From f69ecb4f8cbf0f1d1638f9fb01d8845a5c84a3c0 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Thu, 13 May 2004 22:45:04 +0000
Subject: [PATCH] Reorganize backend code to more cleanly manage executable
 names and backend startup.

---
 src/backend/port/beos/support.c      |  4 +--
 src/backend/port/dynloader/bsdi.c    |  6 ++--
 src/backend/port/dynloader/linux.c   |  4 +--
 src/backend/port/dynloader/ultrix4.c |  6 ++--
 src/backend/postmaster/pgstat.c      | 14 +++++-----
 src/backend/postmaster/postmaster.c  | 41 ++++++++++++++--------------
 src/backend/tcop/postgres.c          | 10 +++----
 src/backend/utils/init/globals.c     |  5 ++--
 src/include/miscadmin.h              |  6 ++--
 src/port/exec.c                      | 28 +++++++++----------
 10 files changed, 61 insertions(+), 63 deletions(-)

diff --git a/src/backend/port/beos/support.c b/src/backend/port/beos/support.c
index 6a31adad578..86053d79c09 100644
--- a/src/backend/port/beos/support.c
+++ b/src/backend/port/beos/support.c
@@ -16,7 +16,7 @@ port_id		beos_dl_port_out = 0;
 sem_id		beos_shm_sem;
 
 /* Global var containing the postgres path */
-extern char pg_pathname[];
+extern char my_exec_path[];
 
 
 /* Shared library loading doesn't work after fork in beos. The solution is to use an exact
@@ -50,7 +50,7 @@ beos_dl_open(char *filename)
 			char		Cmd[4000];
 
 			/* Build arg list */
-			sprintf(Cmd, "%s -beossupportserver %d %d &", pg_pathname, (int) beos_dl_port_in, (int) beos_dl_port_out);
+			sprintf(Cmd, "%s -beossupportserver %d %d &", my_exec_path, (int) beos_dl_port_in, (int) beos_dl_port_out);
 
 			/* Lauch process */
 			system(Cmd);
diff --git a/src/backend/port/dynloader/bsdi.c b/src/backend/port/dynloader/bsdi.c
index e2ad50d2841..af72ef9f07c 100644
--- a/src/backend/port/dynloader/bsdi.c
+++ b/src/backend/port/dynloader/bsdi.c
@@ -11,14 +11,14 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/port/dynloader/bsdi.c,v 1.23 2003/11/29 19:51:54 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/port/dynloader/bsdi.c,v 1.24 2004/05/13 22:45:02 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 #ifndef HAVE_DLOPEN
 
-extern char pg_pathname[];
+extern char my_exec_path[];
 
 void *
 pg_dlopen(char *filename)
@@ -31,7 +31,7 @@ pg_dlopen(char *filename)
 	 */
 	if (!dl_initialized)
 	{
-		if (dld_init(dld_find_executable(pg_pathname)))
+		if (dld_init(dld_find_executable(my_exec_path)))
 			return NULL;
 
 		/*
diff --git a/src/backend/port/dynloader/linux.c b/src/backend/port/dynloader/linux.c
index a49c7f0bc30..967b4a3d73d 100644
--- a/src/backend/port/dynloader/linux.c
+++ b/src/backend/port/dynloader/linux.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/port/dynloader/linux.c,v 1.27 2003/11/29 19:51:54 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/port/dynloader/linux.c,v 1.28 2004/05/13 22:45:02 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,7 +43,7 @@ pg_dlopen(char *filename)
 	 */
 	if (!dl_initialized)
 	{
-		if (dld_init(dld_find_executable(pg_pathname)))
+		if (dld_init(dld_find_executable(my_exec_path)))
 			return NULL;
 
 		/*
diff --git a/src/backend/port/dynloader/ultrix4.c b/src/backend/port/dynloader/ultrix4.c
index 2114707ad5f..7ab99033579 100644
--- a/src/backend/port/dynloader/ultrix4.c
+++ b/src/backend/port/dynloader/ultrix4.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/port/dynloader/ultrix4.c,v 1.19 2003/11/29 19:51:54 pgsql Exp $
+ *	  $PostgreSQL: pgsql/src/backend/port/dynloader/ultrix4.c,v 1.20 2004/05/13 22:45:02 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,7 +17,7 @@
 #include "dl.h"
 #include "utils/dynamic_loader.h"
 
