118 lines
3.2 KiB
C
118 lines
3.2 KiB
C
/*-------------------------------------------------------------------------
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*
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* interrupt.c
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* Interrupt handling routines.
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*
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* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
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* Portions Copyright (c) 1994, Regents of the University of California
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*
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* IDENTIFICATION
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* src/backend/postmaster/interrupt.c
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <unistd.h>
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#include "miscadmin.h"
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#include "postmaster/interrupt.h"
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#include "storage/ipc.h"
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#include "storage/latch.h"
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#include "storage/procsignal.h"
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#include "utils/guc.h"
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#include "utils/memutils.h"
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volatile sig_atomic_t ConfigReloadPending = false;
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volatile sig_atomic_t ShutdownRequestPending = false;
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/*
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* Simple interrupt handler for main loops of background processes.
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*/
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void
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HandleMainLoopInterrupts(void)
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{
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if (ProcSignalBarrierPending)
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ProcessProcSignalBarrier();
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if (ConfigReloadPending)
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{
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ConfigReloadPending = false;
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ProcessConfigFile(PGC_SIGHUP);
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}
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if (ShutdownRequestPending)
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proc_exit(0);
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/* Perform logging of memory contexts of this process */
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if (LogMemoryContextPending)
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ProcessLogMemoryContextInterrupt();
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}
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/*
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* Simple signal handler for triggering a configuration reload.
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*
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* Normally, this handler would be used for SIGHUP. The idea is that code
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* which uses it would arrange to check the ConfigReloadPending flag at
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* convenient places inside main loops, or else call HandleMainLoopInterrupts.
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*/
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void
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SignalHandlerForConfigReload(SIGNAL_ARGS)
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{
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int save_errno = errno;
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ConfigReloadPending = true;
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SetLatch(MyLatch);
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errno = save_errno;
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}
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/*
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* Simple signal handler for exiting quickly as if due to a crash.
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*
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* Normally, this would be used for handling SIGQUIT.
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*/
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void
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SignalHandlerForCrashExit(SIGNAL_ARGS)
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{
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/*
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* We DO NOT want to run proc_exit() or atexit() callbacks -- we're here
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* because shared memory may be corrupted, so we don't want to try to
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* clean up our transaction. Just nail the windows shut and get out of
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* town. The callbacks wouldn't be safe to run from a signal handler,
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* anyway.
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*
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* Note we do _exit(2) not _exit(0). This is to force the postmaster into
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* a system reset cycle if someone sends a manual SIGQUIT to a random
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* backend. This is necessary precisely because we don't clean up our
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* shared memory state. (The "dead man switch" mechanism in pmsignal.c
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* should ensure the postmaster sees this as a crash, too, but no harm in
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* being doubly sure.)
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*/
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_exit(2);
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}
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/*
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* Simple signal handler for triggering a long-running background process to
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* shut down and exit.
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*
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* Typically, this handler would be used for SIGTERM, but some processes use
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* other signals. In particular, the checkpointer exits on SIGUSR2, and the WAL
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* writer and the logical replication parallel apply worker exits on either
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* SIGINT or SIGTERM.
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*
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* ShutdownRequestPending should be checked at a convenient place within the
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* main loop, or else the main loop should call HandleMainLoopInterrupts.
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*/
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void
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SignalHandlerForShutdownRequest(SIGNAL_ARGS)
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{
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int save_errno = errno;
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ShutdownRequestPending = true;
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SetLatch(MyLatch);
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errno = save_errno;
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}
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