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1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. |
2 // Use of this source code is governed by a BSD-style license that can be | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "base/lock_impl.h" | 5 #include "base/lock_impl.h" |
6 #include "base/logging.h" | 6 #include "base/logging.h" |
7 | 7 |
8 // NOTE: Although windows critical sections support recursive locks, we do not | 8 // NOTE: Although windows critical sections support recursive locks, we do not |
9 // allow this, and we will commonly fire a DCHECK() if a thread attempts to | 9 // allow this, and we will commonly fire a DCHECK() if a thread attempts to |
10 // acquire the lock a second time (while already holding it). | 10 // acquire the lock a second time (while already holding it). |
11 | 11 |
12 LockImpl::LockImpl() { | 12 LockImpl::LockImpl() { |
13 #ifndef NDEBUG | 13 #ifndef NDEBUG |
14 recursion_count_shadow_ = 0; | 14 recursion_count_shadow_ = 0; |
15 recursion_used_ = false; | 15 recursion_used_ = false; |
| 16 owning_thread_id_ = 0; |
16 #endif // NDEBUG | 17 #endif // NDEBUG |
17 // The second parameter is the spin count, for short-held locks it avoid the | 18 // The second parameter is the spin count, for short-held locks it avoid the |
18 // contending thread from going to sleep which helps performance greatly. | 19 // contending thread from going to sleep which helps performance greatly. |
19 ::InitializeCriticalSectionAndSpinCount(&os_lock_, 2000); | 20 ::InitializeCriticalSectionAndSpinCount(&os_lock_, 2000); |
20 } | 21 } |
21 | 22 |
22 LockImpl::~LockImpl() { | 23 LockImpl::~LockImpl() { |
23 ::DeleteCriticalSection(&os_lock_); | 24 ::DeleteCriticalSection(&os_lock_); |
24 } | 25 } |
25 | 26 |
26 bool LockImpl::Try() { | 27 bool LockImpl::Try() { |
27 if (::TryEnterCriticalSection(&os_lock_) != FALSE) { | 28 if (::TryEnterCriticalSection(&os_lock_) != FALSE) { |
28 #ifndef NDEBUG | 29 #ifndef NDEBUG |
| 30 // ONLY access data after locking. |
| 31 owning_thread_id_ = PlatformThread::CurrentId(); |
| 32 DCHECK_NE(owning_thread_id_, 0); |
29 recursion_count_shadow_++; | 33 recursion_count_shadow_++; |
30 if (2 == recursion_count_shadow_ && !recursion_used_) { | 34 if (2 == recursion_count_shadow_ && !recursion_used_) { |
31 recursion_used_ = true; | 35 recursion_used_ = true; |
32 DCHECK(false); // Catch accidental redundant lock acquisition. | 36 DCHECK(false); // Catch accidental redundant lock acquisition. |
33 } | 37 } |
34 #endif | 38 #endif |
35 return true; | 39 return true; |
36 } | 40 } |
37 return false; | 41 return false; |
38 } | 42 } |
39 | 43 |
40 void LockImpl::Lock() { | 44 void LockImpl::Lock() { |
41 ::EnterCriticalSection(&os_lock_); | 45 ::EnterCriticalSection(&os_lock_); |
42 #ifndef NDEBUG | 46 #ifndef NDEBUG |
43 // ONLY access data after locking. | 47 // ONLY access data after locking. |
| 48 owning_thread_id_ = PlatformThread::CurrentId(); |
| 49 DCHECK_NE(owning_thread_id_, 0); |
44 recursion_count_shadow_++; | 50 recursion_count_shadow_++; |
45 if (2 == recursion_count_shadow_ && !recursion_used_) { | 51 if (2 == recursion_count_shadow_ && !recursion_used_) { |
46 recursion_used_ = true; | 52 recursion_used_ = true; |
47 DCHECK(false); // Catch accidental redundant lock acquisition. | 53 DCHECK(false); // Catch accidental redundant lock acquisition. |
48 } | 54 } |
49 #endif // NDEBUG | 55 #endif // NDEBUG |
50 } | 56 } |
51 | 57 |
52 void LockImpl::Unlock() { | 58 void LockImpl::Unlock() { |
53 #ifndef NDEBUG | 59 #ifndef NDEBUG |
54 --recursion_count_shadow_; // ONLY access while lock is still held. | 60 --recursion_count_shadow_; // ONLY access while lock is still held. |
55 DCHECK(0 <= recursion_count_shadow_); | 61 DCHECK(0 <= recursion_count_shadow_); |
| 62 owning_thread_id_ = 0; |
56 #endif // NDEBUG | 63 #endif // NDEBUG |
57 ::LeaveCriticalSection(&os_lock_); | 64 ::LeaveCriticalSection(&os_lock_); |
58 } | 65 } |
| 66 |
| 67 // In non-debug builds, this method is declared as an empty inline method. |
| 68 #ifndef NDEBUG |
| 69 void LockImpl::AssertAcquired() { |
| 70 DCHECK(recursion_count_shadow_ > 0); |
| 71 DCHECK_EQ(owning_thread_id_, PlatformThread::CurrentId()); |
| 72 } |
| 73 #endif |
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