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-rw-r--r--src/common/scoped_ptr.h487
1 files changed, 278 insertions, 209 deletions
diff --git a/src/common/scoped_ptr.h b/src/common/scoped_ptr.h
index 2dbc40df..d137c186 100644
--- a/src/common/scoped_ptr.h
+++ b/src/common/scoped_ptr.h
@@ -1,231 +1,285 @@
-// (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
-// Copyright (c) 2001, 2002 Peter Dimov
+// Copyright 2013 Google Inc. All Rights Reserved.
//
-// Permission to copy, use, modify, sell and distribute this software
-// is granted provided this copyright notice appears in all copies.
-// This software is provided "as is" without express or implied
-// warranty, and with no claim as to its suitability for any purpose.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
//
-// See http://www.boost.org/libs/smart_ptr/scoped_ptr.htm for documentation.
+// * 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.
//
-
-// scoped_ptr mimics a built-in pointer except that it guarantees deletion
-// of the object pointed to, either on destruction of the scoped_ptr or via
-// an explicit reset(). scoped_ptr is a simple solution for simple needs;
-// use shared_ptr or std::auto_ptr if your needs are more complex.
-
-// *** NOTE ***
-// If your scoped_ptr is a class member of class FOO pointing to a
-// forward declared type BAR (as shown below), then you MUST use a non-inlined
-// version of the destructor. The destructor of a scoped_ptr (called from
-// FOO's destructor) must have a complete definition of BAR in order to
-// destroy it. Example:
+// 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.
+
+// 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 correspond
+// to the operators new/delete and new[]/delete[].
//
-// -- foo.h --
-// class BAR;
+// Example usage (scoped_ptr):
+// {
+// scoped_ptr<Foo> foo(new Foo("wee"));
+// } // foo goes out of scope, releasing the pointer with it.
//
-// class FOO {
-// public:
-// FOO();
-// ~FOO(); // Required for sources that instantiate class FOO to compile!
-//
-// private:
-// scoped_ptr<BAR> bar_;
-// };
+// {
+// scoped_ptr<Foo> 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 ownership, 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.
//
-// -- foo.cc --
-// #include "foo.h"
-// FOO::~FOO() {} // Empty, but must be non-inlined to FOO's class definition.
-
-// scoped_ptr_malloc added by Google
-// When one of these goes out of scope, instead of doing a delete or
-// delete[], it calls free(). scoped_ptr_malloc<char> is likely to see
-// much more use than any other specializations.
-
-// release() added by Google
-// Use this to conditionally transfer ownership of a heap-allocated object
-// to the caller, usually on method success.
+// Example usage (scoped_array):
+// {
+// scoped_array<Foo> foo(new Foo[100]);
+// foo.get()->Method(); // Foo::Method on the 0th element.
+// foo[10].Method(); // Foo::Method on the 10th element.
+// }
#ifndef COMMON_SCOPED_PTR_H_
#define COMMON_SCOPED_PTR_H_
-#include <cstddef> // for std::ptrdiff_t
-#include <assert.h> // for assert
-#include <stdlib.h> // for free() decl
+// 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 <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
namespace google_breakpad {
-template <typename T>
+// A scoped_ptr<T> is like a T*, except that the destructor of scoped_ptr<T>
+// automatically deletes the pointer it holds (if any).
+// That is, scoped_ptr<T> owns the T object that it points to.
+// Like a T*, a scoped_ptr<T> may hold either NULL or a pointer to a T object.
