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postgresql/src/backend/tcop/postgres.c

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/*-------------------------------------------------------------------------
*
* postgres.c
* POSTGRES C Backend Interface
*
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.172 2000/08/27 19:00:31 petere 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 <sys/types.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <errno.h>
#if HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif /* aix */
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif
#include "commands/async.h"
#include "commands/trigger.h"
#include "commands/variable.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/parser.h"
#include "rewrite/rewriteHandler.h"
#include "tcop/fastpath.h"
#include "tcop/pquery.h"
#include "tcop/tcopprot.h"
#include "tcop/utility.h"
#include "storage/proc.h"
#include "utils/exc.h"
#include "utils/guc.h"
#include "utils/memutils.h"
#include "utils/ps_status.h"
#include "utils/temprel.h"
#ifdef MULTIBYTE
#include "mb/pg_wchar.h"
#endif
/* ----------------
* global variables
* ----------------
*/
/*
* XXX For ps display. That stuff needs to be cleaned up.
*/
bool HostnameLookup;
bool ShowPortNumber;
bool Log_connections = false;
CommandDest whereToSendOutput = Debug;
extern void StartupXLOG(void);
extern void ShutdownXLOG(void);
extern void HandleDeadLock(int signum);
extern char XLogDir[];
extern char ControlFilePath[];
static bool dontExecute = false;
static bool IsEmptyQuery = false;
/* note: these declarations had better match tcopprot.h */
DLLIMPORT sigjmp_buf Warn_restart;
bool Warn_restart_ready = false;
bool InError = false;
bool ExitAfterAbort = false;
static bool EchoQuery = false; /* default don't echo */
char pg_pathname[MAXPGPATH];
FILE *StatFp = NULL;
/* ----------------
* people who want to use EOF should #define DONTUSENEWLINE in
* tcop/tcopdebug.h
* ----------------
*/
#ifndef TCOP_DONTUSENEWLINE
int UseNewLine = 1; /* Use newlines query delimiters (the
* default) */
#else
int UseNewLine = 0; /* Use EOF as query delimiters */
#endif /* TCOP_DONTUSENEWLINE */
/*
** Flags for expensive function optimization -- JMH 3/9/92
*/
int XfuncMode = 0;
/* ----------------------------------------------------------------
* 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 SigHupHandler(int signum);
static void FloatExceptionHandler(int signum);
static void quickdie(int signum);
/*
* 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;
/* ----------------------------------------------------------------
* routines to obtain user input
* ----------------------------------------------------------------
*/
/* ----------------
* InteractiveBackend() is called for user interactive connections
* the string entered by the user is placed in its parameter inBuf.
*
* 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';
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;
}
/* ----------------
* if the query echo flag was given, print the query..
* ----------------
*/
if (EchoQuery)
printf("query: %s\n", inBuf->data);
fflush(stdout);
return 'Q';
}
/* ----------------
* SocketBackend() Is called for frontend-backend connections
*
* If the input is a query (case 'Q') then the string entered by
* the user is placed in its parameter inBuf.
*
* If the input is a fastpath function call (case 'F') then
* the function call is processed in HandleFunctionRequest()
* (now called from PostgresMain()).
*
* EOF is returned if the connection is lost.
* ----------------
*/
static int
SocketBackend(StringInfo inBuf)
{
char qtype;
char result = '\0';
/* ----------------
* get input from the frontend
* ----------------
*/
qtype = '?';
if (pq_getbytes(&qtype, 1) == EOF)
return EOF;
switch (qtype)
{
/* ----------------
* 'Q': user entered a query
* ----------------
*/
case 'Q':
if (pq_getstr(inBuf))
return EOF;
result = 'Q';
break;
/* ----------------
* 'F': calling user/system functions
* ----------------
*/
case 'F':
if (pq_getstr(inBuf))
return EOF; /* ignore "string" at start of F message */
result = 'F';
break;
/* ----------------
* 'X': frontend is exiting
* ----------------
*/
case 'X':
result = 'X';
break;
/* ----------------
* otherwise we got garbage from the frontend.
*
* XXX are we certain that we want to do an elog(FATAL) here?
* -cim 1/24/90
* ----------------
*/
default:
elog(FATAL, "Socket command type %c unknown", qtype);
break;
}
return result;
}
/* ----------------
* ReadCommand reads a command from either the frontend or
* standard input, places it in inBuf, and returns a char
* representing whether the string is a 'Q'uery or a 'F'astpath
* call. EOF is returned if end of file.
