+2019-07-12 Mike Crowe <mac@mcrowe.com>
+
+ nptl: Add clockid parameter to futex timed wait calls
+ * sysdeps/nptl/lowlevellock-futex.h,
+ sysdeps/unix/sysv/linux/lowlevellock-futex.h: Replace
+ lll_futex_timed_wait_bitset with lll_futex_clock_wait_bitset that
+ takes a clockid rather than a special clockbit.
+ * sysdeps/nptl/lowlevellock-futex.h: Add
+ lll_futex_supported_clockid so that client functions can check
+ whether their clockid parameter is valid even if they don't
+ ultimately end up calling lll_futex_clock_wait_bitset.
+ * sysdeps/nptl/futex-internal.h,
+ sysdeps/unix/sysv/linux/futex-internal.h
+ (futex_abstimed_wait, futex_abstimed_wait_cancelable): Add
+ clockid_t parameter to indicate which clock the absolute time
+ passed should be measured against. Pass that clockid onto
+ lll_futex_clock_wait_bitset. Add invalid clock as reason for
+ returning -EINVAL.
+ * sysdeps/nptl/futex-internal.h,
+ sysdeps/unix/sysv/linux/futex-internal.h: Introduce
+ futex_abstimed_supported_clockid so that client functions can check
+ whether their clockid parameter is valid even if they don't
+ ultimately end up calling futex_abstimed_wait.
+ * nptl/pthread_cond_wait.c (__pthread_cond_wait_common): Remove
+ code to calculate relative timeout for
+ __PTHREAD_COND_CLOCK_MONOTONIC_MASK and just pass CLOCK_MONOTONIC
+ or CLOCK_REALTIME as required to futex_abstimed_wait_cancelable.
+ * nptl/pthread_rwlock_common (__pthread_rwlock_rdlock_full)
+ (__pthread_wrlock_full), nptl/sem_waitcommon (do_futex_wait): Pass
+ additional CLOCK_REALTIME to futex_abstimed_wait_cancelable.
+ * nptl/pthread_mutex_timedlock.c (__pthread_mutex_timedlock):
+ Switch to lll_futex_clock_wait_bitset and pass CLOCK_REALTIME
+
2019-07-10 Adhemerval Zanella <adhemerval.zanella@linaro.org>
[BZ #24699]
values despite them being valid. */
if (__glibc_unlikely (abstime->tv_sec < 0))
err = ETIMEDOUT;
-
- else if ((flags & __PTHREAD_COND_CLOCK_MONOTONIC_MASK) != 0)
- {
- /* CLOCK_MONOTONIC is requested. */
- struct timespec rt;
- if (__clock_gettime (CLOCK_MONOTONIC, &rt) != 0)
- __libc_fatal ("clock_gettime does not support "
- "CLOCK_MONOTONIC\n");
- /* Convert the absolute timeout value to a relative
- timeout. */
- rt.tv_sec = abstime->tv_sec - rt.tv_sec;
- rt.tv_nsec = abstime->tv_nsec - rt.tv_nsec;
- if (rt.tv_nsec < 0)
- {
- rt.tv_nsec += 1000000000;
- --rt.tv_sec;
- }
- /* Did we already time out? */
- if (__glibc_unlikely (rt.tv_sec < 0))
- err = ETIMEDOUT;
- else
- err = futex_reltimed_wait_cancelable
- (cond->__data.__g_signals + g, 0, &rt, private);
- }
else
{
- /* Use CLOCK_REALTIME. */
+ const clockid_t clockid =
+ ((flags & __PTHREAD_COND_CLOCK_MONOTONIC_MASK) != 0) ?
