ManagedStatic.h revision 771cbf30bc1ff025316d1a80aeb5102375c1598e
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===-- llvm/Support/ManagedStatic.h - Static Global wrapper ----*- C++ -*-===// 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The LLVM Compiler Infrastructure 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file was developed by Chris Lattner and is distributed under 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// the University of Illinois Open Source License. See LICENSE.TXT for details. 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// This file defines the ManagedStatic class and the llvm_shutdown() function. 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)//===----------------------------------------------------------------------===// 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef LLVM_SUPPORT_MANAGED_STATIC_H 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define LLVM_SUPPORT_MANAGED_STATIC_H 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace llvm { 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// object_deleter - Helper method for ManagedStatic. 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template<class C> 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void object_deleter(void *Ptr) { 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) delete (C*)Ptr; 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// ManagedStaticBase - Common base class for ManagedStatic instances. 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class ManagedStaticBase { 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)protected: 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This should only be used as a static variable, which guarantees that this 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // will be zero initialized. 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mutable void *Ptr; 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mutable void (*DeleterFn)(void*); 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mutable const ManagedStaticBase *Next; 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void RegisterManagedStatic(void *ObjPtr, void (*deleter)(void*)) const; 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public: 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void destroy() const; 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// ManagedStatic - This transparently changes the behavior of global statics to 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// be lazily constructed on demand (good for reducing startup times of dynamic 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// libraries that link in LLVM components) and for making destruction be 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// explicit through the llvm_shutdown() function call. 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)template<class C> 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class ManagedStatic : public ManagedStaticBase { 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public: 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Accessors. 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) C &operator*() { 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!Ptr) LazyInit(); 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return *static_cast<C*>(Ptr); 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) C *operator->() { 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!Ptr) LazyInit(); 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return static_cast<C*>(Ptr); 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const C &operator*() const { 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!Ptr) LazyInit(); 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return *static_cast<C*>(Ptr); 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const C *operator->() const { 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (!Ptr) LazyInit(); 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return static_cast<C*>(Ptr); 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public: 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void LazyInit() const { 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) RegisterManagedStatic(new C(), object_deleter<C>); 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/// llvm_shutdown - Deallocate and destroy all ManagedStatic variables. 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void llvm_shutdown(); 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)