Port LockImpl, Lock, and ConditionVariable to pthreads-supporting platforms.

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@567 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 195 insertions, 78 deletions

diff --git a/base/base.xcodeproj/project.pbxproj b/base/base.xcodeproj/project.pbxproj
index 529183c..d17a22e 100644
--- a/base/base.xcodeproj/project.pbxproj
+++ b/base/base.xcodeproj/project.pbxproj
@@ -49,7 +49,7 @@
 		824652C10DC12044007C2BAA /* hash_tables.h in Headers */ = {isa = PBXBuildFile; fileRef = 824652C00DC12044007C2BAA /* hash_tables.h */; };
 		824653450DC1230B007C2BAA /* lock.cc in Sources */ = {isa = PBXBuildFile; fileRef = 825403250D92D2090006B936 /* lock.cc */; };
 		824653460DC1230C007C2BAA /* lock.h in Headers */ = {isa = PBXBuildFile; fileRef = 825403260D92D2090006B936 /* lock.h */; };
-		824653680DC12CEC007C2BAA /* condition_variable_mac.cc in Sources */ = {isa = PBXBuildFile; fileRef = 824653670DC12CEC007C2BAA /* condition_variable_mac.cc */; };
+		824653680DC12CEC007C2BAA /* condition_variable_posix.cc in Sources */ = {isa = PBXBuildFile; fileRef = 824653670DC12CEC007C2BAA /* condition_variable_posix.cc */; };
 		824653690DC12CF2007C2BAA /* condition_variable.h in Headers */ = {isa = PBXBuildFile; fileRef = 825402EB0D92D1940006B936 /* condition_variable.h */; };
 		824653740DC12D0E007C2BAA /* shared_memory_posix.cc in Sources */ = {isa = PBXBuildFile; fileRef = 824653730DC12D0E007C2BAA /* shared_memory_posix.cc */; };
 		824653750DC12D0F007C2BAA /* shared_memory.h in Headers */ = {isa = PBXBuildFile; fileRef = 825403760D92D2CF0006B936 /* shared_memory.h */; };
@@ -85,7 +85,7 @@
 		829E31340DBFDB6F00819EBF /* CoreGraphics.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 829E31330DBFDB6F00819EBF /* CoreGraphics.framework */; };
 		829E35D50DC0DC9400819EBF /* logging.cc in Sources */ = {isa = PBXBuildFile; fileRef = 825403270D92D2090006B936 /* logging.cc */; };
 		829E35D60DC0DC9400819EBF /* logging.h in Headers */ = {isa = PBXBuildFile; fileRef = 825403280D92D2090006B936 /* logging.h */; };
-		829E35DA0DC0DD0400819EBF /* lock_impl_mac.cc in Sources */ = {isa = PBXBuildFile; fileRef = 7BEFC29D0D99832D000829AD /* lock_impl_mac.cc */; };
+		829E35DA0DC0DD0400819EBF /* lock_impl_posix.cc in Sources */ = {isa = PBXBuildFile; fileRef = 7BEFC29D0D99832D000829AD /* lock_impl_posix.cc */; };
 		829E35DB0DC0DD0500819EBF /* lock_impl.h in Headers */ = {isa = PBXBuildFile; fileRef = 7BEFC29C0D99832D000829AD /* lock_impl.h */; };
 		829E36420DC0F69D00819EBF /* string16.h in Headers */ = {isa = PBXBuildFile; fileRef = 821B91680DAABD7F00F350D7 /* string16.h */; };
 		829E36430DC0F69E00819EBF /* string_util_mac.h in Headers */ = {isa = PBXBuildFile; fileRef = 7BEE52C10D9D84FD0067FF23 /* string_util_mac.h */; };
@@ -308,7 +308,7 @@
 		7BEB834D0D9C4BE0009BA8DD /* string_util_mac.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = string_util_mac.cc; sourceTree = "<group>"; };
 		7BEE52C10D9D84FD0067FF23 /* string_util_mac.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = string_util_mac.h; sourceTree = "<group>"; };
 		7BEFC29C0D99832D000829AD /* lock_impl.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = lock_impl.h; sourceTree = "<group>"; };
-		7BEFC29D0D99832D000829AD /* lock_impl_mac.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = lock_impl_mac.cc; sourceTree = "<group>"; };
+		7BEFC29D0D99832D000829AD /* lock_impl_posix.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = lock_impl_posix.cc; sourceTree = "<group>"; };
 		820EB4EB0E3A60FE009668FC /* idle_timer.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = idle_timer.cc; sourceTree = "<group>"; };
 		820EB4EC0E3A60FE009668FC /* idle_timer.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = idle_timer.h; sourceTree = "<group>"; };
 		820EB4EF0E3A610A009668FC /* linked_ptr.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = linked_ptr.h; sourceTree = "<group>"; };
