diff options
| -rw-r--r-- | base/lock.cc | 70 | ||||
| -rw-r--r-- | base/lock.h | 29 | ||||
| -rw-r--r-- | base/lock_impl.h | 7 | ||||
| -rw-r--r-- | base/lock_impl_win.cc | 34 |
4 files changed, 46 insertions, 94 deletions
diff --git a/base/lock.cc b/base/lock.cc index dc17c47..9ff963b 100644 --- a/base/lock.cc +++ b/base/lock.cc @@ -2,74 +2,6 @@ // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. -// Provide place to put profiling methods for the // Lock class. -// The Lock class is used everywhere, and hence any changes -// to lock.h tend to require a complete rebuild. To facilitate -// profiler development, all the profiling methods are listed -// here. -#include "base/lock.h" -#include "base/logging.h" - -#ifndef NDEBUG -Lock::Lock() - : lock_(), - recursion_count_shadow_(0), - recursion_used_(false), - acquisition_count_(0), - contention_count_(0) { -} -#else // NDEBUG -Lock::Lock() - : lock_() { -} -#endif // NDEBUG - -Lock::~Lock() { -} - -void Lock::Acquire() { -#ifdef NDEBUG - lock_.Lock(); -#else // NDEBUG - if (!lock_.Try()) { - // We have contention. - lock_.Lock(); - contention_count_++; - } - // ONLY access data after locking. - recursion_count_shadow_++; - acquisition_count_++; - if (2 == recursion_count_shadow_ && !recursion_used_) { - recursion_used_ = true; - // TODO(jar): this is causing failures in ThreadTest.Restart and - // ChromeThreadTest.Get on Linux. - // DCHECK(false); // Catch accidental redundant lock acquisition. - } -#endif // NDEBUG -} - -void Lock::Release() { -#ifndef NDEBUG - --recursion_count_shadow_; // ONLY access while lock is still held. - DCHECK(0 <= recursion_count_shadow_); -#endif // NDEBUG - lock_.Unlock(); -} - -bool Lock::Try() { - if (lock_.Try()) { -#ifndef NDEBUG - recursion_count_shadow_++; - acquisition_count_++; - if (2 == recursion_count_shadow_ && !recursion_used_) { - recursion_used_ = true; - DCHECK(false); // Catch accidental redundant lock acquisition. - } -#endif - return true; - } else { - return false; - } -} +// Depricated file. See lock_impl_*.cc for platform specific versions. diff --git a/base/lock.h b/base/lock.h index b43e6ef..49cb37a 100644 --- a/base/lock.h +++ b/base/lock.h @@ -8,24 +8,16 @@ #include "base/lock_impl.h" // A convenient wrapper for an OS specific critical section. -// -// 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). -// -// Complication: UnitTest for DeathTests catch DCHECK exceptions, so we need -// to write code assuming DCHECK will throw. This means we need to save any -// assertable value in a local until we can safely throw. class Lock { public: - Lock(); - ~Lock(); - void Acquire(); - void Release(); + 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(); + bool Try() { return lock_.Try(); } // Return the underlying lock implementation. // TODO(awalker): refactor lock and condition variables so that this is @@ -33,16 +25,7 @@ class Lock { LockImpl* lock_impl() { return &lock_; } private: - LockImpl lock_; // User-supplied underlying lock implementation. - -#ifndef NDEBUG - // All private data is implicitly protected by lock_. - // Be VERY careful to only access members under that lock. - int32 recursion_count_shadow_; - bool recursion_used_; // Allow debugging to continued after a DCHECK(). - int32 acquisition_count_; // Number of times lock was acquired. - int32 contention_count_; // Number of times there was contention. -#endif // NDEBUG + LockImpl lock_; // Platform specific underlying lock implementation. DISALLOW_COPY_AND_ASSIGN(Lock); }; diff --git a/base/lock_impl.h b/base/lock_impl.h index 4bd27dc..b3b6237 100644 --- a/base/lock_impl.h +++ b/base/lock_impl.h @@ -48,6 +48,13 @@ class LockImpl { private: OSLockType os_lock_; +#if !defined(NDEBUG) && defined(OS_WIN) + // All private data is implicitly protected by lock_. + // Be VERY careful to only access members under that lock. + int32 recursion_count_shadow_; + bool recursion_used_; // Allow debugging to continued after a DCHECK(). +#endif // NDEBUG + DISALLOW_COPY_AND_ASSIGN(LockImpl); }; diff --git a/base/lock_impl_win.cc b/base/lock_impl_win.cc index e40db6d..8bb1943 100644 --- a/base/lock_impl_win.cc +++ b/base/lock_impl_win.cc @@ -3,8 +3,17 @@ // found in the LICENSE file. #include "base/lock_impl.h" +#include "base/logging.h" + +// 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). LockImpl::LockImpl() { +#ifndef NDEBUG + recursion_count_shadow_ = 0; + recursion_used_ = false; +#endif // NDEBUG // The second parameter is the spin count, for short-held locks it avoid the // contending thread from going to sleep which helps performance greatly. ::InitializeCriticalSectionAndSpinCount(&os_lock_, 2000); @@ -15,14 +24,35 @@ LockImpl::~LockImpl() { } bool LockImpl::Try() { - return ::TryEnterCriticalSection(&os_lock_) != FALSE; + if (::TryEnterCriticalSection(&os_lock_) != FALSE) { +#ifndef NDEBUG + recursion_count_shadow_++; + if (2 == recursion_count_shadow_ && !recursion_used_) { + recursion_used_ = true; + DCHECK(false); // Catch accidental redundant lock acquisition. + } +#endif + return true; + } + return false; } void LockImpl::Lock() { ::EnterCriticalSection(&os_lock_); +#ifndef NDEBUG + // ONLY access data after locking. + recursion_count_shadow_++; + if (2 == recursion_count_shadow_ && !recursion_used_) { + recursion_used_ = true; + DCHECK(false); // Catch accidental redundant lock acquisition. + } +#endif // NDEBUG } void LockImpl::Unlock() { +#ifndef NDEBUG + --recursion_count_shadow_; // ONLY access while lock is still held. + DCHECK(0 <= recursion_count_shadow_); +#endif // NDEBUG ::LeaveCriticalSection(&os_lock_); } - |