-extern char pg_pathname[];
+extern char my_exec_path[];
 
 void *
 pg_dlopen(char *filename)
@@ -31,7 +31,7 @@ pg_dlopen(char *filename)
 	 */
 	if (!dl_initialized)
 	{
-		if (!dl_init(pg_pathname))
+		if (!dl_init(my_exec_path))
 			return NULL;
 
 		/*
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 65a37fd6a38..1c76fd97708 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -13,7 +13,7 @@
  *
  *	Copyright (c) 2001-2003, PostgreSQL Global Development Group
  *
- *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.68 2004/05/06 19:23:25 momjian Exp $
+ *	$PostgreSQL: pgsql/src/backend/postmaster/pgstat.c,v 1.69 2004/05/13 22:45:02 momjian Exp $
  * ----------
  */
 #include "postgres.h"
@@ -487,7 +487,7 @@ pgstat_forkexec(STATS_PROCESS_TYPE procType)
 	/* + the pstat file names, and postgres pathname */
 	snprintf(pgstatBuf[bufc++],MAXPGPATH,"\"%s\"",pgStat_tmpfname);
 	snprintf(pgstatBuf[bufc++],MAXPGPATH,"\"%s\"",pgStat_fname);
-	snprintf(pgstatBuf[bufc++],MAXPGPATH,"\"%s\"",pg_pathname);
+	snprintf(pgstatBuf[bufc++],MAXPGPATH,"\"%s\"",my_exec_path); /* used? */
 	snprintf(pgstatBuf[bufc++],MAXPGPATH,"\"%s\"",DataDir);
 
 	/* Add to the arg list */
@@ -500,9 +500,9 @@ pgstat_forkexec(STATS_PROCESS_TYPE procType)
 
 	/* Fire off execv in child */
 #ifdef WIN32
-	pid = win32_forkexec(pg_pathname,av);
+	pid = win32_forkexec(my_exec_path, av);
 #else
-	if ((pid = fork()) == 0 && (execv(pg_pathname,av) == -1))
+	if ((pid = fork()) == 0 && (execv(my_exec_path, av) == -1))
 		/* FIXME: [fork/exec] suggestions for what to do here? Can't call elog... */
 		abort();
 #endif
@@ -530,9 +530,9 @@ pgstat_parseArgs(PGSTAT_FORK_ARGS)
 	pgStatPipe[0]	= atoi(argv[argc++]);
 	pgStatPipe[1]	= atoi(argv[argc++]);
 	MaxBackends		= atoi(argv[argc++]);
-	strncpy(pgStat_tmpfname,argv[argc++],MAXPGPATH);
-	strncpy(pgStat_fname,	argv[argc++],MAXPGPATH);
-	strncpy(pg_pathname,	argv[argc++],MAXPGPATH);
+	StrNCpy(pgStat_tmpfname,argv[argc++],MAXPGPATH);
+	StrNCpy(pgStat_fname,	argv[argc++],MAXPGPATH);
+	StrNCpy(my_exec_path,	argv[argc++],MAXPGPATH);
 	DataDir			= strdup(argv[argc++]);
 
 	read_nondefault_variables();
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index bd183739204..c9783560e13 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.385 2004/05/12 13:38:39 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/postmaster.c,v 1.386 2004/05/13 22:45:02 momjian Exp $
  *
  * NOTES
  *
@@ -181,7 +181,6 @@ static int	ListenSocket[MAXLISTEN];
 /* Used to reduce macros tests */
 #ifdef EXEC_BACKEND
 const bool	ExecBackend = true;
-
 #else
 const bool	ExecBackend = false;
 #endif
@@ -286,7 +285,7 @@ static long PostmasterRandom(void);
 static void RandomSalt(char *cryptSalt, char *md5Salt);
 static void SignalChildren(int signal);
 static int	CountChildren(void);
-static bool CreateOptsFile(int argc, char *argv[]);
+static bool CreateOptsFile(int argc, char *argv[], char *fullprogname);
 NON_EXEC_STATIC void SSDataBaseInit(int xlop);
 static pid_t SSDataBase(int xlop);
 static void
@@ -295,6 +294,9 @@ postmaster_error(const char *fmt,...)
 __attribute__((format(printf, 1, 2)));
 
 #ifdef EXEC_BACKEND
+
+static char	postgres_exec_path[MAXPGPATH];
+
 #ifdef WIN32
 pid_t win32_forkexec(const char* path, char *argv[]);
 
@@ -323,7 +325,6 @@ static void ShmemBackendArrayRemove(pid_t pid);
 #define StartBackgroundWriter()	SSDataBase(BS_XLOG_BGWRITER)
 #define ShutdownDataBase()		SSDataBase(BS_XLOG_SHUTDOWN)
 
