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XLOG (also known as WAL -:)) Bootstrap/Startup/Shutdown.

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First step in cleaning up backend initialization code.
Fix for FATAL: now FATAL is ERROR + exit.
This commit is contained in:
Vadim B. Mikheev
1999-10-06 21:58:18 +00:00
parent 9dcd8c528f
commit 4793740367
20 changed files with 1158 additions and 1015 deletions
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521
src/backend/postmaster/postmaster.c
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@@ -10,7 +10,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.120 1999/09/30 02:45:17 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.121 1999/10/06 21:58:03 vadim Exp $
*
* NOTES
*
@@ -87,6 +87,7 @@
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/proc.h"
#include "access/xlog.h"
#include "tcop/tcopprot.h"
#include "utils/trace.h"
#include "version.h"
@@ -98,10 +99,13 @@
#define INVALID_SOCK (-1)
#define ARGV_SIZE 64
/*
* Max time in seconds for socket to linger (close() to block) waiting
* for frontend to retrieve its message from us.
*/
#ifdef HAVE_SIGPROCMASK
sigset_t UnBlockSig,
BlockSig;
#else
int UnBlockSig,
BlockSig;
#endif
/*
* Info for garbage collection. Whenever a process dies, the Postmaster
@@ -124,7 +128,6 @@ static Dllist *BackendList;
static Dllist *PortList;
static unsigned short PostPortName = 0;
static short ActiveBackends = FALSE;
/*
* This is a boolean indicating that there is at least one backend that
@@ -209,18 +212,16 @@ static bool SecureNetServer = false; /* if not zero, postmaster listens for only
* non-local connections */
#endif
/*
* GH: For !HAVE_SIGPROCMASK (NEXTSTEP), TRH implemented an
* alternative interface.
*/
#ifdef HAVE_SIGPROCMASK
static sigset_t oldsigmask,
newsigmask;
static pid_t StartupPID = 0,
ShutdownPID = 0;
#else
static int orgsigmask = sigblock(0);
#define NoShutdown 0
#define SmartShutdown 1
#define FastShutdown 2
#endif
static int Shutdown = NoShutdown;
static bool FatalError = false;
/*
* State for assigning random salts and cancel keys.
@@ -234,30 +235,35 @@ extern char *optarg;
extern int optind,
opterr;
/*
* postmaster.c - function prototypes
*/
static void pmdaemonize(void);
static Port *ConnCreate(int serverFd);
static void ConnFree(Port *port);
static void reset_shared(unsigned short port);
static void pmdie(SIGNAL_ARGS);
static void reaper(SIGNAL_ARGS);
static void dumpstatus(SIGNAL_ARGS);
static void CleanupProc(int pid, int exitstatus);
static int DoBackend(Port *port);
static void ExitPostmaster(int status);
static void usage(const char *);
static int ServerLoop(void);
static int BackendStartup(Port *port);
static int readStartupPacket(void *arg, PacketLen len, void *pkt);
static int processCancelRequest(Port *port, PacketLen len, void *pkt);
static int initMasks(fd_set *rmask, fd_set *wmask);
static long PostmasterRandom(void);
static void RandomSalt(char *salt);
static void SignalChildren(SIGNAL_ARGS);
static int CountChildren(void);
static void pmdaemonize(void);
static Port *ConnCreate(int serverFd);
static void ConnFree(Port *port);
static void reset_shared(unsigned short port);
static void pmdie(SIGNAL_ARGS);
static void reaper(SIGNAL_ARGS);
static void dumpstatus(SIGNAL_ARGS);
static void CleanupProc(int pid, int exitstatus);
static int DoBackend(Port *port);
static void ExitPostmaster(int status);
static void usage(const char *);
static int ServerLoop(void);
static int BackendStartup(Port *port);
static int readStartupPacket(void *arg, PacketLen len, void *pkt);
static int processCancelRequest(Port *port, PacketLen len, void *pkt);
static int initMasks(fd_set *rmask, fd_set *wmask);
static long PostmasterRandom(void);
static void RandomSalt(char *salt);
static void SignalChildren(SIGNAL_ARGS);
static int CountChildren(void);
extern int BootstrapMain(int argc, char *argv[]);
static pid_t SSDataBase(bool startup);
#define StartupDataBase() SSDataBase(true)
#define ShutdownDataBase() SSDataBase(false)
#ifdef USE_SSL
static void InitSSL(void);
#endif
@@ -613,18 +619,23 @@ PostmasterMain(int argc, char *argv[])
/*
* Set up signal handlers for the postmaster process.
