpath.c cope with old-style input of this */
doing_extended_query_message = false;
break;
case 'X': /* terminate */
doing_extended_query_message = false;
ignore_till_sync = false;
break;
case 'B': /* bind */
case 'C': /* close */
case 'D': /* describe */
case 'E': /* execute */
case 'H': /* flush */
case 'P': /* parse */
doing_extended_query_message = true;
/* these are only legal in protocol 3 */
if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d", qtype)));
break;
case 'S': /* sync */
/* stop any active skip-till-Sync */
ignore_till_sync = false;
/* mark not-extended, so that a new error doesn't begin skip */
doing_extended_query_message = false;
/* only legal in protocol 3 */
if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d", qtype)));
break;
case 'd': /* copy data */
case 'c': /* copy done */
case 'f': /* copy fail */
doing_extended_query_message = false;
/* these are only legal in protocol 3 */
if (PG_PROTOCOL_MAJOR(FrontendProtocol) < 3)
ereport(FATAL, (errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d", qtype)));
break;
default:
/*
* Otherwise we got garbage from the frontend. We treat this as
* fatal because we have probably lost message boundary sync, and
* there's no good way to recover.
*/
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d", qtype)));
break;
}
/*
* In protocol version 3, all frontend messages have a length word next
* after the type code; we can read the message contents independently of
* the type.
*/
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 3)
{
if (pq_getmessage(inBuf, 0))
return EOF; /* suitable message already logged */
}
return qtype;
}
/* ----------------
* ReadCommand reads a command from either the frontend or
* standard input, places it in inBuf, and returns the
* message type code (first byte of the message).
* EOF is returned if end of file.
* ----------------
*/
static int
ReadCommand(StringInfo inBuf)
{
int result;
if (whereToSendOutput == DestRemote)
result = SocketBackend(inBuf);
else
result = InteractiveBackend(inBuf);
return result;
}
/*
* prepare_for_client_read -- set up to possibly block on client input
*
* This must be called immediately before any low-level read from the
* client connection. It is necessary to do it at a sufficiently low level
* that there won't be any other operations except the read kernel call
* itself between this call and the subsequent client_read_ended() call.
* In particular there mustn't be use of malloc() or other potentially
* non-reentrant libc functions. This restriction makes it safe for us
* to allow interrupt service routines to execute nontrivial code while
* we are waiting for input.
*/
void
prepare_for_client_read(void)
{
if (DoingCommandRead)
{
/* Enable immediate processing of asynchronous signals */
EnableNotifyInterrupt();
EnableCatchupInterrupt();
/* Allow cancel/die interrupts to be processed while waiting */
ImmediateInterruptOK = true;
/* And don't forget to detect one that already arrived */
CHECK_FOR_INTERRUPTS();
}
}
/*
* client_read_ended -- get out of the client-input state
*/
void
client_read_ended(void)
{
if (DoingCommandRead)
{
ImmediateInterruptOK = false;
DisableNotifyInterrupt();
DisableCatchupInterrupt();
}
}
/*
* Do raw parsing (only).
*
* A list of parsetrees is returned, since there might be multiple
* commands in the given string.
*
* NOTE: for interactive queries, it is important to keep this routine
* separate from the analysis & rewrite stages. Analysis and rewriting
* cannot be done in an aborted transaction, since they require access to
* database tables. So, we rely on the raw parser to determine whether
* we've seen a COMMIT or ABORT command; when we are in abort state, other
* commands are not processed any further than the raw parse stage.
*/
List *
pg_parse_query(const char *query_string)
{
List *raw_parsetree_list;
TRACE_POSTGRESQL_QUERY_PARSE_START(query_string);
if (log_parser_stats)
ResetUsage();
raw_parsetree_list = raw_parser(query_string);
if (log_parser_stats)
ShowUsage("PARSER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass raw parsetrees through copyObject() */
{
List *new_list = (List *) copyObject(raw_parsetree_list);
/* This checks both copyObject() and the equal() routines... */
if (!equal(new_list, raw_parsetree_list))
elog(WARNING, "copyObject() failed to produce an equal raw parse tree");
else
raw_parsetree_list = new_list;
}
#endif
TRACE_POSTGRESQL_QUERY_PARSE_DONE(query_string);
return raw_parsetree_list;
}
/*
* Given a raw parsetree (gram.y output), and optionally information about
* types of parameter symbols ($n), perform parse analysis and rule rewriting.
*
* A list of Query nodes is returned, since either the analyzer or the
* rewriter might expand one query to several.
*
* NOTE: for reasons mentioned above, this must be separate from raw parsing.
*/
List *
pg_analyze_and_rewrite(Node *parsetree, const char *query_string,
Oid *paramTypes, int numParams)
{
Query *query;
List *querytree_list;
TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
/*
* (1) Perform parse analysis.
*/
if (log_parser_stats)
ResetUsage();
query = parse_analyze(parsetree, query_string, paramTypes, numParams);
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
/*
* (2) Rewrite the queries, as necessary
*/
querytree_list = pg_rewrite_query(query);
TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
return querytree_list;
}
/*
* Do parse analysis and rewriting. This is the same as pg_analyze_and_rewrite
* except that external-parameter resolution is determined by parser callback
* hooks instead of a fixed list of parameter datatypes.
*/
List *
pg_analyze_and_rewrite_params(Node *parsetree,
const char *query_string,
ParserSetupHook parserSetup,
void *parserSetupArg)
{
ParseState *pstate;
Query *query;
List *querytree_list;
Assert(query_string != NULL); /* required as of 8.4 */
TRACE_POSTGRESQL_QUERY_REWRITE_START(query_string);
/*
* (1) Perform parse analysis.
*/
if (log_parser_stats)
ResetUsage();
pstate = make_parsestate(NULL);
pstate->p_sourcetext = query_string;
(*parserSetup) (pstate, parserSetupArg);
query = transformStmt(pstate, parsetree);
free_parsestate(pstate);
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
/*
* (2) Rewrite the queries, as necessary
*/
querytree_list = pg_rewrite_query(query);
TRACE_POSTGRESQL_QUERY_REWRITE_DONE(query_string);
return querytree_list;
}
/*
* Perform rewriting of a query produced by parse analysis.
*
* Note: query must just have come from the parser, because we do not do
* AcquireRewriteLocks() on it.
*/
static List *
pg_rewrite_query(Query *query)
{
List *querytree_list;
if (Debug_print_parse)
elog_node_display(LOG, "parse tree", query,
Debug_pretty_print);
if (log_parser_stats)
ResetUsage();
if (query->commandType == CMD_UTILITY)
{
/* don't rewrite utilities, just dump 'em into result list */
querytree_list = list_make1(query);
}
else
{
/* rewrite regular queries */
querytree_list = QueryRewrite(query);
}
if (log_parser_stats)
ShowUsage("REWRITER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass querytree output through copyObject() */
{
List *new_list;
new_list = (List *) copyObject(querytree_list);
/* This checks both copyObject() and the equal() routines... */
if (!equal(new_list, querytree_list))
elog(WARNING, "copyObject() failed to produce equal parse tree");
else
querytree_list = new_list;
}
#endif
if (Debug_print_rewritten)
elog_node_display(LOG, "rewritten parse tree", querytree_list,
Debug_pretty_print);
return querytree_list;
}
/*
* Generate a plan for a single already-rewritten query.
* This is a thin wrapper around planner() and takes the same parameters.
*/
PlannedStmt *
pg_plan_query(Query *querytree, int cursorOptions, ParamListInfo boundParams)
{
PlannedStmt *plan;
/* Utility commands have no plans. */
if (querytree->commandType == CMD_UTILITY)
return NULL;
/* Planner must have a snapshot in case it calls user-defined functions. */
Assert(ActiveSnapshotSet());
TRACE_POSTGRESQL_QUERY_PLAN_START();
if (log_planner_stats)
ResetUsage();
/* call the optimizer */
plan = planner(querytree, cursorOptions, boundParams);
if (log_planner_stats)
ShowUsage("PLANNER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass plan output through copyObject() */
{
PlannedStmt *new_plan = (PlannedStmt *) copyObject(plan);
/*
* equal() currently does not have routines to compare Plan nodes, so
* don't try to test equality here. Perhaps fix someday?
*/
#ifdef NOT_USED
/* This checks both copyObject() and the equal() routines... */
if (!equal(new_plan, plan))
elog(WARNING, "copyObject() failed to produce an equal plan tree");
else
#endif
plan = new_plan;
}
#endif
/*
* Print plan if debugging.
*/
if (Debug_print_plan)
elog_node_display(LOG, "plan", plan, Debug_pretty_print);
TRACE_POSTGRESQL_QUERY_PLAN_DONE();
return plan;
}
/*
* Generate plans for a list of already-rewritten queries.
*
* Normal optimizable statements generate PlannedStmt entries in the result
* list. Utility statements are simply represented by their statement nodes.
*/
List *
pg_plan_queries(List *querytrees, int cursorOptions, ParamListInfo boundParams)
{
List *stmt_list = NIL;
ListCell *query_list;
foreach(query_list, querytrees) {
Query *query = (Query *) lfirst(query_list);
Node *stmt;
if (query->commandType == CMD_UTILITY)
{
/* Utility commands have no plans. */
stmt = query->utilityStmt;
}
else
{
stmt = (Node *) pg_plan_query(query, cursorOptions, boundParams);
}
stmt_list = lappend(stmt_list, stmt);
}
return stmt_list;
}
/*
* exec_simple_query
*
* Execute a "simple Query" protocol message.
*/
static void
exec_simple_query(const char *query_string)
{
CommandDest dest = whereToSendOutput;
MemoryContext oldcontext;
List *parsetree_list;
ListCell *parsetree_item;
bool save_log_statement_stats = log_statement_stats;
bool was_logged = false;
bool isTopLevel;
char msec_str[32];
/*
* Report query to various monitoring facilities.
*/
debug_query_string = query_string;
pgstat_report_activity(query_string);
TRACE_POSTGRESQL_QUERY_START(query_string);
/*
* We use save_log_statement_stats so ShowUsage doesn't report incorrect
* results because ResetUsage wasn't called.
*/
if (save_log_statement_stats)
ResetUsage();
/*
* Start up a transaction command. All queries generated by the
* query_string will be in this same command block, *unless* we find a
* BEGIN/COMMIT/ABORT statement; we have to force a new xact command after
* one of those, else bad things will happen in xact.c. (Note that this
* will normally change current memory context.)
*/
start_xact_command();
/*
* Zap any pre-existing unnamed statement. (While not strictly necessary,
* it seems best to define simple-Query mode as if it used the unnamed
* statement and portal; this ensures we recover any storage used by prior
* unnamed operations.)
*/ drop_unnamed_stmt();
/*
* Switch to appropriate context for constructing parsetrees.
*/
oldcontext = MemoryContextSwitchTo(MessageContext);
/*
* Do basic parsing of the query or queries (this should be safe even if
* we are in aborted transaction state!)
*/
parsetree_list = pg_parse_query(query_string);
/* Log immediately if dictated by log_statement */
if (check_log_statement(parsetree_list))
{
ereport(LOG,
(errmsg("statement: %s", query_string),
errhidestmt(true),
errdetail_execute(parsetree_list)));
was_logged = true;
}
/*
* Switch back to transaction context to enter the loop.
*/
MemoryContextSwitchTo(oldcontext);
/*
* We'll tell PortalRun it's a top-level command iff there's exactly one
* raw parsetree. If more than one, it's effectively a transaction block
* and we want PreventTransactionChain to reject unsafe commands. (Note:
* we're assuming that query rewrite cannot add commands that are
* significant to PreventTransactionChain.)
*/
isTopLevel = (list_length(parsetree_list) == 1);
/*
* Run through the raw parsetree(s) and process each one.
*/
foreach(parsetree_item, parsetree_list)
{
Node *parsetree = (Node *) lfirst(parsetree_item);
bool snapshot_set = false;
const char *commandTag;
char completionTag[COMPLETION_TAG_BUFSIZE];
List *querytree_list,
*plantree_list;
Portal portal;
DestReceiver *receiver;
int16 format;
/*
* Get the command name for use in status display (it also becomes the
* default completion tag, down inside PortalRun). Set ps_status and
* do any special start-of-SQL-command processing needed by the
* destination.
