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Bruce Momjian authoredBruce Momjian authored
postgres.c 84.25 KiB
/*-------------------------------------------------------------------------
*
* postgres.c
* POSTGRES C Backend Interface
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.410 2004/05/19 18:58:44 momjian Exp $
*
* NOTES
* this is the "main" module of the postgres backend and
* hence the main module of the "traffic cop".
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <errno.h>
#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include "access/printtup.h"
#include "access/xlog.h"
#include "catalog/pg_type.h"
#include "commands/async.h"
#include "commands/prepare.h"
#include "commands/trigger.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "libpq/pqsignal.h"
#include "miscadmin.h"
#include "nodes/print.h"
#include "optimizer/cost.h"
#include "optimizer/planner.h"
#include "parser/analyze.h"
#include "parser/parser.h"
#include "rewrite/rewriteHandler.h"
#include "storage/freespace.h"
#include "storage/ipc.h"
#include "storage/pg_shmem.h"
#include "storage/proc.h"
#include "tcop/fastpath.h"
#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
#include "tcop/utility.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "mb/pg_wchar.h"
#include "pgstat.h"
extern int optind;
extern char *optarg;
/* ----------------
* global variables
* ----------------
*/
const char *debug_query_string; /* for pgmonitor and
* log_min_error_statement */
/* Note: whereToSendOutput is initialized for the bootstrap/standalone case */
CommandDest whereToSendOutput = Debug;
/* note: these declarations had better match tcopprot.h */
sigjmp_buf Warn_restart;
bool Warn_restart_ready = false;
bool InError = false;
/* flag for logging end of session */
bool Log_disconnections = false;
LogStmtLevel log_statement = LOGSTMT_NONE;
/* GUC variable for maximum stack depth (measured in kilobytes) */
int max_stack_depth = 2048;
/* ----------------
* private variables
* ----------------
*/
/* max_stack_depth converted to bytes for speed of checking */
static int max_stack_depth_bytes = 2048*1024;
/* stack base pointer (initialized by PostgresMain) */
static char *stack_base_ptr = NULL;
/*
* 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 bool 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;
/*
* 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 MemoryContext unnamed_stmt_context = NULL;
static PreparedStatement *unnamed_stmt_pstmt = NULL;
static bool EchoQuery = false; /* default don't echo */
/*
* 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 */
/* ----------------------------------------------------------------
* decls for routines only used in this file
* ----------------------------------------------------------------
*/
static int InteractiveBackend(StringInfo inBuf);
static int SocketBackend(StringInfo inBuf);
static int ReadCommand(StringInfo inBuf);
static void start_xact_command(void);
static void finish_xact_command(void);
static void SigHupHandler(SIGNAL_ARGS);
static void FloatExceptionHandler(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);
/* Reset inBuf to empty */
inBuf->len = 0;
inBuf->data[0] = '\0';
inBuf->cursor = 0;
for (;;)
{
if (UseNewLine)
{
/*
* if we are using \n as a delimiter, then read characters
* until the \n.
*/
while ((c = getc(stdin)) != 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 = getc(stdin)) != EOF)
appendStringInfoChar(inBuf, (char) c);
if (inBuf->len == 0)
end = true;
}
if (end)
return EOF;
/*
* otherwise we have a user query so process it.
*/
break;
}
/* 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';
}
/* ----------------
* 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 == Remote)
result = SocketBackend(inBuf);
else
result = InteractiveBackend(inBuf);
return result;
}
/*
* Parse a query string and pass it through the rewriter.
*
* A list of Query nodes is returned, since the string might contain
* multiple queries and/or the rewriter might expand one query to several.
* * NOTE: this routine is no longer used for processing interactive queries,
* but it is still needed for parsing of SQL function bodies.
*/
List *
pg_parse_and_rewrite(const char *query_string, /* string to execute */
Oid *paramTypes, /* parameter types */
int numParams) /* number of parameters */
{
List *raw_parsetree_list;
List *querytree_list;
List *list_item;
/*
* (1) parse the request string into a list of raw parse trees.
*/
raw_parsetree_list = pg_parse_query(query_string);
/*
* (2) Do parse analysis and rule rewrite.
*/
querytree_list = NIL;
foreach(list_item, raw_parsetree_list)
{
Node *parsetree = (Node *) lfirst(list_item);
querytree_list = nconc(querytree_list,
pg_analyze_and_rewrite(parsetree,
paramTypes,
numParams));
}
return querytree_list;
}
/*
* 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,
*parsetree_item;
if (log_statement == LOGSTMT_ALL)
ereport(LOG,
(errmsg("statement: %s", query_string)));
if (log_parser_stats)
ResetUsage();
raw_parsetree_list = raw_parser(query_string);
/* do log_statement tests for mod and ddl */
if (log_statement == LOGSTMT_MOD ||
log_statement == LOGSTMT_DDL)
{
foreach(parsetree_item, raw_parsetree_list)
{
Node *parsetree = (Node *) lfirst(parsetree_item);
const char *commandTag;
if (IsA(parsetree, ExplainStmt) &&
((ExplainStmt *)parsetree)->analyze)
parsetree = (Node *)(((ExplainStmt *)parsetree)->query);
if (IsA(parsetree, PrepareStmt))
parsetree = (Node *)(((PrepareStmt *)parsetree)->query);
if (IsA(parsetree, SelectStmt))
continue; /* optimization for frequent command */
if (log_statement == LOGSTMT_MOD &&
(IsA(parsetree, InsertStmt) ||
IsA(parsetree, UpdateStmt) ||
IsA(parsetree, DeleteStmt) ||
IsA(parsetree, TruncateStmt) ||
(IsA(parsetree, CopyStmt) &&
((CopyStmt *)parsetree)->is_from))) /* COPY FROM */
{
ereport(LOG,
(errmsg("statement: %s", query_string)));
break;
}
commandTag = CreateCommandTag(parsetree);
if (strncmp(commandTag, "CREATE ", strlen("CREATE ")) == 0 ||
strncmp(commandTag, "ALTER ", strlen("ALTER ")) == 0 ||
strncmp(commandTag, "DROP ", strlen("DROP ")) == 0 ||
IsA(parsetree, GrantStmt) || /* GRANT or REVOKE */
IsA(parsetree, CommentStmt))
{
ereport(LOG,
(errmsg("statement: %s", query_string)));
break;
}
}
}
if (log_parser_stats)
ShowUsage("PARSER STATISTICS");
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, Oid *paramTypes, int numParams)
{
List *querytree_list;
/*
* (1) Perform parse analysis.
