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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-02-21 13:33:54 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2019-05-14 08:48:02 -0300 |
| commit | c50e1c263ec15e98da3235e663049156fd1afcfa (patch) | |
| tree | 47d22df898622b32fdc262f830978f29d6fa800e /sysdeps/nptl | |
| parent | 959aff9fa22c45e0fa11cd88c9f8ea10bd9ba494 (diff) | |
| download | glibc-c50e1c263ec15e98da3235e663049156fd1afcfa.tar.gz glibc-c50e1c263ec15e98da3235e663049156fd1afcfa.tar.xz glibc-c50e1c263ec15e98da3235e663049156fd1afcfa.zip | |
x86: Remove arch-specific low level lock implementation
This patch removes the arch-specific x86 assembly implementation for low level locking and consolidate both 64 bits and 32 bits in a single implementation. Different than other architectures, x86 lll_trylock, lll_lock, and lll_unlock implements a single-thread optimization to avoid atomic operation, using cmpxchgl instead. This patch implements by using the new single-thread.h definitions in a generic way, although using the previous semantic. The lll_cond_trylock, lll_cond_lock, and lll_timedlock just use atomic operations plus calls to lll_lock_wait*. For __lll_lock_wait_private and __lll_lock_wait the generic implemtation there is no indication that assembly implementation is required performance-wise. Checked on x86_64-linux-gnu and i686-linux-gnu. * sysdeps/nptl/lowlevellock.h (__lll_trylock): New macro. (lll_trylock): Call __lll_trylock. * sysdeps/unix/sysv/linux/i386/libc-lowlevellock.S: Remove file. * sysdeps/unix/sysv/linux/i386/lll_timedlock_wait.c: Likewise. * sysdeps/unix/sysv/linux/i386/lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/i386/lowlevellock.h: Likewise. * sysdeps/unix/sysv/linux/x86_64/libc-lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lll_timedlock_wait.c: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise. * sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Likewise. * sysdeps/unix/sysv/linux/x86/lowlevellock.h: New file. * sysdeps/unix/sysv/linux/x86_64/cancellation.S: Include lowlevellock-futex.h.
Diffstat (limited to 'sysdeps/nptl')
| -rw-r--r-- | sysdeps/nptl/lowlevellock.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/sysdeps/nptl/lowlevellock.h b/sysdeps/nptl/lowlevellock.h index 6f017afdd5..e905829ee4 100644 --- a/sysdeps/nptl/lowlevellock.h +++ b/sysdeps/nptl/lowlevellock.h @@ -63,8 +63,10 @@ /* If LOCK is 0 (not acquired), set to 1 (acquired with no waiters) and return 0. Otherwise leave lock unchanged and return non-zero to indicate that the lock was not acquired. */ +#define __lll_trylock(lock) \ + __glibc_unlikely (atomic_compare_and_exchange_bool_acq ((lock), 1, 0)) #define lll_trylock(lock) \ - __glibc_unlikely (atomic_compare_and_exchange_bool_acq (&(lock), 1, 0)) + __lll_trylock (&(lock)) /* If LOCK is 0 (not acquired), set to 2 (acquired, possibly with waiters) and return 0. Otherwise leave lock unchanged and return non-zero to indicate |