*/
commandTag = CreateCommandTag(parsetree);
set_ps_display(commandTag, false);
BeginCommand(commandTag, dest);
/*
* If we are in an aborted transaction, reject all commands except
* COMMIT/ABORT. It is important that this test occur before we try
* to do parse analysis, rewrite, or planning, since all those phases
* try to do database accesses, which may fail in abort state. (It
* might be safe to allow some additional utility commands in this * state, but not many...)
*/
if (IsAbortedTransactionBlockState() &&
!IsTransactionExitStmt(parsetree))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/* Make sure we are in a transaction command */
start_xact_command();
/* If we got a cancel signal in parsing or prior command, quit */
CHECK_FOR_INTERRUPTS();
/*
* Set up a snapshot if parse analysis/planning will need one.
*/
if (analyze_requires_snapshot(parsetree))
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
* OK to analyze, rewrite, and plan this query.
*
* Switch to appropriate context for constructing querytrees (again,
* these must outlive the execution context).
*/
oldcontext = MemoryContextSwitchTo(MessageContext);
querytree_list = pg_analyze_and_rewrite(parsetree, query_string,
NULL, 0);
plantree_list = pg_plan_queries(querytree_list, 0, NULL);
/* Done with the snapshot used for parsing/planning */
if (snapshot_set)
PopActiveSnapshot();
/* If we got a cancel signal in analysis or planning, quit */
CHECK_FOR_INTERRUPTS();
/*
* Create unnamed portal to run the query or queries in. If there
* already is one, silently drop it.
*/
portal = CreatePortal("", true, true);
/* Don't display the portal in pg_cursors */
portal->visible = false;
/*
* We don't have to copy anything into the portal, because everything
* we are passing here is in MessageContext, which will outlive the
* portal anyway.
*/
PortalDefineQuery(portal,
NULL,
query_string,
commandTag,
plantree_list,
NULL);
/*
* Start the portal. No parameters here.
*/
PortalStart(portal, NULL, InvalidSnapshot);
/*
* Select the appropriate output format: text unless we are doing a
* FETCH from a binary cursor. (Pretty grotty to have to do this here
* --- but it avoids grottiness in other places. Ah, the joys of
* backward compatibility...)
*/
format = 0; /* TEXT is default */
if (IsA(parsetree, FetchStmt))
{
FetchStmt *stmt = (FetchStmt *) parsetree;
if (!stmt->ismove)
{
Portal fportal = GetPortalByName(stmt->portalname);
if (PortalIsValid(fportal) &&
(fportal->cursorOptions & CURSOR_OPT_BINARY))
format = 1; /* BINARY */
}
}
PortalSetResultFormat(portal, 1, &format);
/*
* Now we can create the destination receiver object.
*/
receiver = CreateDestReceiver(dest);
if (dest == DestRemote)
SetRemoteDestReceiverParams(receiver, portal);
/*
* Switch back to transaction context for execution.
*/
MemoryContextSwitchTo(oldcontext);
/*
* Run the portal to completion, and then drop it (and the receiver).
*/
(void) PortalRun(portal,
FETCH_ALL,
isTopLevel,
receiver,
receiver,
completionTag);
(*receiver->rDestroy) (receiver);
PortalDrop(portal, false);
if (IsA(parsetree, TransactionStmt))
{
/*
* If this was a transaction control statement, commit it. We will
* start a new xact command for the next command (if any).
*/
finish_xact_command();
}
else if (lnext(parsetree_item) == NULL)
{
/*
* If this is the last parsetree of the query string, close down
* transaction statement before reporting command-complete. This
* is so that any end-of-transaction errors are reported before
* the command-complete message is issued, to avoid confusing
* clients who will expect either a command-complete message or an
* error, not one and then the other. But for compatibility with
* historical Postgres behavior, we do not force a transaction
* boundary between queries appearing in a single query string.
*/
finish_xact_command();
} else
{
/*
* We need a CommandCounterIncrement after every query, except
* those that start or end a transaction block.
*/
CommandCounterIncrement();
}
/*
* Tell client that we're done with this query. Note we emit exactly
* one EndCommand report for each raw parsetree, thus one for each SQL
* command the client sent, regardless of rewriting. (But a command
* aborted by error will not send an EndCommand report at all.)
*/
EndCommand(completionTag, dest);
} /* end loop over parsetrees */
/*
* Close down transaction statement, if one is open.
*/
finish_xact_command();
/*
* If there were no parsetrees, return EmptyQueryResponse message.
*/
if (!parsetree_list)
NullCommand(dest);
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, was_logged))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms statement: %s",
msec_str, query_string),
errhidestmt(true),
errdetail_execute(parsetree_list)));
break;
}
if (save_log_statement_stats)
ShowUsage("QUERY STATISTICS");
TRACE_POSTGRESQL_QUERY_DONE(query_string);
debug_query_string = NULL;
}
/*
* exec_parse_message
*
* Execute a "Parse" protocol message.
*/
static void
exec_parse_message(const char *query_string, /* string to execute */
const char *stmt_name, /* name for prepared stmt */
Oid *paramTypes, /* parameter types */
int numParams) /* number of parameters */
{
MemoryContext oldcontext;
List *parsetree_list;
Node *raw_parse_tree; const char *commandTag;
List *querytree_list,
*stmt_list;
bool is_named;
bool fully_planned;
bool save_log_statement_stats = log_statement_stats;
char msec_str[32];
/*
* Report query to various monitoring facilities.
*/
debug_query_string = query_string;
pgstat_report_activity(query_string);
set_ps_display("PARSE", false);
if (save_log_statement_stats)
ResetUsage();
ereport(DEBUG2,
(errmsg("parse %s: %s",
*stmt_name ? stmt_name : "<unnamed>",
query_string)));
/*
* Start up a transaction command so we can run parse analysis etc. (Note
* that this will normally change current memory context.) Nothing happens
* if we are already in one.
*/
start_xact_command();
/*
* Switch to appropriate context for constructing parsetrees.
*
* We have two strategies depending on whether the prepared statement is
* named or not. For a named prepared statement, we do parsing in
* MessageContext and copy the finished trees into the prepared
* statement's plancache entry; then the reset of MessageContext releases
* temporary space used by parsing and planning. For an unnamed prepared
* statement, we assume the statement isn't going to hang around long, so
* getting rid of temp space quickly is probably not worth the costs of
* copying parse/plan trees. So in this case, we create the plancache
* entry's context here, and do all the parsing work therein.
*/
is_named = (stmt_name[0] != '\0');
if (is_named)
{
/* Named prepared statement --- parse in MessageContext */
oldcontext = MemoryContextSwitchTo(MessageContext);
}
else
{
/* Unnamed prepared statement --- release any prior unnamed stmt */
drop_unnamed_stmt();
/* Create context for parsing/planning */
unnamed_stmt_context =
AllocSetContextCreate(CacheMemoryContext,
"unnamed prepared statement",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldcontext = MemoryContextSwitchTo(unnamed_stmt_context);
}
/*
* Do basic parsing of the query or queries (this should be safe even if
* we are in aborted transaction state!)
*/
parsetree_list = pg_parse_query(query_string);
/*
* We only allow a single user statement in a prepared statement. This is
* mainly to keep the protocol simple --- otherwise we'd need to worry
* about multiple result tupdescs and things like that.
*/
if (list_length(parsetree_list) > 1)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot insert multiple commands into a prepared statement")));
if (parsetree_list != NIL)
{
Query *query;
bool snapshot_set = false;
int i;
raw_parse_tree = (Node *) linitial(parsetree_list);
/*
* Get the command name for possible use in status display.
*/
commandTag = CreateCommandTag(raw_parse_tree);
/*
* If we are in an aborted transaction, reject all commands except
* COMMIT/ROLLBACK. It is important that this test occur before we
* try to do parse analysis, rewrite, or planning, since all those
* phases try to do database accesses, which may fail in abort state.
* (It might be safe to allow some additional utility commands in this
* state, but not many...)
*/
if (IsAbortedTransactionBlockState() &&
!IsTransactionExitStmt(raw_parse_tree))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/*
* Set up a snapshot if parse analysis/planning will need one.
*/
if (analyze_requires_snapshot(raw_parse_tree))
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
* OK to analyze, rewrite, and plan this query. Note that the
* originally specified parameter set is not required to be complete,
* so we have to use parse_analyze_varparams().
*
* XXX must use copyObject here since parse analysis scribbles on its
* input, and we need the unmodified raw parse tree for possible
* replanning later.
*/
if (log_parser_stats)
ResetUsage();
query = parse_analyze_varparams(copyObject(raw_parse_tree),
query_string,
¶mTypes,
&numParams);
/*
* Check all parameter types got determined.
*/
for (i = 0; i < numParams; i++) {
Oid ptype = paramTypes[i];
if (ptype == InvalidOid || ptype == UNKNOWNOID)
ereport(ERROR,
(errcode(ERRCODE_INDETERMINATE_DATATYPE),
errmsg("could not determine data type of parameter $%d",
i + 1)));
}
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
querytree_list = pg_rewrite_query(query);
/*
* If this is the unnamed statement and it has parameters, defer query
* planning until Bind. Otherwise do it now.
*/
if (!is_named && numParams > 0)
{
stmt_list = querytree_list;
fully_planned = false;
}
else
{
stmt_list = pg_plan_queries(querytree_list, 0, NULL);
fully_planned = true;
}
/* Done with the snapshot used for parsing/planning */
if (snapshot_set)
PopActiveSnapshot();
}
else
{
/* Empty input string. This is legal. */
raw_parse_tree = NULL;
commandTag = NULL;
stmt_list = NIL;
fully_planned = true;
}
/* If we got a cancel signal in analysis or planning, quit */
CHECK_FOR_INTERRUPTS();
/*
* Store the query as a prepared statement. See above comments.
*/
if (is_named)
{
StorePreparedStatement(stmt_name,
raw_parse_tree,
query_string,
commandTag,
paramTypes,
numParams,
0, /* default cursor options */
stmt_list,
false);
}
else
{
/*
* paramTypes and query_string need to be copied into
* unnamed_stmt_context. The rest is there already
*/
Oid *newParamTypes;
if (numParams > 0) {
newParamTypes = (Oid *) palloc(numParams * sizeof(Oid));
memcpy(newParamTypes, paramTypes, numParams * sizeof(Oid));
}
else
newParamTypes = NULL;
unnamed_stmt_psrc = FastCreateCachedPlan(raw_parse_tree,
pstrdup(query_string),
commandTag,
newParamTypes,
numParams,
0, /* cursor options */
stmt_list,
fully_planned,
true,
unnamed_stmt_context);
/* context now belongs to the plancache entry */
unnamed_stmt_context = NULL;
}
MemoryContextSwitchTo(oldcontext);
/*
* We do NOT close the open transaction command here; that only happens
* when the client sends Sync. Instead, do CommandCounterIncrement just
* in case something happened during parse/plan.
*/
CommandCounterIncrement();
/*
* Send ParseComplete.
