mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-09-13 20:19:44 +02:00
f06e79525a
Natoli and Bruce Momjian (and some cosmetic fixes from Neil Conway).
Changes:
- remove duplicate signal definitions from pqsignal.h
- replace pqkill() with kill() and redefine kill() in Win32
- use ereport() in place of fprintf() in some error handling in
pqsignal.c
- export pg_queue_signal() and make use of it where necessary
- add a console control handler for Ctrl-C and similar handling
on Win32
- do WaitForSingleObjectEx() in CHECK_FOR_INTERRUPTS() on Win32;
query cancelling should now work on Win32
- various other fixes and cleanups
86 lines
2.3 KiB
C
86 lines
2.3 KiB
C
/*-------------------------------------------------------------------------
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*
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* pmsignal.c
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* routines for signaling the postmaster from its child processes
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*
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*
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* Portions Copyright (c) 1996-2003, 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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* $PostgreSQL: pgsql/src/backend/storage/ipc/pmsignal.c,v 1.13 2004/02/08 22:28:56 neilc Exp $
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*
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*-------------------------------------------------------------------------
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*/
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#include "postgres.h"
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#include <signal.h>
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#include <unistd.h>
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#include "miscadmin.h"
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#include "storage/pmsignal.h"
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#include "storage/shmem.h"
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/*
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* The postmaster is signaled by its children by sending SIGUSR1. The
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* specific reason is communicated via flags in shared memory. We keep
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* a boolean flag for each possible "reason", so that different reasons
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* can be signaled by different backends at the same time. (However,
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* if the same reason is signaled more than once simultaneously, the
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* postmaster will observe it only once.)
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*
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* The flags are actually declared as "volatile sig_atomic_t" for maximum
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* portability. This should ensure that loads and stores of the flag
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* values are atomic, allowing us to dispense with any explicit locking.
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*/
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static volatile sig_atomic_t *PMSignalFlags;
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/*
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* PMSignalInit - initialize during shared-memory creation
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*/
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void
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PMSignalInit(void)
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{
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bool found;
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PMSignalFlags = (sig_atomic_t *)
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ShmemInitStruct("PMSignalFlags",NUM_PMSIGNALS * sizeof(sig_atomic_t),&found);
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if (!found)
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MemSet(PMSignalFlags, 0, NUM_PMSIGNALS * sizeof(sig_atomic_t));
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}
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/*
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* SendPostmasterSignal - signal the postmaster from a child process
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*/
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void
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SendPostmasterSignal(PMSignalReason reason)
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{
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/* If called in a standalone backend, do nothing */
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if (!IsUnderPostmaster)
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return;
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/* Atomically set the proper flag */
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PMSignalFlags[reason] = true;
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/* Send signal to postmaster */
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kill(PostmasterPid, SIGUSR1);
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}
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/*
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* CheckPostmasterSignal - check to see if a particular reason has been
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* signaled, and clear the signal flag. Should be called by postmaster
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* after receiving SIGUSR1.
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*/
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bool
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CheckPostmasterSignal(PMSignalReason reason)
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{
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/* Careful here --- don't clear flag if we haven't seen it set */
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if (PMSignalFlags[reason])
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{
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PMSignalFlags[reason] = false;
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return true;
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}
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return false;
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}
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