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-rw-r--r--runtime/base/mutex.cc142
1 files changed, 8 insertions, 134 deletions
diff --git a/runtime/base/mutex.cc b/runtime/base/mutex.cc
index b99e7c9..b048bbb 100644
--- a/runtime/base/mutex.cc
+++ b/runtime/base/mutex.cc
@@ -31,54 +31,6 @@
namespace art {
-#if defined(__APPLE__)
-
-// This works on Mac OS 10.6 but hasn't been tested on older releases.
-struct __attribute__((__may_alias__)) darwin_pthread_mutex_t {
- long padding0; // NOLINT(runtime/int) exact match to darwin type
- int padding1;
- uint32_t padding2;
- int16_t padding3;
- int16_t padding4;
- uint32_t padding5;
- pthread_t darwin_pthread_mutex_owner;
- // ...other stuff we don't care about.
-};
-
-struct __attribute__((__may_alias__)) darwin_pthread_rwlock_t {
- long padding0; // NOLINT(runtime/int) exact match to darwin type
- pthread_mutex_t padding1;
- int padding2;
- pthread_cond_t padding3;
- pthread_cond_t padding4;
- int padding5;
- int padding6;
- pthread_t darwin_pthread_rwlock_owner;
- // ...other stuff we don't care about.
-};
-
-#endif // __APPLE__
-
-#if defined(__GLIBC__)
-
-struct __attribute__((__may_alias__)) glibc_pthread_mutex_t {
- int32_t padding0[2];
- int owner;
- // ...other stuff we don't care about.
-};
-
-struct __attribute__((__may_alias__)) glibc_pthread_rwlock_t {
-#ifdef __LP64__
- int32_t padding0[6];
-#else
- int32_t padding0[7];
-#endif
- int writer;
- // ...other stuff we don't care about.
-};
-
-#endif // __GLIBC__
-
#if ART_USE_FUTEXES
static bool ComputeRelativeTimeSpec(timespec* result_ts, const timespec& lhs, const timespec& rhs) {
const int32_t one_sec = 1000 * 1000 * 1000; // one second in nanoseconds.
@@ -346,7 +298,7 @@ void Mutex::ExclusiveLock(Thread* self) {
bool done = false;
do {
int32_t cur_state = state_;
- if (cur_state == 0) {
+ if (LIKELY(cur_state == 0)) {
// Change state from 0 to 1.
done = android_atomic_acquire_cas(0, 1, &state_) == 0;
} else {
@@ -432,14 +384,14 @@ void Mutex::ExclusiveUnlock(Thread* self) {
bool done = false;
do {
int32_t cur_state = state_;
- if (cur_state == 1) {
+ if (LIKELY(cur_state == 1)) {
// We're no longer the owner.
exclusive_owner_ = 0;
// Change state to 0.
done = android_atomic_release_cas(cur_state, 0, &state_) == 0;
- if (done) { // Spurious fail?
+ if (LIKELY(done)) { // Spurious fail?
// Wake a contender
- if (num_contenders_ > 0) {
+ if (UNLIKELY(num_contenders_ > 0)) {
futex(&state_, FUTEX_WAKE, 1, NULL, NULL, 0);
}
}
@@ -461,41 +413,6 @@ void Mutex::ExclusiveUnlock(Thread* self) {
}
}
-bool Mutex::IsExclusiveHeld(const Thread* self) const {
- DCHECK(self == NULL || self == Thread::Current());
- bool result = (GetExclusiveOwnerTid() == SafeGetTid(self));
- if (kDebugLocking) {
- // Sanity debug check that if we think it is locked we have it in our held mutexes.
- if (result && self != NULL && level_ != kMonitorLock && !gAborting) {
- CHECK_EQ(self->GetHeldMutex(level_), this);
- }
- }
- return result;
-}
-
-uint64_t Mutex::GetExclusiveOwnerTid() const {
-#if ART_USE_FUTEXES
- return exclusive_owner_;
-#elif defined(__BIONIC__)
- return static_cast<uint64_t>((mutex_.value >> 16) & 0xffff);
-#elif defined(__GLIBC__)
- return reinterpret_cast<const glibc_pthread_mutex_t*>(&mutex_)->owner;
-#elif defined(__APPLE__)
- const darwin_pthread_mutex_t* dpmutex = reinterpret_cast<const darwin_pthread_mutex_t*>(&mutex_);
- pthread_t owner = dpmutex->darwin_pthread_mutex_owner;
- // 0 for unowned, -1 for PTHREAD_MTX_TID_SWITCHING
- // TODO: should we make darwin_pthread_mutex_owner volatile and recheck until not -1?