*/
if (whereToSendOutput == DestRemote)
pq_putemptymessage('1');
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, false))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms parse %s: %s",
msec_str,
*stmt_name ? stmt_name : "<unnamed>",
query_string),
errhidestmt(true)));
break;
}
if (save_log_statement_stats)
ShowUsage("PARSE MESSAGE STATISTICS");
debug_query_string = NULL;
}
/*
* exec_bind_message
*
* Process a "Bind" message to create a portal from a prepared statement
*/
static void
exec_bind_message(StringInfo input_message)
{ const char *portal_name;
const char *stmt_name;
int numPFormats;
int16 *pformats = NULL;
int numParams;
int numRFormats;
int16 *rformats = NULL;
CachedPlanSource *psrc;
CachedPlan *cplan;
Portal portal;
char *query_string;
char *saved_stmt_name;
ParamListInfo params;
List *plan_list;
MemoryContext oldContext;
bool save_log_statement_stats = log_statement_stats;
bool snapshot_set = false;
char msec_str[32];
/* Get the fixed part of the message */
portal_name = pq_getmsgstring(input_message);
stmt_name = pq_getmsgstring(input_message);
ereport(DEBUG2,
(errmsg("bind %s to %s",
*portal_name ? portal_name : "<unnamed>",
*stmt_name ? stmt_name : "<unnamed>")));
/* Find prepared statement */
if (stmt_name[0] != '\0')
{
PreparedStatement *pstmt;
pstmt = FetchPreparedStatement(stmt_name, true);
psrc = pstmt->plansource;
}
else
{
/* Unnamed statements are re-prepared for every bind */
psrc = unnamed_stmt_psrc;
if (!psrc)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PSTATEMENT),
errmsg("unnamed prepared statement does not exist")));
}
/*
* Report query to various monitoring facilities.
*/
debug_query_string = psrc->query_string;
pgstat_report_activity(psrc->query_string);
set_ps_display("BIND", false);
if (save_log_statement_stats)
ResetUsage();
/*
* Start up a transaction command so we can call functions etc. (Note that
* this will normally change current memory context.) Nothing happens if
* we are already in one.
*/
start_xact_command();
/* Switch back to message context */
MemoryContextSwitchTo(MessageContext);
/* Get the parameter format codes */
numPFormats = pq_getmsgint(input_message, 2); if (numPFormats > 0)
{
int i;
pformats = (int16 *) palloc(numPFormats * sizeof(int16));
for (i = 0; i < numPFormats; i++)
pformats[i] = pq_getmsgint(input_message, 2);
}
/* Get the parameter value count */
numParams = pq_getmsgint(input_message, 2);
if (numPFormats > 1 && numPFormats != numParams)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("bind message has %d parameter formats but %d parameters",
numPFormats, numParams)));
if (numParams != psrc->num_params)
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d",
numParams, stmt_name, psrc->num_params)));
/*
* If we are in aborted transaction state, the only portals we can
* actually run are those containing COMMIT or ROLLBACK commands. We
* disallow binding anything else to avoid problems with infrastructure
* that expects to run inside a valid transaction. We also disallow
* binding any parameters, since we can't risk calling user-defined I/O
* functions.
*/
if (IsAbortedTransactionBlockState() &&
(!IsTransactionExitStmt(psrc->raw_parse_tree) ||
numParams != 0))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/*
* Create the portal. Allow silent replacement of an existing portal only
* if the unnamed portal is specified.
*/
if (portal_name[0] == '\0')
portal = CreatePortal(portal_name, true, true);
else
portal = CreatePortal(portal_name, false, false);
/*
* Prepare to copy stuff into the portal's memory context. We do all this
* copying first, because it could possibly fail (out-of-memory) and we
* don't want a failure to occur between RevalidateCachedPlan and
* PortalDefineQuery; that would result in leaking our plancache refcount.
*/
oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
/* Copy the plan's query string into the portal */
query_string = pstrdup(psrc->query_string);
/* Likewise make a copy of the statement name, unless it's unnamed */
if (stmt_name[0])
saved_stmt_name = pstrdup(stmt_name);
else
saved_stmt_name = NULL;
/*
* Set a snapshot if we have parameters to fetch (since the input
* functions might need it) or the query isn't a utility command (and * hence could require redoing parse analysis and planning).
*/
if (numParams > 0 || analyze_requires_snapshot(psrc->raw_parse_tree))
{
PushActiveSnapshot(GetTransactionSnapshot());
snapshot_set = true;
}
/*
* Fetch parameters, if any, and store in the portal's memory context.
*/
if (numParams > 0)
{
int paramno;
/* sizeof(ParamListInfoData) includes the first array element */
params = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
(numParams - 1) * sizeof(ParamExternData));
/* we have static list of params, so no hooks needed */
params->paramFetch = NULL;
params->paramFetchArg = NULL;
params->parserSetup = NULL;
params->parserSetupArg = NULL;
params->numParams = numParams;
for (paramno = 0; paramno < numParams; paramno++)
{
Oid ptype = psrc->param_types[paramno];
int32 plength;
Datum pval;
bool isNull;
StringInfoData pbuf;
char csave;
int16 pformat;
plength = pq_getmsgint(input_message, 4);
isNull = (plength == -1);
if (!isNull)
{
const char *pvalue = pq_getmsgbytes(input_message, plength);
/*
* Rather than copying data around, we just set up a phony
* StringInfo pointing to the correct portion of the message
* buffer. We assume we can scribble on the message buffer so
* as to maintain the convention that StringInfos have a
* trailing null. This is grotty but is a big win when
* dealing with very large parameter strings.
*/
pbuf.data = (char *) pvalue;
pbuf.maxlen = plength + 1;
pbuf.len = plength;
pbuf.cursor = 0;
csave = pbuf.data[plength];
pbuf.data[plength] = '\0';
}
else
{
pbuf.data = NULL; /* keep compiler quiet */
csave = 0;
}
if (numPFormats > 1)
pformat = pformats[paramno];
else if (numPFormats > 0)
pformat = pformats[0];
else
pformat = 0; /* default = text */
if (pformat == 0) /* text mode */
{
Oid typinput;
Oid typioparam;
char *pstring;
getTypeInputInfo(ptype, &typinput, &typioparam);
/*
* We have to do encoding conversion before calling the
* typinput routine.
*/
if (isNull)
pstring = NULL;
else
pstring = pg_client_to_server(pbuf.data, plength);
pval = OidInputFunctionCall(typinput, pstring, typioparam, -1);
/* Free result of encoding conversion, if any */
if (pstring && pstring != pbuf.data)
pfree(pstring);
}
else if (pformat == 1) /* binary mode */
{
Oid typreceive;
Oid typioparam;
StringInfo bufptr;
/*
* Call the parameter type's binary input converter
*/
getTypeBinaryInputInfo(ptype, &typreceive, &typioparam);
if (isNull)
bufptr = NULL;
else
bufptr = &pbuf;
pval = OidReceiveFunctionCall(typreceive, bufptr, typioparam, -1);
/* Trouble if it didn't eat the whole buffer */
if (!isNull && pbuf.cursor != pbuf.len)
ereport(ERROR,
(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
errmsg("incorrect binary data format in bind parameter %d",
paramno + 1)));
}
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unsupported format code: %d",
pformat)));
pval = 0; /* keep compiler quiet */
}
/* Restore message buffer contents */
if (!isNull)
pbuf.data[plength] = csave;
params->params[paramno].value = pval;
params->params[paramno].isnull = isNull;
/*
* We mark the params as CONST. This has no effect if we already
* did planning, but if we didn't, it licenses the planner to
* substitute the parameters directly into the one-shot plan we
* will generate below. */
params->params[paramno].pflags = PARAM_FLAG_CONST;
params->params[paramno].ptype = ptype;
}
}
else
params = NULL;
/* Done storing stuff in portal's context */
MemoryContextSwitchTo(oldContext);
/* Get the result format codes */
numRFormats = pq_getmsgint(input_message, 2);
if (numRFormats > 0)
{
int i;
rformats = (int16 *) palloc(numRFormats * sizeof(int16));
for (i = 0; i < numRFormats; i++)
rformats[i] = pq_getmsgint(input_message, 2);
}
pq_getmsgend(input_message);
if (psrc->fully_planned)
{
/*
* Revalidate the cached plan; this may result in replanning. Any
* cruft will be generated in MessageContext. The plan refcount will
* be assigned to the Portal, so it will be released at portal
* destruction.
*/
cplan = RevalidateCachedPlan(psrc, false);
plan_list = cplan->stmt_list;
}
else
{
List *query_list;
/*
* Revalidate the cached plan; this may result in redoing parse
* analysis and rewriting (but not planning). Any cruft will be
* generated in MessageContext. The plan refcount is assigned to
* CurrentResourceOwner.
*/
cplan = RevalidateCachedPlan(psrc, true);
/*
* We didn't plan the query before, so do it now. This allows the
* planner to make use of the concrete parameter values we now have.
* Because we use PARAM_FLAG_CONST, the plan is good only for this set
* of param values, and so we generate the plan in the portal's own
* memory context where it will be thrown away after use. As in
* exec_parse_message, we make no attempt to recover planner temporary
* memory until the end of the operation.
*
* XXX because the planner has a bad habit of scribbling on its input,
* we have to make a copy of the parse trees. FIXME someday.
*/
oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
query_list = copyObject(cplan->stmt_list);
plan_list = pg_plan_queries(query_list, 0, params);
MemoryContextSwitchTo(oldContext);
/* We no longer need the cached plan refcount ... */
ReleaseCachedPlan(cplan, true);
/* ... and we don't want the portal to depend on it, either */
cplan = NULL;
}
/*
* Now we can define the portal.
*
* DO NOT put any code that could possibly throw an error between the
* above "RevalidateCachedPlan(psrc, false)" call and here.
*/
PortalDefineQuery(portal,
saved_stmt_name,
query_string,
psrc->commandTag,
plan_list,
cplan);
/* Done with the snapshot used for parameter I/O and parsing/planning */
if (snapshot_set)
PopActiveSnapshot();
/*
* And we're ready to start portal execution.
*/
PortalStart(portal, params, InvalidSnapshot);
/*
* Apply the result format requests to the portal.
*/
PortalSetResultFormat(portal, numRFormats, rformats);
/*
* Send BindComplete.
*/
if (whereToSendOutput == DestRemote)
pq_putemptymessage('2');
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, false))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms bind %s%s%s: %s",
msec_str,
*stmt_name ? stmt_name : "<unnamed>",
*portal_name ? "/" : "",
*portal_name ? portal_name : "",
psrc->query_string),
errhidestmt(true),
errdetail_params(params)));
break;
}
if (save_log_statement_stats)
ShowUsage("BIND MESSAGE STATISTICS");
debug_query_string = NULL;
}
/*
* exec_execute_message
*
* Process an "Execute" message for a portal
*/
static void
exec_execute_message(const char *portal_name, long max_rows)
{ CommandDest dest;
DestReceiver *receiver;
Portal portal;
bool completed;
char completionTag[COMPLETION_TAG_BUFSIZE];
const char *sourceText;
const char *prepStmtName;
ParamListInfo portalParams;
bool save_log_statement_stats = log_statement_stats;
bool is_xact_command;
bool execute_is_fetch;
bool was_logged = false;
char msec_str[32];
/* Adjust destination to tell printtup.c what to do */
dest = whereToSendOutput;
if (dest == DestRemote)
dest = DestRemoteExecute;
portal = GetPortalByName(portal_name);
if (!PortalIsValid(portal))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_CURSOR),
errmsg("portal \"%s\" does not exist", portal_name)));
/*
* If the original query was a null string, just return
* EmptyQueryResponse.
*/
if (portal->commandTag == NULL)
{
Assert(portal->stmts == NIL);
NullCommand(dest);
return;
}
/* Does the portal contain a transaction command? */
is_xact_command = IsTransactionStmtList(portal->stmts);
/*
* We must copy the sourceText and prepStmtName into MessageContext in
* case the portal is destroyed during finish_xact_command. Can avoid the
* copy if it's not an xact command, though.
*/
if (is_xact_command)
{
sourceText = pstrdup(portal->sourceText);
if (portal->prepStmtName)
prepStmtName = pstrdup(portal->prepStmtName);
else
prepStmtName = "<unnamed>";
/*
* An xact command shouldn't have any parameters, which is a good
* thing because they wouldn't be around after finish_xact_command.
*/
portalParams = NULL;
}
else
{
sourceText = portal->sourceText;
if (portal->prepStmtName)
prepStmtName = portal->prepStmtName;
else
prepStmtName = "<unnamed>";
portalParams = portal->portalParams;
}
/*
* Report query to various monitoring facilities. */
debug_query_string = sourceText;
pgstat_report_activity(sourceText);
set_ps_display(portal->commandTag, false);
if (save_log_statement_stats)
ResetUsage();
BeginCommand(portal->commandTag, dest);
/*
* Create dest receiver in MessageContext (we don't want it in transaction
* context, because that may get deleted if portal contains VACUUM).
