Revert r211287, "Remove support for LLVM runtime multi-threading."
libclang still requires it on cygming, lack of incomplete <mutex>.
llvm-svn: 211592
diff --git a/llvm/include/llvm-c/Core.h b/llvm/include/llvm-c/Core.h
index 8693a30..0e78ed7 100644
--- a/llvm/include/llvm-c/Core.h
+++ b/llvm/include/llvm-c/Core.h
@@ -2848,13 +2848,16 @@
* @{
*/
-/** Deprecated: Multi-threading can only be enabled/disabled with the compile
- time define LLVM_ENABLE_THREADS. This function always returns
- LLVMIsMultithreaded(). */
+/** Allocate and initialize structures needed to make LLVM safe for
+ multithreading. The return value indicates whether multithreaded
+ initialization succeeded. Must be executed in isolation from all
+ other LLVM api calls.
+ @see llvm::llvm_start_multithreaded */
LLVMBool LLVMStartMultithreaded(void);
-/** Deprecated: Multi-threading can only be enabled/disabled with the compile
- time define LLVM_ENABLE_THREADS. */
+/** Deallocate structures necessary to make LLVM safe for multithreading.
+ Must be executed in isolation from all other LLVM api calls.
+ @see llvm::llvm_stop_multithreaded */
void LLVMStopMultithreaded(void);
/** Check whether LLVM is executing in thread-safe mode or not.
diff --git a/llvm/include/llvm/Support/ManagedStatic.h b/llvm/include/llvm/Support/ManagedStatic.h
index d8fbfeb..1bb8cea 100644
--- a/llvm/include/llvm/Support/ManagedStatic.h
+++ b/llvm/include/llvm/Support/ManagedStatic.h
@@ -103,6 +103,9 @@
/// llvm_shutdown() when it is destroyed.
struct llvm_shutdown_obj {
llvm_shutdown_obj() { }
+ explicit llvm_shutdown_obj(bool multithreaded) {
+ if (multithreaded) llvm_start_multithreaded();
+ }
~llvm_shutdown_obj() { llvm_shutdown(); }
};
diff --git a/llvm/include/llvm/Support/Threading.h b/llvm/include/llvm/Support/Threading.h
index 7e87584..d84d118 100644
--- a/llvm/include/llvm/Support/Threading.h
+++ b/llvm/include/llvm/Support/Threading.h
@@ -7,8 +7,7 @@
//
//===----------------------------------------------------------------------===//
//
-// This file declares helper functions for running LLVM in a multi-threaded
-// environment.
+// TThis file defines llvm_start_multithreaded() and friends.
//
//===----------------------------------------------------------------------===//
@@ -16,8 +15,22 @@
#define LLVM_SUPPORT_THREADING_H
namespace llvm {
- /// Returns true if LLVM is compiled with support for multi-threading, and
- /// false otherwise.
+ /// 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();
/// llvm_execute_on_thread - Execute the given \p UserFn on a separate