* ----------------
*/
static int
ReadCommand(StringInfo inBuf)
{
int result;
if (IsUnderPostmaster)
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.
*/
List *
pg_parse_and_rewrite(char *query_string, /* string to execute */
Oid *typev, /* parameter types */
int nargs) /* number of parameters */
{
List *querytree_list;
List *querytree_list_item;
Query *querytree;
List *new_list;
if (Debug_print_query)
elog(DEBUG, "query: %s", query_string);
/* ----------------
* (1) parse the request string into a list of parse trees
* ----------------
*/
if (Show_parser_stats)
ResetUsage();
querytree_list = parser(query_string, typev, nargs);
if (Show_parser_stats)
{
fprintf(StatFp, "PARSER STATISTICS\n");
ShowUsage();
}
/* ----------------
* (2) rewrite the queries, as necessary
*
* rewritten queries are collected in new_list. Note there may be
* more or fewer than in the original list.
* ----------------
*/
new_list = NIL;
foreach(querytree_list_item, querytree_list)
{
querytree = (Query *) lfirst(querytree_list_item);
if (Debug_print_parse)
{
if (Debug_pretty_print)
{
elog(DEBUG, "parse tree:");
nodeDisplay(querytree);
}
else
elog(DEBUG, "parse tree: %s", nodeToString(querytree));
}
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;
#ifdef COPY_PARSE_PLAN_TREES
/* Optional debugging check: pass parsetree output through copyObject() */
/*
* Note: we run this test after rewrite, not before, because copyObject()
* does not handle most kinds of nodes that are used only in raw parse
* trees. The present (bizarre) implementation of UNION/INTERSECT/EXCEPT
* doesn't run analysis of the second and later subqueries until rewrite,
* so we'd get false failures on these queries if we did it beforehand.
*/
new_list = (List *) copyObject(querytree_list);
/* This checks both copyObject() and the equal() routines... */
if (! equal(new_list, querytree_list))
elog(NOTICE, "pg_parse_and_rewrite: copyObject failed on parse tree");
else
querytree_list = new_list;
#endif
if (Debug_print_rewritten)
{
if (Debug_pretty_print)
{
elog(DEBUG, "rewritten parse tree:");
foreach(querytree_list_item, querytree_list)
{
querytree = (Query *) lfirst(querytree_list_item);
nodeDisplay(querytree);
printf("\n");
}
}
else
{
elog(DEBUG, "rewritten parse tree:");
foreach(querytree_list_item, querytree_list)
{
querytree = (Query *) lfirst(querytree_list_item);
elog(DEBUG, "%s", nodeToString(querytree));
}
}
}
return querytree_list;
}
/* Generate a plan for a single query. */
Plan *
pg_plan_query(Query *querytree)
{
Plan *plan;
/* Utility commands have no plans. */
if (querytree->commandType == CMD_UTILITY)
return NULL;
if (Show_planner_stats)
ResetUsage();
/* call that optimizer */
plan = planner(querytree);
if (Show_planner_stats)
{
fprintf(stderr, "PLANNER STATISTICS\n");
ShowUsage();
}
#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(NOTICE, "pg_plan_query: copyObject failed on plan tree");
else
#endif
plan = new_plan;
}
#endif
/* ----------------
* Print plan if debugging.
* ----------------
*/
if (Debug_print_plan)
{
if (Debug_pretty_print)
{
elog(DEBUG, "plan:");
nodeDisplay(plan);
}
else
elog(DEBUG, "plan: %s", nodeToString(plan));
}
return plan;
}
/* ----------------------------------------------------------------
* pg_exec_query_dest()
*
* Takes a querystring, runs the parser/utilities or
* parser/planner/executor over it as necessary.
*
* Assumptions:
*
* Caller is responsible for calling StartTransactionCommand() beforehand
* and CommitTransactionCommand() afterwards (if successful).
*
* The CurrentMemoryContext at entry references a context that is
* appropriate for execution of individual queries (typically this will be
* TransactionCommandContext). Note that this routine resets that context
* after each individual query, so don't store anything there that
* must outlive the call!
*
* parse_context references a context suitable for holding the
* parse/rewrite trees (typically this will be QueryContext).
* This context *must* be longer-lived than the CurrentMemoryContext!
* In fact, if the query string might contain BEGIN/COMMIT commands,
* parse_context had better outlive TopTransactionContext!
