postgres.c

来自「PostgreSQL7.4.6 for Linux」· C语言 代码 · 共 2,551 行 · 第 1/5 页

		{
			puts("postgres (PostgreSQL) " PG_VERSION);
			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 default values for command-line options.
	 */
	Noversion = false;
	EchoQuery = false;

	if (!IsUnderPostmaster /* when exec || ExecBackend */ )
	{
		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:CD:d:Eef:FiNOPo:p:S:st:v:W:x:-:")) != -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 'C':

				/*
				 * don't print version string
				 */
				Noversion = true;
				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)
				{
#ifdef EXEC_BACKEND
					char	   *p;
					int			i;
					int			PMcanAcceptConnections; /* will eventually be
														 * global or static,
														 * when fork */

					sscanf(optarg, "%d,%d,%d,%p,", &MyProcPort->sock, &PMcanAcceptConnections,
						   &UsedShmemSegID, &UsedShmemSegAddr);
					/* Grab dbname as last param */
					for (i = 0, p = optarg - 1; i < 4 && p; i++)
						p = strchr(p + 1, ',');
					if (i == 4 && p)
						dbname = strdup(p + 1);
#else
					dbname = strdup(optarg);
#endif
					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("sort_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
				 */
				sleep(atoi(optarg));
				break;

			case 'x':
#ifdef NOT_USED					/* planner/xfunc.h */

				/*
				 * control joey hellerstein's expensive function
				 * optimization
				 */
				if (XfuncMode != 0)
				{
					elog(WARNING, "only one -x flag is allowed");
					errs++;
					break;
				}
				if (strcmp(optarg, "off") == 0)
					XfuncMode = XFUNC_OFF;
				else if (strcmp(optarg, "nor") == 0)
					XfuncMode = XFUNC_NOR;
				else if (strcmp(optarg, "nopull") == 0)
					XfuncMode = XFUNC_NOPULL;
				else if (strcmp(optarg, "nopm") == 0)
					XfuncMode = XFUNC_NOPM;
				else if (strcmp(optarg, "pullall") == 0)
					XfuncMode = XFUNC_PULLALL;
				else if (strcmp(optarg, "wait") == 0)
					XfuncMode = XFUNC_WAIT;
				else
				{
					elog(WARNING, "use -x {off,nor,nopull,nopm,pullall,wait}");
					errs++;
				}
#endif
				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);
	if (debug_flag >= 2)
		SetConfigOption("log_statement", "true", 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);
		}
	}

	/*
	 * Post-processing for command line options.
	 */
	if (log_statement_stats &&
		(log_parser_stats || log_planner_stats || log_executor_stats))
	{
		ereport(WARNING,
				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
				 errmsg("statement-level statistics are disabled because parser, planner, or executor statistics are on")));
		SetConfigOption("log_statement_stats", "false", ctx, gucsource);
	}

	if (!IsUnderPostmaster)
	{
		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