*/
if (log_parser_stats)
ResetUsage();
querytree_list = parse_analyze(parsetree, paramTypes, numParams);
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
/*
* (2) Rewrite the queries, as necessary */
querytree_list = pg_rewrite_queries(querytree_list);
return querytree_list;
}
/*
* Perform rewriting of a list of queries produced by parse analysis.
*/
List *
pg_rewrite_queries(List *querytree_list)
{
List *new_list = NIL;
List *list_item;
if (log_parser_stats)
ResetUsage();
/*
* rewritten queries are collected in new_list. Note there may be
* more or fewer than in the original list.
*/
foreach(list_item, querytree_list)
{
Query *querytree = (Query *) lfirst(list_item);
if (Debug_print_parse)
elog_node_display(DEBUG1, "parse tree", querytree,
Debug_pretty_print);
if (querytree->commandType == CMD_UTILITY)
{
/* don't rewrite utilities, just dump 'em into new_list */
new_list = lappend(new_list, querytree);
}
else
{
/* rewrite regular queries */
List *rewritten = QueryRewrite(querytree);
new_list = nconc(new_list, rewritten);
}
}
querytree_list = new_list;
if (log_parser_stats)
ShowUsage("REWRITER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/*
* Optional debugging check: pass querytree output through
* copyObject()
*/
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 an equal parse tree");
else
querytree_list = new_list;
#endif
if (Debug_print_rewritten)
elog_node_display(DEBUG1, "rewritten parse tree", querytree_list,
Debug_pretty_print);
return querytree_list;
}
/* Generate a plan for a single already-rewritten query. */
Plan *
pg_plan_query(Query *querytree)
{
Plan *plan;
/* Utility commands have no plans. */
if (querytree->commandType == CMD_UTILITY)
return NULL;
if (log_planner_stats)
ResetUsage();
/* call the optimizer */
plan = planner(querytree, false, 0);
if (log_planner_stats)
ShowUsage("PLANNER STATISTICS");
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass plan output through copyObject() */
{
Plan *new_plan = (Plan *) 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(DEBUG1, "plan", plan, Debug_pretty_print);
return plan;
}
/*
* Generate plans for a list of already-rewritten queries.
*
* If needSnapshot is TRUE, we haven't yet set a snapshot for the current
* query. A snapshot must be set before invoking the planner, since it
* might try to evaluate user-defined functions. But we must not set a
* snapshot if the list contains only utility statements, because some
* utility statements depend on not having frozen the snapshot yet.
* (We assume that such statements cannot appear together with plannable
* statements in the rewriter's output.)
*/
List *
pg_plan_queries(List *querytrees, bool needSnapshot)
{
List *plan_list = NIL;
List *query_list;
foreach(query_list, querytrees)
{
Query *query = (Query *) lfirst(query_list);
Plan *plan;
if (query->commandType == CMD_UTILITY)
{
/* Utility commands have no plans. */
plan = NULL;
}
else
{
if (needSnapshot)
{
SetQuerySnapshot();
needSnapshot = false;
}
plan = pg_plan_query(query);
}
plan_list = lappend(plan_list, plan);
}
return plan_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,
*parsetree_item;
struct timeval start_t,
stop_t;
bool save_log_duration = log_duration;
int save_log_min_duration_statement = log_min_duration_statement;
bool save_log_statement_stats = log_statement_stats;
/*
* Report query to various monitoring facilities.
*/
debug_query_string = query_string;
pgstat_report_activity(query_string);
/*
* We use save_log_* so "SET log_duration = true" and "SET
* log_min_duration_statement = true" don't report incorrect time
* because gettimeofday() wasn't called. Similarly,
* log_statement_stats has to be captured once.
*/
if (save_log_duration || save_log_min_duration_statement != -1)
gettimeofday(&start_t, NULL);
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.)
*/
unnamed_stmt_pstmt = NULL;
if (unnamed_stmt_context)
{
DropDependentPortals(unnamed_stmt_context);
MemoryContextDelete(unnamed_stmt_context);
}
unnamed_stmt_context = NULL;
/*
* Switch to appropriate context for constructing parsetrees.
*/
oldcontext = MemoryContextSwitchTo(MessageContext);
QueryContext = CurrentMemoryContext;
/*
* 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);
/*
* Switch back to transaction context to enter the loop.
*/
MemoryContextSwitchTo(oldcontext);
/*
* Run through the raw parsetree(s) and process each one.
*/
foreach(parsetree_item, parsetree_list)
{
Node *parsetree = (Node *) lfirst(parsetree_item);
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);
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())
{
bool allowit = false;
if (IsA(parsetree, TransactionStmt))
{ TransactionStmt *stmt = (TransactionStmt *) parsetree;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_ROLLBACK)
allowit = true;
}
if (!allowit)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block")));
}
/* 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();
/*
* 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, NULL, 0);
plantree_list = pg_plan_queries(querytree_list, true);
/* 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);
PortalDefineQuery(portal,
query_string,
commandTag,
querytree_list,
plantree_list,
MessageContext);
/*
* Start the portal. No parameters here.
*/
PortalStart(portal, NULL);
/*
* 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, 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,
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) == NIL)
{
/*
* 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);
QueryContext = NULL;
/*
* Combine processing here as we need to calculate the query duration
* in both instances.
*/
if (save_log_duration || save_log_min_duration_statement != -1)
{
long usecs;
gettimeofday(&stop_t, NULL);
if (stop_t.tv_usec < start_t.tv_usec)
{
stop_t.tv_sec--;
stop_t.tv_usec += 1000000;
}
usecs = (long) (stop_t.tv_sec - start_t.tv_sec) * 1000000 + (long) (stop_t.tv_usec - start_t.tv_usec);
if (save_log_duration)
ereport(LOG,
(errmsg("duration: %ld.%03ld ms",
(long) ((stop_t.tv_sec - start_t.tv_sec) * 1000 +
(stop_t.tv_usec - start_t.tv_usec) / 1000),
(long) (stop_t.tv_usec - start_t.tv_usec) % 1000)));
/*
* Output a duration_statement to the log if the query has exceeded
* the min duration, or if we are to print all durations.
