Invent on_exit_nicely for pg_dump.

Per recent discussions on pgsql-hackers regarding parallel pg_dump.

Author: robertmhaas

src/bin/pg_dump/common.c

@@ -770,7 +770,7 @@ findParentsByOid(TableInfo *self,
 							  inhinfo[i].inhparent,
 							  self->dobj.name,
 							  oid);
-					exit_nicely();
+					exit_nicely(1);
 				}
 				self->parents[j++] = parent;
 			}
@@ -809,7 +809,7 @@ parseOidArray(const char *str, Oid *array, int arraysize)
 				if (argNum >= arraysize)
 				{
 					write_msg(NULL, "could not parse numeric array \"%s\": too many numbers\n", str);
-					exit_nicely();
+					exit_nicely(1);
 				}
 				temp[j] = '\0';
 				array[argNum++] = atooid(temp);
@@ -824,7 +824,7 @@ parseOidArray(const char *str, Oid *array, int arraysize)
 				j >= sizeof(temp) - 1)
 			{
 				write_msg(NULL, "could not parse numeric array \"%s\": invalid character in number\n", str);
-				exit_nicely();
+				exit_nicely(1);
 			}
 			temp[j++] = s;
 		}

src/bin/pg_dump/compress_io.c

@@ -54,6 +54,7 @@
 
 #include "compress_io.h"
 #include "dumpmem.h"
+#include "dumputils.h"
 
 /*----------------------
  * Compressor API
@@ -109,8 +110,8 @@ ParseCompressionOption(int compression, CompressionAlgorithm *alg, int *level)
 		*alg = COMPR_ALG_NONE;
 	else
 	{
-		die_horribly(NULL, modulename, "Invalid compression code: %d\n",
-					 compression);
+		exit_horribly(modulename, "Invalid compression code: %d\n",
+					  compression);
 		*alg = COMPR_ALG_NONE;	/* keep compiler quiet */
 	}
 
@@ -133,7 +134,7 @@ AllocateCompressor(int compression, WriteFunc writeF)
 
 #ifndef HAVE_LIBZ
 	if (alg == COMPR_ALG_LIBZ)
-		die_horribly(NULL, modulename, "not built with zlib support\n");
+		exit_horribly(modulename, "not built with zlib support\n");
 #endif
 
 	cs = (CompressorState *) pg_calloc(1, sizeof(CompressorState));
@@ -169,7 +170,7 @@ ReadDataFromArchive(ArchiveHandle *AH, int compression, ReadFunc readF)
 #ifdef HAVE_LIBZ
 		ReadDataFromArchiveZlib(AH, readF);
 #else
-		die_horribly(NULL, modulename, "not built with zlib support\n");
+		exit_horribly(modulename, "not built with zlib support\n");
 #endif
 	}
 }
@@ -187,7 +188,7 @@ WriteDataToArchive(ArchiveHandle *AH, CompressorState *cs,
 #ifdef HAVE_LIBZ
 			return WriteDataToArchiveZlib(AH, cs, data, dLen);
 #else
-			die_horribly(NULL, modulename, "not built with zlib support\n");
+			exit_horribly(modulename, "not built with zlib support\n");
 #endif
 		case COMPR_ALG_NONE:
 			return WriteDataToArchiveNone(AH, cs, data, dLen);
@@ -234,9 +235,9 @@ InitCompressorZlib(CompressorState *cs, int level)
 	cs->zlibOutSize = ZLIB_OUT_SIZE;
 
 	if (deflateInit(zp, level) != Z_OK)
-		die_horribly(NULL, modulename,
-					 "could not initialize compression library: %s\n",
-					 zp->msg);
+		exit_horribly(modulename,
+					  "could not initialize compression library: %s\n",
+					  zp->msg);
 
 	/* Just be paranoid - maybe End is called after Start, with no Write */
 	zp->next_out = (void *) cs->zlibOut;
@@ -343,9 +344,9 @@ ReadDataFromArchiveZlib(ArchiveHandle *AH, ReadFunc readF)
 	out = pg_malloc(ZLIB_OUT_SIZE + 1);
 
 	if (inflateInit(zp) != Z_OK)
-		die_horribly(NULL, modulename,
-					 "could not initialize compression library: %s\n",
-					 zp->msg);
+		exit_horribly(modulename,
+					  "could not initialize compression library: %s\n",
+					  zp->msg);
 