*/
receiver = CreateDestReceiver(dest);
if (dest == DestRemoteExecute)
SetRemoteDestReceiverParams(receiver, portal);
/*
* Ensure we are in a transaction command (this should normally be the
* case already due to prior BIND).
*/
start_xact_command();
/*
* If we re-issue an Execute protocol request against an existing portal,
* then we are only fetching more rows rather than completely re-executing
* the query from the start. atStart is never reset for a v3 portal, so we
* are safe to use this check.
*/
execute_is_fetch = !portal->atStart;
/* Log immediately if dictated by log_statement */
if (check_log_statement(portal->stmts))
{
ereport(LOG,
(errmsg("%s %s%s%s: %s",
execute_is_fetch ?
_("execute fetch from") :
_("execute"),
prepStmtName,
*portal_name ? "/" : "",
*portal_name ? portal_name : "",
sourceText),
errhidestmt(true),
errdetail_params(portalParams)));
was_logged = true;
}
/*
* If we are in aborted transaction state, the only portals we can
* actually run are those containing COMMIT or ROLLBACK commands.
*/
if (IsAbortedTransactionBlockState() &&
!IsTransactionExitStmtList(portal->stmts))
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
/* Check for cancel signal before we start execution */
CHECK_FOR_INTERRUPTS();
/*
* Okay to run the portal.
*/
if (max_rows <= 0) max_rows = FETCH_ALL;
completed = PortalRun(portal,
max_rows,
true, /* always top level */
receiver,
receiver,
completionTag);
(*receiver->rDestroy) (receiver);
if (completed)
{
if (is_xact_command)
{
/*
* If this was a transaction control statement, commit it. We
* will start a new xact command for the next command (if any).
*/
finish_xact_command();
}
else
{
/*
* We need a CommandCounterIncrement after every query, except
* those that start or end a transaction block.
*/
CommandCounterIncrement();
}
/* Send appropriate CommandComplete to client */
EndCommand(completionTag, dest);
}
else
{
/* Portal run not complete, so send PortalSuspended */
if (whereToSendOutput == DestRemote)
pq_putemptymessage('s');
}
/*
* Emit duration logging if appropriate.
*/
switch (check_log_duration(msec_str, was_logged))
{
case 1:
ereport(LOG,
(errmsg("duration: %s ms", msec_str),
errhidestmt(true)));
break;
case 2:
ereport(LOG,
(errmsg("duration: %s ms %s %s%s%s: %s",
msec_str,
execute_is_fetch ?
_("execute fetch from") :
_("execute"),
prepStmtName,
*portal_name ? "/" : "",
*portal_name ? portal_name : "",
sourceText),
errhidestmt(true),
errdetail_params(portalParams)));
break;
}
if (save_log_statement_stats)
ShowUsage("EXECUTE MESSAGE STATISTICS");
debug_query_string = NULL;}
/*
* check_log_statement
* Determine whether command should be logged because of log_statement
*
* parsetree_list can be either raw grammar output or a list of planned
* statements
*/
static bool
check_log_statement(List *stmt_list)
{
ListCell *stmt_item;
if (log_statement == LOGSTMT_NONE)
return false;
if (log_statement == LOGSTMT_ALL)
return true;
/* Else we have to inspect the statement(s) to see whether to log */
foreach(stmt_item, stmt_list)
{
Node *stmt = (Node *) lfirst(stmt_item);
if (GetCommandLogLevel(stmt) <= log_statement)
return true;
}
return false;
}
/*
* check_log_duration
* Determine whether current command's duration should be logged
*
* Returns:
* 0 if no logging is needed
* 1 if just the duration should be logged
* 2 if duration and query details should be logged
*
* If logging is needed, the duration in msec is formatted into msec_str[],
* which must be a 32-byte buffer.
*
* was_logged should be TRUE if caller already logged query details (this
* essentially prevents 2 from being returned).
*/
int
check_log_duration(char *msec_str, bool was_logged)
{
if (log_duration || log_min_duration_statement >= 0)
{
long secs;
int usecs;
int msecs;
bool exceeded;
TimestampDifference(GetCurrentStatementStartTimestamp(),
GetCurrentTimestamp(),
&secs, &usecs);
msecs = usecs / 1000;
/*
* This odd-looking test for log_min_duration_statement being exceeded
* is designed to avoid integer overflow with very long durations:
* don't compute secs * 1000 until we've verified it will fit in int.
*/
exceeded = (log_min_duration_statement == 0 ||
(log_min_duration_statement > 0 &&
(secs > log_min_duration_statement / 1000 ||
secs * 1000 + msecs >= log_min_duration_statement)));
if (exceeded || log_duration)
{
snprintf(msec_str, 32, "%ld.%03d",
secs * 1000 + msecs, usecs % 1000);
if (exceeded && !was_logged)
return 2;
else
return 1;
}
}
return 0;
}
/*
* errdetail_execute
*
* Add an errdetail() line showing the query referenced by an EXECUTE, if any.
* The argument is the raw parsetree list.
*/
static int
errdetail_execute(List *raw_parsetree_list)
{
ListCell *parsetree_item;
foreach(parsetree_item, raw_parsetree_list)
{
Node *parsetree = (Node *) lfirst(parsetree_item);
if (IsA(parsetree, ExecuteStmt))
{
ExecuteStmt *stmt = (ExecuteStmt *) parsetree;
PreparedStatement *pstmt;
pstmt = FetchPreparedStatement(stmt->name, false);
if (pstmt)
{
errdetail("prepare: %s", pstmt->plansource->query_string);
return 0;
}
}
}
return 0;
}
/*
* errdetail_params
*
* Add an errdetail() line showing bind-parameter data, if available.
*/
static int
errdetail_params(ParamListInfo params)
{
/* We mustn't call user-defined I/O functions when in an aborted xact */
if (params && params->numParams > 0 && !IsAbortedTransactionBlockState())
{
StringInfoData param_str;
MemoryContext oldcontext;
int paramno;
/* Make sure any trash is generated in MessageContext */
oldcontext = MemoryContextSwitchTo(MessageContext);
initStringInfo(¶m_str);
for (paramno = 0; paramno < params->numParams; paramno++)
{
ParamExternData *prm = ¶ms->params[paramno]; Oid typoutput;
bool typisvarlena;
char *pstring;
char *p;
appendStringInfo(¶m_str, "%s$%d = ",
paramno > 0 ? ", " : "",
paramno + 1);
if (prm->isnull || !OidIsValid(prm->ptype))
{
appendStringInfoString(¶m_str, "NULL");
continue;
}
getTypeOutputInfo(prm->ptype, &typoutput, &typisvarlena);
pstring = OidOutputFunctionCall(typoutput, prm->value);
appendStringInfoCharMacro(¶m_str, '\'');
for (p = pstring; *p; p++)
{
if (*p == '\'') /* double single quotes */
appendStringInfoCharMacro(¶m_str, *p);
appendStringInfoCharMacro(¶m_str, *p);
}
appendStringInfoCharMacro(¶m_str, '\'');
pfree(pstring);
}
errdetail("parameters: %s", param_str.data);
pfree(param_str.data);
MemoryContextSwitchTo(oldcontext);
}
return 0;
}
/*
* errdetail_abort
*
* Add an errdetail() line showing abort reason, if any.
*/
static int
errdetail_abort(void)
{
if (MyProc->recoveryConflictPending)
errdetail("abort reason: recovery conflict");
return 0;
}
/*
* errdetail_recovery_conflict
*
* Add an errdetail() line showing conflict source.
*/
static int
errdetail_recovery_conflict(void)
{
switch (RecoveryConflictReason)
{
case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
errdetail("User was holding shared buffer pin for too long.");
break;
case PROCSIG_RECOVERY_CONFLICT_LOCK:
errdetail("User was holding a relation lock for too long."); break;
case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
errdetail("User was or might have been using tablespace that must be dropped.");
break;
case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
errdetail("User query might have needed to see row versions that must be removed.");
break;
case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
errdetail("User transaction caused buffer deadlock with recovery.");
break;
case PROCSIG_RECOVERY_CONFLICT_DATABASE:
errdetail("User was connected to a database that must be dropped.");
break;
default:
break;
/* no errdetail */
}
return 0;
}
/*
* exec_describe_statement_message
*
* Process a "Describe" message for a prepared statement
*/
static void
exec_describe_statement_message(const char *stmt_name)
{
CachedPlanSource *psrc;
StringInfoData buf;
int i;
/*
* Start up a transaction command. (Note that this will normally change
* current memory context.) Nothing happens if we are already in one.
*/
start_xact_command();
/* Switch back to message context */
MemoryContextSwitchTo(MessageContext);
/* Find prepared statement */
if (stmt_name[0] != '\0')
{
PreparedStatement *pstmt;
pstmt = FetchPreparedStatement(stmt_name, true);
psrc = pstmt->plansource;
}
else
{
/* special-case the unnamed statement */
psrc = unnamed_stmt_psrc;
if (!psrc)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PSTATEMENT),
errmsg("unnamed prepared statement does not exist")));
}
/* Prepared statements shouldn't have changeable result descs */
Assert(psrc->fixed_result);
/*
* If we are in aborted transaction state, we can't run
* SendRowDescriptionMessage(), because that needs catalog accesses. (We
* can't do RevalidateCachedPlan, either, but that's a lesser problem.)
* Hence, refuse to Describe statements that return data. (We shouldn't
* just refuse all Describes, since that might break the ability of some
* clients to issue COMMIT or ROLLBACK commands, if they use code that * blindly Describes whatever it does.) We can Describe parameters
* without doing anything dangerous, so we don't restrict that.
*/
if (IsAbortedTransactionBlockState() &&
psrc->resultDesc)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
if (whereToSendOutput != DestRemote)
return; /* can't actually do anything... */
/*
* First describe the parameters...
*/
pq_beginmessage(&buf, 't'); /* parameter description message type */
pq_sendint(&buf, psrc->num_params, 2);
for (i = 0; i < psrc->num_params; i++)
{
Oid ptype = psrc->param_types[i];
pq_sendint(&buf, (int) ptype, 4);
}
pq_endmessage(&buf);
/*
* Next send RowDescription or NoData to describe the result...
*/
if (psrc->resultDesc)
{
CachedPlan *cplan;
List *tlist;
/* Make sure the plan is up to date */
cplan = RevalidateCachedPlan(psrc, true);
/* Get the primary statement and find out what it returns */
tlist = FetchStatementTargetList(PortalListGetPrimaryStmt(cplan->stmt_list));
SendRowDescriptionMessage(psrc->resultDesc, tlist, NULL);
ReleaseCachedPlan(cplan, true);
}
else
pq_putemptymessage('n'); /* NoData */
}
/*
* exec_describe_portal_message
*
* Process a "Describe" message for a portal
*/
static void
exec_describe_portal_message(const char *portal_name)
{
Portal portal;
/*
* Start up a transaction command. (Note that this will normally change
* current memory context.) Nothing happens if we are already in one.
*/
start_xact_command();
/* Switch back to message context */
MemoryContextSwitchTo(MessageContext);
portal = GetPortalByName(portal_name);
if (!PortalIsValid(portal))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_CURSOR),
errmsg("portal \"%s\" does not exist", portal_name)));
/*
* If we are in aborted transaction state, we can't run
* SendRowDescriptionMessage(), because that needs catalog accesses.
* Hence, refuse to Describe portals that return data. (We shouldn't just
* refuse all Describes, since that might break the ability of some
* clients to issue COMMIT or ROLLBACK commands, if they use code that
* blindly Describes whatever it does.)
*/
if (IsAbortedTransactionBlockState() &&
portal->tupDesc)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block"),
errdetail_abort()));
if (whereToSendOutput != DestRemote)
return; /* can't actually do anything... */
if (portal->tupDesc)
SendRowDescriptionMessage(portal->tupDesc,
FetchPortalTargetList(portal),
portal->formats);
else
pq_putemptymessage('n'); /* NoData */
}
/*
* Convenience routines for starting/committing a single command.