*/
if (save_log_min_duration_statement == 0 ||
(save_log_min_duration_statement > 0 &&
usecs >= save_log_min_duration_statement * 1000))
ereport(LOG,
(errmsg("duration: %ld.%03ld ms statement: %s",
(long) ((stop_t.tv_sec - start_t.tv_sec) * 1000 +
(stop_t.tv_usec - start_t.tv_usec) / 1000),
(long) (stop_t.tv_usec - start_t.tv_usec) % 1000,
query_string)));
}
if (save_log_statement_stats)
ShowUsage("QUERY STATISTICS");
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;
const char *commandTag;
List *querytree_list,
*plantree_list,
*param_list;
bool is_named;
bool save_log_statement_stats = log_statement_stats;
/*
* Report query to various monitoring facilities.
*/
debug_query_string = query_string;
pgstat_report_activity(query_string);
set_ps_display("PARSE");
if (save_log_statement_stats)
ResetUsage();
/*
* 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 private context; 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 set up a special context for the unnamed statement, and do all
* the parsing/planning 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 */
unnamed_stmt_pstmt = NULL;
if (unnamed_stmt_context)
{
DropDependentPortals(unnamed_stmt_context);
MemoryContextDelete(unnamed_stmt_context);
}
unnamed_stmt_context = NULL;
/* create context for parsing/planning */
unnamed_stmt_context =
AllocSetContextCreate(TopMemoryContext,
"unnamed prepared statement",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
oldcontext = MemoryContextSwitchTo(unnamed_stmt_context);
}
QueryContext = CurrentMemoryContext;
/*
* 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 (length(parsetree_list) > 1)
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("cannot insert multiple commands into a prepared statement")));
if (parsetree_list != NIL)
{
Node *parsetree = (Node *) lfirst(parsetree_list);
int i;
/*
* Get the command name for possible use in status display.
*/
commandTag = CreateCommandTag(parsetree);
/*
* 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())
{
bool allowit = false;
if (IsA(parsetree, TransactionStmt))
{
TransactionStmt *stmt = (TransactionStmt *) parsetree;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_ROLLBACK)
allowit = true;
}
if (!allowit)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block")));
}
/*
* 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().
*/
if (log_parser_stats)
ResetUsage();
querytree_list = parse_analyze_varparams(parsetree,
¶mTypes,
&numParams);
/*
* Check all parameter types got determined, and convert array
* representation to a list for storage.
*/ param_list = NIL;
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)));
param_list = lappendo(param_list, ptype);
}
if (log_parser_stats)
ShowUsage("PARSE ANALYSIS STATISTICS");
querytree_list = pg_rewrite_queries(querytree_list);
plantree_list = pg_plan_queries(querytree_list, true);
}
else
{
/* Empty input string. This is legal. */
commandTag = NULL;
querytree_list = NIL;
plantree_list = NIL;
param_list = NIL;
}
/* 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,
query_string,
commandTag,
querytree_list,
plantree_list,
param_list);
}
else
{
PreparedStatement *pstmt;
pstmt = (PreparedStatement *) palloc0(sizeof(PreparedStatement));
/* query_string needs to be copied into unnamed_stmt_context */
pstmt->query_string = pstrdup(query_string);
/* the rest is there already */
pstmt->commandTag = commandTag;
pstmt->query_list = querytree_list;
pstmt->plan_list = plantree_list;
pstmt->argtype_list = param_list;
pstmt->context = unnamed_stmt_context;
/* Now the unnamed statement is complete and valid */
unnamed_stmt_pstmt = pstmt;
}
MemoryContextSwitchTo(oldcontext);
QueryContext = NULL;
/*
* 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 == Remote)
pq_putemptymessage('1');
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;
int i;
PreparedStatement *pstmt;
Portal portal;
ParamListInfo params;
pgstat_report_activity("<BIND>");
set_ps_display("BIND");
/*
* 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 fixed part of the message */
portal_name = pq_getmsgstring(input_message);
stmt_name = pq_getmsgstring(input_message);
/* Get the parameter format codes */
numPFormats = pq_getmsgint(input_message, 2);
if (numPFormats > 0)
{
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)));
/* Find prepared statement */
if (stmt_name[0] != '\0')
pstmt = FetchPreparedStatement(stmt_name, true);
else
{
/* special-case the unnamed statement */
pstmt = unnamed_stmt_pstmt;
if (!pstmt)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PSTATEMENT),
errmsg("unnamed prepared statement does not exist")));
}
if (numParams != length(pstmt->argtype_list))
ereport(ERROR,
(errcode(ERRCODE_PROTOCOL_VIOLATION),
errmsg("bind message supplies %d parameters, but prepared statement \"%s\" requires %d",
numParams, stmt_name, length(pstmt->argtype_list))));
/*
* 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);
PortalDefineQuery(portal,
pstmt->query_string,
pstmt->commandTag,
pstmt->query_list,
pstmt->plan_list,
pstmt->context);
/*
* Fetch parameters, if any, and store in the portal's memory context.
*
* In an aborted transaction, we can't risk calling user-defined
* functions, but we can't fail to Bind either, so bind all parameters
* to null values.
*/
if (numParams > 0)
{
bool isaborted = IsAbortedTransactionBlockState();
List *l;
MemoryContext oldContext;
oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
params = (ParamListInfo)
palloc0((numParams + 1) * sizeof(ParamListInfoData));
i = 0;
foreach(l, pstmt->argtype_list)
{
Oid ptype = lfirsto(l);
int32 plength;
bool isNull;
plength = pq_getmsgint(input_message, 4);
isNull = (plength == -1);
if (!isNull)
{
const char *pvalue = pq_getmsgbytes(input_message, plength);
if (isaborted)
{ /* We don't bother to check the format in this case */
isNull = true;
}
else
{
int16 pformat;
StringInfoData pbuf;
char csave;
if (numPFormats > 1)
pformat = pformats[i];
else if (numPFormats > 0)
pformat = pformats[0];
else
pformat = 0; /* default = text */
/*
* 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';
if (pformat == 0)
{
Oid typInput;
Oid typElem;
char *pstring;
getTypeInputInfo(ptype, &typInput, &typElem);
/*
* We have to do encoding conversion before
* calling the typinput routine.