*
* We could have hard-wired knowledge about QueryContext and
* TransactionCommandContext into this routine, but it seems better
* not to, in case callers from outside this module need to use some
* other contexts.
*
* ----------------------------------------------------------------
*/
void
pg_exec_query_dest(char *query_string, /* string to execute */
CommandDest dest, /* where results should go */
MemoryContext parse_context) /* context for parsetrees */
{
MemoryContext oldcontext;
List *querytree_list,
*querytree_item;
/*
* If you called this routine with parse_context = CurrentMemoryContext,
* you blew it. They *must* be different, else the context reset
* at the bottom of the loop will destroy the querytree list.
* (We really ought to check that parse_context isn't a child of
* CurrentMemoryContext either, but that would take more cycles than
* it's likely to be worth.)
*/
Assert(parse_context != CurrentMemoryContext);
/*
* Switch to appropriate context for constructing parsetrees.
*/
oldcontext = MemoryContextSwitchTo(parse_context);
/*
* Parse and rewrite the query or queries.
*/
querytree_list = pg_parse_and_rewrite(query_string, NULL, 0);
/*
* Switch back to execution context for planning and execution.
*/
MemoryContextSwitchTo(oldcontext);
/*
* Run through the query or queries and execute each one.
*/
foreach(querytree_item, querytree_list)
{
Query *querytree = (Query *) lfirst(querytree_item);
/* if we got a cancel signal in parsing or prior command, quit */
if (QueryCancel)
CancelQuery();
if (querytree->commandType == CMD_UTILITY)
{
/* ----------------
* process utility functions (create, destroy, etc..)
*
* Note: we do not check for the transaction aborted state
* because that is done in ProcessUtility.
* ----------------
*/
if (Debug_print_query)
elog(DEBUG, "ProcessUtility: %s", query_string);
else if (DebugLvl > 1)
elog(DEBUG, "ProcessUtility");
ProcessUtility(querytree->utilityStmt, dest);
}
else
{
Plan *plan;
/* If aborted transaction, skip planning and execution */
if (IsAbortedTransactionBlockState())
{
/* ----------------
* the EndCommand() stuff is to tell the frontend
* that the command ended. -cim 6/1/90
* ----------------
*/
char *tag = "*ABORT STATE*";
elog(NOTICE, "current transaction is aborted, "
"queries ignored until end of transaction block");
EndCommand(tag, dest);
/*
* We continue in the loop, on the off chance that there
* is a COMMIT or ROLLBACK utility command later in the
* query string.
*/
continue;
}
plan = pg_plan_query(querytree);
/* if we got a cancel signal whilst planning, quit */
if (QueryCancel)
CancelQuery();
/* Initialize snapshot state for query */
SetQuerySnapshot();
/*
* execute the plan
*/
if (Show_executor_stats)
ResetUsage();
if (dontExecute)
{
/* don't execute it, just show the query plan */
print_plan(plan, querytree);
}
else
{
if (DebugLvl > 1)
elog(DEBUG, "ProcessQuery");
ProcessQuery(querytree, plan, dest);
}
if (Show_executor_stats)
{
fprintf(stderr, "EXECUTOR STATISTICS\n");
ShowUsage();
}
}
/*
* In a query block, we want to increment the command counter
* between queries so that the effects of early queries are
* visible to subsequent ones.
*/
CommandCounterIncrement();
/*
* Also, clear the execution context to recover temporary
* memory used by the query. NOTE: if query string contains
* BEGIN/COMMIT transaction commands, execution context may
* now be different from what we were originally passed;
* so be careful to clear current context not "oldcontext".
*/
MemoryContextResetAndDeleteChildren(CurrentMemoryContext);
}
}
/* --------------------------------
* signal handler routines used in PostgresMain()
*
* handle_warn() catches SIGQUIT. It forces control back to the main
* loop, just as if an internal error (elog(ERROR,...)) had occurred.
* elog() used to actually use kill(2) to induce a SIGQUIT to get here!
* But that's not 100% reliable on some systems, so now it does its own
* siglongjmp() instead.
* We still provide the signal catcher so that an error quit can be
* forced externally. This should be done only with great caution,
* however, since an asynchronous signal could leave the system in
* who-knows-what inconsistent state.
*
* quickdie() occurs when signalled by the postmaster.
* Some backend has bought the farm,
* so we need to stop what we're doing and exit.
