Revert 8260 "Base RWLockWrapper on rtc::SharedExclusiveLock."

Unfortunately this caused channel teardown to hang.
More details in email(s).

> Base RWLockWrapper on rtc::SharedExclusiveLock.
>
> Also moves rtc::Event and rtc::SharedExclusiveLock to rtc_base_approved.
>
> R=tommi@webrtc.org
> BUG=
>
> Review URL: https://webrtc-codereview.appspot.com/38889004

TBR=pbos@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/34999005

Cr-Commit-Position: refs/heads/master@{#8284}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8284 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/base/BUILD.gn

@@ -106,8 +106,6 @@ static_library("rtc_base_approved") {
   sources = [
     "checks.cc",
     "checks.h",
-    "event.cc",
-    "event.h",
     "exp_filter.cc",
     "exp_filter.h",
     "md5.cc",
@@ -117,8 +115,6 @@ static_library("rtc_base_approved") {
     "platform_file.h",
     "safe_conversions.h",
     "safe_conversions_impl.h",
-    "sharedexclusivelock.cc",
-    "sharedexclusivelock.h",
     "stringencode.cc",
     "stringencode.h",
     "stringutils.cc",
@@ -187,6 +183,8 @@ static_library("rtc_base") {
     "cryptstring.h",
     "diskcache.cc",
     "diskcache.h",
+    "event.cc",
+    "event.h",
     "fileutils.cc",
     "fileutils.h",
     "firewallsocketserver.cc",
@@ -362,6 +360,8 @@ static_library("rtc_base") {
       "scopedptrcollection.h",
       "scoped_ref_ptr.h",
       "sec_buffer.h",
+      "sharedexclusivelock.cc",
+      "sharedexclusivelock.h",
       "sslconfig.h",
       "sslroots.h",
       "stringdigest.h",

webrtc/base/base.gyp

@@ -31,8 +31,6 @@
       'sources': [
         'checks.cc',
         'checks.h',
-        'event.cc',
-        'event.h',
         'exp_filter.cc',
         'exp_filter.h',
         'md5.cc',
@@ -42,8 +40,6 @@
         'platform_file.h',
         'safe_conversions.h',
         'safe_conversions_impl.h',
-        'sharedexclusivelock.cc',
-        'sharedexclusivelock.h',
         'stringencode.cc',
         'stringencode.h',
         'stringutils.cc',
@@ -117,6 +113,8 @@
         'diskcache.h',
         'diskcache_win32.cc',
         'diskcache_win32.h',
+        'event.cc',
+        'event.h',
         'filelock.cc',
         'filelock.h',
         'fileutils.cc',
@@ -229,6 +227,8 @@
         'sha1.cc',
         'sha1.h',
         'sha1digest.h',
+        'sharedexclusivelock.cc',
+        'sharedexclusivelock.h',
         'signalthread.cc',
         'signalthread.h',
         'sigslot.h',

webrtc/base/event.cc

@@ -10,8 +10,6 @@
 
 #include "webrtc/base/event.h"
 
-#include "webrtc/base/checks.h"
-
 #if defined(WEBRTC_WIN)
 #include <windows.h>
 #elif defined(WEBRTC_POSIX)
@@ -33,7 +31,7 @@ Event::Event(bool manual_reset, bool initially_signaled)
                                 is_manual_reset_,
                                 is_initially_signaled_,
                                 NULL);                // Name.
-  CHECK(event_handle_ != NULL);
+  ASSERT(event_handle_ != NULL);
 }
 
 Event::~Event() {
@@ -58,8 +56,8 @@ bool Event::Wait(int cms) {
 Event::Event(bool manual_reset, bool initially_signaled)
     : is_manual_reset_(manual_reset),
       event_status_(initially_signaled) {
-  CHECK(pthread_mutex_init(&event_mutex_, NULL) == 0);
+  VERIFY(pthread_mutex_init(&event_mutex_, NULL) == 0);
-  CHECK(pthread_cond_init(&event_cond_, NULL) == 0);
+  VERIFY(pthread_cond_init(&event_cond_, NULL) == 0);
 }
 