+ CLOCK_MONOTONIC : CLOCK_REALTIME;
+
err = futex_abstimed_wait_cancelable
- (cond->__data.__g_signals + g, 0, abstime, private);
+ (cond->__data.__g_signals + g, 0, clockid, abstime,
+ private);
}
}
assume_other_futex_waiters |= FUTEX_WAITERS;
/* Block using the futex. */
- int err = lll_futex_timed_wait_bitset (&mutex->__data.__lock,
- oldval, abstime, FUTEX_CLOCK_REALTIME,
+ int err = lll_futex_clock_wait_bitset (&mutex->__data.__lock,
+ oldval, CLOCK_REALTIME, abstime,
PTHREAD_ROBUST_MUTEX_PSHARED (mutex));
/* The futex call timed out. */
if (err == -ETIMEDOUT)
{
int private = __pthread_rwlock_get_private (rwlock);
int err = futex_abstimed_wait (&rwlock->__data.__readers,
- r, abstime, private);
+ r, CLOCK_REALTIME, abstime, private);
/* We ignore EAGAIN and EINTR. On time-outs, we can just
return because we don't need to clean up anything. */
if (err == ETIMEDOUT)
continue;
int err = futex_abstimed_wait (&rwlock->__data.__wrphase_futex,
1 | PTHREAD_RWLOCK_FUTEX_USED,
- abstime, private);
+ CLOCK_REALTIME, abstime, private);
if (err == ETIMEDOUT)
{
/* If we timed out, we need to unregister. If no read phase
may_share_futex_used_flag = true;
int err = futex_abstimed_wait (&rwlock->__data.__writers_futex,
1 | PTHREAD_RWLOCK_FUTEX_USED,
- abstime, private);
+ CLOCK_REALTIME, abstime, private);
if (err == ETIMEDOUT)
{
if (prefer_writer)
continue;
int err = futex_abstimed_wait (&rwlock->__data.__wrphase_futex,
PTHREAD_RWLOCK_FUTEX_USED,
- abstime, private);
+ CLOCK_REALTIME, abstime, private);
if (err == ETIMEDOUT)
{
if (rwlock->__data.__flags != PTHREAD_RWLOCK_PREFER_READER_NP)
#if __HAVE_64B_ATOMICS
err = futex_abstimed_wait_cancelable (
- (unsigned int *) &sem->data + SEM_VALUE_OFFSET, 0, abstime,
+ (unsigned int *) &sem->data + SEM_VALUE_OFFSET, 0,
+ CLOCK_REALTIME, abstime,
sem->private);
#else
err = futex_abstimed_wait_cancelable (&sem->value, SEM_NWAITERS_MASK,
- abstime, sem->private);
+ CLOCK_REALTIME, abstime,
+ sem->private);
#endif
return err;
futex word.
Both absolute and relative timeouts can be used. An absolute timeout
- expires when the given specific point in time on the CLOCK_REALTIME clock
+ expires when the given specific point in time on the specified clock
passes, or when it already has passed. A relative timeout expires when
the given duration of time on the CLOCK_MONOTONIC clock passes. Relative
timeouts may be imprecise (see futex_supports_exact_relative_timeouts).
unsigned int expected,
const struct timespec* reltime, int private);
+/* Check whether the specified clockid is supported by
+ futex_abstimed_wait and futex_abstimed_wait_cancelable. */
+static __always_inline int
+futex_abstimed_supported_clockid (clockid_t clockid);
+
/* Like futex_reltimed_wait, but the provided timeout (ABSTIME) is an
absolute point in time; a call will time out after this point in time. */
static __always_inline int
futex_abstimed_wait (unsigned int* futex_word, unsigned int expected,
+ clockid_t clockid,
const struct timespec* abstime, int private);
/* Like futex_reltimed_wait but is a POSIX cancellation point. */
static __always_inline int
futex_abstimed_wait_cancelable (unsigned int* futex_word,
unsigned int expected,
+ clockid_t clockid,
const struct timespec* abstime, int private);
/* Atomically wrt other futex operations on the same futex, this unblocks the
#define lll_futex_timed_wait(futexp, val, timeout, private) \
-ENOSYS
-/* If CLOCKBIT is zero, this is identical to lll_futex_timed_wait.