*/
static void
start_xact_command(void)
{
if (!xact_started)
{
ereport(DEBUG3,
(errmsg_internal("StartTransactionCommand")));
StartTransactionCommand();
/* Set statement timeout running, if any */
/* NB: this mustn't be enabled until we are within an xact */
if (StatementTimeout > 0)
enable_sig_alarm(StatementTimeout, true);
else
cancel_from_timeout = false;
xact_started = true;
}
}
static void
finish_xact_command(void)
{
if (xact_started)
{
/* Cancel any active statement timeout before committing */
disable_sig_alarm(true);
/* Now commit the command */
ereport(DEBUG3,
(errmsg_internal("CommitTransactionCommand")));
CommitTransactionCommand();
#ifdef MEMORY_CONTEXT_CHECKING
/* Check all memory contexts that weren't freed during commit */
/* (those that were, were checked before being deleted) */
MemoryContextCheck(TopMemoryContext);
#endif
#ifdef SHOW_MEMORY_STATS
/* Print mem stats after each commit for leak tracking */
MemoryContextStats(TopMemoryContext);
#endif
xact_started = false;
}
}
/*
* Convenience routines for checking whether a statement is one of the
* ones that we allow in transaction-aborted state.
*/
/* Test a bare parsetree */
static bool
IsTransactionExitStmt(Node *parsetree)
{
if (parsetree && IsA(parsetree, TransactionStmt))
{
TransactionStmt *stmt = (TransactionStmt *) parsetree;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_PREPARE ||
stmt->kind == TRANS_STMT_ROLLBACK ||
stmt->kind == TRANS_STMT_ROLLBACK_TO)
return true;
}
return false;
}
/* Test a list that might contain Query nodes or bare parsetrees */
static bool
IsTransactionExitStmtList(List *parseTrees)
{
if (list_length(parseTrees) == 1)
{
Node *stmt = (Node *) linitial(parseTrees);
if (IsA(stmt, Query))
{
Query *query = (Query *) stmt;
if (query->commandType == CMD_UTILITY &&
IsTransactionExitStmt(query->utilityStmt))
return true;
}
else if (IsTransactionExitStmt(stmt))
return true;
}
return false;
}
/* Test a list that might contain Query nodes or bare parsetrees */
static bool
IsTransactionStmtList(List *parseTrees)
{
if (list_length(parseTrees) == 1)
{
Node *stmt = (Node *) linitial(parseTrees);
if (IsA(stmt, Query)) {
Query *query = (Query *) stmt;
if (query->commandType == CMD_UTILITY &&
IsA(query->utilityStmt, TransactionStmt))
return true;
}
else if (IsA(stmt, TransactionStmt))
return true;
}
return false;
}
/* Release any existing unnamed prepared statement */
static void
drop_unnamed_stmt(void)
{
/* Release any completed unnamed statement */
if (unnamed_stmt_psrc)
DropCachedPlan(unnamed_stmt_psrc);
unnamed_stmt_psrc = NULL;
/*
* If we failed while trying to build a prior unnamed statement, we may
* have a memory context that wasn't assigned to a completed plancache
* entry. If so, drop it to avoid a permanent memory leak.
*/
if (unnamed_stmt_context)
MemoryContextDelete(unnamed_stmt_context);
unnamed_stmt_context = NULL;
}
/* --------------------------------
* signal handler routines used in PostgresMain()
* --------------------------------
*/
/*
* quickdie() occurs when signalled SIGQUIT by the postmaster.
*
* Some backend has bought the farm,
* so we need to stop what we're doing and exit.
*/
void
quickdie(SIGNAL_ARGS)
{
sigaddset(&BlockSig, SIGQUIT); /* prevent nested calls */
PG_SETMASK(&BlockSig);
/*
* If we're aborting out of client auth, don't risk trying to send
* anything to the client; we will likely violate the protocol, not to
* mention that we may have interrupted the guts of OpenSSL or some
* authentication library.
*/
if (ClientAuthInProgress && whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
/*
* Ideally this should be ereport(FATAL), but then we'd not get control
* back...
*/
ereport(WARNING,
(errcode(ERRCODE_CRASH_SHUTDOWN),
errmsg("terminating connection because of crash of another server process"),
errdetail("The postmaster has commanded this server process to roll back"
" the current transaction and exit, because another"
" server process exited abnormally and possibly corrupted"
" shared memory."), errhint("In a moment you should be able to reconnect to the"
" database and repeat your command.")));
/*
* We DO NOT want to run proc_exit() callbacks -- we're here because
* shared memory may be corrupted, so we don't want to try to clean up our
* transaction. Just nail the windows shut and get out of town. Now that
* there's an atexit callback to prevent third-party code from breaking
* things by calling exit() directly, we have to reset the callbacks
* explicitly to make this work as intended.
*/
on_exit_reset();
/*
* Note we do exit(2) not exit(0). This is to force the postmaster into a
* system reset cycle if some idiot DBA sends a manual SIGQUIT to a random
* backend. This is necessary precisely because we don't clean up our
* shared memory state. (The "dead man switch" mechanism in pmsignal.c
* should ensure the postmaster sees this as a crash, too, but no harm in
* being doubly sure.)
*/
exit(2);
}
/*
* Shutdown signal from postmaster: abort transaction and exit
* at soonest convenient time
*/
void
die(SIGNAL_ARGS)
{
int save_errno = errno;
/* Don't joggle the elbow of proc_exit */
if (!proc_exit_inprogress)
{
InterruptPending = true;
ProcDiePending = true;
/*
* If it's safe to interrupt, and we're waiting for input or a lock,
* service the interrupt immediately
*/
if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
CritSectionCount == 0)
{
/* bump holdoff count to make ProcessInterrupts() a no-op */
/* until we are done getting ready for it */
InterruptHoldoffCount++;
LockWaitCancel(); /* prevent CheckDeadLock from running */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
InterruptHoldoffCount--;
ProcessInterrupts();
}
/* Interrupt any sync rep wait which is currently in progress. */
SetLatch(&(MyProc->waitLatch));
}
errno = save_errno;
}
/*
* Query-cancel signal from postmaster: abort current transaction
* at soonest convenient time
*/
void
StatementCancelHandler(SIGNAL_ARGS)
{ int save_errno = errno;
/*
* Don't joggle the elbow of proc_exit
*/
if (!proc_exit_inprogress)
{
InterruptPending = true;
QueryCancelPending = true;
/*
* If it's safe to interrupt, and we're waiting for input or a lock,
* service the interrupt immediately
*/
if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
CritSectionCount == 0)
{
/* bump holdoff count to make ProcessInterrupts() a no-op */
/* until we are done getting ready for it */
InterruptHoldoffCount++;
LockWaitCancel(); /* prevent CheckDeadLock from running */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
InterruptHoldoffCount--;
ProcessInterrupts();
}
/* Interrupt any sync rep wait which is currently in progress. */
SetLatch(&(MyProc->waitLatch));
}
errno = save_errno;
}
/* signal handler for floating point exception */
void
FloatExceptionHandler(SIGNAL_ARGS)
{
ereport(ERROR,
(errcode(ERRCODE_FLOATING_POINT_EXCEPTION),
errmsg("floating-point exception"),
errdetail("An invalid floating-point operation was signaled. "
"This probably means an out-of-range result or an "
"invalid operation, such as division by zero.")));
}
/* SIGHUP: set flag to re-read config file at next convenient time */
static void
SigHupHandler(SIGNAL_ARGS)
{
got_SIGHUP = true;
}
/*
* RecoveryConflictInterrupt: out-of-line portion of recovery conflict
* handling following receipt of SIGUSR1. Designed to be similar to die()
* and StatementCancelHandler(). Called only by a normal user backend
* that begins a transaction during recovery.
*/
void
RecoveryConflictInterrupt(ProcSignalReason reason)
{
int save_errno = errno;
/*
* Don't joggle the elbow of proc_exit
*/
if (!proc_exit_inprogress)
{
RecoveryConflictReason = reason; switch (reason)
{
case PROCSIG_RECOVERY_CONFLICT_STARTUP_DEADLOCK:
/*
* If we aren't waiting for a lock we can never deadlock.
*/
if (!IsWaitingForLock())
return;
/* Intentional drop through to check wait for pin */
case PROCSIG_RECOVERY_CONFLICT_BUFFERPIN:
/*
* If we aren't blocking the Startup process there is nothing
* more to do.
*/
if (!HoldingBufferPinThatDelaysRecovery())
return;
MyProc->recoveryConflictPending = true;
/* Intentional drop through to error handling */
case PROCSIG_RECOVERY_CONFLICT_LOCK:
case PROCSIG_RECOVERY_CONFLICT_TABLESPACE:
case PROCSIG_RECOVERY_CONFLICT_SNAPSHOT:
/*
* If we aren't in a transaction any longer then ignore.
*/
if (!IsTransactionOrTransactionBlock())
return;
/*
* If we can abort just the current subtransaction then we are
* OK to throw an ERROR to resolve the conflict. Otherwise
* drop through to the FATAL case.
*
* XXX other times that we can throw just an ERROR *may* be
* PROCSIG_RECOVERY_CONFLICT_LOCK if no locks are held in
* parent transactions
*
* PROCSIG_RECOVERY_CONFLICT_SNAPSHOT if no snapshots are held
* by parent transactions and the transaction is not
* transaction-snapshot mode
*
* PROCSIG_RECOVERY_CONFLICT_TABLESPACE if no temp files or
* cursors open in parent transactions
*/
if (!IsSubTransaction())
{
/*
* If we already aborted then we no longer need to cancel.
* We do this here since we do not wish to ignore aborted
* subtransactions, which must cause FATAL, currently.
*/
if (IsAbortedTransactionBlockState())
return;
RecoveryConflictPending = true;
QueryCancelPending = true;
InterruptPending = true;
break;
}
/* Intentional drop through to session cancel */
case PROCSIG_RECOVERY_CONFLICT_DATABASE: RecoveryConflictPending = true;
ProcDiePending = true;
InterruptPending = true;
break;
default:
elog(FATAL, "unrecognized conflict mode: %d",
(int) reason);
}
Assert(RecoveryConflictPending && (QueryCancelPending || ProcDiePending));
/*
* All conflicts apart from database cause dynamic errors where the
* command or transaction can be retried at a later point with some
* potential for success. No need to reset this, since non-retryable
* conflict errors are currently FATAL.
*/
if (reason == PROCSIG_RECOVERY_CONFLICT_DATABASE)
RecoveryConflictRetryable = false;
/*
* If it's safe to interrupt, and we're waiting for input or a lock,
* service the interrupt immediately
*/
if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
CritSectionCount == 0)
{
/* bump holdoff count to make ProcessInterrupts() a no-op */
/* until we are done getting ready for it */
InterruptHoldoffCount++;
LockWaitCancel(); /* prevent CheckDeadLock from running */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
InterruptHoldoffCount--;
ProcessInterrupts();
}
}
errno = save_errno;
}
/*
* ProcessInterrupts: out-of-line portion of CHECK_FOR_INTERRUPTS() macro
*
* If an interrupt condition is pending, and it's safe to service it,
* then clear the flag and accept the interrupt. Called only when
* InterruptPending is true.