*/
PG_INITMASK();
PG_SETMASK(&BlockSig);
pqsignal(SIGHUP, pmdie); /* send SIGHUP, don't die */
pqsignal(SIGINT, pmdie); /* die */
pqsignal(SIGQUIT, pmdie); /* send SIGTERM and die */
pqsignal(SIGTERM, pmdie); /* send SIGTERM,SIGKILL and die */
pqsignal(SIGPIPE, SIG_IGN); /* ignored */
pqsignal(SIGUSR1, pmdie); /* send SIGUSR1 and die */
pqsignal(SIGUSR2, pmdie); /* send SIGUSR2, don't die */
pqsignal(SIGCHLD, reaper); /* handle child termination */
pqsignal(SIGTTIN, SIG_IGN); /* ignored */
pqsignal(SIGTTOU, SIG_IGN); /* ignored */
pqsignal(SIGWINCH, dumpstatus); /* dump port status */
pqsignal(SIGHUP, pmdie); /* send SIGHUP, don't die */
pqsignal(SIGINT, pmdie); /* send SIGTERM and ShutdownDataBase */
pqsignal(SIGQUIT, pmdie); /* send SIGUSR1 and die */
pqsignal(SIGTERM, pmdie); /* wait for children and ShutdownDataBase */
pqsignal(SIGALRM, SIG_IGN); /* ignored */
pqsignal(SIGPIPE, SIG_IGN); /* ignored */
pqsignal(SIGUSR1, SIG_IGN); /* ignored */
pqsignal(SIGUSR2, pmdie); /* send SIGUSR2, don't die */
pqsignal(SIGCHLD, reaper); /* handle child termination */
pqsignal(SIGTTIN, SIG_IGN); /* ignored */
pqsignal(SIGTTOU, SIG_IGN); /* ignored */
pqsignal(SIGWINCH, dumpstatus); /* dump port status */
StartupPID = StartupDataBase();
status = ServerLoop();
@@ -702,12 +713,6 @@ ServerLoop(void)
nSockets = initMasks(&readmask, &writemask);
#ifdef HAVE_SIGPROCMASK
sigprocmask(0, NULL, &oldsigmask);
sigemptyset(&newsigmask);
sigaddset(&newsigmask, SIGCHLD);
#endif
for (;;)
{
Port *port;
@@ -717,25 +722,25 @@ ServerLoop(void)
int no_select = 0;
#endif
#ifdef HAVE_SIGPROCMASK
sigprocmask(SIG_SETMASK, &oldsigmask, 0);
#else
sigsetmask(orgsigmask);
#endif
memmove((char *) &rmask, (char *) &readmask, sizeof(fd_set));
memmove((char *) &wmask, (char *) &writemask, sizeof(fd_set));
#ifdef USE_SSL
for (curr = DLGetHead(PortList); curr; curr = DLGetSucc(curr))
if (((Port *)DLE_VAL(curr))->ssl &&
SSL_pending(((Port *)DLE_VAL(curr))->ssl) > 0) {
no_select = 1;
break;
}
{
if (((Port *)DLE_VAL(curr))->ssl &&
SSL_pending(((Port *)DLE_VAL(curr))->ssl) > 0)
{
no_select = 1;
break;
}
}
PG_SETMASK(&UnBlockSig);
if (no_select)
FD_ZERO(&rmask); /* So we don't accept() anything below */
else
#else
PG_SETMASK(&UnBlockSig);
#endif
if (select(nSockets, &rmask, &wmask, (fd_set *) NULL,
(struct timeval *) NULL) < 0)
@@ -765,16 +770,9 @@ ServerLoop(void)
}
/*
* [TRH] To avoid race conditions, block SIGCHLD signals while we
* are handling the request. (both reaper() and ConnCreate()
* manipulate the BackEnd list, and reaper() calls free() which is
* usually non-reentrant.)
* Block all signals
*/
#ifdef HAVE_SIGPROCMASK
sigprocmask(SIG_BLOCK, &newsigmask, &oldsigmask);
#else
sigblock(sigmask(SIGCHLD)); /* XXX[TRH] portability */
#endif
PG_SETMASK(&BlockSig);
/* new connection pending on our well-known port's socket */
@@ -817,8 +815,8 @@ ServerLoop(void)
}
else
#endif
if (FD_ISSET(port->sock, &rmask))
readyread = 1;
if (FD_ISSET(port->sock, &rmask))
readyread = 1;
if (readyread)
{
@@ -852,13 +850,25 @@ ServerLoop(void)
if (status == STATUS_OK && port->pktInfo.state == Idle)
{
/* Can't start backend if max backend count is exceeded. */
if (CountChildren() >= MaxBackends)
/*
* Can't start backend if max backend count is exceeded.
