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| author | Rich Felker <dalias@aerifal.cx> | 2011-03-28 22:36:55 -0400 |
|---|---|---|
| committer | Rich Felker <dalias@aerifal.cx> | 2011-03-28 22:36:55 -0400 |
| commit | 4106cdcd2de34bf3b9839e042344d92eae887ecb (patch) | |
| tree | 9d14a51c59eb318024aa0edf2a1c19ffa0ed6583 | |
| parent | 4cc78719dd22a685ddd89b92ac3bfc308c4c19b3 (diff) | |
| download | musl-4106cdcd2de34bf3b9839e042344d92eae887ecb.tar.gz musl-4106cdcd2de34bf3b9839e042344d92eae887ecb.tar.xz musl-4106cdcd2de34bf3b9839e042344d92eae887ecb.zip | |
revert some more spin optimizations that turned out to be pessimizations
| -rw-r--r-- | src/stdio/__lockfile.c | 2 | ||||
| -rw-r--r-- | src/thread/pthread_spin_lock.c | 2 | ||||
| -rw-r--r-- | src/thread/pthread_spin_trylock.c | 3 |
3 files changed, 3 insertions, 4 deletions
diff --git a/src/stdio/__lockfile.c b/src/stdio/__lockfile.c index 93c94867..c0948255 100644 --- a/src/stdio/__lockfile.c +++ b/src/stdio/__lockfile.c @@ -13,7 +13,7 @@ void __lockfile(FILE *f) f->lockcount++; return; } - while (f->lock || a_cas(&f->lock, 0, tid)) + while (a_cas(&f->lock, 0, tid)) if (spins) spins--, a_spin(); else syscall(SYS_sched_yield); f->lockcount = 1; diff --git a/src/thread/pthread_spin_lock.c b/src/thread/pthread_spin_lock.c index 59fa6ea8..0ab3d64f 100644 --- a/src/thread/pthread_spin_lock.c +++ b/src/thread/pthread_spin_lock.c @@ -2,6 +2,6 @@ int pthread_spin_lock(pthread_spinlock_t *s) { - while (a_xchg(s, 1)); + while (a_xchg(s, 1)) a_spin(); return 0; } diff --git a/src/thread/pthread_spin_trylock.c b/src/thread/pthread_spin_trylock.c index 1fc5f73c..c12696b3 100644 --- a/src/thread/pthread_spin_trylock.c +++ b/src/thread/pthread_spin_trylock.c @@ -2,6 +2,5 @@ int pthread_spin_trylock(pthread_spinlock_t *s) { - if (*s || a_xchg(s, 1)) return EBUSY; - return 0; + return -a_xchg(s, 1) & EBUSY; } |