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| author | Rich Felker <dalias@aerifal.cx> | 2011-09-25 02:38:03 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-09-25 02:38:03 -0400 |
| commit | cba4e1c0a3423ed07ef5c79f6e29360996f32fd7 (patch) | |
| tree | b0b71361525510d796f448dd506d8f8f6140ca41 /src/thread/pthread_cond_init.c | |
| parent | 97c5b5a87c3d9df54278e1073d6177f77536bd32 (diff) | |
| download | musl-cba4e1c0a3423ed07ef5c79f6e29360996f32fd7.tar.gz musl-cba4e1c0a3423ed07ef5c79f6e29360996f32fd7.tar.bz2 musl-cba4e1c0a3423ed07ef5c79f6e29360996f32fd7.tar.xz musl-cba4e1c0a3423ed07ef5c79f6e29360996f32fd7.zip | |
new futex-requeue-based pthread_cond_broadcast implementation
this avoids the "stampede effect" where pthread_cond_broadcast would
result in all waiters waking up simultaneously, only to immediately
contend for the mutex and go back to sleep.
Diffstat (limited to 'src/thread/pthread_cond_init.c')
| -rw-r--r-- | src/thread/pthread_cond_init.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/thread/pthread_cond_init.c b/src/thread/pthread_cond_init.c index dc4fb981..03aff768 100644 --- a/src/thread/pthread_cond_init.c +++ b/src/thread/pthread_cond_init.c @@ -3,6 +3,9 @@ int pthread_cond_init(pthread_cond_t *c, const pthread_condattr_t *a) { memset(c, 0, sizeof *c); - if (a) c->_c_clock = *a & 0x7fffffff; + if (a) { + c->_c_clock = *a & 0x7fffffff; + if (*a>>31) c->_c_mutex = (void *)-1; + } return 0; } |