[llvm-commits] [llvm] r119718 - /llvm/trunk/lib/System/DynamicLibrary.cpp

[Owen Anderson]

Author: resistor
Date: Thu Nov 18 12:49:05 2010
New Revision: 119718

URL: http://llvm.org/viewvc/llvm-project?rev=119718&view=rev
Log:
Use thread-safe statics to avoid a static constructor here.  This isn't thread-safe on MSVC, but we don't
support threaded LLVM there anyways.

Modified:
    llvm/trunk/lib/System/DynamicLibrary.cpp

Modified: llvm/trunk/lib/System/DynamicLibrary.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/System/DynamicLibrary.cpp?rev=119718&r1=119717&r2=119718&view=diff
==============================================================================
--- llvm/trunk/lib/System/DynamicLibrary.cpp (original)
+++ llvm/trunk/lib/System/DynamicLibrary.cpp Thu Nov 18 12:49:05 2010
@@ -61,9 +61,19 @@
 //===          independent code.
 //===----------------------------------------------------------------------===//
 
-static SmartMutex<true> HandlesMutex;
+static SmartMutex<true>* HandlesMutex;
 static std::vector<void *> *OpenedHandles = 0;
 
+static bool InitializeMutex() {
+  HandlesMutex = new SmartMutex<true>;
+  return HandlesMutex != 0;
+}
+
+static bool EnsureMutexInitialized() {
+  static bool result = InitializeMutex();
+  return result;
+}
+
 
 bool DynamicLibrary::LoadLibraryPermanently(const char *Filename,
                                             std::string *ErrMsg) {
@@ -78,7 +88,8 @@
   if (Filename == NULL)
     H = RTLD_DEFAULT;
 #endif
-  SmartScopedLock<true> Lock(HandlesMutex);
+  EnsureMutexInitialized();
+  SmartScopedLock<true> Lock(*HandlesMutex);
   if (OpenedHandles == 0)
     OpenedHandles = new std::vector<void *>();
   OpenedHandles->push_back(H);
@@ -113,7 +124,8 @@
 
 #if HAVE_DLFCN_H
   // Now search the libraries.
-  SmartScopedLock<true> Lock(HandlesMutex);
+  EnsureMutexInitialized();
+  SmartScopedLock<true> Lock(*HandlesMutex);
   if (OpenedHandles) {
     for (std::vector<void *>::iterator I = OpenedHandles->begin(),
          E = OpenedHandles->end(); I != E; ++I) {