diff options
Diffstat (limited to 'libpthread/nptl/sysdeps/unix/sysv/linux/lowlevellock.c')
| -rw-r--r-- | libpthread/nptl/sysdeps/unix/sysv/linux/lowlevellock.c | 64 |
1 files changed, 29 insertions, 35 deletions
diff --git a/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevellock.c b/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevellock.c index f93891431..f459bcf6e 100644 --- a/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevellock.c +++ b/libpthread/nptl/sysdeps/unix/sysv/linux/lowlevellock.c @@ -1,5 +1,5 @@ /* low level locking for pthread library. Generic futex-using version. - Copyright (C) 2003 Free Software Foundation, Inc. + Copyright (C) 2003, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Paul Mackerras <paulus@au.ibm.com>, 2003. @@ -25,34 +25,46 @@ void -__lll_lock_wait (int *futex) +__lll_lock_wait_private (int *futex) { - do - { - int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1); - if (oldval != 0) - lll_futex_wait (futex, 2); - } - while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0); + if (*futex == 2) + lll_futex_wait (futex, 2, LLL_PRIVATE); + + while (atomic_exchange_acq (futex, 2) != 0) + lll_futex_wait (futex, 2, LLL_PRIVATE); +} + + +/* These functions don't get included in libc.so */ +#ifdef IS_IN_libpthread +void +__lll_lock_wait (int *futex, int private) +{ + if (*futex == 2) + lll_futex_wait (futex, 2, private); + + while (atomic_exchange_acq (futex, 2) != 0) + lll_futex_wait (futex, 2, private); } int -__lll_timedlock_wait (int *futex, const struct timespec *abstime) +__lll_timedlock_wait (int *futex, const struct timespec *abstime, int private) { /* Reject invalid timeouts. */ if (abstime->tv_nsec < 0 || abstime->tv_nsec >= 1000000000) return EINVAL; - do + /* Try locking. */ + while (atomic_exchange_acq (futex, 2) != 0) { struct timeval tv; - struct timespec rt; /* Get the current time. */ (void) gettimeofday (&tv, NULL); /* Compute relative timeout. */ + struct timespec rt; rt.tv_sec = abstime->tv_sec - tv.tv_sec; rt.tv_nsec = abstime->tv_nsec - tv.tv_usec * 1000; if (rt.tv_nsec < 0) @@ -61,30 +73,12 @@ __lll_timedlock_wait (int *futex, const struct timespec *abstime) --rt.tv_sec; } - /* Already timed out? */ if (rt.tv_sec < 0) return ETIMEDOUT; /* Wait. */ - int oldval = atomic_compare_and_exchange_val_acq (futex, 2, 1); - if (oldval != 0) - lll_futex_timed_wait (futex, 2, &rt); + lll_futex_timed_wait (futex, 2, &rt, private); } - while (atomic_compare_and_exchange_bool_acq (futex, 2, 0) != 0); - - return 0; -} - - -/* These don't get included in libc.so */ -#ifdef IS_IN_libpthread -int -lll_unlock_wake_cb (int *futex) -{ - int val = atomic_exchange_rel (futex, 0); - - if (__builtin_expect (val > 1, 0)) - lll_futex_wake (futex, 1); return 0; } @@ -105,7 +99,7 @@ __lll_timedwait_tid (int *tidp, const struct timespec *abstime) struct timespec rt; /* Get the current time. */ - (void) gettimeofday (&tv, NULL); + (void) __gettimeofday (&tv, NULL); /* Compute relative timeout. */ rt.tv_sec = abstime->tv_sec - tv.tv_sec; @@ -120,12 +114,12 @@ __lll_timedwait_tid (int *tidp, const struct timespec *abstime) if (rt.tv_sec < 0) return ETIMEDOUT; - /* Wait until thread terminates. */ - if (lll_futex_timed_wait (tidp, tid, &rt) == -ETIMEDOUT) + /* Wait until thread terminates. The kernel so far does not use + the private futex operations for this. */ + if (lll_futex_timed_wait (tidp, tid, &rt, LLL_SHARED) == -ETIMEDOUT) return ETIMEDOUT; } return 0; } - #endif |