@@ -326,7 +326,7 @@
 		821B91680DAABD7F00F350D7 /* string16.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = string16.h; sourceTree = "<group>"; };
 		822BDC710DF739F000034F4C /* message_loop_mac.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = message_loop_mac.mm; sourceTree = "<group>"; };
 		824652C00DC12044007C2BAA /* hash_tables.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = hash_tables.h; sourceTree = "<group>"; };
-		824653670DC12CEC007C2BAA /* condition_variable_mac.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = condition_variable_mac.cc; sourceTree = "<group>"; };
+		824653670DC12CEC007C2BAA /* condition_variable_posix.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = condition_variable_posix.cc; sourceTree = "<group>"; };
 		824653730DC12D0E007C2BAA /* shared_memory_posix.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = shared_memory_posix.cc; sourceTree = "<group>"; };
 		824654900DC25A8C007C2BAA /* time.cc */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = time.cc; sourceTree = "<group>"; };
 		825402BB0D92D0FA0006B936 /* libbase.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = libbase.a; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -561,7 +561,7 @@
 				E4A133490E37A41D00110AA2 /* command_line.cc */,
 				E4A1334A0E37A41D00110AA2 /* command_line.h */,
 				825402EB0D92D1940006B936 /* condition_variable.h */,
-				824653670DC12CEC007C2BAA /* condition_variable_mac.cc */,
+				824653670DC12CEC007C2BAA /* condition_variable_posix.cc */,
 				825402F30D92D1AC0006B936 /* debug_on_start.h */,
 				825402F40D92D1AC0006B936 /* debug_on_start.cc */,
 				825402F10D92D1AC0006B936 /* debug_util.h */,
@@ -595,7 +595,7 @@
 				825403250D92D2090006B936 /* lock.cc */,
 				825403260D92D2090006B936 /* lock.h */,
 				7BEFC29C0D99832D000829AD /* lock_impl.h */,
-				7BEFC29D0D99832D000829AD /* lock_impl_mac.cc */,
+				7BEFC29D0D99832D000829AD /* lock_impl_posix.cc */,
 				825403270D92D2090006B936 /* logging.cc */,
 				825403280D92D2090006B936 /* logging.h */,
 				825403290D92D2090006B936 /* md5.cc */,
@@ -1091,13 +1091,13 @@
 			buildActionMask = 2147483647;
 			files = (
 				829E35D50DC0DC9400819EBF /* logging.cc in Sources */,
-				829E35DA0DC0DD0400819EBF /* lock_impl_mac.cc in Sources */,
+				829E35DA0DC0DD0400819EBF /* lock_impl_posix.cc in Sources */,
 				829E36440DC0F69F00819EBF /* string_util_mac.cc in Sources */,
 				829E36460DC0F6AC00819EBF /* string_util.cc in Sources */,
 				829E365F0DC0FB1C00819EBF /* stats_table.cc in Sources */,
 				829E36730DC0FBAD00819EBF /* thread_local_storage_posix.cc in Sources */,
 				824653450DC1230B007C2BAA /* lock.cc in Sources */,
-				824653680DC12CEC007C2BAA /* condition_variable_mac.cc in Sources */,
+				824653680DC12CEC007C2BAA /* condition_variable_posix.cc in Sources */,
 				824653740DC12D0E007C2BAA /* shared_memory_posix.cc in Sources */,
 				824654530DC25633007C2BAA /* time_mac.cc in Sources */,
 				8246548C0DC259DB007C2BAA /* revocable_store.cc in Sources */,
diff --git a/base/build/base.vcproj b/base/build/base.vcproj
index a5257cb..3e2cd15 100644
--- a/base/build/base.vcproj
+++ b/base/build/base.vcproj
@@ -234,11 +234,11 @@
 			>
 		</File>
 		<File
-			RelativePath="..\condition_variable.cc"
+			RelativePath="..\condition_variable.h"
 			>
 		</File>
 		<File
-			RelativePath="..\condition_variable.h"
+			RelativePath="..\condition_variable_win.cc"
 			>
 		</File>
 		<File
diff --git a/base/condition_variable.h b/base/condition_variable.h
index bdb9a19..f30ffba 100644
--- a/base/condition_variable.h
+++ b/base/condition_variable.h
@@ -27,37 +27,35 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// ConditionVariable is a reasonable attempt at simulating
-// the newer Posix and Vista-only construct for condition variable
-// synchronization.  This functionality is very helpful for having several