*
* die() performs an orderly cleanup via proc_exit()
* --------------------------------
*/
void
handle_warn(int signum)
{
siglongjmp(Warn_restart, 1);
}
static void
quickdie(int signum)
{
PG_SETMASK(&BlockSig);
elog(NOTICE, "Message from PostgreSQL backend:"
"\n\tThe Postmaster has informed me that some other backend"
" died abnormally and possibly corrupted shared memory."
"\n\tI have rolled back the current transaction and am"
" going to terminate your database system connection and exit."
"\n\tPlease reconnect to the database system and repeat your query.");
/*
* DO NOT proc_exit(0) -- we're here because shared memory may be
* corrupted, so we don't want to flush any shared state to stable
* storage. Just nail the windows shut and get out of town.
*/
exit(1);
}
/*
* Abort transaction and exit
*/
void
die(int signum)
{
PG_SETMASK(&BlockSig);
/*
* If ERROR/FATAL is in progress...
*/
if (InError)
{
ExitAfterAbort = true;
return;
}
elog(FATAL, "The system is shutting down");
}
/* signal handler for floating point exception */
static void
FloatExceptionHandler(int signum)
{
elog(ERROR, "floating point exception!"
" The last floating point operation either exceeded legal ranges"
" or was a divide by zero");
}
/* signal handler for query cancel signal from postmaster */
static void
QueryCancelHandler(int signum)
{
QueryCancel = true;
LockWaitCancel();
}
void
CancelQuery(void)
{
/*
* QueryCancel flag will be reset in main loop, which we reach by
* longjmp from elog().
*/
elog(ERROR, "Query was cancelled.");
}
static void
SigHupHandler(int signum)
{
got_SIGHUP = true;
}
static void
usage(char *progname)
{
fprintf(stderr,
"Usage: %s [options] [dbname]\n", progname);
#ifdef USE_ASSERT_CHECKING
fprintf(stderr, "\t-A on\t\tenable/disable assert checking\n");
#endif
fprintf(stderr, "\t-B buffers\tset number of buffers in buffer pool\n");
fprintf(stderr, "\t-C \t\tsuppress version info\n");
fprintf(stderr, "\t-D dir\t\tdata directory\n");
fprintf(stderr, "\t-E \t\techo query before execution\n");
fprintf(stderr, "\t-F \t\tturn fsync off\n");
fprintf(stderr, "\t-L \t\tturn off locking\n");
fprintf(stderr, "\t-N \t\tdon't use newline as interactive query delimiter\n");
fprintf(stderr, "\t-O \t\tallow system table structure changes\n");
fprintf(stderr, "\t-Q \t\tsuppress informational messages\n");
fprintf(stderr, "\t-S kbytes\tset amount of memory for sorts (in kbytes)\n");
fprintf(stderr, "\t-T options\tspecify pg_options\n");
fprintf(stderr, "\t-W sec\t\twait N seconds to allow attach from a debugger\n");
fprintf(stderr, "\t-d [1-5]\tset debug level\n");
fprintf(stderr, "\t-e \t\tturn on European date format\n");
fprintf(stderr, "\t-f [s|i|n|m|h]\tforbid use of some plan types\n");
fprintf(stderr, "\t-i \t\tdon't execute queries\n");
fprintf(stderr, "\t-o file\t\tsend stdout and stderr to given filename\n");
fprintf(stderr, "\t-p database\tbackend is started under a postmaster\n");
fprintf(stderr, "\t-s \t\tshow stats after each query\n");
fprintf(stderr, "\t-t [pa|pl|ex]\tshow timings after each query\n");
fprintf(stderr, "\t-v version\tset protocol version being used by frontend\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.
* real_argc/real_argv point to the original argv array, which is needed by
* PS_INIT_STATUS on some platforms.
* ----------------------------------------------------------------
*/
int
PostgresMain(int argc, char *argv[], int real_argc, char *real_argv[])
{
int flag;
char *DBName = NULL;
bool secure = true;
int errs = 0;
int firstchar;
StringInfo parser_input;
char *userName;
char *remote_host;
unsigned short remote_port;
extern int optind;
extern char *optarg;
extern int DebugLvl;
/*
* Fire up essential subsystems: error and memory management
*
* If we are running under the postmaster, this is done already.
*/
if (!IsUnderPostmaster)
{
EnableExceptionHandling(true);
MemoryContextInit();
}
/*
* Set default values for command-line options.