-
 static void
 checkDataDir(const char *checkdir)
 {
@@ -692,11 +693,18 @@ PostmasterMain(int argc, char *argv[])
 	/*
 	 * On some systems our dynloader code needs the executable's pathname.
 	 */
-	if (find_my_exec(pg_pathname, argv[0]) < 0)
+	if (find_my_exec(my_exec_path, argv[0]) < 0)
 		ereport(FATAL,
-				(errmsg("%s: could not locate postgres executable",
+				(errmsg("%s: could not locate my own executable path",
 						progname)));
 
+#ifdef EXEC_BACKEND
+	if (find_other_exec(postgres_exec_path, argv[0], "postgres", PG_VERSIONSTR) < 0)
+		ereport(FATAL,
+				(errmsg("%s: could not locate postgres executable or non-matching version",
+						progname)));
+#endif
+						
 	/*
 	 * Initialize SSL library, if specified.
 	 */
@@ -852,7 +860,7 @@ PostmasterMain(int argc, char *argv[])
 	 * recording bogus options (eg, NBuffers too high for available
 	 * memory).
 	 */
-	if (!CreateOptsFile(argc, argv))
+	if (!CreateOptsFile(argc, argv, my_exec_path))
 		ExitPostmaster(1);
 
 	/*
@@ -2754,10 +2762,10 @@ Backend_forkexec(Port *port)
   	Assert(ac <= lengthof(av));
 
 #ifdef WIN32
-	pid = win32_forkexec(pg_pathname,av); /* logs on error */
+	pid = win32_forkexec(postgres_exec_path, av); /* logs on error */
 #else
 	/* Fire off execv in child */
-	if ((pid = fork()) == 0 && (execv(pg_pathname,av) == -1))
+	if ((pid = fork()) == 0 && (execv(postgres_exec_path, av) == -1))
 		/*
 		 * FIXME: [fork/exec] suggestions for what to do here?
 		 *  Probably OK to issue error (unlike pgstat case)
@@ -3116,12 +3124,12 @@ SSDataBase(int xlop)
 #ifdef EXEC_BACKEND
 		/* EXEC_BACKEND case; fork/exec here */
 #ifdef WIN32
-		pid = win32_forkexec(pg_pathname,av); /* logs on error */
+		pid = win32_forkexec(postgres_exec_path, av); /* logs on error */
 #else
-		if ((pid = fork()) == 0 && (execv(pg_pathname,av) == -1))
+		if ((pid = fork()) == 0 && (execv(postgres_exec_path, av) == -1))
 		{
 			/* in child */
-			elog(ERROR,"unable to execv in SSDataBase: %m");
+			elog(ERROR, "unable to execv in SSDataBase: %m");
 			exit(0);
 		}
 #endif
@@ -3215,19 +3223,12 @@ SSDataBase(int xlop)
  * Create the opts file
  */
 static bool
-CreateOptsFile(int argc, char *argv[])
+CreateOptsFile(int argc, char *argv[], char *fullprogname)
 {
-	char		fullprogname[MAXPGPATH];
 	char		filename[MAXPGPATH];
 	FILE	   *fp;
 	int			i;
 
-	if (find_my_exec(fullprogname, argv[0]) < 0)
-	{
-		elog(LOG, "could not locate postmaster");
-		return false;
-	}
-
 	snprintf(filename, sizeof(filename), "%s/postmaster.opts", DataDir);
 
 	if ((fp = fopen(filename, "w")) == NULL)
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 4c006f00b8b..97c4d1dde16 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.404 2004/05/12 13:38:40 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.405 2004/05/13 22:45:03 momjian Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -2159,7 +2159,7 @@ PostgresMain(int argc, char *argv[], const char *username)
 		}
 		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
 		{
-			puts("postgres (PostgreSQL) " PG_VERSION);
+			puts(PG_VERSIONSTR);
 			exit(0);
 		}
 	}
@@ -2646,14 +2646,12 @@ PostgresMain(int argc, char *argv[], const char *username)
 		}
 
