diff -r 000000000000 -r 6474c204b198 ipc/chromium/src/base/scoped_ptr.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/ipc/chromium/src/base/scoped_ptr.h Wed Dec 31 06:09:35 2014 +0100 @@ -0,0 +1,380 @@ +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Scopers help you manage ownership of a pointer, helping you easily manage the +// a pointer within a scope, and automatically destroying the pointer at the +// end of a scope. There are two main classes you will use, which coorespond +// to the operators new/delete and new[]/delete[]. +// +// Example usage (scoped_ptr): +// { +// scoped_ptr foo(new Foo("wee")); +// } // foo goes out of scope, releasing the pointer with it. +// +// { +// scoped_ptr foo; // No pointer managed. +// foo.reset(new Foo("wee")); // Now a pointer is managed. +// foo.reset(new Foo("wee2")); // Foo("wee") was destroyed. +// foo.reset(new Foo("wee3")); // Foo("wee2") was destroyed. +// foo->Method(); // Foo::Method() called. +// foo.get()->Method(); // Foo::Method() called. +// SomeFunc(foo.Release()); // SomeFunc takes owernship, foo no longer +// // manages a pointer. +// foo.reset(new Foo("wee4")); // foo manages a pointer again. +// foo.reset(); // Foo("wee4") destroyed, foo no longer +// // manages a pointer. +// } // foo wasn't managing a pointer, so nothing was destroyed. +// +// Example usage (scoped_array): +// { +// scoped_array foo(new Foo[100]); +// foo.get()->Method(); // Foo::Method on the 0th element. +// foo[10].Method(); // Foo::Method on the 10th element. +// } + +#ifndef BASE_SCOPED_PTR_H_ +#define BASE_SCOPED_PTR_H_ + +// This is an implementation designed to match the anticipated future TR2 +// implementation of the scoped_ptr class, and its closely-related brethren, +// scoped_array, scoped_ptr_malloc. + +#include +#include +#include + +// A scoped_ptr is like a T*, except that the destructor of scoped_ptr +// automatically deletes the pointer it holds (if any). +// That is, scoped_ptr owns the T object that it points to. +// Like a T*, a scoped_ptr may hold either NULL or a pointer to a T object. +// Also like T*, scoped_ptr is thread-compatible, and once you +// dereference it, you get the threadsafety guarantees of T. +// +// The size of a scoped_ptr is small: +// sizeof(scoped_ptr) == sizeof(C*) +template +class scoped_ptr { + public: + + // The element type + typedef C element_type; + + // Constructor. Defaults to intializing with NULL. + // There is no way to create an uninitialized scoped_ptr. + // The input parameter must be allocated with new. + explicit scoped_ptr(C* p = NULL) : ptr_(p) { } + + // Destructor. If there is a C object, delete it. + // We don't need to test ptr_ == NULL because C++ does that for us. + ~scoped_ptr() { + enum { type_must_be_complete = sizeof(C) }; + delete ptr_; + } + + // Reset. Deletes the current owned object, if any. + // Then takes ownership of a new object, if given. + // this->reset(this->get()) works. + void reset(C* p = NULL) { + if (p != ptr_) { + enum { type_must_be_complete = sizeof(C) }; + delete ptr_; + ptr_ = p; + } + } + + // Accessors to get the owned object. + // operator* and operator-> will assert() if there is no current object. + C& operator*() const { + assert(ptr_ != NULL); + return *ptr_; + } + C* operator->() const { + assert(ptr_ != NULL); + return ptr_; + } + C* get() const { return ptr_; } + + // Comparison operators. + // These return whether two scoped_ptr refer to the same object, not just to + // two different but equal objects. + bool operator==(C* p) const { return ptr_ == p; } + bool operator!=(C* p) const { return ptr_ != p; } + + // Swap two scoped pointers. + void swap(scoped_ptr& p2) { + C* tmp = ptr_; + ptr_ = p2.ptr_; + p2.ptr_ = tmp; + } + + // Release a pointer. + // The return value is the current pointer held by this object. + // If this object holds a NULL pointer, the return value is NULL. + // After this operation, this object will hold a NULL pointer, + // and will not own the object any more. + C* release() { + C* retVal = ptr_; + ptr_ = NULL; + return retVal; + } + + private: + C* ptr_; + + // Forbid comparison of scoped_ptr types. If C2 != C, it totally doesn't + // make sense, and if C2 == C, it still doesn't make sense because you should + // never have the same object owned by two different scoped_ptrs. + template bool operator==(scoped_ptr const& p2) const; + template bool operator!=(scoped_ptr const& p2) const; + + // Disallow evil constructors + scoped_ptr(const scoped_ptr&); + void operator=(const scoped_ptr&); +}; + +// Free functions +template +void swap(scoped_ptr& p1, scoped_ptr& p2) { + p1.swap(p2); +} + +template +bool operator==(C* p1, const scoped_ptr& p2) { + return p1 == p2.get(); +} + +template +bool operator!