/3rd_party/llvm/include/llvm/Support/ManagedStatic.h
https://code.google.com/p/softart/ · C++ Header · 114 lines · 68 code · 18 blank · 28 comment · 10 complexity · daffa88ba7d0bbda6b4b1d73bd93ea8e MD5 · raw file
- //===-- llvm/Support/ManagedStatic.h - Static Global wrapper ----*- C++ -*-===//
- //
- // The LLVM Compiler Infrastructure
- //
- // This file is distributed under the University of Illinois Open Source
- // License. See LICENSE.TXT for details.
- //
- //===----------------------------------------------------------------------===//
- //
- // This file defines the ManagedStatic class and the llvm_shutdown() function.
- //
- //===----------------------------------------------------------------------===//
- #ifndef LLVM_SUPPORT_MANAGED_STATIC_H
- #define LLVM_SUPPORT_MANAGED_STATIC_H
- #include "llvm/Support/Atomic.h"
- #include "llvm/Support/Threading.h"
- #include "llvm/Support/Valgrind.h"
- namespace llvm {
- /// object_creator - Helper method for ManagedStatic.
- template<class C>
- void* object_creator() {
- return new C();
- }
- /// object_deleter - Helper method for ManagedStatic.
- ///
- template<typename T> struct object_deleter {
- static void call(void * Ptr) { delete (T*)Ptr; }
- };
- template<typename T, size_t N> struct object_deleter<T[N]> {
- static void call(void * Ptr) { delete[] (T*)Ptr; }
- };
- /// ManagedStaticBase - Common base class for ManagedStatic instances.
- class ManagedStaticBase {
- protected:
- // This should only be used as a static variable, which guarantees that this
- // will be zero initialized.
- mutable void *Ptr;
- mutable void (*DeleterFn)(void*);
- mutable const ManagedStaticBase *Next;
- void RegisterManagedStatic(void *(*creator)(), void (*deleter)(void*)) const;
- public:
- /// isConstructed - Return true if this object has not been created yet.
- bool isConstructed() const { return Ptr != 0; }
- void destroy() const;
- };
- /// ManagedStatic - This transparently changes the behavior of global statics to
- /// be lazily constructed on demand (good for reducing startup times of dynamic
- /// libraries that link in LLVM components) and for making destruction be
- /// explicit through the llvm_shutdown() function call.
- ///
- template<class C>
- class ManagedStatic : public ManagedStaticBase {
- public:
- // Accessors.
- C &operator*() {
- void* tmp = Ptr;
- if (llvm_is_multithreaded()) sys::MemoryFence();
- if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
- TsanHappensAfter(this);
- return *static_cast<C*>(Ptr);
- }
- C *operator->() {
- void* tmp = Ptr;
- if (llvm_is_multithreaded()) sys::MemoryFence();
- if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
- TsanHappensAfter(this);
- return static_cast<C*>(Ptr);
- }
- const C &operator*() const {
- void* tmp = Ptr;
- if (llvm_is_multithreaded()) sys::MemoryFence();
- if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
- TsanHappensAfter(this);
- return *static_cast<C*>(Ptr);
- }
- const C *operator->() const {
- void* tmp = Ptr;
- if (llvm_is_multithreaded()) sys::MemoryFence();
- if (!tmp) RegisterManagedStatic(object_creator<C>, object_deleter<C>::call);
- TsanHappensAfter(this);
- return static_cast<C*>(Ptr);
- }
- };
- /// llvm_shutdown - Deallocate and destroy all ManagedStatic variables.
- void llvm_shutdown();
- /// llvm_shutdown_obj - This is a simple helper class that calls
- /// 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(); }
- };
- }
- #endif