- If CLOCKBIT has FUTEX_CLOCK_REALTIME set, then it's the same but
- TIMEOUT is counted by CLOCK_REALTIME rather than CLOCK_MONOTONIC. */
-#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \
+/* Verify whether the supplied clockid is supported by
+ lll_futex_clock_wait_bitset. */
+#define lll_futex_supported_clockid(clockid) \
+ (0)
+
+/* Wait until a lll_futex_wake call on FUTEXP, or the absolute TIMEOUT
+ measured against CLOCKID elapses. CLOCKID may be CLOCK_REALTIME or
+ CLOCK_MONOTONIC. */
+#define lll_futex_clock_wait_bitset(futexp, val, clockid, timeout, private) \
-ENOSYS
/* Wake up up to NR waiters on FUTEXP. */
/* See sysdeps/nptl/futex-internal.h for details. */
static __always_inline int
+futex_abstimed_supported_clockid (clockid_t clockid)
+{
+ return lll_futex_supported_clockid (clockid);
+}
+
+/* See sysdeps/nptl/futex-internal.h for details. */
+static __always_inline int
futex_abstimed_wait (unsigned int *futex_word, unsigned int expected,
+ clockid_t clockid,
const struct timespec *abstime, int private)
{
/* Work around the fact that the kernel rejects negative timeout values
despite them being valid. */
if (__glibc_unlikely ((abstime != NULL) && (abstime->tv_sec < 0)))
return ETIMEDOUT;
- int err = lll_futex_timed_wait_bitset (futex_word, expected, abstime,
- FUTEX_CLOCK_REALTIME, private);
+ int err = lll_futex_clock_wait_bitset (futex_word, expected,
+ clockid, abstime,
+ private);
switch (err)
{
case 0:
return -err;
case -EFAULT: /* Must have been caused by a glibc or application bug. */
- case -EINVAL: /* Either due to wrong alignment or due to the timeout not
- being normalized. Must have been caused by a glibc or
+ case -EINVAL: /* Either due to wrong alignment, unsupported
+ clockid or due to the timeout not being
+ normalized. Must have been caused by a glibc or
application bug. */
case -ENOSYS: /* Must have been caused by a glibc bug. */
/* No other errors are documented at this time. */
static __always_inline int
futex_abstimed_wait_cancelable (unsigned int *futex_word,
unsigned int expected,
+ clockid_t clockid,
const struct timespec *abstime, int private)
{
/* Work around the fact that the kernel rejects negative timeout values
return ETIMEDOUT;
int oldtype;
oldtype = __pthread_enable_asynccancel ();
- int err = lll_futex_timed_wait_bitset (futex_word, expected, abstime,
- FUTEX_CLOCK_REALTIME, private);
+ int err = lll_futex_clock_wait_bitset (futex_word, expected,
+ clockid, abstime,
+ private);
__pthread_disable_asynccancel (oldtype);
switch (err)
{
__lll_private_flag (FUTEX_WAIT, private), \
val, timeout)
-#define lll_futex_timed_wait_bitset(futexp, val, timeout, clockbit, private) \
- lll_futex_syscall (6, futexp, \
- __lll_private_flag (FUTEX_WAIT_BITSET | (clockbit), \
- private), \
- val, timeout, NULL /* Unused. */, \
- FUTEX_BITSET_MATCH_ANY)
+/* Verify whether the supplied clockid is supported by
+ lll_futex_clock_wait_bitset. */
+#define lll_futex_supported_clockid(clockid) \
+ ((clockid) == CLOCK_REALTIME || (clockid) == CLOCK_MONOTONIC)
+
+/* The kernel currently only supports CLOCK_MONOTONIC or
+ CLOCK_REALTIME timeouts for FUTEX_WAIT_BITSET. We could attempt to
+ convert others here but currently do not. */
+#define lll_futex_clock_wait_bitset(futexp, val, clockid, timeout, private) \
+ ({ \
+ long int __ret; \
+ if (lll_futex_supported_clockid (clockid)) \
+ { \
+ const unsigned int clockbit = \
+ (clockid == CLOCK_REALTIME) ? FUTEX_CLOCK_REALTIME : 0; \
+ const int op = \
+ __lll_private_flag (FUTEX_WAIT_BITSET | clockbit, private); \
+ \
+ __ret = lll_futex_syscall (6, futexp, op, val, \
+ timeout, NULL /* Unused. */, \
+ FUTEX_BITSET_MATCH_ANY); \
+ } \
+ else \
+ __ret = -EINVAL; \
+ __ret; \
+ })
#define lll_futex_wake(futexp, nr, private) \
lll_futex_syscall (4, futexp, \
projects / external / glibc.git / commitdiff