 	/* no minimal chunk size for zlib */
 	while ((cnt = readF(AH, &buf, &buflen)))
@@ -514,7 +515,7 @@ cfopen_write(const char *path, const char *mode, int compression)
 		fp = cfopen(fname, mode, 1);
 		free(fname);
 #else
-		die_horribly(NULL, modulename, "not built with zlib support\n");
+		exit_horribly(modulename, "not built with zlib support\n");
 		fp = NULL;				/* keep compiler quiet */
 #endif
 	}
@@ -541,7 +542,7 @@ cfopen(const char *path, const char *mode, int compression)
 			fp = NULL;
 		}
 #else
-		die_horribly(NULL, modulename, "not built with zlib support\n");
+		exit_horribly(modulename, "not built with zlib support\n");
 #endif
 	}
 	else

src/bin/pg_dump/dumputils.c

@@ -26,6 +26,15 @@
 int			quote_all_identifiers = 0;
 const char *progname = NULL;
 
+#define MAX_ON_EXIT_NICELY				20
+
+static struct
+{
+	on_exit_nicely_callback	function;
+	void	   *arg;
+} on_exit_nicely_list[MAX_ON_EXIT_NICELY];
+
+static int on_exit_nicely_index;
 
 #define supports_grant_options(version) ((version) >= 70400)
 
@@ -1261,7 +1270,7 @@ exit_horribly(const char *modulename, const char *fmt,...)
 	vwrite_msg(modulename, fmt, ap);
 	va_end(ap);
 
-	exit(1);
+	exit_nicely(1);
 }
 
 /*
@@ -1289,6 +1298,27 @@ set_section (const char *arg, int *dumpSections)
 				progname, arg);
 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 				progname);
-		exit(1);
+		exit_nicely(1);
 	}
 }
+
+/* Register a callback to be run when exit_nicely is invoked. */
+void
+on_exit_nicely(on_exit_nicely_callback function, void *arg)
+{
+	if (on_exit_nicely_index >= MAX_ON_EXIT_NICELY)
+		exit_horribly(NULL, "out of on_exit_nicely slots");
+	on_exit_nicely_list[on_exit_nicely_index].function = function;
+	on_exit_nicely_list[on_exit_nicely_index].arg = arg;
+	on_exit_nicely_index++;
+}
+
+/* Run accumulated on_exit_nicely callbacks and then exit quietly. */
+void
+exit_nicely(int code)
+{
+	while (--on_exit_nicely_index >= 0)
+		(*on_exit_nicely_list[on_exit_nicely_index].function)(code,
+			on_exit_nicely_list[on_exit_nicely_index].arg);
+	exit(code);
+}

src/bin/pg_dump/dumputils.h

@@ -60,4 +60,8 @@ extern void exit_horribly(const char *modulename, const char *fmt,...)
 				__attribute__((format(PG_PRINTF_ATTRIBUTE, 2, 3), noreturn));
 extern void set_section (const char *arg, int *dumpSections);
 
+typedef void (*on_exit_nicely_callback) (int code, void *arg);
+extern void on_exit_nicely(on_exit_nicely_callback function, void *arg);
+extern void exit_nicely(int code) __attribute__((noreturn));
+
 #endif   /* DUMPUTILS_H */

src/bin/pg_dump/pg_backup.h

@@ -159,15 +159,13 @@ typedef struct _restoreOptions
  * Main archiver interface.
  */
 
-
-/* Lets the archive know we have a DB connection to shutdown if it dies */
-
-PGconn *ConnectDatabase(Archive *AH,
+extern PGconn *ConnectDatabase(Archive *AH,
 				const char *dbname,
 				const char *pghost,
 				const char *pgport,
 				const char *username,
 				enum trivalue prompt_password);
+extern void DisconnectDatabase(Archive *AHX);
 
 /* Called to add a TOC entry */
 extern void ArchiveEntry(Archive *AHX,

src/bin/pg_dump/pg_backup_archiver.c

@@ -459,10 +459,7 @@ RestoreArchive(Archive *AHX, RestoreOptions *ropt)
 		RestoreOutput(AH, sav);
 
 	if (ropt->useDB)
-	{
-		PQfinish(AH->connection);
-		AH->connection = NULL;
-	}
+		DisconnectDatabase(&AH->public);
 }
 
 /*
@@ -1435,11 +1432,10 @@ vdie_horribly(ArchiveHandle *AH, const char *modulename,
 	{
 		if (AH->public.verbose)
 			write_msg(NULL, "*** aborted because of error\n");
-		if (AH->connection)
-			PQfinish(AH->connection);
+		DisconnectDatabase(&AH->public);
 	}
 