*
* The same when shutdowning data base.
*/
if (Shutdown > NoShutdown)
PacketSendError(&port->pktInfo,
"The Data Base System is shutting down");
else if (StartupPID)
PacketSendError(&port->pktInfo,
"The Data Base System is starting up");
else if (FatalError)
PacketSendError(&port->pktInfo,
"The Data Base System is in recovery mode");
else if (CountChildren() >= MaxBackends)
PacketSendError(&port->pktInfo,
"Sorry, too many clients already");
else
{
/*
* If the backend start fails then keep the connection
* open to report it. Otherwise, pretend there is an
@@ -1113,6 +1123,7 @@ ConnCreate(int serverFd)
{
fprintf(stderr, "%s: ConnCreate: malloc failed\n",
progname);
SignalChildren(SIGUSR1);
ExitPostmaster(1);
}
@@ -1154,7 +1165,6 @@ reset_shared(unsigned short port)
{
ipc_key = port * 1000 + shmem_seq * 100;
CreateSharedMemoryAndSemaphores(ipc_key, MaxBackends);
ActiveBackends = FALSE;
shmem_seq += 1;
if (shmem_seq >= 10)
shmem_seq -= 10;
@@ -1166,49 +1176,94 @@ reset_shared(unsigned short port)
static void
pmdie(SIGNAL_ARGS)
{
int i;
PG_SETMASK(&BlockSig);
TPRINTF(TRACE_VERBOSE, "pmdie %d", postgres_signal_arg);
/*
* Kill self and/or children processes depending on signal number.
*/
switch (postgres_signal_arg)
{
case SIGHUP:
/* Send SIGHUP to all children (update options flags) */
/*
* Send SIGHUP to all children (update options flags)
*/
if (Shutdown > SmartShutdown)
return;
SignalChildren(SIGHUP);
/* Don't die */
return;
case SIGINT:
/* Die without killing children */
break;
case SIGQUIT:
/* Shutdown all children with SIGTERM */
SignalChildren(SIGTERM);
/* Don't die */
return;
case SIGTERM:
/* Shutdown all children with SIGTERM and SIGKILL, then die */
SignalChildren(SIGTERM);
for (i = 0; i < 10; i++)
{
if (!DLGetHead(BackendList))
break;
sleep(1);
}
if (DLGetHead(BackendList))
SignalChildren(SIGKILL);
break;
case SIGUSR1:
/* Quick die all children with SIGUSR1 and die */
SignalChildren(SIGUSR1);
break;
case SIGUSR2:
/* Send SIGUSR2 to all children (AsyncNotifyHandler) */
/*
* Send SIGUSR2 to all children (AsyncNotifyHandler)
*/
if (Shutdown > SmartShutdown)
return;
SignalChildren(SIGUSR2);
/* Don't die */
return;
case SIGTERM:
/*
* Smart Shutdown:
*
* let children to end their work and ShutdownDataBase.
*/
if (Shutdown >= SmartShutdown)
return;
Shutdown = SmartShutdown;
if (DLGetHead(BackendList)) /* let reaper() handle this */
return;
/*
* No children left. Shutdown data base system.
*/
if (StartupPID > 0 || FatalError) /* let reaper() handle this */
return;
if (ShutdownPID > 0)
abort();
ShutdownPID = ShutdownDataBase();
return;
case SIGINT:
/*
* Fast Shutdown:
*
* abort all children with SIGTERM (rollback active
* transactions and exit) and ShutdownDataBase.
*/
if (Shutdown >= FastShutdown)
return;
if (DLGetHead(BackendList)) /* let reaper() handle this */
{
if (!FatalError)
SignalChildren(SIGTERM);
return;
}
if (Shutdown > NoShutdown)
return;
Shutdown = FastShutdown;
/*
* No children left. Shutdown data base system.
*/
if (StartupPID > 0 || FatalError) /* let reaper() handle this */
return;
if (ShutdownPID > 0)
abort();
ShutdownPID = ShutdownDataBase(); /* flag for reaper() */
return;
case SIGQUIT:
/*
* Immediate Shutdown:
*
* abort all children with SIGUSR1 and exit without
* attempt to properly shutdown data base system.