*/
pstring = (char *)
pg_client_to_server((unsigned char *) pbuf.data,
plength);
params[i].value =
OidFunctionCall3(typInput,
CStringGetDatum(pstring),
ObjectIdGetDatum(typElem),
Int32GetDatum(-1));
/* Free result of encoding conversion, if any */
if (pstring != pbuf.data)
pfree(pstring);
}
else if (pformat == 1)
{
Oid typReceive;
Oid typElem;
/*
* Call the parameter type's binary input
* converter
*/
getTypeBinaryInputInfo(ptype, &typReceive, &typElem);
params[i].value =
OidFunctionCall2(typReceive, PointerGetDatum(&pbuf),
ObjectIdGetDatum(typElem));
/* Trouble if it didn't eat the whole buffer */
if (pbuf.cursor != pbuf.len)
ereport(ERROR,
(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
errmsg("incorrect binary data format in bind parameter %d",
i + 1)));
}
else
{
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("unsupported format code: %d",
pformat)));
}
/* Restore message buffer contents */
pbuf.data[plength] = csave;
}
}
params[i].kind = PARAM_NUM;
params[i].id = i + 1;
params[i].isnull = isNull;
i++;
}
params[i].kind = PARAM_INVALID;
MemoryContextSwitchTo(oldContext);
}
else
params = NULL;
/* Get the result format codes */
numRFormats = pq_getmsgint(input_message, 2);
if (numRFormats > 0)
{
rformats = (int16 *) palloc(numRFormats * sizeof(int16));
for (i = 0; i < numRFormats; i++)
rformats[i] = pq_getmsgint(input_message, 2);
}
pq_getmsgend(input_message);
/*
* Start portal execution.
*/
PortalStart(portal, params);
/*
* Apply the result format requests to the portal.
*/
PortalSetResultFormat(portal, numRFormats, rformats);
/*
* Send BindComplete.
*/
if (whereToSendOutput == Remote)
pq_putemptymessage('2');
}
/*
* 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 is_trans_stmt = false;
bool is_trans_exit = false;
bool completed;
char completionTag[COMPLETION_TAG_BUFSIZE];
/* Adjust destination to tell printtup.c what to do */
dest = whereToSendOutput;
if (dest == Remote)
dest = RemoteExecute;
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->parseTrees == NIL);
NullCommand(dest);
return;
}
if (portal->sourceText)
{
debug_query_string = portal->sourceText;
pgstat_report_activity(portal->sourceText);
}
else
{
debug_query_string = "execute message";
pgstat_report_activity("<EXECUTE>");
}
set_ps_display(portal->commandTag);
BeginCommand(portal->commandTag, dest);
/* Check for transaction-control commands */
if (length(portal->parseTrees) == 1)
{
Query *query = (Query *) lfirst(portal->parseTrees);
if (query->commandType == CMD_UTILITY &&
query->utilityStmt != NULL &&
IsA(query->utilityStmt, TransactionStmt))
{
TransactionStmt *stmt = (TransactionStmt *) query->utilityStmt;
is_trans_stmt = true;
if (stmt->kind == TRANS_STMT_COMMIT ||
stmt->kind == TRANS_STMT_ROLLBACK)
is_trans_exit = true;
}
}
/*
* 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, portal);
/*
* Ensure we are in a transaction command (this should normally be the
* case already due to prior BIND).
*/
start_xact_command();
/*
* If we are in aborted transaction state, the only portals we can
* actually run are those containing COMMIT or ROLLBACK commands.
*/
if (IsAbortedTransactionBlockState())
{
if (!is_trans_exit)
ereport(ERROR,
(errcode(ERRCODE_IN_FAILED_SQL_TRANSACTION),
errmsg("current transaction is aborted, "
"commands ignored until end of transaction block")));
}
/* 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,
receiver,
receiver,
completionTag);
(*receiver->rDestroy) (receiver);
if (completed)
{
if (is_trans_stmt)
{
/*
* 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 == Remote)
pq_putemptymessage('s');
}
debug_query_string = NULL;}
/*
* exec_describe_statement_message
*
* Process a "Describe" message for a prepared statement
*/
static void
exec_describe_statement_message(const char *stmt_name)
{
PreparedStatement *pstmt;
TupleDesc tupdesc;
List *l;
StringInfoData buf;
/* Find prepared statement */
if (stmt_name[0] != '\0')
pstmt = FetchPreparedStatement(stmt_name, true);
else
{
/* special-case the unnamed statement */
pstmt = unnamed_stmt_pstmt;
if (!pstmt)
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_PSTATEMENT),
errmsg("unnamed prepared statement does not exist")));
}
if (whereToSendOutput != Remote)
return; /* can't actually do anything... */
/*
* First describe the parameters...
*/
pq_beginmessage(&buf, 't'); /* parameter description message type */
pq_sendint(&buf, length(pstmt->argtype_list), 2);
foreach(l, pstmt->argtype_list)
{
Oid ptype = lfirsto(l);
pq_sendint(&buf, (int) ptype, 4);
}
pq_endmessage(&buf);
/*
* Next send RowDescription or NoData to describe the result...
