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author | Colin Cross <ccross@android.com> | 2022-04-13 03:15:00 +0000 |
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committer | Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com> | 2022-04-13 03:15:00 +0000 |
commit | 6c9587948173932b64d97c288a947e43d2a2ac14 (patch) | |
tree | 2ce94d7f0804ccb77d1fa9b2a1bca00eecdff1e2 /third_party/abseil-cpp/absl/synchronization/internal/waiter.cc | |
parent | f60eaea2240ba9e1c508e8e0c91d39ee9fc47be5 (diff) | |
parent | 43d8f56cdc20240b37c36bf417dd0d6999bce738 (diff) | |
download | webrtc-6c9587948173932b64d97c288a947e43d2a2ac14.tar.gz |
Merge changes I0ab600cd,I1e74c64a am: 798f3afdf6 am: 2f9c4b2c3b am: a9167328fc am: 7563023510 am: 43d8f56cdcandroid-13.0.0_r83android-13.0.0_r82android-13.0.0_r81android-13.0.0_r80android-13.0.0_r79android-13.0.0_r78android-13.0.0_r77android-13.0.0_r76android-13.0.0_r75android-13.0.0_r74android-13.0.0_r73android-13.0.0_r72android-13.0.0_r71android-13.0.0_r70android-13.0.0_r69android-13.0.0_r68android-13.0.0_r67android-13.0.0_r66android-13.0.0_r65android-13.0.0_r64android-13.0.0_r63android-13.0.0_r62android-13.0.0_r61android-13.0.0_r60android-13.0.0_r59android-13.0.0_r58android-13.0.0_r56android-13.0.0_r54android-13.0.0_r53android-13.0.0_r52android-13.0.0_r51android-13.0.0_r50android-13.0.0_r49android-13.0.0_r48android-13.0.0_r47android-13.0.0_r46android-13.0.0_r45android-13.0.0_r44android-13.0.0_r43android-13.0.0_r42android-13.0.0_r41android-13.0.0_r40android-13.0.0_r39android-13.0.0_r38android-13.0.0_r37android-13.0.0_r36android-13.0.0_r35android-13.0.0_r34android-13.0.0_r33android-13.0.0_r32android13-qpr3-s9-releaseandroid13-qpr3-s8-releaseandroid13-qpr3-s7-releaseandroid13-qpr3-s6-releaseandroid13-qpr3-s5-releaseandroid13-qpr3-s4-releaseandroid13-qpr3-s3-releaseandroid13-qpr3-s2-releaseandroid13-qpr3-s14-releaseandroid13-qpr3-s13-releaseandroid13-qpr3-s12-releaseandroid13-qpr3-s11-releaseandroid13-qpr3-s10-releaseandroid13-qpr3-s1-releaseandroid13-qpr3-releaseandroid13-qpr3-c-s8-releaseandroid13-qpr3-c-s7-releaseandroid13-qpr3-c-s6-releaseandroid13-qpr3-c-s5-releaseandroid13-qpr3-c-s4-releaseandroid13-qpr3-c-s3-releaseandroid13-qpr3-c-s2-releaseandroid13-qpr3-c-s12-releaseandroid13-qpr3-c-s11-releaseandroid13-qpr3-c-s10-releaseandroid13-qpr3-c-s1-releaseandroid13-qpr2-s9-releaseandroid13-qpr2-s8-releaseandroid13-qpr2-s7-releaseandroid13-qpr2-s6-releaseandroid13-qpr2-s5-releaseandroid13-qpr2-s3-releaseandroid13-qpr2-s2-releaseandroid13-qpr2-s12-releaseandroid13-qpr2-s11-releaseandroid13-qpr2-s10-releaseandroid13-qpr2-s1-releaseandroid13-qpr2-releaseandroid13-qpr2-b-s1-releaseandroid13-d4-s2-releaseandroid13-d4-s1-releaseandroid13-d4-release
Original change: https://android-review.googlesource.com/c/platform/external/webrtc/+/2062410
Change-Id: I1aa9f459b825711b800cc65782979943a9151ec7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
Diffstat (limited to 'third_party/abseil-cpp/absl/synchronization/internal/waiter.cc')