*/
if (ShutdownPID > 0)
kill(ShutdownPID, SIGQUIT);
else if (StartupPID > 0)
kill(StartupPID, SIGQUIT);
else if (DLGetHead(BackendList))
SignalChildren(SIGUSR1);
break;
}
/* exit postmaster */
@@ -1224,29 +1279,82 @@ reaper(SIGNAL_ARGS)
/* GH: replace waitpid for !HAVE_WAITPID. Does this work ? */
#ifdef HAVE_WAITPID
int status; /* backend exit status */
#else
union wait statusp; /* backend exit status */
union wait status; /* backend exit status */
#endif
int exitstatus;
int pid; /* process id of dead backend */
PG_SETMASK(&BlockSig);
if (DebugLvl)
fprintf(stderr, "%s: reaping dead processes...\n",
progname);
#ifdef HAVE_WAITPID
while ((pid = waitpid(-1, &status, WNOHANG)) > 0)
{
CleanupProc(pid, status);
pqsignal(SIGCHLD, reaper);
}
exitstatus = status;
#else
while ((pid = wait3(&statusp, WNOHANG, NULL)) > 0)
while ((pid = wait3(&status, WNOHANG, NULL)) > 0)
{
CleanupProc(pid, statusp.w_status);
pqsignal(SIGCHLD, reaper);
}
exitstatus = status.w_status;
#endif
if (ShutdownPID > 0)
{
if (pid != ShutdownPID)
abort();
if (exitstatus != 0)
abort();
proc_exit(0);
}
if (StartupPID > 0)
{
if (pid != StartupPID)
abort();
if (exitstatus != 0)
abort();
StartupPID = 0;
FatalError = false;
if (Shutdown > NoShutdown)
{
if (ShutdownPID > 0)
abort();
ShutdownPID = ShutdownDataBase();
}
pqsignal(SIGCHLD, reaper);
return;
}
CleanupProc(pid, exitstatus);
}
pqsignal(SIGCHLD, reaper);
if (FatalError)
{
/*
* Wait for all children exit then StartupDataBase.
*/
if (DLGetHead(BackendList))
return;
if (StartupPID > 0 || ShutdownPID > 0)
return;
if (DebugLvl)
fprintf(stderr, "%s: CleanupProc: reinitializing shared memory and semaphores\n",
progname);
shmem_exit(0);
reset_shared(PostPortName);
StartupPID = StartupDataBase();
return;
}
if (Shutdown > NoShutdown)
{
if (DLGetHead(BackendList))
return;
if (StartupPID > 0 || ShutdownPID > 0)
return;
ShutdownPID = ShutdownDataBase();
}
}
/*
@@ -1260,8 +1368,8 @@ static void
CleanupProc(int pid,
int exitstatus) /* child's exit status. */
{
Dlelem *prev,
*curr;
Dlelem *curr,
*next;
Backend *bp;
int sig;
@@ -1298,18 +1406,19 @@ CleanupProc(int pid,
return;
}
FatalError = true;
curr = DLGetHead(BackendList);
while (curr)
{
next = DLGetSucc(curr);
bp = (Backend *) DLE_VAL(curr);
/* -----------------
/*
* SIGUSR1 is the special signal that says exit
* without proc_exit and let the user know what's going on.
* ProcSemaphoreKill() cleans up the backends semaphore. If
* SendStop is set (-s on command line), then we send a SIGSTOP so
* that we can core dumps from all backends by hand.
* -----------------
*/
sig = (SendStop) ? SIGSTOP : SIGUSR1;
if (bp->pid != pid)
@@ -1322,36 +1431,25 @@ CleanupProc(int pid,
bp->pid);
kill(bp->pid, sig);
}
ProcRemove(bp->pid);
else
{
/*
* I don't like that we call ProcRemove() here, assuming that
* shmem may be corrupted! But is there another way to free
* backend semaphores? Actually, I believe that we need not
* in per backend semaphore at all (we use them to wait on lock
* only, couldn't we just sigpause?), so probably we'll
* remove this call from here someday. -- vadim 04-10-1999
*/
ProcRemove(pid);
prev = DLGetPred(curr);
DLRemove(curr);
free(bp);
DLFreeElem(curr);
if (!prev)
{ /* removed head */
curr = DLGetHead(BackendList);
continue;
DLRemove(curr);
free(bp);
DLFreeElem(curr);
}
curr = DLGetSucc(prev);
curr = next;
}
/*
* Nothing up my sleeve here, ActiveBackends means that since the last
* time we recreated shared memory and sems another frontend has
* requested and received a connection and I have forked off another
* backend. This prevents me from reinitializing shared stuff more
* than once for the set of backends that caused the failure and were
* killed off.