*/
Noversion = false;
EchoQuery = false;
if (!IsUnderPostmaster)
{
ResetAllOptions();
if (getenv("PGDATA"))
DataDir = strdup(getenv("PGDATA"));
}
StatFp = stderr;
SetProcessingMode(InitProcessing);
/* Check for PGDATESTYLE environment variable */
set_default_datestyle();
/* ----------------
* 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.
* ----------------
*/
optind = 1; /* reset after postmaster's usage */
while ((flag = getopt(argc, argv, "A:B:CD:d:Eef:FiLNOPo:p:S:st:v:W:x:-:")) != EOF)
switch (flag)
{
case 'A':
#ifdef USE_ASSERT_CHECKING
assert_enabled = atoi(optarg);
#else
fprintf(stderr, "Assert checking is not compiled in\n");
#endif
break;
case 'B':
/* ----------------
* specify the size of buffer pool
* ----------------
*/
if (secure)
NBuffers = atoi(optarg);
break;
case 'C':
/* ----------------
* don't print version string
* ----------------
*/
Noversion = true;
break;
case 'D': /* PGDATA directory */
if (secure)
{
if (DataDir)
free(DataDir);
DataDir = strdup(optarg);
}
break;
case 'd': /* debug level */
DebugLvl = atoi(optarg);
if (DebugLvl >= 1);
Log_connections = true;
if (DebugLvl >= 2)
Debug_print_query = true;
if (DebugLvl >= 3)
Debug_print_parse = true;
if (DebugLvl >= 4)
Debug_print_plan = true;
if (DebugLvl >= 5)
Debug_print_rewritten = true;
break;
case 'E':
/* ----------------
* E - echo the query the user entered
* ----------------
*/
EchoQuery = true;
break;
case 'e':
/* --------------------------
* Use european date formats.
* --------------------------
*/
EuroDates = true;
break;
case 'F':
/* --------------------
* turn off fsync
*
* 7.0 buffer manager can support different backends running
* with different fsync settings, so this no longer needs
* to be "if (secure)".
* --------------------
*/
enableFsync = false;
break;
case 'f':
/* -----------------
* f - forbid generation of certain plans
* -----------------
*/
switch (optarg[0])
{
case 's': /* seqscan */
enable_seqscan = false;
break;
case 'i': /* indexscan */
enable_indexscan = false;
break;
case 't': /* tidscan */
enable_tidscan = false;
break;
case 'n': /* nestloop */
enable_nestloop = false;
break;
case 'm': /* mergejoin */
enable_mergejoin = false;
break;
case 'h': /* hashjoin */
enable_hashjoin = false;
break;
default:
errs++;
}
break;
case 'i':
dontExecute = true;
break;
case 'L':
/* --------------------
* turn off locking
* --------------------
*/
if (secure)
lockingOff = 1;
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
* --------------------
*/
if (secure) /* XXX safe to allow from client??? */
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 */
}
break;
case 'S':
/* ----------------
* S - amount of sort memory to use in 1k bytes
* ----------------
*/
{
int S;
S = atoi(optarg);
if (S >= 4 * BLCKSZ / 1024)
SortMem = S;
}
break;
case 's':
/* ----------------
* s - report usage statistics (timings) after each query
* ----------------
*/
Show_query_stats = 1;
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.
* ----------------
*/
switch (optarg[0])
{
case 'p':
if (optarg[1] == 'a')
Show_parser_stats = 1;
else if (optarg[1] == 'l')
Show_planner_stats = 1;
else
errs++;
break;
case 'e':
Show_executor_stats = 1;
break;
default:
errs++;
break;
}
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)
{
fprintf(stderr, "only one -x flag is allowed\n");
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
{
fprintf(stderr, "use -x {off,nor,nopull,nopm,pullall,wait}\n");
errs++;
}
#endif
break;
case '-':
{
char *name, *value;
ParseLongOption(optarg, &name, &value);
if (!value)
elog(ERROR, "--%s requires argument", optarg);
SetConfigOption(name, value, PGC_BACKEND);
free(name);
if (value)
free(value);
break;
}
default:
/* ----------------
* default: bad command line option
* ----------------
*/
errs++;
break;
}
if (Show_query_stats &&
(Show_parser_stats || Show_planner_stats || Show_executor_stats))
{
elog(NOTICE, "Query statistics are disabled because parser, planner, or executor statistics are on.");
Show_query_stats = false;
}
if (!DataDir)
{
fprintf(stderr, "%s does not know where to find the database system "
"data. You must specify the directory that contains the "
"database system either by specifying the -D invocation "
"option or by setting the PGDATA environment variable.\n\n",
argv[0]);
proc_exit(1);
}
/*
* 1. Set BlockSig and UnBlockSig masks. 2. Set up signal handlers. 3.
