Date: Tue, 5 Jan 2010 02:37:59 +0000 (UTC) From: David Xu <davidxu@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src ObsoleteFiles.inc src/include Makefile semaphore.h src/lib/libc/gen Makefile.inc Symbol.map _pthread_stubs.c sem.c sem_new.c src/lib/libc/include libc_private.h src/lib/libthr pthread.map src/lib/libthr/thread Makefile.inc thr_init.c ... Message-ID: <201001050242.o052gdUV087927@repoman.freebsd.org>
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davidxu 2010-01-05 02:37:59 UTC
FreeBSD src repository
Modified files:
. ObsoleteFiles.inc
include Makefile
lib/libc/gen Makefile.inc Symbol.map _pthread_stubs.c
sem.c
lib/libc/include libc_private.h
lib/libthr pthread.map
lib/libthr/thread Makefile.inc thr_init.c thr_private.h
thr_sem.c
sys/kern uipc_sem.c
sys/sys _semaphore.h
Added files:
include semaphore.h
lib/libc/gen sem_new.c
lib/libthr/thread thr_sem_new.c
Removed files:
sys/sys semaphore.h
Log:
SVN rev 201546 on 2010-01-05 02:37:59Z by davidxu
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@
Revision Changes Path
1.218 +2 -0 src/ObsoleteFiles.inc
1.293 +2 -2 src/include/Makefile
1.1 +64 -0 src/include/semaphore.h (new)
1.150 +1 -1 src/lib/libc/gen/Makefile.inc
1.25 +31 -20 src/lib/libc/gen/Symbol.map
1.17 +4 -0 src/lib/libc/gen/_pthread_stubs.c
1.17 +174 -58 src/lib/libc/gen/sem.c
1.1 +470 -0 src/lib/libc/gen/sem_new.c (new)
1.23 +2 -0 src/lib/libc/include/libc_private.h
1.32 +7 -14 src/lib/libthr/pthread.map
1.19 +1 -0 src/lib/libthr/thread/Makefile.inc
1.52 +3 -1 src/lib/libthr/thread/thr_init.c
1.97 +17 -0 src/lib/libthr/thread/thr_private.h
1.16 +40 -216 src/lib/libthr/thread/thr_sem.c
1.1 +103 -0 src/lib/libthr/thread/thr_sem_new.c (new)
1.38 +0 -1 src/sys/kern/uipc_sem.c
1.7 +2 -19 src/sys/sys/_semaphore.h
1.14 +0 -69 src/sys/sys/semaphore.h (dead)
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