Index: src/core/SkLazyPtr.h |
diff --git a/src/core/SkLazyPtr.h b/src/core/SkLazyPtr.h |
deleted file mode 100644 |
index 7273079252a7f89e8ea22c78d9ed620ec31303ac..0000000000000000000000000000000000000000 |
--- a/src/core/SkLazyPtr.h |
+++ /dev/null |
@@ -1,166 +0,0 @@ |
-/* |
- * Copyright 2014 Google Inc. |
- * |
- * Use of this source code is governed by a BSD-style license that can be |
- * found in the LICENSE file. |
- */ |
- |
-#ifndef SkLazyPtr_DEFINED |
-#define SkLazyPtr_DEFINED |
- |
-/** Declare a lazily-chosen static pointer (or array of pointers) of type T. |
- * |
- * Example usage: |
- * |
- * Foo* GetSingletonFoo() { |
- * SK_DECLARE_STATIC_LAZY_PTR(Foo, singleton); // Created with SkNEW, destroyed with SkDELETE. |
- * return singleton.get(); |
- * } |
- * |
- * These macros take an optional T* (*Create)() and void (*Destroy)(T*) at the end. |
- * If not given, we'll use SkNEW and SkDELETE. |
- * These options are most useful when T doesn't have a public constructor or destructor. |
- * Create comes first, so you may use a custom Create with a default Destroy, but not vice versa. |
- * |
- * Foo* CustomCreate() { return ...; } |
- * void CustomDestroy(Foo* ptr) { ... } |
- * Foo* GetSingletonFooWithCustomCleanup() { |
- * SK_DECLARE_STATIC_LAZY_PTR(Foo, singleton, CustomCreate, CustomDestroy); |
- * return singleton.get(); |
- * } |
- * |
- * If you have a bunch of related static pointers of the same type, you can |
- * declare an array of lazy pointers together, and we'll pass the index to Create(). |
- * |
- * Foo* CreateFoo(int i) { return ...; } |
- * Foo* GetCachedFoo(Foo::Enum enumVal) { |
- * SK_DECLARE_STATIC_LAZY_PTR_ARRAY(Foo, Foo::kEnumCount, cachedFoos, CreateFoo); |
- * return cachedFoos[enumVal]; |
- * } |
- * |
- * |
- * You can think of SK_DECLARE_STATIC_LAZY_PTR as a cheaper specialization of |
- * SkOnce. There is no mutex or extra storage used past the pointer itself. |
- * |
- * We may call Create more than once, but all threads will see the same pointer |
- * returned from get(). Any extra calls to Create will be cleaned up. |
- * |
- * These macros must be used in a global scope, not in function scope or as a class member. |
- */ |
- |
-#define SK_DECLARE_STATIC_LAZY_PTR(T, name, ...) \ |
- namespace {} static Private::SkStaticLazyPtr<T, ##__VA_ARGS__> name |
- |
-#define SK_DECLARE_STATIC_LAZY_PTR_ARRAY(T, name, N, ...) \ |
- namespace {} static Private::SkStaticLazyPtrArray<T, N, ##__VA_ARGS__> name |
- |
-// namespace {} forces these macros to only be legal in global scopes. Chrome has thread-safety |
-// problems with them in function-local statics because it uses -fno-threadsafe-statics, and even |
-// in builds with threadsafe statics, those threadsafe statics are just unnecessary overhead. |
- |
-// Everything below here is private implementation details. Don't touch, don't even look. |
- |
-#include "SkDynamicAnnotations.h" |
-#include "SkThread.h" |
-#include "SkThreadPriv.h" |
- |
-// See FIXME below. |
-class SkFontConfigInterfaceDirect; |
- |
-namespace Private { |
- |
-// Set *dst to ptr if *dst is NULL. Returns value of *dst, destroying ptr if not swapped in. |
-// Issues the same memory barriers as sk_atomic_cas: acquire on failure, release on success. |
-template <typename P, void (*Destroy)(P)> |