*/
void
ProcessInterrupts(void)
{
/* OK to accept interrupt now? */
if (InterruptHoldoffCount != 0 || CritSectionCount != 0)
return;
InterruptPending = false;
if (ProcDiePending)
{
ProcDiePending = false;
QueryCancelPending = false; /* ProcDie trumps QueryCancel */
ImmediateInterruptOK = false; /* not idle anymore */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
/* As in quickdie, don't risk sending to client during auth */
if (ClientAuthInProgress && whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
if (IsAutoVacuumWorkerProcess())
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating autovacuum process due to administrator command"))); else if (RecoveryConflictPending && RecoveryConflictRetryable)
{
pgstat_report_recovery_conflict(RecoveryConflictReason);
ereport(FATAL,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("terminating connection due to conflict with recovery"),
errdetail_recovery_conflict()));
}
else if (RecoveryConflictPending)
{
/* Currently there is only one non-retryable recovery conflict */
Assert(RecoveryConflictReason == PROCSIG_RECOVERY_CONFLICT_DATABASE);
pgstat_report_recovery_conflict(RecoveryConflictReason);
ereport(FATAL,
(errcode(ERRCODE_DATABASE_DROPPED),
errmsg("terminating connection due to conflict with recovery"),
errdetail_recovery_conflict()));
}
else
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection due to administrator command")));
}
if (QueryCancelPending)
{
QueryCancelPending = false;
if (ClientAuthInProgress)
{
ImmediateInterruptOK = false; /* not idle anymore */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
/* As in quickdie, don't risk sending to client during auth */
if (whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling authentication due to timeout")));
}
if (cancel_from_timeout)
{
ImmediateInterruptOK = false; /* not idle anymore */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling statement due to statement timeout")));
}
if (IsAutoVacuumWorkerProcess())
{
ImmediateInterruptOK = false; /* not idle anymore */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling autovacuum task")));
}
if (RecoveryConflictPending)
{
ImmediateInterruptOK = false; /* not idle anymore */
RecoveryConflictPending = false;
DisableNotifyInterrupt();
DisableCatchupInterrupt();
pgstat_report_recovery_conflict(RecoveryConflictReason);
if (DoingCommandRead)
ereport(FATAL,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("terminating connection due to conflict with recovery"),
errdetail_recovery_conflict(),
errhint("In a moment you should be able to reconnect to the"
" database and repeat your command."))); else
ereport(ERROR,
(errcode(ERRCODE_T_R_SERIALIZATION_FAILURE),
errmsg("canceling statement due to conflict with recovery"),
errdetail_recovery_conflict()));
}
/*
* If we are reading a command from the client, just ignore the cancel
* request --- sending an extra error message won't accomplish
* anything. Otherwise, go ahead and throw the error.
*/
if (!DoingCommandRead)
{
ImmediateInterruptOK = false; /* not idle anymore */
DisableNotifyInterrupt();
DisableCatchupInterrupt();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling statement due to user request")));
}
}
/* If we get here, do nothing (probably, QueryCancelPending was reset) */
}
/*
* IA64-specific code to fetch the AR.BSP register for stack depth checks.
*
* We currently support gcc and icc here.
*/
#if defined(__ia64__) || defined(__ia64)
#ifdef __INTEL_COMPILER
#include <asm/ia64regs.h>
#endif
static __inline__ char *
ia64_get_bsp(void)
{
char *ret;
#ifndef __INTEL_COMPILER
/* the ;; is a "stop", seems to be required before fetching BSP */
__asm__ __volatile__(
";;\n"
" mov %0=ar.bsp \n"
: "=r"(ret));
#else
ret = (char *) __getReg(_IA64_REG_AR_BSP);
#endif
return ret;
}
#endif /* IA64 */
/*
* check_stack_depth: check for excessively deep recursion
*
* This should be called someplace in any recursive routine that might possibly
* recurse deep enough to overflow the stack. Most Unixen treat stack
* overflow as an unrecoverable SIGSEGV, so we want to error out ourselves
* before hitting the hardware limit.
*/
void
check_stack_depth(void)
{
char stack_top_loc;
long stack_depth;
/*
* Compute distance from PostgresMain's local variables to my own
*/
stack_depth = (long) (stack_base_ptr - &stack_top_loc);
/*
* Take abs value, since stacks grow up on some machines, down on others
*/
if (stack_depth < 0)
stack_depth = -stack_depth;
/*
* Trouble?
*
* The test on stack_base_ptr prevents us from erroring out if called
* during process setup or in a non-backend process. Logically it should
* be done first, but putting it here avoids wasting cycles during normal
* cases.
*/
if (stack_depth > max_stack_depth_bytes &&
stack_base_ptr != NULL)
{
ereport(ERROR,
(errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
errmsg("stack depth limit exceeded"),
errhint("Increase the configuration parameter \"max_stack_depth\" (currently %dkB), "
"after ensuring the platform's stack depth limit is adequate.",
max_stack_depth)));
}
/*
* On IA64 there is a separate "register" stack that requires its own
* independent check. For this, we have to measure the change in the
* "BSP" pointer from PostgresMain to here. Logic is just as above,
* except that we know IA64's register stack grows up.
*
* Note we assume that the same max_stack_depth applies to both stacks.
*/
#if defined(__ia64__) || defined(__ia64)
stack_depth = (long) (ia64_get_bsp() - register_stack_base_ptr);
if (stack_depth > max_stack_depth_bytes &&
register_stack_base_ptr != NULL)
{
ereport(ERROR,
(errcode(ERRCODE_STATEMENT_TOO_COMPLEX),
errmsg("stack depth limit exceeded"),
errhint("Increase the configuration parameter \"max_stack_depth\" (currently %dkB), "
"after ensuring the platform's stack depth limit is adequate.",
max_stack_depth)));
}
#endif /* IA64 */
}
/* GUC check hook for max_stack_depth */
bool
check_max_stack_depth(int *newval, void **extra, GucSource source)
{
long newval_bytes = *newval * 1024L;
long stack_rlimit = get_stack_depth_rlimit();
if (stack_rlimit > 0 && newval_bytes > stack_rlimit - STACK_DEPTH_SLOP)
{
GUC_check_errdetail("\"max_stack_depth\" must not exceed %ldkB.",
(stack_rlimit - STACK_DEPTH_SLOP) / 1024L);
GUC_check_errhint("Increase the platform's stack depth limit via \"ulimit -s\" or local equivalent.");
return false;
}
return true;
}
/* GUC assign hook for max_stack_depth */
void
assign_max_stack_depth(int newval, void *extra)
{
long newval_bytes = newval * 1024L;
max_stack_depth_bytes = newval_bytes;
}
/*
* set_debug_options --- apply "-d N" command line option
*
* -d is not quite the same as setting log_min_messages because it enables
* other output options.
*/
void
set_debug_options(int debug_flag, GucContext context, GucSource source)
{
if (debug_flag > 0)
{
char debugstr[64];
sprintf(debugstr, "debug%d", debug_flag);
SetConfigOption("log_min_messages", debugstr, context, source);
}
else
SetConfigOption("log_min_messages", "notice", context, source);
if (debug_flag >= 1 && context == PGC_POSTMASTER)
{
SetConfigOption("log_connections", "true", context, source);
SetConfigOption("log_disconnections", "true", context, source);
}
if (debug_flag >= 2)
SetConfigOption("log_statement", "all", context, source);
if (debug_flag >= 3)
SetConfigOption("debug_print_parse", "true", context, source);
if (debug_flag >= 4)
SetConfigOption("debug_print_plan", "true", context, source);
if (debug_flag >= 5)
SetConfigOption("debug_print_rewritten", "true", context, source);
}
bool
set_plan_disabling_options(const char *arg, GucContext context, GucSource source)
{
char *tmp = NULL;
switch (arg[0])
{
case 's': /* seqscan */
tmp = "enable_seqscan";
break;
case 'i': /* indexscan */
tmp = "enable_indexscan";
break;
case 'b': /* bitmapscan */
tmp = "enable_bitmapscan";
break;
case 't': /* tidscan */
tmp = "enable_tidscan";
break;
case 'n': /* nestloop */
tmp = "enable_nestloop";
break;
case 'm': /* mergejoin */
tmp = "enable_mergejoin"; break;
case 'h': /* hashjoin */
tmp = "enable_hashjoin";
break;
}
if (tmp)
{
SetConfigOption(tmp, "false", context, source);
return true;
}
else
return false;
}
const char *
get_stats_option_name(const char *arg)
{
switch (arg[0])
{
case 'p':
if (optarg[1] == 'a') /* "parser" */
return "log_parser_stats";
else if (optarg[1] == 'l') /* "planner" */
return "log_planner_stats";
break;
case 'e': /* "executor" */
return "log_executor_stats";
break;
}
return NULL;
}
/* ----------------------------------------------------------------
* process_postgres_switches
* Parse command line arguments for PostgresMain
*
* This is called twice, once for the "secure" options coming from the
* postmaster or command line, and once for the "insecure" options coming
* from the client's startup packet. The latter have the same syntax but
* may be restricted in what they can do.
*
* argv[0] is ignored in either case (it's assumed to be the program name).
*
* ctx is PGC_POSTMASTER for secure options, PGC_BACKEND for insecure options
* coming from the client, or PGC_SUSET for insecure options coming from
* a superuser client.
*
* Returns the database name extracted from the command line, if any.
* ----------------------------------------------------------------
*/
const char *
process_postgres_switches(int argc, char *argv[], GucContext ctx)
{
const char *dbname;
bool secure = (ctx == PGC_POSTMASTER);
int errs = 0;
GucSource gucsource;
int flag;
if (secure)
{
gucsource = PGC_S_ARGV; /* switches came from command line */
/* Ignore the initial --single argument, if present */
if (argc > 1 && strcmp(argv[1], "--single") == 0)
{ argv++;
argc--;
}
}
else
{
gucsource = PGC_S_CLIENT; /* switches came from client */
}
/*
* Parse command-line options. CAUTION: keep this in sync with
* postmaster/postmaster.c (the option sets should not conflict) and with
* the common help() function in main/main.c.
*/
while ((flag = getopt(argc, argv, "A:B:c:D:d:EeFf:h:ijk:lN:nOo:Pp:r:S:sTt:v:W:-:")) != -1)
{
switch (flag)
{
case 'A':
SetConfigOption("debug_assertions", optarg, ctx, gucsource);
break;
case 'B':
SetConfigOption("shared_buffers", optarg, ctx, gucsource);
break;
case 'D':
if (secure)
userDoption = strdup(optarg);
break;
case 'd':
set_debug_options(atoi(optarg), ctx, gucsource);
break;
case 'E':
EchoQuery = true;
break;
case 'e':
SetConfigOption("datestyle", "euro", ctx, gucsource);
break;
case 'F':
SetConfigOption("fsync", "false", ctx, gucsource);
break;
case 'f':
if (!set_plan_disabling_options(optarg, ctx, gucsource))
errs++;
break;
case 'h':
SetConfigOption("listen_addresses", optarg, ctx, gucsource);
break;
case 'i':
SetConfigOption("listen_addresses", "*", ctx, gucsource);
break;
case 'j':
UseNewLine = 0;
break;
case 'k':
SetConfigOption("unix_socket_directory", optarg, ctx, gucsource);
break;
case 'l':
SetConfigOption("ssl", "true", ctx, gucsource); break;
case 'N':
SetConfigOption("max_connections", optarg, ctx, gucsource);
break;
case 'n':
/* ignored for consistency with postmaster */
break;
case 'O':
SetConfigOption("allow_system_table_mods", "true", ctx, gucsource);
break;
case 'o':
errs++;
break;
case 'P':
SetConfigOption("ignore_system_indexes", "true", ctx, gucsource);
break;
case 'p':
SetConfigOption("port", optarg, ctx, gucsource);
break;
case 'r':
/* send output (stdout and stderr) to the given file */
if (secure)
strlcpy(OutputFileName, optarg, MAXPGPATH);
break;
case 'S':
SetConfigOption("work_mem", optarg, ctx, gucsource);
break;
case 's':
SetConfigOption("log_statement_stats", "true", ctx, gucsource);
break;
case 'T':
/* ignored for consistency with postmaster */
break;
case 't':
{
const char *tmp = get_stats_option_name(optarg);
if (tmp)
SetConfigOption(tmp, "true", ctx, gucsource);
else
errs++;
break;
}
case 'v':
/*
* -v is no longer used in normal operation, since
* FrontendProtocol is already set before we get here. We keep
* the switch only for possible use in standalone operation,
* in case we ever support using normal FE/BE protocol with a
* standalone backend.