*/
tupdesc = FetchPreparedStatementResultDesc(pstmt);
if (tupdesc)
{
List *targetlist;
if (ChoosePortalStrategy(pstmt->query_list) == PORTAL_ONE_SELECT)
targetlist = ((Query *) lfirst(pstmt->query_list))->targetList;
else
targetlist = NIL;
SendRowDescriptionMessage(tupdesc, targetlist, NULL);
}
else
pq_putemptymessage('n'); /* NoData */
}
/*
* exec_describe_portal_message
*
* Process a "Describe" message for a portal
*/
static voidexec_describe_portal_message(const char *portal_name)
{
Portal portal;
portal = GetPortalByName(portal_name);
if (!PortalIsValid(portal))
ereport(ERROR,
(errcode(ERRCODE_UNDEFINED_CURSOR),
errmsg("portal \"%s\" does not exist", portal_name)));
if (whereToSendOutput != Remote)
return; /* can't actually do anything... */
if (portal->tupDesc)
{
List *targetlist;
if (portal->strategy == PORTAL_ONE_SELECT)
targetlist = ((Query *) lfirst(portal->parseTrees))->targetList;
else
targetlist = NIL;
SendRowDescriptionMessage(portal->tupDesc, targetlist,
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 */
if (StatementTimeout > 0)
enable_sig_alarm(StatementTimeout, true);
xact_started = true;
}
}
static void
finish_xact_command(void)
{
if (xact_started)
{
/* Invoke IMMEDIATE constraint triggers */
DeferredTriggerEndQuery();
/* 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 */
if (ShowStats)
MemoryContextStats(TopMemoryContext);
#endif
xact_started = false;
}
}
/* --------------------------------
* 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)
{
PG_SETMASK(&BlockSig);
/*
* Ideally this should be ereport(FATAL), but then we'd not get
* control back (perhaps could fix by doing local sigsetjmp?)
*/
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.")));
/*
* DO NOT proc_exit() -- 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.
*
* Note we do exit(1) 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.
*/
exit(1);
}
/*
* 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++;
DisableNotifyInterrupt();
/* Make sure CheckDeadLock won't run while shutting down... */
LockWaitCancel();
InterruptHoldoffCount--;
ProcessInterrupts();
}
}
errno = save_errno;
}
/*
* Timeout or shutdown signal from postmaster during client authentication.
* Simply exit(0).
*
* XXX: possible future improvement: try to send a message indicating
* why we are disconnecting. Problem is to be sure we don't block while
* doing so, nor mess up the authentication message exchange.
*/
void
authdie(SIGNAL_ARGS)
{
exit(0);
}
/*
* Query-cancel signal from postmaster: abort current transaction
* at soonest convenient time
*/
static void
StatementCancelHandler(SIGNAL_ARGS)
{
int save_errno = errno;
/*
* Don't joggle the elbow of proc_exit, nor an already-in-progress
* abort
*/
if (!proc_exit_inprogress && !InError)
{
InterruptPending = true;
QueryCancelPending = true;
/*
* If it's safe to interrupt, and we're waiting for a lock,
* service the interrupt immediately. No point in interrupting if
* we're waiting for input, however.
*/
if (ImmediateInterruptOK && InterruptHoldoffCount == 0 &&
CritSectionCount == 0)
{
/* bump holdoff count to make ProcessInterrupts() a no-op */
/* until we are done getting ready for it */
InterruptHoldoffCount++;
if (LockWaitCancel())
{
DisableNotifyInterrupt();
InterruptHoldoffCount--;
ProcessInterrupts(); }
else
InterruptHoldoffCount--;
}
}
errno = save_errno;
}
/* signal handler for floating point exception */
static 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;
}
/*
* 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();
ereport(FATAL,
(errcode(ERRCODE_ADMIN_SHUTDOWN),
errmsg("terminating connection due to administrator command")));
}
if (QueryCancelPending)
{
QueryCancelPending = false;
ImmediateInterruptOK = false; /* not idle anymore */
DisableNotifyInterrupt();
ereport(ERROR,
(errcode(ERRCODE_QUERY_CANCELED),
errmsg("canceling query due to user request")));
}
/* If we get here, do nothing (probably, QueryCancelPending was reset) */
}
/*
* 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. Unfortunately we have no direct way
* to detect the hardware limit, so we have to rely on the admin to set a
* GUC variable for it ...
*/
void
check_stack_depth(void)
{
char stack_top_loc;
int stack_depth;
/*
* Compute distance from PostgresMain's local variables to my own
*
* Note: in theory stack_depth should be ptrdiff_t or some such, but
* since the whole point of this code is to bound the value to something
* much less than integer-sized, int should work fine.
*/
stack_depth = (int) (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\".")));
}
}
/* GUC assign hook to update max_stack_depth_bytes from max_stack_depth */
bool
assign_max_stack_depth(int newval, bool doit, GucSource source)
{
/* Range check was already handled by guc.c */
if (doit)
max_stack_depth_bytes = newval * 1024;
return true;
}
static void
usage(const char *progname)
{
printf(gettext("%s is the PostgreSQL stand-alone backend. It is not\nintended to be used by normal users.\n\n"), progname);
printf(gettext("Usage:\n %s [OPTION]... [DBNAME]\n\n"), progname);
printf(gettext("Options:\n"));
#ifdef USE_ASSERT_CHECKING
printf(gettext(" -A 1|0 enable/disable run-time assert checking\n"));
#endif
printf(gettext(" -B NBUFFERS number of shared buffers\n"));
printf(gettext(" -c NAME=VALUE set run-time parameter\n"));
printf(gettext(" -d 0-5 debugging level (0 is off)\n"));
printf(gettext(" -D DATADIR database directory\n"));
printf(gettext(" -e use European date input format (DMY)\n"));
printf(gettext(" -E echo query before execution\n")); printf(gettext(" -F turn fsync off\n"));
printf(gettext(" -N do not use newline as interactive query delimiter\n"));
printf(gettext(" -o FILENAME send stdout and stderr to given file\n"));
printf(gettext(" -P disable system indexes\n"));
printf(gettext(" -s show statistics after each query\n"));
printf(gettext(" -S WORK-MEM set amount of memory for sorts (in kbytes)\n"));
printf(gettext(" --describe-config describe configuration parameters, then exit\n"));
printf(gettext(" --help show this help, then exit\n"));
printf(gettext(" --version output version information, then exit\n"));
printf(gettext("\nDeveloper options:\n"));
printf(gettext(" -f s|i|n|m|h forbid use of some plan types\n"));
printf(gettext(" -i do not execute queries\n"));
printf(gettext(" -O allow system table structure changes\n"));
printf(gettext(" -t pa|pl|ex show timings after each query\n"));
printf(gettext(" -W NUM wait NUM seconds to allow attach from a debugger\n"));
printf(gettext("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
}
/* ----------------------------------------------------------------
* 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)
{
int flag;
const char *dbname = NULL;
char *potential_DataDir = NULL;
bool secure;
int errs = 0;
int debug_flag = 0;
GucContext ctx,
debug_context;
GucSource gucsource;
char *tmp;
int firstchar;
char stack_base;
StringInfoData input_message;
volatile bool send_rfq = true;
/*
* Catch standard options before doing much else. This even works on
* systems without getopt_long.
