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-rw-r--r--base/lock.h68
1 files changed, 10 insertions, 58 deletions
diff --git a/base/lock.h b/base/lock.h
index 64b8f74..31ad9a0 100644
--- a/base/lock.h
+++ b/base/lock.h
@@ -7,78 +7,30 @@
#include "base/lock_impl.h"
-// A convenient wrapper for an OS specific critical section. The only real
-// intelligence in this class is in debug mode for the support for the
-// AssertAcquired() method.
+// A convenient wrapper for an OS specific critical section.
class Lock {
public:
-#if defined(NDEBUG) // Optimized wrapper implementation
Lock() : lock_() {}
~Lock() {}
void Acquire() { lock_.Lock(); }
void Release() { lock_.Unlock(); }
-
// If the lock is not held, take it and return true. If the lock is already
// held by another thread, immediately return false.
bool Try() { return lock_.Try(); }
- // Null implementation if not debug.
- void AssertAcquired() const {}
-#else
- Lock();
- ~Lock() {}
-
- // NOTE: Although windows critical sections support recursive locks, we do not
- // allow this, and we will commonly fire a DCHECK() if a thread attempts to
- // acquire the lock a second time (while already holding it).
- void Acquire() {
- lock_.Lock();
- CheckUnheldAndMark();
- }
- void Release() {
- CheckHeldAndUnmark();
- lock_.Unlock();
- }
+ // In debug builds this method checks that the lock has been acquired by the
+ // calling thread. If the lock has not been acquired, then the method
+ // will DCHECK(). In non-debug builds, the LockImpl's implementation of
+ // AssertAcquired() is an empty inline method.
+ void AssertAcquired() const { return lock_.AssertAcquired(); }
- bool Try() {
- bool rv = lock_.Try();
- if (rv) {
- CheckUnheldAndMark();
- }
- return rv;
- }
-
- void AssertAcquired() const;
-#endif // NDEBUG
-
-#if defined(OS_POSIX)
- // The posix implementation of ConditionVariable needs to be able
- // to see our lock and tweak our debugging counters, as it releases
- // and acquires locks inside of pthread_cond_{timed,}wait.
- // Windows doesn't need to do this as it calls the Lock::* methods.
- friend class ConditionVariable;
-#endif
+ // Return the underlying lock implementation.
+ // TODO(awalker): refactor lock and condition variables so that this is
+ // unnecessary.
+ LockImpl* lock_impl() { return &lock_; }
private:
-#if !defined(NDEBUG)
- // Members and routines taking care of locks assertions.
- // Note that this checks for recursive locks and allows them
- // if the variable is set. This is allowed by the underlying implementation
- // on windows but not on Posix, so we're doing unneeded checks on Posix.
- // It's worth it to share the code.
- void CheckHeldAndUnmark();
- void CheckUnheldAndMark();
-
- // All private data is implicitly protected by lock_.
- // Be VERY careful to only access members under that lock.
-
- // Determines validity of owning_thread_id_. Needed as we don't have
- // a null owning_thread_id_ value.
- bool owned_by_thread_;
- PlatformThreadId owning_thread_id_;
-#endif // NDEBUG
-
LockImpl lock_; // Platform specific underlying lock implementation.
DISALLOW_COPY_AND_ASSIGN(Lock);