-static P try_cas(void** dst, P ptr) { |
- P prev = (P)sk_atomic_cas(dst, NULL, ptr); |
- |
- if (prev) { |
- // We need an acquire barrier before returning prev, which sk_atomic_cas provided. |
- Destroy(ptr); |
- return prev; |
- } else { |
- // We need a release barrier before returning ptr, which sk_atomic_cas provided. |
- return ptr; |
- } |
-} |
- |
-template <typename T> T* sk_new() { return SkNEW(T); } |
-template <typename T> void sk_delete(T* ptr) { SkDELETE(ptr); } |
- |
-// We're basing these implementations here on this article: |
-// http://preshing.com/20140709/the-purpose-of-memory_order_consume-in-cpp11/ |
-// |
-// Because the users of SkLazyPtr and SkLazyPtrArray will read the pointers |
-// _through_ our atomically set pointer, there is a data dependency between our |
-// atomic and the guarded data, and so we only need writer-releases / |
-// reader-consumes memory pairing rather than the more general write-releases / |
-// reader-acquires convention. |
-// |
-// This is nice, because a sk_consume_load is free on all our platforms: x86, |
-// ARM, MIPS. In contrast, sk_acquire_load issues a memory barrier on non-x86. |
- |
-// This has no constructor and must be zero-initalized (the macro above does this). |
-template <typename T, T* (*Create)() = sk_new<T>, void (*Destroy)(T*) = sk_delete<T> > |
-class SkStaticLazyPtr { |
-public: |
- T* get() { |
- // If fPtr has already been filled, we need a consume barrier when loading it. |
- // If not, we need a release barrier when setting it. try_cas will do that. |
- T* ptr = (T*)sk_consume_load(&fPtr); |
- return ptr ? ptr : try_cas<T*, Destroy>(&fPtr, Create()); |
- } |
- |
-private: |
- void* fPtr; |
-}; |
- |
-template <typename T> T* sk_new_arg(int i) { return SkNEW_ARGS(T, (i)); } |
- |
-// This has no constructor and must be zero-initalized (the macro above does this). |
-template <typename T, int N, T* (*Create)(int) = sk_new_arg<T>, void (*Destroy)(T*) = sk_delete<T> > |
-class SkStaticLazyPtrArray { |
-public: |
- T* operator[](int i) { |
- SkASSERT(i >= 0 && i < N); |
- // If fPtr has already been filled, we need an consume barrier when loading it. |
- // If not, we need a release barrier when setting it. try_cas will do that. |
- T* ptr = (T*)sk_consume_load(&fArray[i]); |
- return ptr ? ptr : try_cas<T*, Destroy>(&fArray[i], Create(i)); |
- } |
- |
-private: |
- void* fArray[N]; |
-}; |
- |
-} // namespace Private |
- |
-// This version is suitable for use as a class member. |
-// It's much the same as above except: |
-// - it has a constructor to zero itself; |
-// - it has a destructor to clean up; |
-// - get() calls SkNew(T) to create the pointer; |
-// - get(functor) calls functor to create the pointer. |
-template <typename T, void (*Destroy)(T*) = Private::sk_delete<T> > |
-class SkLazyPtr : SkNoncopyable { |
-public: |
- SkLazyPtr() : fPtr(NULL) {} |
- ~SkLazyPtr() { if (fPtr) { Destroy((T*)fPtr); } } |
- |
- T* get() { |
- T* ptr = (T*)sk_consume_load(&fPtr); |
- return ptr ? ptr : Private::try_cas<T*, Destroy>(&fPtr, SkNEW(T)); |
- } |
- |
- template <typename Create> |
- T* get(const Create& create) { |
- T* ptr = (T*)sk_consume_load(&fPtr); |
- return ptr ? ptr : Private::try_cas<T*, Destroy>(&fPtr, create()); |
- } |
- |
-private: |
- void* fPtr; |
-}; |
- |
- |
-#endif//SkLazyPtr_DEFINED |