* Allow only SIGUSR1 signal (we never block it) during
* initialization.
*
* Note that postmaster already blocked ALL signals to make us happy.
*/
pqinitmask();
#ifdef HAVE_SIGPROCMASK
sigdelset(&BlockSig, SIGUSR1);
#else
BlockSig &= ~(sigmask(SIGUSR1));
#endif
PG_SETMASK(&BlockSig); /* block everything except SIGUSR1 */
pqsignal(SIGHUP, SigHupHandler); /* set flag to read config file */
pqsignal(SIGINT, QueryCancelHandler); /* cancel current query */
pqsignal(SIGQUIT, handle_warn); /* handle error */
pqsignal(SIGTERM, die);
pqsignal(SIGALRM, HandleDeadLock);
/*
* 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, quickdie);
pqsignal(SIGUSR2, Async_NotifyHandler); /* flush also sinval cache */
pqsignal(SIGFPE, FloatExceptionHandler);
pqsignal(SIGCHLD, SIG_IGN); /* ignored, sent by LockOwners */
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
/*
* Get user name (needed now in case it is the default database name)
* and check command line validity
*/
SetPgUserName();
userName = GetPgUserName();
if (IsUnderPostmaster)
{
/* noninteractive case: nothing should be left after switches */
if (errs || argc != optind || DBName == NULL)
{
usage(argv[0]);
proc_exit(0);
}
pq_init(); /* initialize libpq at backend startup */
whereToSendOutput = Remote;
BaseInit();
}
else
{
/* interactive case: database name can be last arg on command line */
whereToSendOutput = Debug;
if (errs || argc - optind > 1)
{
usage(argv[0]);
proc_exit(0);
}
else if (argc - optind == 1)
DBName = argv[optind];
else if ((DBName = userName) == NULL)
{
fprintf(stderr, "%s: USER undefined and no database specified\n",
argv[0]);
proc_exit(0);
}
/*
* Try to create pid file.
*/
SetPidFname(DataDir);
if (SetPidFile(-getpid()))
proc_exit(0);
/*
* Register clean up proc.
*/
on_proc_exit(UnlinkPidFile, NULL);
BaseInit();
snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
StartupXLOG();
}
/*
* Set up additional info.
*/
#ifdef CYR_RECODE
SetCharSet();
#endif
/* On some systems our dynloader code needs the executable's pathname */
if (FindExec(pg_pathname, real_argv[0], "postgres") < 0)
elog(FATAL, "%s: could not locate executable, bailing out...",
real_argv[0]);
/*
* Find remote host name or address.
*/
remote_host = NULL;
if (IsUnderPostmaster)
{
if (MyProcPort->raddr.sa.sa_family == AF_INET)
{
struct hostent *host_ent;
char * host_addr;
remote_port = ntohs(MyProcPort->raddr.in.sin_port);
host_addr = inet_ntoa(MyProcPort->raddr.in.sin_addr);
if (HostnameLookup)
{
host_ent = gethostbyaddr((char *) &MyProcPort->raddr.in.sin_addr, sizeof(MyProcPort->raddr.in.sin_addr), AF_INET);
if (host_ent)
{
remote_host = palloc(strlen(host_addr) + strlen(host_ent->h_name) + 3);
sprintf(remote_host, "%s[%s]", host_ent->h_name, host_addr);
}
}
if (remote_host == NULL)
remote_host = pstrdup(host_addr);
if (ShowPortNumber)
{
char * str = palloc(strlen(remote_host) + 7);
sprintf(str, "%s:%hu", remote_host, remote_port);
pfree(remote_host);
remote_host = str;
}
}
else /* not AF_INET */
remote_host = "[local]";
/*
* Set process parameters for ps
*
* WARNING: On some platforms the environment will be moved
* around to make room for the ps display string. So any
* references to optarg or getenv() from above will be invalid
* after this call. Better use strdup or something similar.