 Event::~Event() {

webrtc/base/event.h

@@ -20,6 +20,7 @@
 #endif
 
 #include "webrtc/base/basictypes.h"
+#include "webrtc/base/common.h"
 
 namespace rtc {
 

webrtc/system_wrappers/BUILD.gn

@@ -76,6 +76,12 @@ static_library("system_wrappers") {
     "source/logging.cc",
     "source/rtp_to_ntp.cc",
     "source/rw_lock.cc",
+    "source/rw_lock_generic.cc",
+    "source/rw_lock_generic.h",
+    "source/rw_lock_posix.cc",
+    "source/rw_lock_posix.h",
+    "source/rw_lock_win.cc",
+    "source/rw_lock_win.h",
     "source/set_thread_name_win.h",
     "source/sleep.cc",
     "source/sort.cc",

webrtc/system_wrappers/interface/rw_lock_wrapper.h

@@ -13,6 +13,10 @@
 
 #include "webrtc/base/thread_annotations.h"
 
+// Note, Windows pre-Vista version of RW locks are not supported natively. For
+// these OSs regular critical sections have been used to approximate RW lock
+// functionality and will therefore have worse performance.
+
 namespace webrtc {
 
 class LOCKABLE RWLockWrapper {
@@ -27,6 +31,8 @@ class LOCKABLE RWLockWrapper {
   virtual void ReleaseLockShared() UNLOCK_FUNCTION() = 0;
 };
 
+// RAII extensions of the RW lock. Prevents Acquire/Release missmatches and
+// provides more compact locking syntax.
 class SCOPED_LOCKABLE ReadLockScoped {
  public:
   ReadLockScoped(RWLockWrapper& rw_lock) SHARED_LOCK_FUNCTION(rw_lock)

webrtc/system_wrappers/source/rw_lock.cc

@@ -10,32 +10,28 @@
 
 #include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
 
-#include "webrtc/base/sharedexclusivelock.h"
+#include <assert.h>
-#include "webrtc/base/thread_annotations.h"
+
+#if defined(_WIN32)
+#include "webrtc/system_wrappers/source/rw_lock_generic.h"
+#include "webrtc/system_wrappers/source/rw_lock_win.h"
+#else
+#include "webrtc/system_wrappers/source/rw_lock_posix.h"
+#endif
 
 namespace webrtc {
 
-class LOCKABLE RwLock : public RWLockWrapper {
-  virtual void AcquireLockExclusive() override EXCLUSIVE_LOCK_FUNCTION() {
-    lock_.LockExclusive();
-  }
-  virtual void ReleaseLockExclusive() override UNLOCK_FUNCTION() {
-    lock_.UnlockExclusive();
-  }
-
-  virtual void AcquireLockShared() override SHARED_LOCK_FUNCTION() {
-    lock_.LockShared();
-  }
-  virtual void ReleaseLockShared() override UNLOCK_FUNCTION() {
-    lock_.UnlockShared();
-  }
-
- private:
-  rtc::SharedExclusiveLock lock_;
-};
-
 RWLockWrapper* RWLockWrapper::CreateRWLock() {
-  return new RwLock();
+#ifdef _WIN32
+  // Native implementation is faster, so use that if available.
+  RWLockWrapper* lock = RWLockWin::Create();
+  if (lock) {
+    return lock;
+  }
+  return new RWLockGeneric();
+#else
+  return RWLockPosix::Create();
+#endif
 }
 
 }  // namespace webrtc

webrtc/system_wrappers/source/rw_lock_generic.cc

@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/system_wrappers/source/rw_lock_generic.h"
+
+#include "webrtc/system_wrappers/interface/condition_variable_wrapper.h"
+#include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
+
+namespace webrtc {
+
+RWLockGeneric::RWLockGeneric()
+    : readers_active_(0),
+      writer_active_(false),
+      readers_waiting_(0),
+      writers_waiting_(0) {
+  critical_section_ = CriticalSectionWrapper::CreateCriticalSection();
+  read_condition_ = ConditionVariableWrapper::CreateConditionVariable();
+  write_condition_ = ConditionVariableWrapper::CreateConditionVariable();
+}
+
+RWLockGeneric::~RWLockGeneric() {
+  delete write_condition_;
+  delete read_condition_;
+  delete critical_section_;
+}
+
+void RWLockGeneric::AcquireLockExclusive() {
+  CriticalSectionScoped cs(critical_section_);
+  if (writer_active_ || readers_active_ > 0) {
+    ++writers_waiting_;
+    while (writer_active_ || readers_active_ > 0) {
+      write_condition_->SleepCS(*critical_section_);
+    }
+    --writers_waiting_;
+  }
+  writer_active_ = true;
+}
+
+void RWLockGeneric::ReleaseLockExclusive() {
+  CriticalSectionScoped cs(critical_section_);
+  writer_active_ = false;
+  if (writers_waiting_ > 0) {
+    write_condition_->Wake();
+  } else if (readers_waiting_ > 0) {
+    read_condition_->WakeAll();
+  }
+}
+
+void RWLockGeneric::AcquireLockShared() {
+  CriticalSectionScoped cs(critical_section_);
+  if (writer_active_ || writers_waiting_ > 0) {
+    ++readers_waiting_;
+
+    while (writer_active_ || writers_waiting_ > 0) {
+      read_condition_->SleepCS(*critical_section_);
+    }
+    --readers_waiting_;
+  }
+  ++readers_active_;
+}
+
+void RWLockGeneric::ReleaseLockShared() {
+  CriticalSectionScoped cs(critical_section_);
+  --readers_active_;
+  if (readers_active_ == 0 && writers_waiting_ > 0) {
+    write_condition_->Wake();
+  }
+}
+
+}  // namespace webrtc

