Move Threading.[h|cpp] from Support to System.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73707 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/System/Threading.h

@@ -0,0 +1,45 @@
+//===-- llvm/System/Threading.h - Control multithreading mode --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// TThis file defines llvm_start_multithreaded() and friends.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_SYSTEM_THREADING_H
+#define LLVM_SYSTEM_THREADING_H
+
+namespace llvm {
+  /// llvm_start_multithreaded - Allocate and initialize structures needed to
+  /// make LLVM safe for multithreading.  The return value indicates whether
+  /// multithreaded initialization succeeded.  LLVM will still be operational
+  /// on "failed" return, and will still be safe for hosting threading 
+  /// applications in the JIT, but will not be safe for concurrent calls to the
+  /// LLVM APIs.
+  /// THIS MUST EXECUTE IN ISOLATION FROM ALL OTHER LLVM API CALLS.
+  bool llvm_start_multithreaded();
+  
+  /// llvm_stop_multithreaded - Deallocate structures necessary to make LLVM
+  /// safe for multithreading.
+  /// THIS MUST EXECUTE IN ISOLATION FROM ALL OTHER LLVM API CALLS.
+  void llvm_stop_multithreaded();
+  
+  /// llvm_is_multithreaded - Check whether LLVM is executing in thread-safe
+  /// mode or not.
+  bool llvm_is_multithreaded();
+  
+  /// acquire_global_lock - Acquire the global lock.  This is a no-op if called
+  /// before llvm_start_multithreaded().
+  void llvm_acquire_global_lock();
+  
+  /// release_global_lock - Release the global lock.  This is a no-op if called
+  /// before llvm_start_multithreaded().
+  void llvm_release_global_lock();
+}
+
+#endif