*/
if (!IsUnderPostmaster && argc > 1)
{
if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
{
usage(argv[0]);
exit(0);
}
if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
{
puts(PG_VERSIONSTR);
exit(0);
}
}
/*
* initialize globals (already done if under postmaster, but not if
* standalone; cheap enough to do over)
*/ MyProcPid = getpid();
/*
* Fire up essential subsystems: error and memory management
*
* If we are running under the postmaster, this is done already.
*/
if (!IsUnderPostmaster)
MemoryContextInit();
set_ps_display("startup");
SetProcessingMode(InitProcessing);
/* Set up reference point for stack depth checking */
stack_base_ptr = &stack_base;
if (find_my_exec(argv[0], my_exec_path) < 0)
elog(FATAL,
gettext("%s: could not locate my own executable path"),
argv[0]);
get_pkglib_path(my_exec_path, pkglib_path);
/*
* Set default values for command-line options.
*/
EchoQuery = false;
if (!IsUnderPostmaster)
{
InitializeGUCOptions();
potential_DataDir = getenv("PGDATA");
}
/* ----------------
* parse command line arguments
*
* There are now two styles of command line layout for the backend:
*
* For interactive use (not started from postmaster) the format is
* postgres [switches] [databasename]
* If the databasename is omitted it is taken to be the user name.
*
* When started from the postmaster, the format is
* postgres [secure switches] -p databasename [insecure switches]
* Switches appearing after -p came from the client (via "options"
* field of connection request). For security reasons we restrict
* what these switches can do.
* ----------------
*/
/* all options are allowed until '-p' */
secure = true;
ctx = debug_context = PGC_POSTMASTER;
gucsource = PGC_S_ARGV; /* initial switches came from command line */
while ((flag = getopt(argc, argv, "A:B:c:D:d:Eef:FiNOPo:p:S:st:v:W:-:")) != -1)
switch (flag)
{
case 'A':
#ifdef USE_ASSERT_CHECKING
SetConfigOption("debug_assertions", optarg, ctx, gucsource);
#else
ereport(WARNING,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("assert checking is not compiled in")));
#endif
break;
case 'B':
/*
* specify the size of buffer pool
*/
SetConfigOption("shared_buffers", optarg, ctx, gucsource);
break;
case 'D': /* PGDATA directory */
if (secure)
potential_DataDir = optarg;
break;
case 'd': /* debug level */
{
/*
* Client option can't decrease debug level. We have
* to do the test here because we group priv and
* client set GUC calls below, after we know the final
* debug value.
*/
if (ctx != PGC_BACKEND || atoi(optarg) > debug_flag)
{
debug_flag = atoi(optarg);
debug_context = ctx; /* save context for use
* below */
/* Set server debugging level. */
if (debug_flag != 0)
{
char *debugstr = palloc(strlen("debug") + strlen(optarg) + 1);
sprintf(debugstr, "debug%s", optarg);
SetConfigOption("log_min_messages", debugstr, ctx, gucsource);
pfree(debugstr);
}
else
/*
* -d0 allows user to prevent postmaster debug
* from propagating to backend. It would be
* nice to set it to the postgresql.conf value
* here.
*/
SetConfigOption("log_min_messages", "notice",
ctx, gucsource);
}
}
break;
case 'E':
/*
* E - echo the query the user entered
*/
EchoQuery = true;
break;
case 'e':
/*
* Use European date input format (DMY)
*/
SetConfigOption("datestyle", "euro", ctx, gucsource);
break;
case 'F':
/*
* turn off fsync */
SetConfigOption("fsync", "false", ctx, gucsource);
break;
case 'f':
/*
* f - forbid generation of certain plans
*/
tmp = NULL;
switch (optarg[0])
{
case 's': /* seqscan */
tmp = "enable_seqscan";
break;
case 'i': /* indexscan */
tmp = "enable_indexscan";
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;
default:
errs++;
}
if (tmp)
SetConfigOption(tmp, "false", ctx, gucsource);
break;
case 'N':
/*
* N - Don't use newline as a query delimiter
*/
UseNewLine = 0;
break;
case 'O':
/*
* allow system table structure modifications
*/
if (secure) /* XXX safe to allow from client??? */
allowSystemTableMods = true;
break;
case 'P':
/*
* ignore system indexes
*
* As of PG 7.4 this is safe to allow from the client,
* since it only disables reading the system indexes,
* not writing them. Worst case consequence is slowness.
*/
IgnoreSystemIndexes(true);
break;
case 'o':
/*
* o - send output (stdout and stderr) to the given file */
if (secure)
StrNCpy(OutputFileName, optarg, MAXPGPATH);
break;
case 'p':
/*
* p - special flag passed if backend was forked by a
* postmaster.
*/
if (secure)
{
dbname = strdup(optarg);
secure = false; /* subsequent switches are NOT
* secure */
ctx = PGC_BACKEND;
gucsource = PGC_S_CLIENT;
}
break;
case 'S':
/*
* S - amount of sort memory to use in 1k bytes
*/
SetConfigOption("work_mem", optarg, ctx, gucsource);
break;
case 's':
/*
* s - report usage statistics (timings) after each query
*/
SetConfigOption("log_statement_stats", "true", ctx, gucsource);
break;
case 't':
/* ---------------
* tell postgres to report usage statistics (timings) for
* each query
*
* -tpa[rser] = print stats for parser time of each query
* -tpl[anner] = print stats for planner time of each query
* -te[xecutor] = print stats for executor time of each query
* caution: -s can not be used together with -t.