webrtc/system_wrappers/source/rw_lock_generic.h

@@ -0,0 +1,46 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_GENERIC_H_
+#define WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_GENERIC_H_
+
+#include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+class CriticalSectionWrapper;
+class ConditionVariableWrapper;
+
+class RWLockGeneric : public RWLockWrapper {
+ public:
+  RWLockGeneric();
+  virtual ~RWLockGeneric();
+
+  virtual void AcquireLockExclusive() OVERRIDE;
+  virtual void ReleaseLockExclusive() OVERRIDE;
+
+  virtual void AcquireLockShared() OVERRIDE;
+  virtual void ReleaseLockShared() OVERRIDE;
+
+ private:
+  CriticalSectionWrapper* critical_section_;
+  ConditionVariableWrapper* read_condition_;
+  ConditionVariableWrapper* write_condition_;
+
+  int readers_active_;
+  bool writer_active_;
+  int readers_waiting_;
+  int writers_waiting_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_GENERIC_H_

webrtc/system_wrappers/source/rw_lock_posix.cc

@@ -0,0 +1,51 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/system_wrappers/source/rw_lock_posix.h"
+
+namespace webrtc {
+
+RWLockPosix::RWLockPosix() : lock_() {
+}
+
+RWLockPosix::~RWLockPosix() {
+  pthread_rwlock_destroy(&lock_);
+}
+
+RWLockPosix* RWLockPosix::Create() {
+  RWLockPosix* ret_val = new RWLockPosix();
+  if (!ret_val->Init()) {
+    delete ret_val;
+    return NULL;
+  }
+  return ret_val;
+}
+
+bool RWLockPosix::Init() {
+  return pthread_rwlock_init(&lock_, 0) == 0;
+}
+
+void RWLockPosix::AcquireLockExclusive() {
+  pthread_rwlock_wrlock(&lock_);
+}
+
+void RWLockPosix::ReleaseLockExclusive() {
+  pthread_rwlock_unlock(&lock_);
+}
+
+void RWLockPosix::AcquireLockShared() {
+  pthread_rwlock_rdlock(&lock_);
+}
+
+void RWLockPosix::ReleaseLockShared() {
+  pthread_rwlock_unlock(&lock_);
+}
+
+}  // namespace webrtc

webrtc/system_wrappers/source/rw_lock_posix.h

@@ -0,0 +1,41 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_POSIX_H_
+#define WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_POSIX_H_
+
+#include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
+#include "webrtc/typedefs.h"
+
+#include <pthread.h>
+
+namespace webrtc {
+
+class RWLockPosix : public RWLockWrapper {
+ public:
+  static RWLockPosix* Create();
+  virtual ~RWLockPosix();
+
+  virtual void AcquireLockExclusive() OVERRIDE;
+  virtual void ReleaseLockExclusive() OVERRIDE;
+
+  virtual void AcquireLockShared() OVERRIDE;
+  virtual void ReleaseLockShared() OVERRIDE;
+
+ private:
+  RWLockPosix();
+  bool Init();
+
+  pthread_rwlock_t lock_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_POSIX_H_

