| //===-- llvm/Support/ManagedStatic.h - Static Global wrapper ----*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file was developed by Chris Lattner and 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 |
| |
| namespace llvm { |
| |
| /// object_deleter - Helper method for ManagedStatic. |
| /// |
| template<class C> |
| void object_deleter(void *Ptr) { |
| delete (C*)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 *ObjPtr, 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*() { |
| if (!Ptr) LazyInit(); |
| return *static_cast<C*>(Ptr); |
| } |
| C *operator->() { |
| if (!Ptr) LazyInit(); |
| return static_cast<C*>(Ptr); |
| } |
| const C &operator*() const { |
| if (!Ptr) LazyInit(); |
| return *static_cast<C*>(Ptr); |
| } |
| const C *operator->() const { |
| if (!Ptr) LazyInit(); |
| return static_cast<C*>(Ptr); |
| } |
| |
| public: |
| void LazyInit() const { |
| RegisterManagedStatic(new C(), object_deleter<C>); |
| } |
| }; |
| |
| template<void (*CleanupFn)(void*)> |
| class ManagedCleanup : public ManagedStaticBase { |
| public: |
| void Register() { RegisterManagedStatic(0, CleanupFn); } |
| }; |
| |
| |
| /// 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() {} |
| ~llvm_shutdown_obj() { llvm_shutdown(); } |
| }; |
| |
| } |
| |
| #endif |