=(C* p1, const scoped_ptr& p2) { + return p1 != p2.get(); +} + +// scoped_array is like scoped_ptr, except that the caller must allocate +// with new [] and the destructor deletes objects with delete []. +// +// As with scoped_ptr, a scoped_array either points to an object +// or is NULL. A scoped_array owns the object that it points to. +// scoped_array is thread-compatible, and once you index into it, +// the returned objects have only the threadsafety guarantees of T. +// +// Size: sizeof(scoped_array) == sizeof(C*) +template +class scoped_array { + public: + + // The element type + typedef C element_type; + + // Constructor. Defaults to intializing with NULL. + // There is no way to create an uninitialized scoped_array. + // The input parameter must be allocated with new []. + explicit scoped_array(C* p = NULL) : array_(p) { } + + // Destructor. If there is a C object, delete it. + // We don't need to test ptr_ == NULL because C++ does that for us. + ~scoped_array() { + enum { type_must_be_complete = sizeof(C) }; + delete[] array_; + } + + // Reset. Deletes the current owned object, if any. + // Then takes ownership of a new object, if given. + // this->reset(this->get()) works. + void reset(C* p = NULL) { + if (p != array_) { + enum { type_must_be_complete = sizeof(C) }; + delete[] array_; + array_ = p; + } + } + + // Get one element of the current object. + // Will assert() if there is no current object, or index i is negative. + C& operator[](std::ptrdiff_t i) const { + assert(i >= 0); + assert(array_ != NULL); + return array_[i]; + } + + // Get a pointer to the zeroth element of the current object. + // If there is no current object, return NULL. + C* get() const { + return array_; + } + + // Comparison operators. + // These return whether two scoped_array refer to the same object, not just to + // two different but equal objects. + bool operator==(C* p) const { return array_ == p; } + bool operator!=(C* p) const { return array_ != p; } + + // Swap two scoped arrays. + void swap(scoped_array& p2) { + C* tmp = array_; + array_ = p2.array_; + p2.array_ = tmp; + } + + // Release an array. + // The return value is the current pointer held by this object. + // If this object holds a NULL pointer, the return value is NULL. + // After this operation, this object will hold a NULL pointer, + // and will not own the object any more. + C* release() { + C* retVal = array_; + array_ = NULL; + return retVal; + } + + private: + C* array_; + + // Forbid comparison of different scoped_array types. + template bool operator==(scoped_array const& p2) const; + template bool operator!=(scoped_array const& p2) const; + + // Disallow evil constructors + scoped_array(const scoped_array&); + void operator=(const scoped_array&); +}; + +// Free functions +template +void swap(scoped_array& p1, scoped_array& p2) { + p1.swap(p2); +} + +template +bool operator==(C* p1, const scoped_array& p2) { + return p1 == p2.get(); +} + +template +bool operator!=(C* p1, const scoped_array& p2) { + return p1 != p2.get(); +} + +// This class wraps the c library function free() in a class that can be +// passed as a template argument to scoped_ptr_malloc below. +class ScopedPtrMallocFree { + public: + inline void operator()(void* x) const { + free(x); + } +}; + +// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a +// second template argument, the functor used to free the object. + +template +class scoped_ptr_malloc { + public: + + // The element type + typedef C element_type; + + // Constructor. Defaults to intializing with NULL. + // There is no way to create an uninitialized scoped_ptr. + // The input parameter must be allocated with an allocator that matches the + // Free functor. For the default Free functor, this is malloc, calloc, or + // realloc. + explicit scoped_ptr_malloc(C* p = NULL): ptr_(p) {} + + // Destructor. If there is a C object, call the Free functor. + ~scoped_ptr_malloc() { + free_(ptr_); + } + + // Reset. Calls the Free functor on the current owned object, if any. + // Then takes ownership of a new object, if given. + // this->reset(this->get()) works. + void reset(C* p = NULL) { + if (ptr_ != p) { + free_(ptr_); + ptr_ = p; + } + } + + // Get the current object. + // operator* and operator-> will cause an assert() failure if there is + // no current object. + C& operator*() const { + assert(ptr_ != NULL); + return *ptr_; + } + + C* operator->() const { + assert(ptr_ != NULL); + return ptr_; + } + + C* get() const { + return ptr_; + } + + // Comparison operators. + // These return whether a scoped_ptr_malloc and a plain pointer refer + // to the same object, not just to two different but equal objects. + // For compatibility wwith the boost-derived implementation, these + // take non-const arguments. + bool operator==(C* p) const { + return ptr_ == p; + } + + bool operator!=(C* p) const { + return ptr_ != p; + } + + // Swap two scoped pointers. + void swap(scoped_ptr_malloc & b) { + C* tmp = b.ptr_; + b.ptr_ = ptr_; + ptr_ = tmp; + } + + // Release a pointer. + // The return value is the current pointer held by this object. + // If this object holds a NULL pointer, the return value is NULL. + // After this operation, this object will hold a NULL pointer, + // and will not own the object any more. + C* release() { + C* tmp = ptr_; + ptr_ = NULL; + return tmp; + } + + private: + C* ptr_; + + // no reason to use these: each scoped_ptr_malloc should have its own object + template + bool operator==(scoped_ptr_malloc const& p) const; + template + bool operator!=(scoped_ptr_malloc const& p) const; + + static FreeProc const free_; + + // Disallow evil constructors + scoped_ptr_malloc(const scoped_ptr_malloc&); + void operator=(const scoped_ptr_malloc&); +}; + +template +FP const scoped_ptr_malloc::free_ = FP(); + +template inline +void swap(scoped_ptr_malloc& a, scoped_ptr_malloc& b) { + a.swap(b); +} + +template inline +bool operator==(C* p, const scoped_ptr_malloc& b) { + return p == b.get(); +} + +template inline +bool operator!=(C* p, const scoped_ptr_malloc& b) { + return p != b.get(); +} + +#endif // BASE_SCOPED_PTR_H_