diff options
Diffstat (limited to 'absl/synchronization/mutex.cc')
| -rw-r--r-- | absl/synchronization/mutex.cc | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/absl/synchronization/mutex.cc b/absl/synchronization/mutex.cc index 16a8fbff..0742680c 100644 --- a/absl/synchronization/mutex.cc +++ b/absl/synchronization/mutex.cc @@ -639,18 +639,18 @@ void Mutex::InternalAttemptToUseMutexInFatalSignalHandler() { // o kMuWriter / kMuReader == kMuWrWait / kMuWait, // to enable the bit-twiddling trick in CheckForMutexCorruption(). static const intptr_t kMuReader = 0x0001L; // a reader holds the lock -static const intptr_t kMuDesig = 0x0002L; // there's a designated waker -static const intptr_t kMuWait = 0x0004L; // threads are waiting -static const intptr_t kMuWriter = 0x0008L; // a writer holds the lock -static const intptr_t kMuEvent = 0x0010L; // record this mutex's events +// There's a designated waker. // INVARIANT1: there's a thread that was blocked on the mutex, is // no longer, yet has not yet acquired the mutex. If there's a // designated waker, all threads can avoid taking the slow path in // unlock because the designated waker will subsequently acquire // the lock and wake someone. To maintain INVARIANT1 the bit is // set when a thread is unblocked(INV1a), and threads that were -// unblocked reset the bit when they either acquire or re-block -// (INV1b). +// unblocked reset the bit when they either acquire or re-block (INV1b). +static const intptr_t kMuDesig = 0x0002L; +static const intptr_t kMuWait = 0x0004L; // threads are waiting +static const intptr_t kMuWriter = 0x0008L; // a writer holds the lock +static const intptr_t kMuEvent = 0x0010L; // record this mutex's events static const intptr_t kMuWrWait = 0x0020L; // runnable writer is waiting // for a reader static const intptr_t kMuSpin = 0x0040L; // spinlock protects wait list |