Req #65626 [Nab]: uniqid(null, false) should guarantee unique identifier

Edit report at https://bugs.php.net/bug.php?id=65626&edit=1 ID: 65626 Updated by: yohgaki@php.net Reported by: cmbecker69 at gmx dot de Summary: uniqid(null, false) should guarantee unique identifier Status: Not a bug Type: Feature/Change Request Package: Unknown/Other Function Operating System: WIN32 PHP Version: 5.4.19 Block user comment: N Private report: N New Comment: It seems uniqid() has protection under UNIXes. #if HAVE_USLEEP && !defined(PHP_WIN32) if (!more_entropy) { #if defined(__CYGWIN__) php_error_docref(NULL TSRMLS_CC, E_WARNING, "You must use 'more entropy' under CYGWIN"); RETURN_FALSE; #else usleep(1); #endif } #endif Why is this disabled for windows? Previous Comments: ------------------------------------------------------------------------ [2014-02-08 20:30:04] ab@php.net I think helly's comment is pretty much matching. Also, an integral part of that function relies on the microtime API, but those implementation is platform dependent. For instance, on win8 a snippet "while(uniqid(null, false) != uniqid(null, false));" loops forever with 5.4 even if it doesn't have to. Otherwise you can use usleep() in userspace to ensure some better result. ------------------------------------------------------------------------ [2013-09-05 22:46:43] cmbecker69 at gmx dot de Description: ------------ From looking at the sources[1], it occurs to me that uniqid(null, false) doesn't *guarantee* to return a unique identifier on WIN32, because usleep(3) is skipped. As usleep() is implemented as PHP userland function since PHP 5.0.0[2], it seems to be reasonable and possible to add the equivalent to usleep(3) there. As far as I can tell, this won't introduce any BC issues, so the change might be done for PHP 5.4.x. Please note that this is related to #37106[3], but helly's comment doesn't seem to fit to the current sources. [1] <http://lxr.php.net/xref/PHP_5_4/ext/standard/uniqid.c#61> [2] <http://lxr.php.net/xref/PHP_5_4/win32/time.c#96> [3] <https://bugs.php.net/bug.php?id=37106> Test script: --------------- var_dump(uniqid(null, false) != uniqid(null, false)); Expected result: ---------------- bool(true) Actual result: -------------- bool(false) // at least sometimes on a fast machine ;) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=65626&edit=1