r211593 - Revert r211121 (and r211285), "Change libclang initialization to use std::call_once instead of"

[NAKAMURA Takumi]

Author: chapuni
Date: Tue Jun 24 08:50:01 2014
New Revision: 211593

URL: http://llvm.org/viewvc/llvm-project?rev=211593&view=rev
Log:
Revert r211121 (and r211285), "Change libclang initialization to use std::call_once instead of"

It broke mingw builder and cygwin-clang stage2, possibly lack of tls in <mutex>.

Modified:
    cfe/trunk/tools/libclang/CIndex.cpp

Modified: cfe/trunk/tools/libclang/CIndex.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/tools/libclang/CIndex.cpp?rev=211593&r1=211592&r2=211593&view=diff
==============================================================================
--- cfe/trunk/tools/libclang/CIndex.cpp (original)
+++ cfe/trunk/tools/libclang/CIndex.cpp Tue Jun 24 08:50:01 2014
@@ -51,7 +51,6 @@
 #include "llvm/Support/Threading.h"
 #include "llvm/Support/Timer.h"
 #include "llvm/Support/raw_ostream.h"
-#include <mutex>
 
 #ifdef __APPLE__
 #include <pthread.h>
@@ -2573,8 +2572,8 @@ buildPieces(unsigned NameFlags, bool IsM
 // Misc. API hooks.
 //===----------------------------------------------------------------------===//               
 
-static llvm::sys::Mutex LoggingMutex;
-static std::once_flag LibclangGlobalInitFlag;
+static llvm::sys::Mutex EnableMultithreadingMutex;
+static bool EnabledMultithreading;
 
 static void fatal_error_handler(void *user_data, const std::string& reason,
                                 bool gen_crash_diag) {
@@ -2584,10 +2583,6 @@ static void fatal_error_handler(void *us
   ::abort();
 }
 
-static void initializeLibClang() {
-  llvm::install_fatal_error_handler(fatal_error_handler, nullptr);
-}
-
 extern "C" {
 CXIndex clang_createIndex(int excludeDeclarationsFromPCH,
                           int displayDiagnostics) {
@@ -2596,7 +2591,15 @@ CXIndex clang_createIndex(int excludeDec
   if (!getenv("LIBCLANG_DISABLE_CRASH_RECOVERY"))
     llvm::CrashRecoveryContext::Enable();
 
-  std::call_once(LibclangGlobalInitFlag, initializeLibClang);
+  // Enable support for multithreading in LLVM.
+  {
+    llvm::sys::ScopedLock L(EnableMultithreadingMutex);
+    if (!EnabledMultithreading) {
+      llvm::install_fatal_error_handler(fatal_error_handler, nullptr);
+      llvm::llvm_start_multithreaded();
+      EnabledMultithreading = true;
+    }
+  }
 
   CIndexer *CIdxr = new CIndexer();
   if (excludeDeclarationsFromPCH)
@@ -6974,7 +6977,7 @@ Logger &cxindex::Logger::operator<<(cons
 cxindex::Logger::~Logger() {
   LogOS.flush();
 
-  llvm::sys::ScopedLock L(LoggingMutex);
+  llvm::sys::ScopedLock L(EnableMultithreadingMutex);
 
   static llvm::TimeRecord sBeginTR = llvm::TimeRecord::getCurrentTime();