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From: "sstewartgallus00 at mylangara dot bc.ca" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sourceware.org Subject: [Bug libc/17168] New: Can GLibc expose futex now? Date: Thu, 17 Jul 2014 04:44:00 -0000 [thread overview] Message-ID: <bug-17168-131@http.sourceware.org/bugzilla/> (raw) https://sourceware.org/bugzilla/show_bug.cgi?id=17168 Bug ID: 17168 Summary: Can GLibc expose futex now? Product: glibc Version: unspecified Status: NEW Severity: enhancement Priority: P2 Component: libc Assignee: unassigned at sourceware dot org Reporter: sstewartgallus00 at mylangara dot bc.ca CC: drepper.fsp at gmail dot com Most application writers should use standard pthread synchronization functionality and not use low level functionality instead. However, certain performance concerned programmers might want to use futexes directly. Unfortunately, as FUTEX_WAIT is a blocking system call this leaves a critical piece of functionality unimplemented and missing. In the past, one could have used FUTEX_FD to wait on memory locations to change asynchronously (although it would have been racy). However, FUTEX_FD is not supported anymore on Linux (as it is racy). Now, the only choice to use FUTEX_WAIT asynchronously is to use multiple threads and cancel the thread waiting on the memory location to change. Except one can't as futex is not exposed by GLibc and I do not want to try reimplementing pthread_cancel myself which might be seriously difficult. Taking the five seconds to wrap the futex calls with the syscall function is not a problem but I can't use futex asynchronously without support from GLibc. -- You are receiving this mail because: You are on the CC list for the bug.
next reply other threads:[~2014-07-17 4:44 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-07-17 4:44 sstewartgallus00 at mylangara dot bc.ca [this message] 2014-07-17 4:57 ` [Bug libc/17168] " sstewartgallus00 at mylangara dot bc.ca 2014-07-19 1:10 ` sstewartgallus00 at mylangara dot bc.ca 2014-07-19 18:34 ` sstewartgallus00 at mylangara dot bc.ca 2014-07-19 18:55 ` bugdal at aerifal dot cx
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