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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-10-30 15:56:39 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-10-31 11:09:01 -0300 |
| commit | 215078017fd25fd64074e25ccd3dde0f6f19d4fe (patch) | |
| tree | c5145504191cfb0aa808ae9b286e6da91882a7af /sysdeps/nptl | |
| parent | b58032743415575661dddd4e813440b6b9430327 (diff) | |
| download | glibc-215078017fd25fd64074e25ccd3dde0f6f19d4fe.tar.gz | |
nptl: Replace non cancellable pause/nanosleep with futex
To help y2038 work avoid duplicate all the logic of nanosleep on
non cancellable version, the patch replace it with a new futex
operation, lll_timedwait. The changes are:
- Add a expected value for __lll_clocklock_wait, so it can be used
to wait for generic values.
- Remove its internal atomic operation and move the logic to
__lll_clocklock. It makes __lll_clocklock_wait even more generic
and __lll_clocklock slight faster on fast-path (since it won't
require a function call anymore).
- Add lll_timedwait, which uses __lll_clocklock_wait, to replace both
__pause_nocancel and __nanosleep_nocancel.
It also allows remove the sparc32 __lll_clocklock_wait implementation
(since it is similar to the generic one).
Checked on x86_64-linux-gnu, sparcv9-linux-gnu, and i686-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Diffstat (limited to 'sysdeps/nptl')
| -rw-r--r-- | sysdeps/nptl/lowlevellock.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h index e3f006537a..92298f3b7e 100644 --- a/sysdeps/nptl/lowlevellock.h +++ b/sysdeps/nptl/lowlevellock.h @@ -21,6 +21,7 @@ #include <atomic.h> #include <lowlevellock-futex.h> +#include <time.h> /* Low-level locks use a combination of atomic operations (to acquire and release lock ownership) and futex operations (to block until the state @@ -121,10 +122,12 @@ extern void __lll_lock_wait (int *futex, int private) attribute_hidden; #define lll_cond_lock(futex, private) __lll_cond_lock (&(futex), private) -extern int __lll_clocklock_wait (int *futex, clockid_t, +extern int __lll_clocklock_wait (int *futex, int val, clockid_t, const struct timespec *, int private) attribute_hidden; +#define lll_timedwait(futex, val, clockid, abstime, private) \ + __lll_clocklock_wait (futex, val, clockid, abstime, private) /* As __lll_lock, but with an absolute timeout measured against the clock specified in CLOCKID. If the timeout occurs then return ETIMEDOUT. If @@ -136,7 +139,15 @@ extern int __lll_clocklock_wait (int *futex, clockid_t, \ if (__glibc_unlikely \ (atomic_compare_and_exchange_bool_acq (__futex, 1, 0))) \ - __val = __lll_clocklock_wait (__futex, clockid, abstime, private); \ + { \ + while (atomic_exchange_acq (futex, 2) != 0) \ + { \ + __val = __lll_clocklock_wait (__futex, 2, clockid, \ + abstime, private); \ + if (__val == EINVAL || __val == ETIMEDOUT) \ + break; \ + } \ + } \ __val; \ }) #define lll_clocklock(futex, clockid, abstime, private) \ |