webrtc/system_wrappers/source/rw_lock_win.cc

@@ -0,0 +1,97 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/system_wrappers/source/rw_lock_win.h"
+
+#include "webrtc/system_wrappers/interface/trace.h"
+
+namespace webrtc {
+
+static bool native_rw_locks_supported = false;
+static bool module_load_attempted = false;
+static HMODULE library = NULL;
+
+typedef void (WINAPI* InitializeSRWLock)(PSRWLOCK);
+
+typedef void (WINAPI* AcquireSRWLockExclusive)(PSRWLOCK);
+typedef void (WINAPI* ReleaseSRWLockExclusive)(PSRWLOCK);
+
+typedef void (WINAPI* AcquireSRWLockShared)(PSRWLOCK);
+typedef void (WINAPI* ReleaseSRWLockShared)(PSRWLOCK);
+
+InitializeSRWLock       initialize_srw_lock;
+AcquireSRWLockExclusive acquire_srw_lock_exclusive;
+AcquireSRWLockShared    acquire_srw_lock_shared;
+ReleaseSRWLockShared    release_srw_lock_shared;
+ReleaseSRWLockExclusive release_srw_lock_exclusive;
+
+RWLockWin::RWLockWin() {
+  initialize_srw_lock(&lock_);
+}
+
+RWLockWin* RWLockWin::Create() {
+  if (!LoadModule()) {
+    return NULL;
+  }
+  return new RWLockWin();
+}
+
+void RWLockWin::AcquireLockExclusive() {
+  acquire_srw_lock_exclusive(&lock_);
+}
+
+void RWLockWin::ReleaseLockExclusive() {
+  release_srw_lock_exclusive(&lock_);
+}
+
+void RWLockWin::AcquireLockShared() {
+  acquire_srw_lock_shared(&lock_);
+}
+
+void RWLockWin::ReleaseLockShared() {
+  release_srw_lock_shared(&lock_);
+}
+
+bool RWLockWin::LoadModule() {
+  if (module_load_attempted) {
+    return native_rw_locks_supported;
+  }
+  module_load_attempted = true;
+  // Use native implementation if supported (i.e Vista+)
+  library = LoadLibrary(TEXT("Kernel32.dll"));
+  if (!library) {
+    return false;
+  }
+  WEBRTC_TRACE(kTraceStateInfo, kTraceUtility, -1, "Loaded Kernel.dll");
+
+  initialize_srw_lock =
+    (InitializeSRWLock)GetProcAddress(library, "InitializeSRWLock");
+
+  acquire_srw_lock_exclusive =
+    (AcquireSRWLockExclusive)GetProcAddress(library,
+                                            "AcquireSRWLockExclusive");
+  release_srw_lock_exclusive =
+    (ReleaseSRWLockExclusive)GetProcAddress(library,
+                                            "ReleaseSRWLockExclusive");
+  acquire_srw_lock_shared =
+    (AcquireSRWLockShared)GetProcAddress(library, "AcquireSRWLockShared");
+  release_srw_lock_shared =
+    (ReleaseSRWLockShared)GetProcAddress(library, "ReleaseSRWLockShared");
+
+  if (initialize_srw_lock && acquire_srw_lock_exclusive &&
+      release_srw_lock_exclusive && acquire_srw_lock_shared &&
+      release_srw_lock_shared) {
+    WEBRTC_TRACE(kTraceStateInfo, kTraceUtility, -1, "Loaded Native RW Lock");
+    native_rw_locks_supported = true;
+  }
+  return native_rw_locks_supported;
+}
+
+}  // namespace webrtc

webrtc/system_wrappers/source/rw_lock_win.h

@@ -0,0 +1,40 @@
+/*
+ *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_WIN_H_
+#define WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_WIN_H_
+
+#include "webrtc/system_wrappers/interface/rw_lock_wrapper.h"
+
+#include <Windows.h>
+
+namespace webrtc {
+
+class RWLockWin : public RWLockWrapper {
+ public:
+  static RWLockWin* Create();
+  ~RWLockWin() {}
+
+  virtual void AcquireLockExclusive();
+  virtual void ReleaseLockExclusive();
+
+  virtual void AcquireLockShared();
+  virtual void ReleaseLockShared();
+
+ private:
+  RWLockWin();
+  static bool LoadModule();
+
+  SRWLOCK lock_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_SYSTEM_WRAPPERS_SOURCE_RW_LOCK_WIN_H_

webrtc/system_wrappers/system_wrappers.gyp

@@ -86,6 +86,12 @@
         'source/logging.cc',
         'source/rtp_to_ntp.cc',
         'source/rw_lock.cc',
+        'source/rw_lock_generic.cc',
+        'source/rw_lock_generic.h',
+        'source/rw_lock_posix.cc',
+        'source/rw_lock_posix.h',
+        'source/rw_lock_win.cc',
+        'source/rw_lock_win.h',
         'source/set_thread_name_win.h',
         'source/sleep.cc',
         'source/sort.cc',