*/
if (secure)
FrontendProtocol = (ProtocolVersion) atoi(optarg);
break;
case 'W':
SetConfigOption("post_auth_delay", optarg, ctx, gucsource); break;
case 'c':
case '-':
{
char *name,
*value;
ParseLongOption(optarg, &name, &value);
if (!value)
{
if (flag == '-')
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("--%s requires a value",
optarg)));
else
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("-c %s requires a value",
optarg)));
}
SetConfigOption(name, value, ctx, gucsource);
free(name);
if (value)
free(value);
break;
}
default:
errs++;
break;
}
}
/*
* Should be no more arguments except an optional database name, and
* that's only in the secure case.
*/
if (errs || argc - optind > 1 || (argc != optind && !secure))
{
/* spell the error message a bit differently depending on context */
if (IsUnderPostmaster)
ereport(FATAL,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid command-line arguments for server process"),
errhint("Try \"%s --help\" for more information.", progname)));
else
ereport(FATAL,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("%s: invalid command-line arguments",
progname),
errhint("Try \"%s --help\" for more information.", progname)));
}
if (argc - optind == 1)
dbname = strdup(argv[optind]);
else
dbname = NULL;
/*
* Reset getopt(3) library so that it will work correctly in subprocesses
* or when this function is called a second time with another array.
*/
optind = 1;
#ifdef HAVE_INT_OPTRESET
optreset = 1; /* some systems need this too */
#endif
return dbname;}
/* ----------------------------------------------------------------
* PostgresMain
* postgres main loop -- all backends, interactive or otherwise start here
*
* argc/argv are the command line arguments to be used. (When being forked
* by the postmaster, these are not the original argv array of the process.)
* username is the (possibly authenticated) PostgreSQL user name to be used
* for the session.
* ----------------------------------------------------------------
*/
int
PostgresMain(int argc, char *argv[], const char *username)
{
const char *dbname;
int firstchar;
char stack_base;
StringInfoData input_message;
sigjmp_buf local_sigjmp_buf;
volatile bool send_ready_for_query = true;
/*
* Initialize globals (already done if under postmaster, but not if
* standalone).
*/
if (!IsUnderPostmaster)
{
MyProcPid = getpid();
MyStartTime = time(NULL);
}
/*
* Fire up essential subsystems: error and memory management
*
* If we are running under the postmaster, this is done already.
*/
if (!IsUnderPostmaster)
MemoryContextInit();
SetProcessingMode(InitProcessing);
/* Set up reference point for stack depth checking */
stack_base_ptr = &stack_base;
#if defined(__ia64__) || defined(__ia64)
register_stack_base_ptr = ia64_get_bsp();
#endif
/* Compute paths, if we didn't inherit them from postmaster */
if (my_exec_path[0] == '\0')
{
if (find_my_exec(argv[0], my_exec_path) < 0)
elog(FATAL, "%s: could not locate my own executable path",
argv[0]);
}
if (pkglib_path[0] == '\0')
get_pkglib_path(my_exec_path, pkglib_path);
/*
* Set default values for command-line options.
*/
if (!IsUnderPostmaster)
InitializeGUCOptions();
/*
* Parse command-line options.
*/ dbname = process_postgres_switches(argc, argv, PGC_POSTMASTER);
/* Must have gotten a database name, or have a default (the username) */
if (dbname == NULL)
{
dbname = username;
if (dbname == NULL)
ereport(FATAL,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("%s: no database nor user name specified",
progname)));
}
/* Acquire configuration parameters, unless inherited from postmaster */
if (!IsUnderPostmaster)
{
if (!SelectConfigFiles(userDoption, progname))
proc_exit(1);
/* If timezone is not set, determine what the OS uses */
pg_timezone_initialize();
/* If timezone_abbreviations is not set, select default */
pg_timezone_abbrev_initialize();
}
/*
* You might expect to see a setsid() call here, but it's not needed,
* because if we are under a postmaster then BackendInitialize() did it.
*/
/*
* Set up signal handlers and masks.
*
* Note that postmaster blocked all signals before forking child process,
* so there is no race condition whereby we might receive a signal before
* we have set up the handler.
*
* Also note: it's best not to use any signals that are SIG_IGNored in the
* postmaster. If such a signal arrives before we are able to change the
* handler to non-SIG_IGN, it'll get dropped. Instead, make a dummy
* handler in the postmaster to reserve the signal. (Of course, this isn't
* an issue for signals that are locally generated, such as SIGALRM and
* SIGPIPE.)
*/
if (am_walsender)
WalSndSignals();
else
{
pqsignal(SIGHUP, SigHupHandler); /* set flag to read config
* file */
pqsignal(SIGINT, StatementCancelHandler); /* cancel current query */
pqsignal(SIGTERM, die); /* cancel current query and exit */
/*
* In a standalone backend, SIGQUIT can be generated from the keyboard
* easily, while SIGTERM cannot, so we make both signals do die()
* rather than quickdie().
*/
if (IsUnderPostmaster)
pqsignal(SIGQUIT, quickdie); /* hard crash time */
else
pqsignal(SIGQUIT, die); /* cancel current query and exit */
pqsignal(SIGALRM, handle_sig_alarm); /* timeout conditions */
/*
* Ignore failure to write to frontend. Note: if frontend closes
* connection, we will notice it and exit cleanly when control next
* returns to outer loop. This seems safer than forcing exit in the
* midst of output during who-knows-what operation...
*/
pqsignal(SIGPIPE, SIG_IGN); pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, SIG_IGN);
pqsignal(SIGFPE, FloatExceptionHandler);
/*
* Reset some signals that are accepted by postmaster but not by
* backend
*/
pqsignal(SIGCHLD, SIG_DFL); /* system() requires this on some
* platforms */
}
pqinitmask();
if (IsUnderPostmaster)
{
/* We allow SIGQUIT (quickdie) at all times */
sigdelset(&BlockSig, SIGQUIT);
}
PG_SETMASK(&BlockSig); /* block everything except SIGQUIT */
if (!IsUnderPostmaster)
{
/*
* Validate we have been given a reasonable-looking DataDir (if under
* postmaster, assume postmaster did this already).
*/
Assert(DataDir);
ValidatePgVersion(DataDir);
/* Change into DataDir (if under postmaster, was done already) */
ChangeToDataDir();
/*
* Create lockfile for data directory.
*/
CreateDataDirLockFile(false);
}
/* Early initialization */
BaseInit();
/*
* Create a per-backend PGPROC struct in shared memory, except in the
* EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
* this before we can use LWLocks (and in the EXEC_BACKEND case we already
* had to do some stuff with LWLocks).
*/
#ifdef EXEC_BACKEND
if (!IsUnderPostmaster)
InitProcess();
#else
InitProcess();
#endif
/* We need to allow SIGINT, etc during the initial transaction */
PG_SETMASK(&UnBlockSig);
/*
* General initialization.
*
* NOTE: if you are tempted to add code in this vicinity, consider putting
* it inside InitPostgres() instead. In particular, anything that
* involves database access should be there, not here.
*/
InitPostgres(dbname, InvalidOid, username, NULL);
/*
* If the PostmasterContext is still around, recycle the space; we don't * need it anymore after InitPostgres completes. Note this does not trash
* *MyProcPort, because ConnCreate() allocated that space with malloc()
* ... else we'd need to copy the Port data first. Also, subsidiary data
* such as the username isn't lost either; see ProcessStartupPacket().
*/
if (PostmasterContext)
{
MemoryContextDelete(PostmasterContext);
PostmasterContext = NULL;
}
SetProcessingMode(NormalProcessing);
/*
* Now all GUC states are fully set up. Report them to client if
* appropriate.
*/
BeginReportingGUCOptions();
/*
* Also set up handler to log session end; we have to wait till now to be
* sure Log_disconnections has its final value.
*/
if (IsUnderPostmaster && Log_disconnections)
on_proc_exit(log_disconnections, 0);
/* If this is a WAL sender process, we're done with initialization. */
if (am_walsender)
proc_exit(WalSenderMain());
/*
* process any libraries that should be preloaded at backend start (this
* likewise can't be done until GUC settings are complete)
*/
process_local_preload_libraries();
/*
* Send this backend's cancellation info to the frontend.
*/
if (whereToSendOutput == DestRemote &&
PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
{
StringInfoData buf;
pq_beginmessage(&buf, 'K');
pq_sendint(&buf, (int32) MyProcPid, sizeof(int32));
pq_sendint(&buf, (int32) MyCancelKey, sizeof(int32));
pq_endmessage(&buf);
/* Need not flush since ReadyForQuery will do it. */
}
/* Welcome banner for standalone case */
if (whereToSendOutput == DestDebug)
printf("\nPostgreSQL stand-alone backend %s\n", PG_VERSION);
/*
* Create the memory context we will use in the main loop.
*
* MessageContext is reset once per iteration of the main loop, ie, upon
* completion of processing of each command message from the client.
*/
MessageContext = AllocSetContextCreate(TopMemoryContext,
"MessageContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* Remember stand-alone backend startup time
*/ if (!IsUnderPostmaster)
PgStartTime = GetCurrentTimestamp();
/*
* POSTGRES main processing loop begins here
*
* If an exception is encountered, processing resumes here so we abort the
* current transaction and start a new one.
*
* You might wonder why this isn't coded as an infinite loop around a
* PG_TRY construct. The reason is that this is the bottom of the
* exception stack, and so with PG_TRY there would be no exception handler
* in force at all during the CATCH part. By leaving the outermost setjmp
* always active, we have at least some chance of recovering from an error
* during error recovery. (If we get into an infinite loop thereby, it
* will soon be stopped by overflow of elog.c's internal state stack.)
*/
if (sigsetjmp(local_sigjmp_buf, 1) != 0)
{
/*
* NOTE: if you are tempted to add more code in this if-block,
* consider the high probability that it should be in
* AbortTransaction() instead. The only stuff done directly here
* should be stuff that is guaranteed to apply *only* for outer-level
* error recovery, such as adjusting the FE/BE protocol status.
*/
/* Since not using PG_TRY, must reset error stack by hand */
error_context_stack = NULL;
/* Prevent interrupts while cleaning up */
HOLD_INTERRUPTS();
/*
* Forget any pending QueryCancel request, since we're returning to
* the idle loop anyway, and cancel the statement timer if running.
*/
QueryCancelPending = false;
disable_sig_alarm(true);
QueryCancelPending = false; /* again in case timeout occurred */
/*
* Turn off these interrupts too. This is only needed here and not in
* other exception-catching places since these interrupts are only
* enabled while we wait for client input.
*/
DoingCommandRead = false;
DisableNotifyInterrupt();
DisableCatchupInterrupt();
/* Make sure libpq is in a good state */
pq_comm_reset();
/* Report the error to the client and/or server log */
EmitErrorReport();
/*
* Make sure debug_query_string gets reset before we possibly clobber
* the storage it points at.
*/
debug_query_string = NULL;
/*
* Abort the current transaction in order to recover.
*/
AbortCurrentTransaction();
/*
* Now return to normal top-level context and clear ErrorContext for * next time.
*/
MemoryContextSwitchTo(TopMemoryContext);
FlushErrorState();
/*
* If we were handling an extended-query-protocol message, initiate
* skip till next Sync. This also causes us not to issue
* ReadyForQuery (until we get Sync).
*/
if (doing_extended_query_message)
ignore_till_sync = true;
/* We don't have a transaction command open anymore */
xact_started = false;
/* Now we can allow interrupts again */
RESUME_INTERRUPTS();
}
/* We can now handle ereport(ERROR) */
PG_exception_stack = &local_sigjmp_buf;
if (!ignore_till_sync)
send_ready_for_query = true; /* initially, or after error */
/*
* Non-error queries loop here.
*/
for (;;)
{
/*
* At top of loop, reset extended-query-message flag, so that any
* errors encountered in "idle" state don't provoke skip.
*/
doing_extended_query_message = false;
/*
* Release storage left over from prior query cycle, and create a new
* query input buffer in the cleared MessageContext.
*/
MemoryContextSwitchTo(MessageContext);
MemoryContextResetAndDeleteChildren(MessageContext);
initStringInfo(&input_message);
/*
* (1) If we've reached idle state, tell the frontend we're ready for
* a new query.
