From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon-590EEB7GvNiWaY/ihj7yzEB+6BGkLq7r@public.gmane.org Subject: [Bug 40852] select(2): document action of close()'ing a fd during a select() Date: Fri, 17 Aug 2012 06:30:36 +0000 (UTC) Message-ID: <20120817063036.DB76211FC6B@bugzilla.kernel.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-man@vger.kernel.org https://bugzilla.kernel.org/show_bug.cgi?id=40852 --- Comment #2 from Michael Kerrisk 2012-08-17 06:30:36 --- I added some text under NOTES in select(2). --- a/man2/select.2 +++ b/man2/select.2 @@ -411,6 +411,22 @@ when .B _GNU_SOURCE is defined. Since glibc 2.2.2 the requirements are as shown in the SYNOPSIS. +.SS Multithreaded applications +If a file descriptor being monitored by +.BR select () +is closed in another thread, the result is unspecified. +On some UNIX systems, +.BR select () +unblocks and returns, with an indication that the file descriptor is ready +(a subsequent I/O operation will likely fail with an error, +unless another the file descriptor reopened between the time +.BR select () +returned and the I/O operations was performed). +On Linux (and some other systems), +closing the file descriptor in another thread has no effect on +.BR select (). +In summary, any application that relies on a particular behavior +in this scenario must be considered buggy. .SS "Linux Notes" The .BR pselect () -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html