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Fix uniqid() performances #18232

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Fix uniqid() performances #18232

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7cdadcd
On some systems, uniqid() is critically slow.
manu0401 Apr 3, 2025
1877950
Use #ifdef HAVE_UUIDGEN and not #ifdef __NetBSD__ I once used
manu0401 Apr 3, 2025
8e15cf4
Remove an early test that I should have removed earlier.
manu0401 Apr 3, 2025
81adbda
Also remove now unused variable
manu0401 Apr 3, 2025
eb40c48
Avoid using the lower bytes of UUID since it may contain the host MAC
manu0401 Apr 3, 2025
5471a5a
Another attempt to addresse the performance when the system clock
manu0401 Apr 6, 2025
f03c2bc
< instead of <= qo that second member can be used
manu0401 Apr 7, 2025
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21 changes: 15 additions & 6 deletions ext/standard/uniqid.c
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Original file line number Diff line number Diff line change
Expand Up @@ -54,13 +54,22 @@ PHP_FUNCTION(uniqid)
ZEND_PARSE_PARAMETERS_END();

/* This implementation needs current microsecond to change,
* hence we poll time until it does. This is much faster than
* calling usleep(1) which may cause the kernel to schedule
* another process, causing a pause of around 10ms.
* If system clock lags and report the same time again,
* we just return the previous value +1us.
* This is much faster than calling usleep(1) which may
* cause the kernel to schedule another process, causing
* a pause of around 10ms.
*/
do {
(void)gettimeofday((struct timeval *) &tv, (struct timezone *) NULL);
} while (tv.tv_sec == prev_tv.tv_sec && tv.tv_usec == prev_tv.tv_usec);
(void)gettimeofday((struct timeval *) &tv, (struct timezone *) NULL);
if (tv.tv_sec < prev_tv.tv_sec ||
(tv.tv_sec == prev_tv.tv_sec && tv.tv_usec <= prev_tv.tv_usec)) {
tv.tv_sec = prev_tv.tv_sec;
tv.tv_usec = prev_tv.tv_usec + 1;
if (tv.tv_usec >= 1000000) {
tv.tv_sec++;
tv.tv_usec -= 1000000;
}
}

prev_tv.tv_sec = tv.tv_sec;
prev_tv.tv_usec = tv.tv_usec;
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