*/
if (ActiveBackends == TRUE && Reinit)
{
if (DebugLvl)
fprintf(stderr, "%s: CleanupProc: reinitializing shared memory and semaphores\n",
progname);
shmem_exit(0);
reset_shared(PostPortName);
}
}
/*
@@ -1516,8 +1614,6 @@ BackendStartup(Port *port)
bn->cancel_key = MyCancelKey;
DLAddHead(BackendList, DLNewElem(bn));
ActiveBackends = TRUE;
return STATUS_OK;
}
@@ -1586,27 +1682,9 @@ DoBackend(Port *port)
/* We don't want the postmaster's proc_exit() handlers */
on_exit_reset();
/* ----------------
* register signal handlers.
* Thanks to the postmaster, these are currently blocked.
* ----------------
/*
* Signal handlers setting is moved to tcop/postgres...
*/
pqsignal(SIGINT, die);
pqsignal(SIGHUP, die);
pqsignal(SIGTERM, die);
pqsignal(SIGPIPE, die);
pqsignal(SIGUSR1, quickdie);
pqsignal(SIGUSR2, Async_NotifyHandler);
pqsignal(SIGFPE, FloatExceptionHandler);
pqsignal(SIGCHLD, SIG_DFL);
pqsignal(SIGTTIN, SIG_DFL);
pqsignal(SIGTTOU, SIG_DFL);
pqsignal(SIGCONT, SIG_DFL);
/* OK, let's unblock our signals, all together now... */
sigprocmask(SIG_SETMASK, &oldsigmask, 0);
/* Close the postmaster sockets */
if (NetServer)
@@ -1739,6 +1817,8 @@ ExitPostmaster(int status)
/*
* Not sure of the semantics here. When the Postmaster dies, should
* the backends all be killed? probably not.
*
* MUST -- vadim 05-10-1999
*/
if (ServerSock_INET != INVALID_SOCK)
StreamClose(ServerSock_INET);
@@ -1752,8 +1832,11 @@ ExitPostmaster(int status)
static void
dumpstatus(SIGNAL_ARGS)
{
Dlelem *curr = DLGetHead(PortList);
Dlelem *curr;
PG_SETMASK(&BlockSig);
curr = DLGetHead(PortList);
while (curr)
{
Port *port = DLE_VAL(curr);
@@ -1837,7 +1920,6 @@ CountChildren(void)
return cnt;
}
#ifdef USE_SSL
/*
* Initialize SSL library and structures
@@ -1868,3 +1950,88 @@ static void InitSSL(void) {
}
}
#endif
static pid_t
SSDataBase(bool startup)
{
pid_t pid;
int i;
static char ssEntry[4][2 * ARGV_SIZE];
for (i = 0; i < 4; ++i)
MemSet(ssEntry[i], 0, 2 * ARGV_SIZE);
sprintf(ssEntry[0], "POSTPORT=%d", PostPortName);
putenv(ssEntry[0]);
sprintf(ssEntry[1], "POSTID=%d", NextBackendTag);
putenv(ssEntry[1]);
if (!getenv("PGDATA"))
{
sprintf(ssEntry[2], "PGDATA=%s", DataDir);
putenv(ssEntry[2]);
}
sprintf(ssEntry[3], "IPC_KEY=%d", ipc_key);
putenv(ssEntry[3]);
fflush(stdout);
fflush(stderr);
if ((pid = fork()) == 0) /* child */
{
char *av[ARGV_SIZE * 2];
int ac = 0;
char execbuf[MAXPATHLEN];
char nbbuf[ARGV_SIZE];
char dbbuf[ARGV_SIZE];
on_exit_reset();
if (NetServer)
StreamClose(ServerSock_INET);
#ifndef __CYGWIN32__
StreamClose(ServerSock_UNIX);
#endif
StrNCpy(execbuf, Execfile, MAXPATHLEN);
av[ac++] = execbuf;
av[ac++] = "-d";
sprintf(nbbuf, "-B%u", NBuffers);
av[ac++] = nbbuf;
if (startup)
av[ac++] = "-x";
av[ac++] = "-p";
StrNCpy(dbbuf, "template1", ARGV_SIZE);
av[ac++] = dbbuf;
av[ac] = (char *) NULL;
optind = 1;
pqsignal(SIGQUIT, SIG_DFL);
#ifdef HAVE_SIGPROCMASK
sigdelset(&BlockSig, SIGQUIT);
#else
BlockSig &= ~(sigmask(SIGQUIT));
#endif
PG_SETMASK(&BlockSig);
BootstrapMain(ac, av);
exit(0);
}
/* in parent */
if (pid < 0)
{
fprintf(stderr, "%s Data Base: fork failed: %s\n",
((startup) ? "Startup" : "Shutdown"), strerror(errno));
ExitPostmaster(1);
}
NextBackendTag -= 1;
return(pid);
}