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Diffstat (limited to 'googletest/include/gtest/internal/gtest-linked_ptr.h')
-rw-r--r-- | googletest/include/gtest/internal/gtest-linked_ptr.h | 243 |
1 files changed, 0 insertions, 243 deletions
diff --git a/googletest/include/gtest/internal/gtest-linked_ptr.h b/googletest/include/gtest/internal/gtest-linked_ptr.h deleted file mode 100644 index d25f7e9..0000000 --- a/googletest/include/gtest/internal/gtest-linked_ptr.h +++ /dev/null @@ -1,243 +0,0 @@ -// Copyright 2003 Google Inc. -// All rights reserved. -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -// -// A "smart" pointer type with reference tracking. Every pointer to a -// particular object is kept on a circular linked list. When the last pointer -// to an object is destroyed or reassigned, the object is deleted. -// -// Used properly, this deletes the object when the last reference goes away. -// There are several caveats: -// - Like all reference counting schemes, cycles lead to leaks. -// - Each smart pointer is actually two pointers (8 bytes instead of 4). -// - Every time a pointer is assigned, the entire list of pointers to that -// object is traversed. This class is therefore NOT SUITABLE when there -// will often be more than two or three pointers to a particular object. -// - References are only tracked as long as linked_ptr<> objects are copied. -// If a linked_ptr<> is converted to a raw pointer and back, BAD THINGS -// will happen (double deletion). -// -// A good use of this class is storing object references in STL containers. -// You can safely put linked_ptr<> in a vector<>. -// Other uses may not be as good. -// -// Note: If you use an incomplete type with linked_ptr<>, the class -// *containing* linked_ptr<> must have a constructor and destructor (even -// if they do nothing!). -// -// Bill Gibbons suggested we use something like this. -// -// Thread Safety: -// Unlike other linked_ptr implementations, in this implementation -// a linked_ptr object is thread-safe in the sense that: -// - it's safe to copy linked_ptr objects concurrently, -// - it's safe to copy *from* a linked_ptr and read its underlying -// raw pointer (e.g. via get()) concurrently, and -// - it's safe to write to two linked_ptrs that point to the same -// shared object concurrently. -// FIXME: rename this to safe_linked_ptr to avoid -// confusion with normal linked_ptr. - -// GOOGLETEST_CM0001 DO NOT DELETE - -#ifndef GTEST_INCLUDE_GTEST_INTERNAL_GTEST_LINKED_PTR_H_ -#define GTEST_INCLUDE_GTEST_INTERNAL_GTEST_LINKED_PTR_H_ - -#include <stdlib.h> -#include <assert.h> - -#include "gtest/internal/gtest-port.h" - -namespace testing { -namespace internal { - -// Protects copying of all linked_ptr objects. -GTEST_API_ GTEST_DECLARE_STATIC_MUTEX_(g_linked_ptr_mutex); - -// This is used internally by all instances of linked_ptr<>. It needs to be -// a non-template class because different types of linked_ptr<> can refer to -// the same object (linked_ptr<Superclass>(obj) vs linked_ptr<Subclass>(obj)). -// So, it needs to be possible for different types of linked_ptr to participate -// in the same circular linked list, so we need a single class type here. -// -// DO NOT USE THIS CLASS DIRECTLY YOURSELF. Use linked_ptr<T>. -class linked_ptr_internal { - public: - // Create a new circle that includes only this instance. - void join_new() { - next_ = this; - } - - // Many linked_ptr operations may change p.link_ for some linked_ptr - // variable p in the same circle as this object. Therefore we need - // to prevent two such operations from occurring concurrently. - // - // Note that different types of linked_ptr objects can coexist