-rw-r--r-- | third_party/abseil-cpp/absl/synchronization/internal/waiter.cc | 60 |
1 files changed, 2 insertions, 58 deletions
diff --git a/third_party/abseil-cpp/absl/synchronization/internal/waiter.cc b/third_party/abseil-cpp/absl/synchronization/internal/waiter.cc index 2949f5a84c..28ef311e4a 100644 --- a/third_party/abseil-cpp/absl/synchronization/internal/waiter.cc +++ b/third_party/abseil-cpp/absl/synchronization/internal/waiter.cc @@ -48,6 +48,7 @@ #include "absl/base/optimization.h" #include "absl/synchronization/internal/kernel_timeout.h" + namespace absl { ABSL_NAMESPACE_BEGIN namespace synchronization_internal { @@ -66,63 +67,6 @@ static void MaybeBecomeIdle() { #if ABSL_WAITER_MODE == ABSL_WAITER_MODE_FUTEX -// Some Android headers are missing these definitions even though they -// support these futex operations. -#ifdef __BIONIC__ -#ifndef SYS_futex -#define SYS_futex __NR_futex -#endif -#ifndef FUTEX_WAIT_BITSET -#define FUTEX_WAIT_BITSET 9 -#endif -#ifndef FUTEX_PRIVATE_FLAG -#define FUTEX_PRIVATE_FLAG 128 -#endif -#ifndef FUTEX_CLOCK_REALTIME -#define FUTEX_CLOCK_REALTIME 256 -#endif -#ifndef FUTEX_BITSET_MATCH_ANY -#define FUTEX_BITSET_MATCH_ANY 0xFFFFFFFF -#endif -#endif - -class Futex { - public: - static int WaitUntil(std::atomic<int32_t> *v, int32_t val, - KernelTimeout t) { - int err = 0; - if (t.has_timeout()) { - // https://locklessinc.com/articles/futex_cheat_sheet/ - // Unlike FUTEX_WAIT, FUTEX_WAIT_BITSET uses absolute time. - struct timespec abs_timeout = t.MakeAbsTimespec(); - // Atomically check that the futex value is still 0, and if it - // is, sleep until abs_timeout or until woken by FUTEX_WAKE. - err = syscall( - SYS_futex, reinterpret_cast<int32_t *>(v), - FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME, val, - &abs_timeout, nullptr, FUTEX_BITSET_MATCH_ANY); - } else { - // Atomically check that the futex value is still 0, and if it - // is, sleep until woken by FUTEX_WAKE. - err = syscall(SYS_futex, reinterpret_cast<int32_t *>(v), - FUTEX_WAIT | FUTEX_PRIVATE_FLAG, val, nullptr); - } - if (err != 0) { - err = -errno; - } - return err; - } - - static int Wake(std::atomic<int32_t> *v, int32_t count) { - int err = syscall(SYS_futex, reinterpret_cast<int32_t *>(v), - FUTEX_WAKE | FUTEX_PRIVATE_FLAG, count); - if (ABSL_PREDICT_FALSE(err < 0)) { - err = -errno; - } - return err; - } -}; - Waiter::Waiter() { futex_.store(0, std::memory_order_relaxed); } @@ -135,6 +79,7 @@ bool Waiter::Wait(KernelTimeout t) { // Note that, since the thread ticker is just reset, we don't need to check // whether the thread is idle on the very first pass of the loop. bool first_pass = true; + while (true) { int32_t x = futex_.load(std::memory_order_relaxed); while (x != 0) { @@ -146,7 +91,6 @@ bool Waiter::Wait(KernelTimeout t) { return true; // Consumed a wakeup, we are done. } - if (!first_pass) MaybeBecomeIdle(); const int err = Futex::WaitUntil(&futex_, 0, t); if (err != 0) { |