Merging r258729:

[oota-llvm.git] / lib / Support / Mutex.cpp

diff --git a/lib/Support/Mutex.cpp b/lib/Support/Mutex.cpp
index b408973bbad1557b922c2a5bc97f081f1fa2e519..c8d3844d0c9618a19133836c06aabac831f42e35 100644 (file)
--- a/lib/Support/Mutex.cpp
+++ b/lib/Support/Mutex.cpp
@@ -19,7 +19,7 @@
 //===          independent code.
 //===----------------------------------------------------------------------===//
 
-#if !defined(ENABLE_THREADS) || ENABLE_THREADS == 0
+#if !defined(LLVM_ENABLE_THREADS) || LLVM_ENABLE_THREADS == 0
 // Define all methods as no-ops if threading is explicitly disabled
 namespace llvm {
 using namespace sys;
@@ -40,109 +40,74 @@ bool MutexImpl::tryacquire() { return true; }
 namespace llvm {
 using namespace sys;
 
-
-// This variable is useful for situations where the pthread library has been
-// compiled with weak linkage for its interface symbols. This allows the
-// threading support to be turned off by simply not linking against -lpthread.
-// In that situation, the value of pthread_mutex_init will be 0 and
-// consequently pthread_enabled will be false. In such situations, all the
-// pthread operations become no-ops and the functions all return false. If
-// pthread_mutex_init does have an address, then mutex support is enabled.
-// Note: all LLVM tools will link against -lpthread if its available since it
-//       is configured into the LIBS variable.
-// Note: this line of code generates a warning if pthread_mutex_init is not
-//       declared with weak linkage. It's safe to ignore the warning.
-static const bool pthread_enabled = true;
-
 // Construct a Mutex using pthread calls
 MutexImpl::MutexImpl( bool recursive)
-  : data_(0)
+  : data_(nullptr)
 {
-  if (pthread_enabled)
-  {
-    // Declare the pthread_mutex data structures
-    pthread_mutex_t* mutex =
-      static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t)));
-    pthread_mutexattr_t attr;
-
-    // Initialize the mutex attributes
-    int errorcode = pthread_mutexattr_init(&attr);
-    assert(errorcode == 0);
-
-    // Initialize the mutex as a recursive mutex, if requested, or normal
-    // otherwise.
-    int kind = ( recursive  ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
-    errorcode = pthread_mutexattr_settype(&attr, kind);
-    assert(errorcode == 0);
-
-#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__) && !defined(__DragonFly__)
-    // Make it a process local mutex
-    errorcode = pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE);
-    assert(errorcode == 0);
-#endif
-
-    // Initialize the mutex
-    errorcode = pthread_mutex_init(mutex, &attr);
-    assert(errorcode == 0);
-
-    // Destroy the attributes
-    errorcode = pthread_mutexattr_destroy(&attr);
-    assert(errorcode == 0);
-
-    // Assign the data member
-    data_ = mutex;
-  }
+  // Declare the pthread_mutex data structures
+  pthread_mutex_t* mutex =
+    static_cast<pthread_mutex_t*>(malloc(sizeof(pthread_mutex_t)));
+  pthread_mutexattr_t attr;
+
+  // Initialize the mutex attributes
+  int errorcode = pthread_mutexattr_init(&attr);
+  assert(errorcode == 0); (void)errorcode;
+
+  // Initialize the mutex as a recursive mutex, if requested, or normal
+  // otherwise.
+  int kind = ( recursive  ? PTHREAD_MUTEX_RECURSIVE : PTHREAD_MUTEX_NORMAL );
+  errorcode = pthread_mutexattr_settype(&attr, kind);
+  assert(errorcode == 0);
+
+  // Initialize the mutex
+  errorcode = pthread_mutex_init(mutex, &attr);
+  assert(errorcode == 0);
+
+  // Destroy the attributes
+  errorcode = pthread_mutexattr_destroy(&attr);
+  assert(errorcode == 0);
+
+  // Assign the data member
+  data_ = mutex;
 }
 
 // Destruct a Mutex
 MutexImpl::~MutexImpl()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
-    pthread_mutex_destroy(mutex);
-    free(mutex);
-  }
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != nullptr);
+  pthread_mutex_destroy(mutex);
+  free(mutex);
 }
 
 bool
 MutexImpl::acquire()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
-
-    int errorcode = pthread_mutex_lock(mutex);
-    return errorcode == 0;
-  } else return false;
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != nullptr);
+
+  int errorcode = pthread_mutex_lock(mutex);
+  return errorcode == 0;
 }
 
 bool
 MutexImpl::release()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
-
-    int errorcode = pthread_mutex_unlock(mutex);
-    return errorcode == 0;
-  } else return false;
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != nullptr);
+
+  int errorcode = pthread_mutex_unlock(mutex);
+  return errorcode == 0;
 }
 
 bool
 MutexImpl::tryacquire()
 {
-  if (pthread_enabled)
-  {
-    pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
-    assert(mutex != 0);
-
-    int errorcode = pthread_mutex_trylock(mutex);
-    return errorcode == 0;
-  } else return false;
+  pthread_mutex_t* mutex = static_cast<pthread_mutex_t*>(data_);
+  assert(mutex != nullptr);
+
+  int errorcode = pthread_mutex_trylock(mutex);
+  return errorcode == 0;
 }
 
 }
@@ -152,6 +117,6 @@ MutexImpl::tryacquire()
 #elif defined( LLVM_ON_WIN32)
 #include "Windows/Mutex.inc"
 #else
-#warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 was set in System/Mutex.cpp
+#warning Neither LLVM_ON_UNIX nor LLVM_ON_WIN32 was set in Support/Mutex.cpp
 #endif
 #endif