*
* Note: this includes fflush()'ing the last of the prior output.
*
* This is also a good time to send collected statistics to the
* collector, and to update the PS stats display. We avoid doing
* those every time through the message loop because it'd slow down
* processing of batched messages, and because we don't want to report
* uncommitted updates (that confuses autovacuum). The notification
* processor wants a call too, if we are not in a transaction block.
*/
if (send_ready_for_query)
{
if (IsAbortedTransactionBlockState())
{
set_ps_display("idle in transaction (aborted)", false);
pgstat_report_activity("<IDLE> in transaction (aborted)");
}
else if (IsTransactionOrTransactionBlock())
{
set_ps_display("idle in transaction", false); pgstat_report_activity("<IDLE> in transaction");
}
else
{
ProcessCompletedNotifies();
pgstat_report_stat(false);
set_ps_display("idle", false);
pgstat_report_activity("<IDLE>");
}
ReadyForQuery(whereToSendOutput);
send_ready_for_query = false;
}
/*
* (2) Allow asynchronous signals to be executed immediately if they
* come in while we are waiting for client input. (This must be
* conditional since we don't want, say, reads on behalf of COPY FROM
* STDIN doing the same thing.)
*/
DoingCommandRead = true;
/*
* (3) read a command (loop blocks here)
*/
firstchar = ReadCommand(&input_message);
/*
* (4) disable async signal conditions again.
*/
DoingCommandRead = false;
/*
* (5) check for any other interesting events that happened while we
* slept.
*/
if (got_SIGHUP)
{
got_SIGHUP = false;
ProcessConfigFile(PGC_SIGHUP);
}
/*
* (6) process the command. But ignore it if we're skipping till
* Sync.
*/
if (ignore_till_sync && firstchar != EOF)
continue;
switch (firstchar)
{
case 'Q': /* simple query */
{
const char *query_string;
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
query_string = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
exec_simple_query(query_string);
send_ready_for_query = true;
}
break;
case 'P': /* parse */
{ const char *stmt_name;
const char *query_string;
int numParams;
Oid *paramTypes = NULL;
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
stmt_name = pq_getmsgstring(&input_message);
query_string = pq_getmsgstring(&input_message);
numParams = pq_getmsgint(&input_message, 2);
if (numParams > 0)
{
int i;
paramTypes = (Oid *) palloc(numParams * sizeof(Oid));
for (i = 0; i < numParams; i++)
paramTypes[i] = pq_getmsgint(&input_message, 4);
}
pq_getmsgend(&input_message);
exec_parse_message(query_string, stmt_name,
paramTypes, numParams);
}
break;
case 'B': /* bind */
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
/*
* this message is complex enough that it seems best to put
* the field extraction out-of-line
*/
exec_bind_message(&input_message);
break;
case 'E': /* execute */
{
const char *portal_name;
int max_rows;
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
portal_name = pq_getmsgstring(&input_message);
max_rows = pq_getmsgint(&input_message, 4);
pq_getmsgend(&input_message);
exec_execute_message(portal_name, max_rows);
}
break;
case 'F': /* fastpath function call */
/* Set statement_timestamp() */
SetCurrentStatementStartTimestamp();
/* Report query to various monitoring facilities. */
pgstat_report_activity("<FASTPATH> function call");
set_ps_display("<FASTPATH>", false);
/* start an xact for this function invocation */
start_xact_command();
/*
* Note: we may at this point be inside an aborted
* transaction. We can't throw error for that until we've
* finished reading the function-call message, so
* HandleFunctionRequest() must check for it after doing so.
* Be careful not to do anything that assumes we're inside a * valid transaction here.
*/
/* switch back to message context */
MemoryContextSwitchTo(MessageContext);
if (HandleFunctionRequest(&input_message) == EOF)
{
/* lost frontend connection during F message input */
/*
* Reset whereToSendOutput to prevent ereport from
* attempting to send any more messages to client.
*/
if (whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
proc_exit(0);
}
/* commit the function-invocation transaction */
finish_xact_command();
send_ready_for_query = true;
break;
case 'C': /* close */
{
int close_type;
const char *close_target;
close_type = pq_getmsgbyte(&input_message);
close_target = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
switch (close_type)
{
case 'S':
if (close_target[0] != '\0')
DropPreparedStatement(close_target, false);
else
{
/* special-case the unnamed statement */
drop_unnamed_stmt();
}
break;
case 'P':
{
Portal portal;
portal = GetPortalByName(close_target);
if (PortalIsValid(portal))
PortalDrop(portal, false);
}
break;
default:
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid CLOSE message subtype %d",
close_type)));
break;
}
if (whereToSendOutput == DestRemote)
pq_putemptymessage('3'); /* CloseComplete */
}
break;
case 'D': /* describe */
{ int describe_type;
const char *describe_target;
/* Set statement_timestamp() (needed for xact) */
SetCurrentStatementStartTimestamp();
describe_type = pq_getmsgbyte(&input_message);
describe_target = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
switch (describe_type)
{
case 'S':
exec_describe_statement_message(describe_target);
break;
case 'P':
exec_describe_portal_message(describe_target);
break;
default:
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid DESCRIBE message subtype %d",
describe_type)));
break;
}
}
break;
case 'H': /* flush */
pq_getmsgend(&input_message);
if (whereToSendOutput == DestRemote)
pq_flush();
break;
case 'S': /* sync */
pq_getmsgend(&input_message);
finish_xact_command();
send_ready_for_query = true;
break;
/*
* 'X' means that the frontend is closing down the socket. EOF
* means unexpected loss of frontend connection. Either way,
* perform normal shutdown.
*/
case 'X':
case EOF:
/*
* Reset whereToSendOutput to prevent ereport from attempting
* to send any more messages to client.
*/
if (whereToSendOutput == DestRemote)
whereToSendOutput = DestNone;
/*
* NOTE: if you are tempted to add more code here, DON'T!
* Whatever you had in mind to do should be set up as an
* on_proc_exit or on_shmem_exit callback, instead. Otherwise
* it will fail to be called during other backend-shutdown
* scenarios.
*/
proc_exit(0);
case 'd': /* copy data */
case 'c': /* copy done */
case 'f': /* copy fail */
/*
* Accept but ignore these messages, per protocol spec; we * probably got here because a COPY failed, and the frontend
* is still sending data.
*/
break;
default:
ereport(FATAL,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("invalid frontend message type %d",
firstchar)));
}
} /* end of input-reading loop */
/* can't get here because the above loop never exits */
Assert(false);
return 1; /* keep compiler quiet */
}
/*
* Obtain platform stack depth limit (in bytes)
*
* Return -1 if unknown
*/
long
get_stack_depth_rlimit(void)
{
#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_STACK)
static long val = 0;
/* This won't change after process launch, so check just once */
if (val == 0)
{
struct rlimit rlim;
if (getrlimit(RLIMIT_STACK, &rlim) < 0)
val = -1;
else if (rlim.rlim_cur == RLIM_INFINITY)
val = LONG_MAX;
/* rlim_cur is probably of an unsigned type, so check for overflow */
else if (rlim.rlim_cur >= LONG_MAX)
val = LONG_MAX;
else
val = rlim.rlim_cur;
}
return val;
#else /* no getrlimit */
#if defined(WIN32) || defined(__CYGWIN__)
/* On Windows we set the backend stack size in src/backend/Makefile */
return WIN32_STACK_RLIMIT;
#else /* not windows ... give up */
return -1;
#endif
#endif
}
static struct rusage Save_r;
static struct timeval Save_t;
void
ResetUsage(void)
{
getrusage(RUSAGE_SELF, &Save_r);
gettimeofday(&Save_t, NULL);
}
void
ShowUsage(const char *title){
StringInfoData str;
struct timeval user,
sys;
struct timeval elapse_t;
struct rusage r;
getrusage(RUSAGE_SELF, &r);
gettimeofday(&elapse_t, NULL);
memcpy((char *) &user, (char *) &r.ru_utime, sizeof(user));
memcpy((char *) &sys, (char *) &r.ru_stime, sizeof(sys));
if (elapse_t.tv_usec < Save_t.tv_usec)
{
elapse_t.tv_sec--;
elapse_t.tv_usec += 1000000;
}
if (r.ru_utime.tv_usec < Save_r.ru_utime.tv_usec)
{
r.ru_utime.tv_sec--;
r.ru_utime.tv_usec += 1000000;
}
if (r.ru_stime.tv_usec < Save_r.ru_stime.tv_usec)
{
r.ru_stime.tv_sec--;
r.ru_stime.tv_usec += 1000000;
}
/*
* the only stats we don't show here are for memory usage -- i can't
* figure out how to interpret the relevant fields in the rusage struct,
* and they change names across o/s platforms, anyway. if you can figure
* out what the entries mean, you can somehow extract resident set size,
* shared text size, and unshared data and stack sizes.
*/
initStringInfo(&str);
appendStringInfo(&str, "! system usage stats:\n");
appendStringInfo(&str,
"!\t%ld.%06ld elapsed %ld.%06ld user %ld.%06ld system sec\n",
(long) (elapse_t.tv_sec - Save_t.tv_sec),
(long) (elapse_t.tv_usec - Save_t.tv_usec),
(long) (r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec),
(long) (r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec),
(long) (r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec),
(long) (r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec));
appendStringInfo(&str,
"!\t[%ld.%06ld user %ld.%06ld sys total]\n",
(long) user.tv_sec,
(long) user.tv_usec,
(long) sys.tv_sec,
(long) sys.tv_usec);
#if defined(HAVE_GETRUSAGE)
appendStringInfo(&str,
"!\t%ld/%ld [%ld/%ld] filesystem blocks in/out\n",
r.ru_inblock - Save_r.ru_inblock,
/* they only drink coffee at dec */
r.ru_oublock - Save_r.ru_oublock,
r.ru_inblock, r.ru_oublock);
appendStringInfo(&str,
"!\t%ld/%ld [%ld/%ld] page faults/reclaims, %ld [%ld] swaps\n",
r.ru_majflt - Save_r.ru_majflt,
r.ru_minflt - Save_r.ru_minflt,
r.ru_majflt, r.ru_minflt,
r.ru_nswap - Save_r.ru_nswap,
r.ru_nswap);
appendStringInfo(&str,
"!\t%ld [%ld] signals rcvd, %ld/%ld [%ld/%ld] messages rcvd/sent\n",
r.ru_nsignals - Save_r.ru_nsignals,
r.ru_nsignals,
r.ru_msgrcv - Save_r.ru_msgrcv, r.ru_msgsnd - Save_r.ru_msgsnd,
r.ru_msgrcv, r.ru_msgsnd);
appendStringInfo(&str,
"!\t%ld/%ld [%ld/%ld] voluntary/involuntary context switches\n",
r.ru_nvcsw - Save_r.ru_nvcsw,
r.ru_nivcsw - Save_r.ru_nivcsw,
r.ru_nvcsw, r.ru_nivcsw);
#endif /* HAVE_GETRUSAGE */
/* remove trailing newline */
if (str.data[str.len - 1] == '\n')
str.data[--str.len] = '\0';
ereport(LOG,
(errmsg_internal("%s", title),
errdetail("%s", str.data)));
pfree(str.data);
}
/*
* on_proc_exit handler to log end of session
*/
static void
log_disconnections(int code, Datum arg)
{
Port *port = MyProcPort;
long secs;
int usecs;
int msecs;
int hours,
minutes,
seconds;
TimestampDifference(port->SessionStartTime,
GetCurrentTimestamp(),
&secs, &usecs);
msecs = usecs / 1000;
hours = secs / SECS_PER_HOUR;
secs %= SECS_PER_HOUR;
minutes = secs / SECS_PER_MINUTE;
seconds = secs % SECS_PER_MINUTE;
ereport(LOG,
(errmsg("disconnection: session time: %d:%02d:%02d.%03d "
"user=%s database=%s host=%s%s%s",
hours, minutes, seconds, msecs,
port->user_name, port->database_name, port->remote_host,
port->remote_port[0] ? " port=" : "", port->remote_port)));
}