-	exit(1);
+	exit_nicely(1);
 }
 
 /* As above, but with variable arg list */
@@ -3332,8 +3328,7 @@ restore_toc_entries_parallel(ArchiveHandle *AH)
 	 * mainly to ensure that we don't exceed the specified number of parallel
 	 * connections.
 	 */
-	PQfinish(AH->connection);
-	AH->connection = NULL;
+	DisconnectDatabase(&AH->public);
 
 	/* blow away any transient state from the old connection */
 	if (AH->currUser)
@@ -3795,8 +3790,7 @@ parallel_restore(RestoreArgs *args)
 	retval = restore_toc_entry(AH, te, ropt, true);
 
 	/* And clean up */
-	PQfinish(AH->connection);
-	AH->connection = NULL;
+	DisconnectDatabase((Archive *) AH);
 
 	/* If we reopened the file, we are done with it, so close it now */
 	if (te->section == SECTION_DATA)

src/bin/pg_dump/pg_backup_db.c

@@ -310,6 +310,15 @@ ConnectDatabase(Archive *AHX,
 	return AH->connection;
 }
 
+void
+DisconnectDatabase(Archive *AHX)
+{
+	ArchiveHandle *AH = (ArchiveHandle *) AHX;
+
+	PQfinish(AH->connection);		/* noop if AH->connection is NULL */
+	AH->connection = NULL;
+}
+
 
 static void
 notice_processor(void *arg, const char *message)

src/bin/pg_dump/pg_backup_directory.c

@@ -35,6 +35,7 @@
 
 #include "compress_io.h"
 #include "dumpmem.h"
+#include "dumputils.h"
 
 #include <dirent.h>
 #include <sys/stat.h>
@@ -633,13 +634,13 @@ createDirectory(const char *dir)
 	if (stat(dir, &st) == 0)
 	{
 		if (S_ISDIR(st.st_mode))
-			die_horribly(NULL, modulename,
-						 "cannot create directory %s, it exists already\n",
-						 dir);
+			exit_horribly(modulename,
+						  "cannot create directory %s, it exists already\n",
+						  dir);
 		else
-			die_horribly(NULL, modulename,
-						 "cannot create directory %s, a file with this name "
-						 "exists already\n", dir);
+			exit_horribly(modulename,
+						  "cannot create directory %s, a file with this name "
+						  "exists already\n", dir);
 	}
 
 	/*
@@ -648,8 +649,8 @@ createDirectory(const char *dir)
 	 * between our two calls.
 	 */
 	if (mkdir(dir, 0700) < 0)
-		die_horribly(NULL, modulename, "could not create directory %s: %s",
-					 dir, strerror(errno));
+		exit_horribly(modulename, "could not create directory %s: %s",
+					  dir, strerror(errno));
 }
 
 

src/bin/pg_dump/pg_backup_files.c

@@ -127,15 +127,15 @@ InitArchiveFmt_Files(ArchiveHandle *AH)
 		{
 			AH->FH = fopen(AH->fSpec, PG_BINARY_W);
 			if (AH->FH == NULL)
-				die_horribly(NULL, modulename, "could not open output file \"%s\": %s\n",
-							 AH->fSpec, strerror(errno));
+				exit_horribly(modulename, "could not open output file \"%s\": %s\n",
+							  AH->fSpec, strerror(errno));
 		}
 		else
 		{
 			AH->FH = stdout;
 			if (AH->FH == NULL)
-				die_horribly(NULL, modulename, "could not open output file: %s\n",
-							 strerror(errno));
+				exit_horribly(modulename, "could not open output file: %s\n",
+							  strerror(errno));
 		}
 
 		ctx->hasSeek = checkSeek(AH->FH);
@@ -152,15 +152,15 @@ InitArchiveFmt_Files(ArchiveHandle *AH)
 		{
 			AH->FH = fopen(AH->fSpec, PG_BINARY_R);
 			if (AH->FH == NULL)
-				die_horribly(NULL, modulename, "could not open input file \"%s\": %s\n",
-							 AH->fSpec, strerror(errno));
+				exit_horribly(modulename, "could not open input file \"%s\": %s\n",
+							  AH->fSpec, strerror(errno));
 		}
 		else
 		{
 			AH->FH = stdin;
 			if (AH->FH == NULL)
-				die_horribly(NULL, modulename, "could not open input file: %s\n",
-							 strerror(errno));
+				exit_horribly(modulename, "could not open input file: %s\n",
+							  strerror(errno));
 		}
 
 		ctx->hasSeek = checkSeek(AH->FH);