*/
init_ps_display(real_argc, real_argv, userName, DBName, remote_host);
set_ps_display("startup");
}
if (Log_connections)
elog(DEBUG, "connection: host=%s user=%s database=%s",
remote_host, userName, DBName);
/*
* general initialization
*/
if (DebugLvl > 1)
elog(DEBUG, "InitPostgres");
InitPostgres(DBName);
#ifdef MULTIBYTE
/* set default client encoding */
if (DebugLvl > 1)
elog(DEBUG, "reset_client_encoding");
reset_client_encoding();
#endif
on_shmem_exit(remove_all_temp_relations, NULL);
/*
* Send this backend's cancellation info to the frontend.
*/
if (whereToSendOutput == Remote &&
PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
{
StringInfoData buf;
pq_beginmessage(&buf);
pq_sendbyte(&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. */
}
if (!IsUnderPostmaster)
{
puts("\nPOSTGRES backend interactive interface ");
puts("$Revision: 1.172 $ $Date: 2000/08/27 19:00:31 $\n");
}
/*
* Initialize the deferred trigger manager
*/
if (DeferredTriggerInit() != 0)
proc_exit(0);
SetProcessingMode(NormalProcessing);
/*
* Create the memory context we will use in the main loop.
*
* QueryContext is reset once per iteration of the main loop,
* ie, upon completion of processing of each supplied query string.
* It can therefore be used for any data that should live just as
* long as the query string --- parse trees, for example.
*/
QueryContext = AllocSetContextCreate(TopMemoryContext,
"QueryContext",
ALLOCSET_DEFAULT_MINSIZE,
ALLOCSET_DEFAULT_INITSIZE,
ALLOCSET_DEFAULT_MAXSIZE);
/*
* 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)
{
/*
* 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);
if (DebugLvl >= 1)
elog(DEBUG, "AbortCurrentTransaction");
AbortCurrentTransaction();
if (ExitAfterAbort)
{
ProcReleaseLocks(); /* Just to be sure... */
proc_exit(0);
}
/*
* If we recovered successfully, return to normal top-level context
* and clear ErrorContext for next time.
*/
MemoryContextSwitchTo(TopMemoryContext);
MemoryContextResetAndDeleteChildren(ErrorContext);
InError = false;
}
Warn_restart_ready = true; /* we can now handle elog(ERROR) */
PG_SETMASK(&UnBlockSig);
/*
* Non-error queries loop here.
*/
for (;;)
{
/*
* Release storage left over from prior query cycle, and
* create a new query input buffer in the cleared QueryContext.
*/
MemoryContextSwitchTo(QueryContext);
MemoryContextResetAndDeleteChildren(QueryContext);
parser_input = makeStringInfo();
/* XXX this could be moved after ReadCommand below to get more
* sensical behaviour */
if (got_SIGHUP)
{
got_SIGHUP = false;
ProcessConfigFile(PGC_SIGHUP);
}
/* ----------------
* (1) tell the frontend we're ready for a new query.
*
* Note: this includes fflush()'ing the last of the prior output.
* ----------------
*/
ReadyForQuery(whereToSendOutput);
/* ----------------
* (2) deal with pending asynchronous NOTIFY from other backends,
* and enable async.c's signal handler to execute NOTIFY directly.
* ----------------
*/
QueryCancel = false; /* forget any earlier CANCEL signal */
SetWaitingForLock(false);
EnableNotifyInterrupt();
/* ----------------
* (3) read a command (loop blocks here)
* ----------------
*/
set_ps_display("idle");
firstchar = ReadCommand(parser_input);
QueryCancel = false; /* forget any earlier CANCEL signal */
/* ----------------
* (4) disable async.c's signal handler.
* ----------------
*/
DisableNotifyInterrupt();
/* ----------------
* (5) process the command.
* ----------------
*/
switch (firstchar)
{
/* ----------------
* 'F' indicates a fastpath call.
* XXX HandleFunctionRequest
* ----------------
*/
case 'F':
IsEmptyQuery = false;
/* start an xact for this function invocation */
if (DebugLvl >= 1)
elog(DEBUG, "StartTransactionCommand");
StartTransactionCommand();
if (HandleFunctionRequest() == EOF)
{
/* lost frontend connection during F message input */
pq_close();
proc_exit(0);
}
break;
/* ----------------
* 'Q' indicates a user query
* ----------------
*/
case 'Q':
if (strspn(parser_input->data, " \t\n") == parser_input->len)
{
/* ----------------
* if there is nothing in the input buffer, don't bother
* trying to parse and execute anything..
* ----------------
*/
IsEmptyQuery = true;
}
else
{
/* ----------------
* otherwise, process the input string.