 		/*
-		 * On some systems our dynloader code needs the executable's
-		 * pathname.  (If under postmaster, this was done already.)
+		 * On some systems our dynloader code needs the executable's pathname.
 		 */
-		if (find_my_exec(pg_pathname, argv[0]) < 0)
+		if (strlen(my_exec_path) == 0 && find_my_exec(my_exec_path, argv[0]) < 0)
 			ereport(FATAL,
 					(errmsg("%s: could not locate postgres executable",
 							argv[0])));
-
 		/*
 		 * Validate we have been given a reasonable-looking DataDir (if
 		 * under postmaster, assume postmaster did this already).
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 8bcf48b2f27..356d45e62e4 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/init/globals.c,v 1.84 2004/02/10 03:42:45 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/init/globals.c,v 1.85 2004/05/13 22:45:03 momjian Exp $
  *
  * NOTES
  *	  Globals used all over the place should be declared here and not
@@ -45,8 +45,7 @@ char	   *DataDir = NULL;
 
 char		OutputFileName[MAXPGPATH];
 
-char		pg_pathname[MAXPGPATH];		/* full path to postgres
-										 * executable */
+char		my_exec_path[MAXPGPATH];	/* full path to postgres executable */
 
 BackendId	MyBackendId;
 
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index fc312b3d74b..09f2cf2aa24 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.157 2004/05/11 21:57:15 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.158 2004/05/13 22:45:04 momjian Exp $
  *
  * NOTES
  *	  some of the information in this file should be moved to
@@ -124,6 +124,8 @@ extern void SubPostmasterMain(int argc, char* argv[]);
 #endif
 extern void ClosePostmasterPorts(bool pgstat_too);
 
+#define PG_VERSIONSTR "postgres (PostgreSQL) " PG_VERSION "\n"
+
 /*
  * from utils/init/globals.c
  */
@@ -140,7 +142,7 @@ extern struct Port *MyProcPort;
 extern long MyCancelKey;
 
 extern char OutputFileName[];
-extern char pg_pathname[];
+extern char my_exec_path[];
 
 /*
  * done in storage/backendid.h for now.
diff --git a/src/port/exec.c b/src/port/exec.c
index d7a95f495df..8810184a377 100644
--- a/src/port/exec.c
+++ b/src/port/exec.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/port/exec.c,v 1.3 2004/05/13 01:47:12 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/port/exec.c,v 1.4 2004/05/13 22:45:04 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -184,7 +184,6 @@ find_my_exec(char *full_path, const char *argv0)
 	char	   *path,
 			   *startp,
 			   *endp;
-	const char *binary_name = get_progname(argv0);
 
 	/*
 	 * First try: use the binary that's located in the
@@ -192,24 +191,23 @@ find_my_exec(char *full_path, const char *argv0)
 	 * Presumably the user used an explicit path because it
 	 * wasn't in PATH, and we don't want to use incompatible executables.
 	 *
-	 * This has the neat property that it works for installed binaries, old
-	 * source trees (obj/support/post{master,gres}) and new source
-	 * trees (obj/post{master,gres}) because they all put the two binaries
-	 * in the same place.
-	 *
-	 * for the binary: First try: if we're given some kind of path, use it
+	 * For the binary: First try: if we're given some kind of path, use it
 	 * (making sure that a relative path is made absolute before returning
 	 * it).
 	 */
-	if (argv0 && (p = last_path_separator(argv0)) && *++p)
+	/* Does argv0 have a separator? */
+	if (argv0 && (p = last_path_separator(argv0)))
 	{
+		if (*++p == '\0')
+		{
+			log_debug("argv[0] ends with a path separator \"%s\"", argv0);
+			return -1;
+		}
 		if (is_absolute_path(argv0) || !getcwd(buf, MAXPGPATH))
 			buf[0] = '\0';
-		else
+		else	/* path is not absolute and getcwd worked */
 			strcat(buf, "/");
 		strcat(buf, argv0);
-		p = last_path_separator(buf);
-		strcpy(++p, binary_name);
 		if (validate_exec(buf) == 0)
 		{
 			strncpy(full_path, buf, MAXPGPATH);
@@ -239,11 +237,11 @@ find_my_exec(char *full_path, const char *argv0)
 				*endp = '\0';
 			if (is_absolute_path(startp) || !getcwd(buf, MAXPGPATH))
 				buf[0] = '\0';
-			else
+			else	/* path is not absolute and getcwd worked */
 				strcat(buf, "/");
 			strcat(buf, startp);
 			strcat(buf, "/");
-			strcat(buf, binary_name);
+			strcat(buf, argv0);
 			switch (validate_exec(buf))
 			{
 				case 0: /* found ok */
@@ -265,7 +263,7 @@ find_my_exec(char *full_path, const char *argv0)
 		free(path);
 	}
 
-	log_debug("could not find a \"%s\" to execute", binary_name);
+	log_debug("could not find a \"%s\" to execute", argv0);
 	return -1;
 }
 
-- 
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