* ----------------
*/
tmp = NULL;
switch (optarg[0])
{
case 'p':
if (optarg[1] == 'a')
tmp = "log_parser_stats";
else if (optarg[1] == 'l')
tmp = "log_planner_stats";
else
errs++;
break;
case 'e':
tmp = "log_executor_stats";
break;
default:
errs++;
break;
}
if (tmp)
SetConfigOption(tmp, "true", ctx, gucsource);
break;
case 'v':
if (secure)
FrontendProtocol = (ProtocolVersion) atoi(optarg);
break;
case 'W':
/*
* wait N seconds to allow attach from a debugger
*/
pg_usleep(atoi(optarg)*1000000L);
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;
}
/*
* -d is not the same as setting log_min_messages because it enables
* other output options.
*/
if (debug_flag >= 1)
{
SetConfigOption("log_connections", "true", debug_context, gucsource);
SetConfigOption("log_disconnections", "true", debug_context, gucsource);
}
if (debug_flag >= 2)
SetConfigOption("log_statement", "all", debug_context, gucsource);
if (debug_flag >= 3)
SetConfigOption("debug_print_parse", "true", debug_context, gucsource);
if (debug_flag >= 4)
SetConfigOption("debug_print_plan", "true", debug_context, gucsource);
if (debug_flag >= 5)
SetConfigOption("debug_print_rewritten", "true", debug_context, gucsource);
/*
* Process any additional GUC variable settings passed in startup
* packet.
*/
if (MyProcPort != NULL) {
List *gucopts = MyProcPort->guc_options;
while (gucopts)
{
char *name,
*value;
name = lfirst(gucopts);
gucopts = lnext(gucopts);
value = lfirst(gucopts);
gucopts = lnext(gucopts);
SetConfigOption(name, value, PGC_BACKEND, PGC_S_CLIENT);
}
/*
* set up handler to log session end.
*/
if (IsUnderPostmaster && Log_disconnections)
on_proc_exit(log_disconnections,0);
}
if (!IsUnderPostmaster || ExecBackend)
{
if (!potential_DataDir)
{
fprintf(stderr,
gettext("%s does not know where to find the database system data.\n"
"You must specify the directory that contains the database system\n"
"either by specifying the -D invocation option or by setting the\n"
"PGDATA environment variable.\n"),
argv[0]);
proc_exit(1);
}
SetDataDir(potential_DataDir);
}
Assert(DataDir);
/* Acquire configuration parameters */
if (IsUnderPostmaster)
{
#ifdef EXEC_BACKEND
read_nondefault_variables();
#endif
} else
ProcessConfigFile(PGC_POSTMASTER);
/*
* 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.)
*/
pqsignal(SIGHUP, SigHupHandler); /* set flag to read config file */
pqsignal(SIGINT, StatementCancelHandler); /* cancel current query */
pqsignal(SIGTERM, die); /* cancel current query and exit */
pqsignal(SIGQUIT, quickdie); /* hard crash time */
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, SIG_IGN); /* this signal available for use */
pqsignal(SIGUSR2, Async_NotifyHandler); /* flush also sinval cache */
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();
/* We allow SIGQUIT (quickdie) at all times */
#ifdef HAVE_SIGPROCMASK
sigdelset(&BlockSig, SIGQUIT);
#else
BlockSig &= ~(sigmask(SIGQUIT));
#endif
PG_SETMASK(&BlockSig); /* block everything except SIGQUIT */
if (IsUnderPostmaster)
{
/* noninteractive case: nothing should be left after switches */
if (errs || argc != optind || dbname == NULL)
{
ereport(FATAL,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("invalid command-line arguments for server process"),
errhint("Try \"%s --help\" for more information.", argv[0])));
}
XLOGPathInit();
BaseInit();
}
else
{
/* interactive case: database name can be last arg on command line */
if (errs || argc - optind > 1)
{
ereport(FATAL,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("%s: invalid command-line arguments",
argv[0]),
errhint("Try \"%s --help\" for more information.", argv[0])));
}
else if (argc - optind == 1)
dbname = argv[optind];
else if ((dbname = username) == NULL)
{
ereport(FATAL,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("%s: no database nor user name specified",
argv[0])));
}
/*
* Validate we have been given a reasonable-looking DataDir (if
* under postmaster, assume postmaster did this already).
*/
ValidatePgVersion(DataDir);
/*
* Create lockfile for data directory.
*/
CreateDataDirLockFile(DataDir, false);
XLOGPathInit();
BaseInit();
/*
* Start up xlog for standalone backend, and register to have it
* closed down at exit.
*/
StartupXLOG();
on_shmem_exit(ShutdownXLOG, 0);
/*
* Read any existing FSM cache file, and register to write one out
* at exit.
*/
LoadFreeSpaceMap();
on_shmem_exit(DumpFreeSpaceMap, 0);
}
/*
* 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.
*/
ereport(DEBUG3,
(errmsg_internal("InitPostgres")));
InitPostgres(dbname, username);
SetProcessingMode(NormalProcessing);
/*
* Send this backend's cancellation info to the frontend.
*/
if (whereToSendOutput == Remote &&
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 == Debug)
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);
/* ----------
* Tell the statistics collector that we're alive and
* to which database we belong. * ----------
*/
pgstat_bestart();
/*
* 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.
*/
if (sigsetjmp(Warn_restart, 1) != 0)
{
/*
* NOTE: if you are tempted to add more code in this if-block,
* consider the probability that it should be in
* AbortTransaction() instead.
*
* Make sure we're not interrupted while cleaning up. Also forget
* any pending QueryCancel request, since we're aborting anyway.
* Force InterruptHoldoffCount to a known state in case we
* ereport'd from inside a holdoff section.
*/
ImmediateInterruptOK = false;
QueryCancelPending = false;
InterruptHoldoffCount = 1;
CritSectionCount = 0; /* should be unnecessary, but... */
disable_sig_alarm(true);
QueryCancelPending = false; /* again in case timeout occurred */
DisableNotifyInterrupt();
debug_query_string = NULL;
/*
* Make sure we are in a valid memory context during recovery.
*
* We use ErrorContext in hopes that it will have some free space
* even if we're otherwise up against it...
*/
MemoryContextSwitchTo(ErrorContext);
/* Do the recovery */
ereport(DEBUG2,
(errmsg_internal("AbortCurrentTransaction")));
AbortCurrentTransaction();
/*
* Now return to normal top-level context and clear ErrorContext
* for next time.
