Date: Wed, 16 Jun 2010 09:16:36 -0300 From: Renato Botelho <rbgarga@gmail.com> To: David Xu <davidxu@freebsd.org> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r201546 - in head: . include lib/libc/gen lib/libc/include lib/libthr lib/libthr/thread sys/kern sys/sys Message-ID: <AANLkTikDxeZcZEc8t1dZvvkToUrK1v_Gfm5F9L9oX3Gr@mail.gmail.com> In-Reply-To: <201001050237.o052bxEd061444@svn.freebsd.org> References: <201001050237.o052bxEd061444@svn.freebsd.org>
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On Mon, Jan 4, 2010 at 11:37 PM, David Xu <davidxu@freebsd.org> wrote: > Author: davidxu > Date: Tue Jan 5 02:37:59 2010 > New Revision: 201546 > URL: http://svn.freebsd.org/changeset/base/201546 > > Log: > Use umtx to implement process sharable semaphore, to make this work, > now type sema_t is a structure which can be put in a shared memory area, > and multiple processes can operate it concurrently. > User can either use mmap(MAP_SHARED) + sem_init(pshared=1) or use sem_open() > to initialize a shared semaphore. > Named semaphore uses file system and is located in /tmp directory, and its > file name is prefixed with 'SEMD', so now it is chroot or jail friendly. > In simplist cases, both for named and un-named semaphore, userland code > does not have to enter kernel to reduce/increase semaphore's count. > The semaphore is designed to be crash-safe, it means even if an application > is crashed in the middle of operating semaphore, the semaphore state is > still safely recovered by later use, there is no waiter counter maintained > by userland code. > The main semaphore code is in libc and libthr only has some necessary stubs, > this makes it possible that a non-threaded application can use semaphore > without linking to thread library. > Old semaphore implementation is kept libc to maintain binary compatibility. > The kernel ksem API is no longer used in the new implemenation. > > Discussed on: threads@ > > Added: > head/include/semaphore.h (contents, props changed) > head/lib/libc/gen/sem_new.c (contents, props changed) > head/lib/libthr/thread/thr_sem_new.c (contents, props changed) > Deleted: > head/sys/sys/semaphore.h > Modified: > head/ObsoleteFiles.inc > head/include/Makefile > head/lib/libc/gen/Makefile.inc > head/lib/libc/gen/Symbol.map > head/lib/libc/gen/_pthread_stubs.c > head/lib/libc/gen/sem.c > head/lib/libc/include/libc_private.h > head/lib/libthr/pthread.map > head/lib/libthr/thread/Makefile.inc > head/lib/libthr/thread/thr_init.c > head/lib/libthr/thread/thr_private.h > head/lib/libthr/thread/thr_sem.c > head/sys/kern/uipc_sem.c > head/sys/sys/_semaphore.h > > Modified: head/ObsoleteFiles.inc > ============================================================================== > --- head/ObsoleteFiles.inc Tue Jan 5 02:06:05 2010 (r201545) > +++ head/ObsoleteFiles.inc Tue Jan 5 02:37:59 2010 (r201546) > @@ -14,6 +14,8 @@ > # The file is partitioned: OLD_FILES first, then OLD_LIBS and OLD_DIRS last. > # > > +# 20100105: new userland semaphore implementation > +OLD_FILES+=usr/include/sys/semaphore.h Everythime I update my -CURRENT this file is installed again, and is listed when i run make check-old, I think there is something wrong. -- Renato Botelho
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