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a4c40f140d
It works on the principle of turning sockets into non-blocking, and then emulate blocking behaviour on top of that, while allowing signals to run. Signals are now implemented using an event instead of APCs, thus getting rid of the issue of APCs not being compatible with "old style" sockets functions. It also moves the win32 specific code away from pqsignal.h/c into port/win32, and also removes the "thread style workaround" of the APC issue previously in place. In order to make things work, a few things are also changed in pgstat.c: 1) There is now a separate pipe to the collector and the bufferer. This is required because the pipe will otherwise only be signalled in one of the processes when the postmaster goes down. The MS winsock code for select() must have some kind of workaround for this behaviour, but I have found no stable way of doing that. You really are not supposed to use the same socket from more than one process (unless you use WSADuplicateSocket(), in which case the docs specifically say that only one will be flagged). 2) The check for "postmaster death" is moved into a separate select() call after the main loop. The previous behaviour select():ed on the postmaster pipe, while later explicitly saying "we do NOT check for postmaster exit inside the loop". The issue was that the code relies on the same select() call seeing both the postmaster pipe *and* the pgstat pipe go away. This does not always happen, and it appears that useing WSAEventSelect() makes it even more common that it does not. Since it's only called when the process exits, I don't think using a separate select() call will have any significant impact on how the stats collector works. Magnus Hagander
46 lines
1.1 KiB
C
46 lines
1.1 KiB
C
/*-------------------------------------------------------------------------
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*
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* pgsleep.c
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* Portable delay handling.
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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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*
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* $PostgreSQL: pgsql/src/port/pgsleep.c,v 1.3 2004/04/12 16:19:18 momjian 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 <unistd.h>
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#include <sys/time.h>
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/*
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* pg_usleep --- delay the specified number of microseconds.
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*
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* NOTE: although the delay is specified in microseconds, the effective
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* resolution is only 1/HZ, or 10 milliseconds, on most Unixen. Expect
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* the requested delay to be rounded up to the next resolution boundary.
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*
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* On machines where "long" is 32 bits, the maximum delay is ~2000 seconds.
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*/
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#ifdef pg_usleep
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#undef pg_usleep
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#endif
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void
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pg_usleep(long microsec)
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{
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if (microsec > 0)
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{
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#ifndef WIN32
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struct timeval delay;
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delay.tv_sec = microsec / 1000000L;
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delay.tv_usec = microsec % 1000000L;
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(void) select(0, NULL, NULL, NULL, &delay);
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#else
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SleepEx((microsec < 500 ? 1 : (microsec + 500) / 1000), FALSE);
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#endif
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}
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}
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