diff options
Diffstat (limited to 'sysdeps')
| -rw-r--r-- | sysdeps/nptl/futex-internal.h | 9 | ||||
| -rw-r--r-- | sysdeps/nptl/lowlevellock-futex.h | 13 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/futex-internal.h | 24 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/lowlevellock-futex.h | 32 |
4 files changed, 61 insertions, 17 deletions
diff --git a/sysdeps/nptl/futex-internal.h b/sysdeps/nptl/futex-internal.h index 86a0818072..f29d6d48b2 100644 --- a/sysdeps/nptl/futex-internal.h +++ b/sysdeps/nptl/futex-internal.h @@ -49,7 +49,7 @@ 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). @@ -159,16 +159,23 @@ futex_reltimed_wait_cancelable (unsigned int* futex_word, 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 diff --git a/sysdeps/nptl/lowlevellock-futex.h b/sysdeps/nptl/lowlevellock-futex.h index 63d917d8da..53fd53d1d4 100644 --- a/sysdeps/nptl/lowlevellock-futex.h +++ b/sysdeps/nptl/lowlevellock-futex.h @@ -43,10 +43,15 @@ #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. */ diff --git a/sysdeps/unix/sysv/linux/futex-internal.h b/sysdeps/unix/sysv/linux/futex-internal.h index 501f993853..299d2489f9 100644 --- a/sysdeps/unix/sysv/linux/futex-internal.h +++ b/sysdeps/unix/sysv/linux/futex-internal.h @@ -162,15 +162,24 @@ futex_reltimed_wait_cancelable (unsigned int *futex_word, /* 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: @@ -180,8 +189,9 @@ futex_abstimed_wait (unsigned int *futex_word, unsigned int expected, 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. */ @@ -194,6 +204,7 @@ futex_abstimed_wait (unsigned int *futex_word, unsigned int expected, 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 @@ -202,8 +213,9 @@ futex_abstimed_wait_cancelable (unsigned int *futex_word, 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) { diff --git a/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/lowlevellock-futex.h index 030a14b8dc..cfa796be2b 100644 --- a/sysdeps/unix/sysv/linux/lowlevellock-futex.h +++ b/sysdeps/unix/sysv/linux/lowlevellock-futex.h @@ -82,12 +82,32 @@ __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, \ |