[llvm] r210603 - Revert "Remove support for runtime multi-threading."
Zachary Turner
zturner at google.com
Tue Jun 10 16:15:44 PDT 2014
Author: zturner
Date: Tue Jun 10 18:15:43 2014
New Revision: 210603
URL: http://llvm.org/viewvc/llvm-project?rev=210603&view=rev
Log:
Revert "Remove support for runtime multi-threading."
This reverts revision r210600.
Modified:
llvm/trunk/include/llvm-c/Core.h
llvm/trunk/include/llvm/Support/ManagedStatic.h
llvm/trunk/include/llvm/Support/Threading.h
llvm/trunk/lib/IR/Core.cpp
llvm/trunk/lib/Support/ErrorHandling.cpp
llvm/trunk/lib/Support/ManagedStatic.cpp
llvm/trunk/lib/Support/Threading.cpp
llvm/trunk/lib/Support/Timer.cpp
Modified: llvm/trunk/include/llvm-c/Core.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm-c/Core.h?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/include/llvm-c/Core.h (original)
+++ llvm/trunk/include/llvm-c/Core.h Tue Jun 10 18:15:43 2014
@@ -2848,13 +2848,16 @@ void LLVMDisposePassManager(LLVMPassMana
* @{
*/
-/** 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.
Modified: llvm/trunk/include/llvm/Support/ManagedStatic.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/ManagedStatic.h?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/ManagedStatic.h (original)
+++ llvm/trunk/include/llvm/Support/ManagedStatic.h Tue Jun 10 18:15:43 2014
@@ -103,6 +103,9 @@ void llvm_shutdown();
/// 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(); }
};
Modified: llvm/trunk/include/llvm/Support/Threading.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Support/Threading.h?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Support/Threading.h (original)
+++ llvm/trunk/include/llvm/Support/Threading.h Tue Jun 10 18:15:43 2014
@@ -14,33 +14,33 @@
#ifndef LLVM_SUPPORT_THREADING_H
#define LLVM_SUPPORT_THREADING_H
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Support/Compiler.h"
-#include <mutex>
-
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();
-#if LLVM_ENABLE_THREADS != 0
- typedef std::mutex mutex;
- typedef std::recursive_mutex recursive_mutex;
-#else
- class null_mutex {
- public:
- void lock() { }
- void unlock() { }
- bool try_lock() { return true; }
- };
- typedef null_mutex mutex;
- typedef null_mutex recursive_mutex;
-#endif
-
- /// llvm_get_global_lock() - returns the llvm global lock object.
- llvm::recursive_mutex &llvm_get_global_lock();
-
- /// llvm_is_multithreaded() - returns true if LLVM is compiled with support
- /// for multiple threads, and false otherwise.
+ /// 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();
+
/// llvm_execute_on_thread - Execute the given \p UserFn on a separate
/// thread, passing it the provided \p UserData.
///
Modified: llvm/trunk/lib/IR/Core.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Core.cpp?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Core.cpp (original)
+++ llvm/trunk/lib/IR/Core.cpp Tue Jun 10 18:15:43 2014
@@ -2702,10 +2702,11 @@ void LLVMDisposePassManager(LLVMPassMana
/*===-- Threading ------------------------------------------------------===*/
LLVMBool LLVMStartMultithreaded() {
- return LLVMIsMultithreaded();
+ return llvm_start_multithreaded();
}
void LLVMStopMultithreaded() {
+ llvm_stop_multithreaded();
}
LLVMBool LLVMIsMultithreaded() {
Modified: llvm/trunk/lib/Support/ErrorHandling.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ErrorHandling.cpp?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/lib/Support/ErrorHandling.cpp (original)
+++ llvm/trunk/lib/Support/ErrorHandling.cpp Tue Jun 10 18:15:43 2014
@@ -23,7 +23,6 @@
#include "llvm/Support/raw_ostream.h"
#include <cassert>
#include <cstdlib>
-#include <mutex>
#if defined(HAVE_UNISTD_H)
# include <unistd.h>
@@ -38,18 +37,16 @@ using namespace llvm;
