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authorColin Cross <ccross@android.com>2022-04-13 03:15:00 +0000
committerAutomerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>2022-04-13 03:15:00 +0000
commit6c9587948173932b64d97c288a947e43d2a2ac14 (patch)
tree2ce94d7f0804ccb77d1fa9b2a1bca00eecdff1e2 /third_party/abseil-cpp/absl/synchronization/internal/waiter.cc
parentf60eaea2240ba9e1c508e8e0c91d39ee9fc47be5 (diff)
parent43d8f56cdc20240b37c36bf417dd0d6999bce738 (diff)
downloadwebrtc-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.cc60
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) {