-// threads wait for an event, as is common with a thread pool
-// managed by a master.  The meaning of such an event in the
-// (worker) thread pool scenario is that additional tasks are
-// now available for processing.  It is used in Chrome in the
-// DNS prefetching system to notify worker threads that a queue
-// now has items (tasks) which need to be tended to.
-// A related use would have a pool manager waiting on a
-// ConditionVariable, waiting for a thread in the pool to announce
-// (signal) that there is now more room in a (bounded size) communications
-// queue for the manager to deposit tasks, or, as a second example, that
-// the queue of tasks is completely empty and all workers are waiting.
-
+// ConditionVariable wraps pthreads condition variable synchronization or, on
+// Windows, simulates it.  This functionality is very helpful for having
+// several threads wait for an event, as is common with a thread pool managed
+// by a master.  The meaning of such an event in the (worker) thread pool
+// scenario is that additional tasks are now available for processing.  It is
+// used in Chrome in the DNS prefetching system to notify worker threads that
+// a queue now has items (tasks) which need to be tended to.  A related use
+// would have a pool manager waiting on a ConditionVariable, waiting for a
+// thread in the pool to announce (signal) that there is now more room in a
+// (bounded size) communications queue for the manager to deposit tasks, or,
+// as a second example, that the queue of tasks is completely empty and all
+// workers are waiting.
+//
 // USAGE NOTE 1: spurious signal events are possible with this and
 // most implementations of condition variables.  As a result, be
 // *sure* to retest your condition before proceeding.  The following
 // is a good example of doing this correctly:
-
+//
 // while (!work_to_be_done()) Wait(...);
-
+//
 // In contrast do NOT do the following:
-
+//
 // if (!work_to_be_done()) Wait(...);  // Don't do this.
-
+//
 // Especially avoid the above if you are relying on some other thread only
 // issuing a signal up *if* there is work-to-do.  There can/will
 // be spurious signals.  Recheck state on waiting thread before
 // assuming the signal was intentional. Caveat caller ;-).
-
+//
 // USAGE NOTE 2: Broadcast() frees up all waiting threads at once,
 // which leads to contention for the locks they all held when they
 // called Wait().  This results in POOR performance.  A much better
@@ -65,11 +63,11 @@
 // thread (upon exiting Wait()) call Signal() to free up another
 // Wait'ing thread.  Look at condition_variable_unittest.cc for
 // both examples.
-
+//
 // Broadcast() can be used nicely during teardown, as it gets the job
 // done, and leaves no sleeping threads... and performance is less
 // critical at that point.
-
+//
 // The semantics of Broadcast() are carefully crafted so that *all*
 // threads that were waiting when the request was made will indeed
 // get signaled.  Some implementations mess up, and don't signal them
@@ -77,7 +75,7 @@
 // for a while while waiting threads come around).  This implementation
 // appears correct, as it will not "lose" any signals, and will guarantee
 // that all threads get signaled by Broadcast().
-
+//
 // This implementation offers support for "performance" in its selection of
 // which thread to revive.  Performance, in direct contrast with "fairness,"
 // assures that the thread that most recently began to Wait() is selected by
@@ -85,20 +83,18 @@
 // thread that has Wait()ed the longest is selected. The default policy
 // may improve performance, as the selected thread may have a greater chance of
 // having some of its stack data in various CPU caches.
-
+//
 // For a discussion of the many very subtle implementation details, see the FAQ
-// at the end of condition_variable.cc.
+// at the end of condition_variable_win.cc.
 
