Merge System into Support.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120298 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Support/Threading.cpp b/lib/Support/Threading.cpp
new file mode 100644
index 0000000..c2f8554
--- /dev/null
+++ b/lib/Support/Threading.cpp
@@ -0,0 +1,116 @@
+//===-- llvm/System/Threading.cpp- 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.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements llvm_start_multithreaded() and friends.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Support/Threading.h"
+#include "llvm/Support/Atomic.h"
+#include "llvm/Support/Mutex.h"
+#include "llvm/Config/config.h"
+#include <cassert>
+
+using namespace llvm;
+
+static bool multithreaded_mode = false;
+
+static sys::Mutex* global_lock = 0;
+
+bool llvm::llvm_start_multithreaded() {
+#ifdef LLVM_MULTITHREADED
+ assert(!multithreaded_mode && "Already multithreaded!");
+ multithreaded_mode = true;
+ global_lock = new sys::Mutex(true);
+
+ // We fence here to ensure that all initialization is complete BEFORE we
+ // return from llvm_start_multithreaded().
+ sys::MemoryFence();
+ return true;
+#else
+ return false;
+#endif
+}
+
+void llvm::llvm_stop_multithreaded() {
+#ifdef LLVM_MULTITHREADED
+ assert(multithreaded_mode && "Not currently multithreaded!");
+
+ // We fence here to insure that all threaded operations are complete BEFORE we
+ // return from llvm_stop_multithreaded().
+ sys::MemoryFence();
+
+ multithreaded_mode = false;
+ delete global_lock;
+#endif
+}
+
+bool llvm::llvm_is_multithreaded() {
+ return multithreaded_mode;
+}
+
+void llvm::llvm_acquire_global_lock() {
+ if (multithreaded_mode) global_lock->acquire();
+}
+
+void llvm::llvm_release_global_lock() {
+ if (multithreaded_mode) global_lock->release();
+}
+
+#if defined(LLVM_MULTITHREADED) && defined(HAVE_PTHREAD_H)
+#include <pthread.h>
+
+struct ThreadInfo {
+ void (*UserFn)(void *);
+ void *UserData;
+};
+static void *ExecuteOnThread_Dispatch(void *Arg) {
+ ThreadInfo *TI = reinterpret_cast<ThreadInfo*>(Arg);
+ TI->UserFn(TI->UserData);
+ return 0;
+}
+
+void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
+ unsigned RequestedStackSize) {
+ ThreadInfo Info = { Fn, UserData };
+ pthread_attr_t Attr;
+ pthread_t Thread;
+
+ // Construct the attributes object.
+ if (::pthread_attr_init(&Attr) != 0)
+ return;
+
+ // Set the requested stack size, if given.
+ if (RequestedStackSize != 0) {
+ if (::pthread_attr_setstacksize(&Attr, RequestedStackSize) != 0)
+ goto error;
+ }
+
+ // Construct and execute the thread.
+ if (::pthread_create(&Thread, &Attr, ExecuteOnThread_Dispatch, &Info) != 0)
+ goto error;
+
+ // Wait for the thread and clean up.
+ ::pthread_join(Thread, 0);
+
+ error:
+ ::pthread_attr_destroy(&Attr);
+}
+
+#else
+
+// No non-pthread implementation, currently.
+
+void llvm::llvm_execute_on_thread(void (*Fn)(void*), void *UserData,
+ unsigned RequestedStackSize) {
+ (void) RequestedStackSize;
+ Fn(UserData);
+}
+
+#endif