| 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
|
|
|