-#ifndef BASE_CONDITION_VARIABLE_H__
-#define BASE_CONDITION_VARIABLE_H__
+#ifndef BASE_CONDITION_VARIABLE_H_
+#define BASE_CONDITION_VARIABLE_H_
 
 #include "base/lock.h"
 #include "base/logging.h"
 #include "base/scoped_ptr.h"
 #include "base/time.h"
 
-class Lock;
-
 class ConditionVariable {
  public:
   // Construct a cv for use with ONLY one user lock.
@@ -108,12 +104,8 @@ class ConditionVariable {
 
   // Wait() releases the caller's critical section atomically as it starts to
   // sleep, and the reacquires it when it is signaled.
+  void Wait();
   void TimedWait(const TimeDelta& max_time);
-  void Wait() {
-    // Default to "wait forever" timing, which means have to get a Signal()
-    // or Broadcast() to come out of this wait state.
-    TimedWait(TimeDelta::FromMilliseconds(INFINITE));
-  }
 
   // Broadcast() revives all waiting threads.
   void Broadcast();
@@ -121,6 +113,9 @@ class ConditionVariable {
   void Signal();
 
  private:
+
+#if defined(OS_WIN)
+
   // Define Event class that is used to form circularly linked lists.
   // The list container is an element with NULL as its handle_ value.
   // The actual list elements have a non-zero handle_ value.
@@ -161,7 +156,7 @@ class ConditionVariable {
     HANDLE handle_;
     Event* next_;
     Event* prev_;
-    DISALLOW_EVIL_CONSTRUCTORS(Event);
+    DISALLOW_COPY_AND_ASSIGN(Event);
   };
 
   // Note that RUNNING is an unlikely number to have in RAM by accident.
@@ -176,6 +171,7 @@ class ConditionVariable {
 
   // Private critical section for access to member data.
   Lock internal_lock_;
+
   // Lock that is acquired before calling Wait().
   Lock& user_lock_;
 
@@ -189,7 +185,14 @@ class ConditionVariable {
   // The number of allocated, but not yet deleted events.
   int allocation_counter_;
 
-  DISALLOW_EVIL_CONSTRUCTORS(ConditionVariable);
+#elif defined(OS_POSIX)
+
+  pthread_cond_t condition_;
+  pthread_mutex_t* user_mutex_;
+
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(ConditionVariable);
 };
 
-#endif  // BASE_CONDITION_VARIABLE_H__
+#endif  // BASE_CONDITION_VARIABLE_H_
diff --git a/base/condition_variable_posix.cc b/base/condition_variable_posix.cc
new file mode 100644
index 0000000..e234ece
--- /dev/null
+++ b/base/condition_variable_posix.cc
@@ -0,0 +1,85 @@
+// Copyright 2008, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "base/condition_variable.h"
+
+#include <errno.h>
+#include <sys/time.h>
+
+#include "base/lock.h"
+#include "base/lock_impl.h"
+#include "base/logging.h"
+
+ConditionVariable::ConditionVariable(Lock* user_lock)
+    : user_mutex_(user_lock->lock_impl()->os_lock()) {
+  int rv = pthread_cond_init(&condition_, NULL);
+  DCHECK(rv == 0);
+}
+
+ConditionVariable::~ConditionVariable() {
+  int rv = pthread_cond_destroy(&condition_);
+  DCHECK(rv == 0);
+}
+
+void ConditionVariable::Wait() {
+  int rv = pthread_cond_wait(&condition_, user_mutex_);
+  DCHECK(rv == 0);
+}
+
+void ConditionVariable::TimedWait(const TimeDelta& max_time) {
+  int64 usecs = max_time.InMicroseconds();
+
+  // The timeout argument to pthread_cond_timedwait is in absolute time.
+  struct timeval now;
+  gettimeofday(&now, NULL);
+
+  const int kMicrosPerUnit = 1000000;
+  const int kNanosPerMicro = 1000;
+  const int kNanosPerUnit = kMicrosPerUnit * kNanosPerMicro;
+
+  struct timespec abstime;
+  abstime.tv_sec = now.tv_sec + (usecs / kMicrosPerUnit);
+  abstime.tv_nsec = (now.tv_usec + (usecs % kMicrosPerUnit)) * kNanosPerMicro;
+  abstime.tv_sec += abstime.tv_nsec / kNanosPerUnit;
+  abstime.tv_nsec %= kNanosPerUnit;
+  DCHECK(abstime.tv_sec >= now.tv_sec);  // Overflow paranoia
+
+  int rv = pthread_cond_timedwait(&condition_, user_mutex_, &abstime);
+  DCHECK(rv == 0 || rv == ETIMEDOUT);
+}
+
+void ConditionVariable::Broadcast() {
+  int rv = pthread_cond_broadcast(&condition_);
+  DCHECK(rv == 0);
+}
+
+void ConditionVariable::Signal() {
+  int rv = pthread_cond_signal(&condition_);
+  DCHECK(rv == 0);
+}
diff --git a/base/condition_variable.cc b/base/condition_variable_win.cc
index 0e4f7c8..9b17261 100644
--- a/base/condition_variable.cc
+++ b/base/condition_variable_win.cc
@@ -65,8 +65,12 @@ ConditionVariable::~ConditionVariable() {
   DCHECK_EQ(recycling_list_size_, allocation_counter_);
 }
 