in a - // circle (e.g. linked_ptr<Base>, linked_ptr<Derived1>, and - // linked_ptr<Derived2>). Therefore we must use a single mutex to - // protect all linked_ptr objects. This can create serious - // contention in production code, but is acceptable in a testing - // framework. - - // Join an existing circle. - void join(linked_ptr_internal const* ptr) - GTEST_LOCK_EXCLUDED_(g_linked_ptr_mutex) { - MutexLock lock(&g_linked_ptr_mutex); - - linked_ptr_internal const* p = ptr; - while (p->next_ != ptr) { - assert(p->next_ != this && - "Trying to join() a linked ring we are already in. " - "Is GMock thread safety enabled?"); - p = p->next_; - } - p->next_ = this; - next_ = ptr; - } - - // Leave whatever circle we're part of. Returns true if we were the - // last member of the circle. Once this is done, you can join() another. - bool depart() - GTEST_LOCK_EXCLUDED_(g_linked_ptr_mutex) { - MutexLock lock(&g_linked_ptr_mutex); - - if (next_ == this) return true; - linked_ptr_internal const* p = next_; - while (p->next_ != this) { - assert(p->next_ != next_ && - "Trying to depart() a linked ring we are not in. " - "Is GMock thread safety enabled?"); - p = p->next_; - } - p->next_ = next_; - return false; - } - - private: - mutable linked_ptr_internal const* next_; -}; - -template <typename T> -class linked_ptr { - public: - typedef T element_type; - - // Take over ownership of a raw pointer. This should happen as soon as - // possible after the object is created. - explicit linked_ptr(T* ptr = nullptr) { capture(ptr); } - ~linked_ptr() { depart(); } - - // Copy an existing linked_ptr<>, adding ourselves to the list of references. - template <typename U> linked_ptr(linked_ptr<U> const& ptr) { copy(&ptr); } - linked_ptr(linked_ptr const& ptr) { // NOLINT - assert(&ptr != this); - copy(&ptr); - } - - // Assignment releases the old value and acquires the new. - template <typename U> linked_ptr& operator=(linked_ptr<U> const& ptr) { - depart(); - copy(&ptr); - return *this; - } - - linked_ptr& operator=(linked_ptr const& ptr) { - if (&ptr != this) { - depart(); - copy(&ptr); - } - return *this; - } - - // Smart pointer members. - void reset(T* ptr = nullptr) { - depart(); - capture(ptr); - } - T* get() const { return value_; } - T* operator->() const { return value_; } - T& operator*() const { return *value_; } - - bool operator==(T* p) const { return value_ == p; } - bool operator!=(T* p) const { return value_ != p; } - template <typename U> - bool operator==(linked_ptr<U> const& ptr) const { - return value_ == ptr.get(); - } - template <typename U> - bool operator!=(linked_ptr<U> const& ptr) const { - return value_ != ptr.get(); - } - - private: - template <typename U> - friend class linked_ptr; - - T* value_; - linked_ptr_internal link_; - - void depart() { - if (link_.depart()) delete value_; - } - - void capture(T* ptr) { - value_ = ptr; - link_.join_new(); - } - - template <typename U> void copy(linked_ptr<U> const* ptr) { - value_ = ptr->get(); - if (value_) - link_.join(&ptr->link_); - else - link_.join_new(); - } -}; - -template<typename T> inline -bool operator==(T* ptr, const linked_ptr<T>& x) { - return ptr == x.get(); -} - -template<typename T> inline -bool operator!=(T* ptr, const linked_ptr<T>& x) { - return ptr != x.get(); -} - -// A function to convert T* into linked_ptr<T> -// Doing e.g. make_linked_ptr(new FooBarBaz<type>(arg)) is a shorter notation -// for linked_ptr<FooBarBaz<type> >(new FooBarBaz<type>(arg)) -template <typename T> -linked_ptr<T> make_linked_ptr(T* ptr) { - return linked_ptr<T>(ptr); -} - -} // namespace internal -} // namespace testing - -#endif // GTEST_INCLUDE_GTEST_INTERNAL_GTEST_LINKED_PTR_H_ |