*/
MemoryContextSwitchTo(TopMemoryContext);
MemoryContextResetAndDeleteChildren(ErrorContext);
ActivePortal = NULL;
PortalContext = NULL;
QueryContext = NULL;
/*
* Clear flag to indicate that we got out of error recovery mode
* successfully. (Flag was set in elog.c before longjmp().)
*/
InError = false;
xact_started = false;
/*
* Clear flag that causes accounting for cost based vacuum.
*/
VacuumCostActive = false;
/*
* 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;
/*
* Exit interrupt holdoff section we implicitly established above.
*/
RESUME_INTERRUPTS();
}
Warn_restart_ready = true; /* we can now handle ereport(ERROR) */
PG_SETMASK(&UnBlockSig);
if (!ignore_till_sync)
send_rfq = 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.
*/
if (send_rfq)
{
pgstat_report_tabstat();
if (IsTransactionOrTransactionBlock())
{
set_ps_display("idle in transaction");
pgstat_report_activity("<IDLE> in transaction");
}
else
{
set_ps_display("idle");
pgstat_report_activity("<IDLE>");
}
ReadyForQuery(whereToSendOutput);
send_rfq = false;
}
/* * (2) deal with pending asynchronous NOTIFY from other backends,
* and enable async.c's signal handler to execute NOTIFY directly.
* Then set up other stuff needed before blocking for input.
*/
QueryCancelPending = false; /* forget any earlier CANCEL
* signal */
EnableNotifyInterrupt();
/* Allow "die" interrupt to be processed while waiting */
ImmediateInterruptOK = true;
/* and don't forget to detect one that already arrived */
QueryCancelPending = false;
CHECK_FOR_INTERRUPTS();
/*
* (3) read a command (loop blocks here)
*/
if (!in_fatal_exit)
firstchar = ReadCommand(&input_message);
else
firstchar = EOF;
/*
* (4) disable async signal conditions again.
*/
ImmediateInterruptOK = false;
QueryCancelPending = false; /* forget any CANCEL signal */
DisableNotifyInterrupt();
/*
* (5) check for any other interesting events that happened while
* we slept.
*/
if (got_SIGHUP)
{
got_SIGHUP = false;
#ifdef EXEC_BACKEND
read_nondefault_variables();
#else
ProcessConfigFile(PGC_SIGHUP);
#endif
}
/*
* (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;
query_string = pq_getmsgstring(&input_message);
pq_getmsgend(&input_message);
exec_simple_query(query_string);
send_rfq = true;
}
break;
case 'P': /* parse */
{
const char *stmt_name; const char *query_string;
int numParams;
Oid *paramTypes = NULL;
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 */
/*
* 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;
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 */
/* Tell the collector what we're doing */
pgstat_report_activity("<FASTPATH> function call");
/* start an xact for this function invocation */
start_xact_command();
/* 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 == Remote)
whereToSendOutput = None;
proc_exit(0);
}
/* commit the function-invocation transaction */
finish_xact_command();
send_rfq = 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 */
unnamed_stmt_pstmt = NULL;
if (unnamed_stmt_context)
{
DropDependentPortals(unnamed_stmt_context);
MemoryContextDelete(unnamed_stmt_context);
}
unnamed_stmt_context = NULL;
}
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 == Remote)
pq_putemptymessage('3'); /* CloseComplete */
}
break;
case 'D': /* describe */
{
int describe_type;
const char *describe_target;
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 == Remote)
pq_flush();
break;
case 'S': /* sync */
pq_getmsgend(&input_message);
finish_xact_command();
send_rfq = 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 == Remote)
whereToSendOutput = None;
/*
* 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(!in_fatal_exit ? 0 : proc_exit_inprogress ||
!IsUnderPostmaster);
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 */
}
#ifndef HAVE_GETRUSAGE
#include "rusagestub.h"
#else
#include <sys/resource.h>
#endif /* HAVE_GETRUSAGE */
static struct rusage Save_r;
static struct timeval Save_t;
void
ResetUsage(void)
{
getrusage(RUSAGE_SELF, &Save_r);
gettimeofday(&Save_t, NULL);
ResetBufferUsage();
/* ResetTupleCount(); */
}
void
ShowUsage(const char *title)
{
StringInfoData str;
struct timeval user,
sys;
struct timeval elapse_t;
struct rusage r;
char *bufusage;
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);
/* BeOS has rusage but only has some fields, and not these... */
#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 */
bufusage = ShowBufferUsage();
appendStringInfo(&str, "! buffer usage stats:\n%s", bufusage);
pfree(bufusage);
/* 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;
struct timeval end;
int hours, minutes, seconds;
char session_time[20];
char uname[6+NAMEDATALEN];
char dbname[10+NAMEDATALEN];
char remote_host[7 + NI_MAXHOST];
char remote_port[7 + NI_MAXSERV];
snprintf(uname, sizeof(uname)," user=%s",port->user_name);
snprintf(dbname, sizeof(dbname)," database=%s",port->database_name);
snprintf(remote_host,sizeof(remote_host)," host=%s",
port->remote_host);
snprintf(remote_port,sizeof(remote_port)," port=%s",port->remote_port);
gettimeofday(&end,NULL);
if (end.tv_usec < port->session_start.tv_usec)
{
end.tv_sec--;
end.tv_usec += 1000000;
}
end.tv_sec -= port->session_start.tv_sec;
end.tv_usec -= port->session_start.tv_usec;
hours = end.tv_sec / 3600;
end.tv_sec %= 3600;
minutes = end.tv_sec / 60;
seconds = end.tv_sec % 60;
/* if time has gone backwards for some reason say so, or print time */
if (end.tv_sec < 0)
snprintf(session_time,sizeof(session_time),"negative!");
else
/* for stricter accuracy here we could round - this is close enough */
snprintf(session_time, sizeof(session_time),
"%d:%02d:%02d.%02d",
hours, minutes, seconds, (int) (end.tv_usec/10000));
ereport(
LOG,
(errmsg("disconnection: session time: %s%s%s%s%s",
session_time,uname,dbname,remote_host,remote_port)));
}