diff options
Diffstat (limited to 'absl/synchronization/mutex.h')
| -rw-r--r-- | absl/synchronization/mutex.h | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/absl/synchronization/mutex.h b/absl/synchronization/mutex.h index f49e0c83..b69b7089 100644 --- a/absl/synchronization/mutex.h +++ b/absl/synchronization/mutex.h @@ -174,9 +174,12 @@ class ABSL_LOCKABLE Mutex { // Mutex::AssertHeld() // - // Return immediately if this thread holds the `Mutex` exclusively (in write - // mode). Otherwise, may report an error (typically by crashing with a - // diagnostic), or may return immediately. + // Require that the mutex be held exclusively (write mode) by this thread. + // + // If the mutex is not currently held by this thread, this function may report + // an error (typically by crashing with a diagnostic) or it may do nothing. + // This function is intended only as a tool to assist debugging; it doesn't + // guarantee correctness. void AssertHeld() const ABSL_ASSERT_EXCLUSIVE_LOCK(); // --------------------------------------------------------------------------- @@ -236,9 +239,13 @@ class ABSL_LOCKABLE Mutex { // Mutex::AssertReaderHeld() // - // Returns immediately if this thread holds the `Mutex` in at least shared - // mode (read mode). Otherwise, may report an error (typically by - // crashing with a diagnostic), or may return immediately. + // Require that the mutex be held at least in shared mode (read mode) by this + // thread. + // + // If the mutex is not currently held by this thread, this function may report + // an error (typically by crashing with a diagnostic) or it may do nothing. + // This function is intended only as a tool to assist debugging; it doesn't + // guarantee correctness. void AssertReaderHeld() const ABSL_ASSERT_SHARED_LOCK(); // Mutex::WriterLock() @@ -778,9 +785,9 @@ class Condition { // // Usage to wake T is: // mu.Lock(); -// // process data, possibly establishing C -// if (C) { cv->Signal(); } -// mu.Unlock(); +// // process data, possibly establishing C +// if (C) { cv->Signal(); } +// mu.Unlock(); // // If C may be useful to more than one waiter, use `SignalAll()` instead of // `Signal()`. @@ -984,14 +991,15 @@ inline Condition::Condition(const T *object, // Register a hook for profiling support. // // The function pointer registered here will be called whenever a mutex is -// contended. The callback is given the absl/base/cycleclock.h timestamp when -// waiting began. +// contended. The callback is given the cycles for which waiting happened (as +// measured by //absl/base/internal/cycleclock.h, and which may not +// be real "cycle" counts.) // // Calls to this function do not race or block, but there is no ordering // guaranteed between calls to this function and call to the provided hook. // In particular, the previously registered hook may still be called for some // time after this function returns. -void RegisterMutexProfiler(void (*fn)(int64_t wait_timestamp)); +void RegisterMutexProfiler(void (*fn)(int64_t wait_cycles)); // Register a hook for Mutex tracing. // |