-// Wait() atomically releases the caller's lock as it starts to Wait, and then
-// reacquires it when it is signaled.
+void ConditionVariable::Wait() {
+  // Default to "wait forever" timing, which means have to get a Signal()
+  // or Broadcast() to come out of this wait state.
+  TimedWait(TimeDelta::FromMilliseconds(INFINITE));
+}
+
 void ConditionVariable::TimedWait(const TimeDelta& max_time) {
   Event* waiting_event;
   HANDLE handle;
diff --git a/base/lock.h b/base/lock.h
index 59b0aea..249dae3 100644
--- a/base/lock.h
+++ b/base/lock.h
@@ -27,8 +27,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef BASE_LOCK_H__
-#define BASE_LOCK_H__
+#ifndef BASE_LOCK_H_
+#define BASE_LOCK_H_
 
 #include "base/lock_impl.h"
 
@@ -50,6 +50,11 @@ class Lock {
   // held by something else, immediately return false.
   bool Try();
 
+  // Return the underlying lock implementation.
+  // TODO(awalker): refactor lock and condition variables so that this is
+  // unnecessary.
+  LockImpl* lock_impl() { return &lock_; }
+
  private:
   LockImpl lock_;  // User-supplied underlying lock implementation.
 
@@ -69,7 +74,7 @@ class Lock {
   int32 contention_count_;
 #endif  // NDEBUG
 
-  DISALLOW_EVIL_CONSTRUCTORS(Lock);
+  DISALLOW_COPY_AND_ASSIGN(Lock);
 };
 
 // A helper class that acquires the given Lock while the AutoLock is in scope.
@@ -85,7 +90,7 @@ class AutoLock {
 
  private:
   Lock& lock_;
-  DISALLOW_EVIL_CONSTRUCTORS(AutoLock);
+  DISALLOW_COPY_AND_ASSIGN(AutoLock);
 };
 
 // AutoUnlock is a helper class for ConditionVariable instances
@@ -111,4 +116,4 @@ class AutoUnlock {
   int release_count_;
 };
 
-#endif  // BASE_LOCK_H__
+#endif  // BASE_LOCK_H_
diff --git a/base/lock_impl.h b/base/lock_impl.h
index 331bdc6..a33f107 100644
--- a/base/lock_impl.h
+++ b/base/lock_impl.h
@@ -27,22 +27,30 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#ifndef BASE_LOCK_IMPL_H__
-#define BASE_LOCK_IMPL_H__
+#ifndef BASE_LOCK_IMPL_H_
+#define BASE_LOCK_IMPL_H_
 
-#include "base/basictypes.h"
+#include "build/build_config.h"
 
-#if defined(WIN32)
-#include <Windows.h>
-#elif defined(__APPLE__)
-#include <libkern/OSAtomic.h>
+#if defined(OS_WIN)
+#include <windows.h>
+#elif defined(OS_POSIX)
+#include <pthread.h>
 #endif
 