- if ((owner == (pthread_t)0) || (owner == (pthread_t)-1)) {
- return 0;
- }
- uint64_t tid;
- CHECK_PTHREAD_CALL(pthread_threadid_np, (owner, &tid), __FUNCTION__); // Requires Mac OS 10.6
- return tid;
-#else
-#error unsupported C library
-#endif
-}
-
void Mutex::Dump(std::ostream& os) const {
os << (recursive_ ? "recursive " : "non-recursive ")
<< name_
@@ -549,7 +466,7 @@ void ReaderWriterMutex::ExclusiveLock(Thread* self) {
bool done = false;
do {
int32_t cur_state = state_;
- if (cur_state == 0) {
+ if (LIKELY(cur_state == 0)) {
// Change state from 0 to -1.
done = android_atomic_acquire_cas(0, -1, &state_) == 0;
} else {
@@ -583,14 +500,14 @@ void ReaderWriterMutex::ExclusiveUnlock(Thread* self) {
bool done = false;
do {
int32_t cur_state = state_;
- if (cur_state == -1) {
+ if (LIKELY(cur_state == -1)) {
// We're no longer the owner.
exclusive_owner_ = 0;
// Change state from -1 to 0.
done = android_atomic_release_cas(-1, 0, &state_) == 0;
- if (done) { // cmpxchg may fail due to noise?
+ if (LIKELY(done)) { // cmpxchg may fail due to noise?
// Wake any waiters.
- if (num_pending_readers_ > 0 || num_pending_writers_ > 0) {
+ if (UNLIKELY(num_pending_readers_ > 0 || num_pending_writers_ > 0)) {
futex(&state_, FUTEX_WAKE, -1, NULL, NULL, 0);
}
}
@@ -687,18 +604,6 @@ bool ReaderWriterMutex::SharedTryLock(Thread* self) {
return true;
}
-bool ReaderWriterMutex::IsExclusiveHeld(const Thread* self) const {
- DCHECK(self == NULL || self == Thread::Current());
- bool result = (GetExclusiveOwnerTid() == SafeGetTid(self));
- if (kDebugLocking) {
- // Sanity that if the pthread thinks we own the lock the Thread agrees.
- if (self != NULL && result) {
- CHECK_EQ(self->GetHeldMutex(level_), this);
- }
- }
- return result;
-}
-
bool ReaderWriterMutex::IsSharedHeld(const Thread* self) const {
DCHECK(self == NULL || self == Thread::Current());
bool result;
@@ -710,37 +615,6 @@ bool ReaderWriterMutex::IsSharedHeld(const Thread* self) const {
return result;
}
-uint64_t ReaderWriterMutex::GetExclusiveOwnerTid() const {
-#if ART_USE_FUTEXES
- int32_t state = state_;
- if (state == 0) {
- return 0; // No owner.
- } else if (state > 0) {
- return -1; // Shared.
- } else {
- return exclusive_owner_;
- }
-#else
-#if defined(__BIONIC__)
- return rwlock_.writerThreadId;
-#elif defined(__GLIBC__)
- return reinterpret_cast<const glibc_pthread_rwlock_t*>(&rwlock_)->writer;
-#elif defined(__APPLE__)
- const darwin_pthread_rwlock_t*
- dprwlock = reinterpret_cast<const darwin_pthread_rwlock_t*>(&rwlock_);
- pthread_t owner = dprwlock->darwin_pthread_rwlock_owner;
- if (owner == (pthread_t)0) {
- return 0;
- }
- uint64_t tid;
- CHECK_PTHREAD_CALL(pthread_threadid_np, (owner, &tid), __FUNCTION__); // Requires Mac OS 10.6
- return tid;
-#else
-#error unsupported C library
-#endif
-#endif
-}
-
void ReaderWriterMutex::Dump(std::ostream& os) const {
os << name_
<< " level=" << static_cast<int>(level_)
generated by cgit v1.1 at 2024-09-15 11:42:36 +0000