static fatal_error_handler_t ErrorHandler = nullptr;
static void *ErrorHandlerUserData = nullptr;
-static llvm::recursive_mutex ErrorHandlerMutex;
-
void llvm::install_fatal_error_handler(fatal_error_handler_t handler,
void *user_data) {
- std::lock_guard<llvm::recursive_mutex> Lock(ErrorHandlerMutex);
+ assert(!llvm_is_multithreaded() &&
+ "Cannot register error handlers after starting multithreaded mode!\n");
assert(!ErrorHandler && "Error handler already registered!\n");
ErrorHandler = handler;
ErrorHandlerUserData = user_data;
}
void llvm::remove_fatal_error_handler() {
- std::lock_guard<llvm::recursive_mutex> Lock(ErrorHandlerMutex);
ErrorHandler = nullptr;
}
@@ -66,7 +63,6 @@ void llvm::report_fatal_error(StringRef
}
void llvm::report_fatal_error(const Twine &Reason, bool GenCrashDiag) {
- std::lock_guard<llvm::recursive_mutex> Lock(ErrorHandlerMutex);
if (ErrorHandler) {
ErrorHandler(ErrorHandlerUserData, Reason.str(), GenCrashDiag);
} else {
Modified: llvm/trunk/lib/Support/ManagedStatic.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/ManagedStatic.cpp?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/lib/Support/ManagedStatic.cpp (original)
+++ llvm/trunk/lib/Support/ManagedStatic.cpp Tue Jun 10 18:15:43 2014
@@ -15,7 +15,6 @@
#include "llvm/Config/config.h"
#include "llvm/Support/Atomic.h"
#include <cassert>
-#include <mutex>
using namespace llvm;
static const ManagedStaticBase *StaticList = nullptr;
@@ -24,7 +23,7 @@ void ManagedStaticBase::RegisterManagedS
void (*Deleter)(void*)) const {
assert(Creator);
if (llvm_is_multithreaded()) {
- std::lock_guard<llvm::recursive_mutex> Lock(llvm_get_global_lock());
+ llvm_acquire_global_lock();
if (!Ptr) {
void* tmp = Creator();
@@ -45,6 +44,7 @@ void ManagedStaticBase::RegisterManagedS
StaticList = this;
}
+ llvm_release_global_lock();
} else {
assert(!Ptr && !DeleterFn && !Next &&
"Partially initialized ManagedStatic!?");
@@ -77,4 +77,6 @@ void ManagedStaticBase::destroy() const
void llvm::llvm_shutdown() {
while (StaticList)
StaticList->destroy();
+
+ if (llvm_is_multithreaded()) llvm_stop_multithreaded();
}
Modified: llvm/trunk/lib/Support/Threading.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Threading.cpp?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Threading.cpp (original)
+++ llvm/trunk/lib/Support/Threading.cpp Tue Jun 10 18:15:43 2014
@@ -19,19 +19,50 @@
using namespace llvm;
-llvm::recursive_mutex& llvm::llvm_get_global_lock() {
- static llvm::recursive_mutex global_lock;
- return global_lock;
-}
+static bool multithreaded_mode = false;
-bool llvm::llvm_is_multithreaded() {
+static sys::Mutex* global_lock = nullptr;
+
+bool llvm::llvm_start_multithreaded() {
#if LLVM_ENABLE_THREADS != 0
+ 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() {
+#if LLVM_ENABLE_THREADS != 0
+ 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 LLVM_ENABLE_THREADS != 0 && defined(HAVE_PTHREAD_H)
#include <pthread.h>
Modified: llvm/trunk/lib/Support/Timer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Support/Timer.cpp?rev=210603&r1=210602&r2=210603&view=diff
==============================================================================
--- llvm/trunk/lib/Support/Timer.cpp (original)
+++ llvm/trunk/lib/Support/Timer.cpp Tue Jun 10 18:15:43 2014
@@ -84,13 +84,14 @@ static TimerGroup *getDefaultTimerGroup(
sys::MemoryFence();
if (tmp) return tmp;
- std::lock_guard<llvm::recursive_mutex> Lock(llvm::llvm_get_global_lock());
+ llvm_acquire_global_lock();
tmp = DefaultTimerGroup;
if (!tmp) {
tmp = new TimerGroup("Miscellaneous Ungrouped Timers");
sys::MemoryFence();
DefaultTimerGroup = tmp;
}
+ llvm_release_global_lock();
return tmp;
}
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