* ----------------
*/
IsEmptyQuery = false;
if (Show_query_stats)
ResetUsage();
/* start an xact for this query */
if (DebugLvl >= 1)
elog(DEBUG, "StartTransactionCommand");
StartTransactionCommand();
pg_exec_query_dest(parser_input->data,
whereToSendOutput,
QueryContext);
/*
* Invoke IMMEDIATE constraint triggers
*
*/
DeferredTriggerEndQuery();
if (Show_query_stats)
{
fprintf(StatFp, "QUERY STATISTICS\n");
ShowUsage();
}
}
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:
if (!IsUnderPostmaster)
ShutdownXLOG();
pq_close();
proc_exit(0);
break;
default:
elog(ERROR, "unknown frontend message was received");
}
/* ----------------
* (6) commit the current transaction
*
* Note: if we had an empty input buffer, then we didn't
* call pg_exec_query_dest, so we don't bother to commit
* this transaction.
* ----------------
*/
if (!IsEmptyQuery)
{
if (DebugLvl >= 1)
elog(DEBUG, "CommitTransactionCommand");
set_ps_display("commit");
CommitTransactionCommand();
#ifdef SHOW_MEMORY_STATS
/* print global-context stats at each commit for leak tracking */
if (ShowStats)
MemoryContextStats(TopMemoryContext);
#endif
}
else
{
if (IsUnderPostmaster)
NullCommand(Remote);
}
#ifdef MEMORY_CONTEXT_CHECKING
/*
* Check all memory after each backend loop
*/
MemoryContextCheck(TopMemoryContext);
#endif
} /* infinite for-loop */
proc_exit(0); /* shouldn't get here... */
return 1;
}
#ifndef HAVE_GETRUSAGE
#include "rusagestub.h"
#else
#include <sys/resource.h>
#endif /* HAVE_GETRUSAGE */
struct rusage Save_r;
struct timeval Save_t;
void
ResetUsage(void)
{
struct timezone tz;
getrusage(RUSAGE_SELF, &Save_r);
gettimeofday(&Save_t, &tz);
ResetBufferUsage();
/* ResetTupleCount(); */
}
void
ShowUsage(void)
{
struct timeval user,
sys;
struct timeval elapse_t;
struct timezone tz;
struct rusage r;
getrusage(RUSAGE_SELF, &r);
gettimeofday(&elapse_t, &tz);
memmove((char *) &user, (char *) &r.ru_utime, sizeof(user));
memmove((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;
}
/*
* Set output destination if not otherwise set
*/
if (StatFp == NULL)
StatFp = stderr;
/*
* 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.
*/
fprintf(StatFp, "! system usage stats:\n");
fprintf(StatFp,
"!\t%ld.%06ld elapsed %ld.%06ld user %ld.%06ld system sec\n",
(long int) elapse_t.tv_sec - Save_t.tv_sec,
(long int) elapse_t.tv_usec - Save_t.tv_usec,
(long int) r.ru_utime.tv_sec - Save_r.ru_utime.tv_sec,
(long int) r.ru_utime.tv_usec - Save_r.ru_utime.tv_usec,
(long int) r.ru_stime.tv_sec - Save_r.ru_stime.tv_sec,
(long int) r.ru_stime.tv_usec - Save_r.ru_stime.tv_usec);
fprintf(StatFp,
"!\t[%ld.%06ld user %ld.%06ld sys total]\n",
(long int) user.tv_sec,
(long int) user.tv_usec,
(long int) sys.tv_sec,
(long int) sys.tv_usec);
#ifdef HAVE_GETRUSAGE
fprintf(StatFp,
"!\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);
fprintf(StatFp,
"!\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);
fprintf(StatFp,
"!\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);
fprintf(StatFp,
"!\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 */
fprintf(StatFp, "! postgres usage stats:\n");
PrintBufferUsage(StatFp);
/* DisplayTupleCount(StatFp); */
}
#ifdef NOT_USED
static int
assertEnable(int val)
{
assert_enabled = val;
return val;
}
#ifdef ASSERT_CHECKING_TEST
int
assertTest(int val)
{
Assert(val == 0);
if (assert_enabled)
{
/* val != 0 should be trapped by previous Assert */
elog(NOTICE, "Assert test successfull (val = %d)", val);
}
else
elog(NOTICE, "Assert checking is disabled (val = %d)", val);
return val;
}
#endif
#endif
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