+#include "base/basictypes.h"
+
 // This class implements the underlying platform-specific spin-lock mechanism
 // used for the Lock class.  Most users should not use LockImpl directly, but
 // should instead use Lock.
 class LockImpl {
  public:
+#if defined(OS_WIN)
+  typedef CRITICAL_SECTION OSLockType;
+#elif defined(OS_POSIX)
+  typedef pthread_mutex_t OSLockType;
+#endif
+
   LockImpl();
   ~LockImpl();
 
@@ -57,14 +65,15 @@ class LockImpl {
   // a successful call to Try, or a call to Lock.
   void Unlock();
 
+  // Return the native underlying lock.
+  // TODO(awalker): refactor lock and condition variables so that this is
+  // unnecessary.
+  OSLockType* os_lock() { return &os_lock_; }
+
  private:
-#if defined(WIN32)
-  CRITICAL_SECTION critical_section_;
-#elif defined(__APPLE__)
-  OSSpinLock spin_lock_;
-#endif
+  OSLockType os_lock_;
 
-  DISALLOW_EVIL_CONSTRUCTORS(LockImpl);
+  DISALLOW_COPY_AND_ASSIGN(LockImpl);
 };
 
 class AutoLockImpl {
@@ -84,4 +93,4 @@ class AutoLockImpl {
   LockImpl* lock_impl_;
 };
 
-#endif  // BASE_LOCK_IMPL_H__
+#endif  // BASE_LOCK_IMPL_H_
diff --git a/base/lock_impl_mac.cc b/base/lock_impl_posix.cc
index fcb630d..aceb414 100644
--- a/base/lock_impl_mac.cc
+++ b/base/lock_impl_posix.cc
@@ -29,21 +29,32 @@
 
 #include "base/lock_impl.h"
 
-LockImpl::LockImpl()
-    : spin_lock_(0) {
+#include <errno.h>
+
+#include "base/logging.h"
+
+LockImpl::LockImpl() {
+  int rv = pthread_mutex_init(&os_lock_, NULL);
+  DCHECK(rv == 0);
 }
 
 LockImpl::~LockImpl() {
+  int rv = pthread_mutex_destroy(&os_lock_);
+  DCHECK(rv == 0);
 }
 
 bool LockImpl::Try() {
-  return ::OSSpinLockTry(&spin_lock_);
+  int rv = pthread_mutex_trylock(&os_lock_);
+  DCHECK(rv == 0 || rv == EBUSY);
+  return rv == 0;
 }
 
 void LockImpl::Lock() {
-  ::OSSpinLockLock(&spin_lock_);
+  int rv = pthread_mutex_lock(&os_lock_);
+  DCHECK(rv == 0);
 }
 
 void LockImpl::Unlock() {
-  ::OSSpinLockUnlock(&spin_lock_);
+  int rv = pthread_mutex_unlock(&os_lock_);
+  DCHECK(rv == 0);
 }
diff --git a/base/lock_impl_win.cc b/base/lock_impl_win.cc
index a45cbdd..5298176 100644
--- a/base/lock_impl_win.cc
+++ b/base/lock_impl_win.cc
@@ -30,21 +30,21 @@
 #include "base/lock_impl.h"
 
 LockImpl::LockImpl() {
-  ::InitializeCriticalSection(&critical_section_);
+  ::InitializeCriticalSection(&os_lock_);
 }
 
 LockImpl::~LockImpl() {
-  ::DeleteCriticalSection(&critical_section_);
+  ::DeleteCriticalSection(&os_lock_);
 }
 
 bool LockImpl::Try() {
-  return ::TryEnterCriticalSection(&critical_section_) != FALSE;
+  return ::TryEnterCriticalSection(&os_lock_) != FALSE;
 }
 
 void LockImpl::Lock() {
-  ::EnterCriticalSection(&critical_section_);
+  ::EnterCriticalSection(&os_lock_);
 }
 
 void LockImpl::Unlock() {
-  ::LeaveCriticalSection(&critical_section_);
+  ::LeaveCriticalSection(&os_lock_);
 }