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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:17:33 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 12:17:33 +0000 |
commit | 5e45211a64149b3c659b90ff2de6fa982a5a93ed (patch) | |
tree | 739caf8c461053357daa9f162bef34516c7bf452 /src/port/pgsleep.c | |
parent | Initial commit. (diff) | |
download | postgresql-15-5e45211a64149b3c659b90ff2de6fa982a5a93ed.tar.xz postgresql-15-5e45211a64149b3c659b90ff2de6fa982a5a93ed.zip |
Adding upstream version 15.5.upstream/15.5
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/port/pgsleep.c')
-rw-r--r-- | src/port/pgsleep.c | 63 |
1 files changed, 63 insertions, 0 deletions
diff --git a/src/port/pgsleep.c b/src/port/pgsleep.c new file mode 100644 index 0000000..a84e6cc --- /dev/null +++ b/src/port/pgsleep.c @@ -0,0 +1,63 @@ +/*------------------------------------------------------------------------- + * + * pgsleep.c + * Portable delay handling. + * + * + * Portions Copyright (c) 1996-2022, PostgreSQL Global Development Group + * + * src/port/pgsleep.c + * + *------------------------------------------------------------------------- + */ +#include "c.h" + +#include <unistd.h> +#include <sys/time.h> +#ifdef HAVE_SYS_SELECT_H +#include <sys/select.h> +#endif + +/* + * In a Windows backend, we don't use this implementation, but rather + * the signal-aware version in src/backend/port/win32/signal.c. + */ +#if defined(FRONTEND) || !defined(WIN32) + +/* + * pg_usleep --- delay the specified number of microseconds. + * + * NOTE: although the delay is specified in microseconds, the effective + * resolution is only 1/HZ, or 10 milliseconds, on most Unixen. Expect + * the requested delay to be rounded up to the next resolution boundary. + * + * On machines where "long" is 32 bits, the maximum delay is ~2000 seconds. + * + * CAUTION: the behavior when a signal arrives during the sleep is platform + * dependent. On most Unix-ish platforms, a signal does not terminate the + * sleep; but on some, it will (the Windows implementation also allows signals + * to terminate pg_usleep). And there are platforms where not only does a + * signal not terminate the sleep, but it actually resets the timeout counter + * so that the sleep effectively starts over! It is therefore rather hazardous + * to use this for long sleeps; a continuing stream of signal events could + * prevent the sleep from ever terminating. Better practice for long sleeps + * is to use WaitLatch() with a timeout. + */ +void +pg_usleep(long microsec) +{ + if (microsec > 0) + { +#ifndef WIN32 + struct timeval delay; + + delay.tv_sec = microsec / 1000000L; + delay.tv_usec = microsec % 1000000L; + (void) select(0, NULL, NULL, NULL, &delay); +#else + SleepEx((microsec < 500 ? 1 : (microsec + 500) / 1000), FALSE); +#endif + } +} + +#endif /* defined(FRONTEND) || !defined(WIN32) */ |