+// Also like T*, scoped_ptr<T> 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<C>) == sizeof(C*)
+template <class C>
class scoped_ptr {
- private:
-
- T* ptr;
-
- scoped_ptr(scoped_ptr const &);
- scoped_ptr & operator=(scoped_ptr const &);
-
public:
- typedef T element_type;
+ // The element type
+ typedef C element_type;
- explicit scoped_ptr(T* p = 0): ptr(p) {}
+ // Constructor. Defaults to initializing 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() {
- typedef char type_must_be_complete[sizeof(T)];
- delete ptr;
+ enum { type_must_be_complete = sizeof(C) };
+ delete ptr_;
}
- void reset(T* p = 0) {
- typedef char type_must_be_complete[sizeof(T)];
-
- if (ptr != p) {
- delete ptr;
- ptr = p;
+ // 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;
}
}
- T& operator*() const {
- assert(ptr != 0);
- return *ptr;
- }
-
- T* operator->() const {
- assert(ptr != 0);
- return ptr;
+ // 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_;
}
-
- bool operator==(T* p) const {
- return ptr == p;
- }
-
- bool operator!=(T* p) const {
- return ptr != p;
+ C* operator->() const {
+ assert(ptr_ != NULL);
+ return ptr_;
}
-
- T* get() const {
- return ptr;
- }
-
- void swap(scoped_ptr & b) {
- T* tmp = b.ptr;
- b.ptr = ptr;
- ptr = tmp;
+ 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;
}
- T* release() {
- T* tmp = ptr;
- ptr = 0;
- return 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 <class C2> bool operator==(scoped_ptr<C2> const& p2) const;
+ template <class C2> bool operator!=(scoped_ptr<C2> const& p2) const;
- // no reason to use these: each scoped_ptr should have its own object
- template <typename U> bool operator==(scoped_ptr<U> const& p) const;
- template <typename U> bool operator!=(scoped_ptr<U> const& p) const;
+ // Disallow evil constructors
+ scoped_ptr(const scoped_ptr&);
+ void operator=(const scoped_ptr&);
};
-template<typename T> inline
-void swap(scoped_ptr<T>& a, scoped_ptr<T>& b) {
- a.swap(b);
+// Free functions
+template <class C>
+void swap(scoped_ptr<C>& p1, scoped_ptr<C>& p2) {
+ p1.swap(p2);
}
-template<typename T> inline
-bool operator==(T* p, const scoped_ptr<T>& b) {
- return p == b.get();
+template <class C>
+bool operator==(C* p1, const scoped_ptr<C>& p2) {
+ return p1 == p2.get();
}
-template<typename T> inline
-bool operator!=(T* p, const scoped_ptr<T>& b) {
- return p != b.get();
+template <class C>
+bool operator!=(C* p1, const scoped_ptr<C>& p2) {
+ return p1 != p2.get();
}
-// scoped_array extends scoped_ptr to arrays. Deletion of the array pointed to
-// is guaranteed, either on destruction of the scoped_array or via an explicit
-// reset(). Use shared_array or std::vector if your needs are more complex.
-
-template<typename T>
+// scoped_array<C> is like scoped_ptr<C>, except that the caller must allocate
+// with new [] and the destructor deletes objects with delete [].
+//
+// As with scoped_ptr<C>, a scoped_array<C> either points to an object
+// or is NULL. A scoped_array<C> owns the object that it points to.
+// scoped_array<T> is thread-compatible, and once you index into it,
+// the returned objects have only the threadsafety guarantees of T.
+//
+// Size: sizeof(scoped_array<C>) == sizeof(C*)
+template <class C>
class scoped_array {
- private:
-
- T* ptr;
-
- scoped_array(scoped_array const &);
- scoped_array & operator=(scoped_array const &);
-
public:
- typedef T element_type;
+ // The element type
+ typedef C element_type;
- explicit scoped_array(T* p = 0) : ptr(p) {}
+ // 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() {
- typedef char type_must_be_complete[sizeof(T)];
- delete[] ptr;
+ enum { type_must_be_complete = sizeof(C) };
+ delete[] array_;
}
- void reset(T* p = 0) {
- typedef char type_must_be_complete[sizeof(T)];
-
- if (ptr != p) {
- delete [] ptr;
- ptr = p;
+ // 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;
}
}
- T& operator[](std::ptrdiff_t i) const {
- assert(ptr != 0);
+ // Get one element of the current object.
+ // Will assert() if there is no current object, or index i is negative.
+ C& operator[](ptrdiff_t i) const {
assert(i >= 0);
- return ptr[i];
- }
-
- bool operator==(T* p) const {
- return ptr == p;
+ assert(array_ != NULL);
+ return array_[i];
}
- bool operator!=(T* p) const {
- return ptr != p;
+ // Get a pointer to the zeroth element of the current object.
+ // If there is no current object, return NULL.
+ C* get() const {
+ return array_;
}
- T* get() const {
- return ptr;
+ // 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;
}
- void swap(scoped_array & b) {
- T* tmp = b.ptr;
- b.ptr = ptr;
- ptr = tmp;
- }
-
- T* release() {
- T* tmp = ptr;
- ptr = 0;
- return 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_;
- // no reason to use these: each scoped_array should have its own object
- template <typename U> bool operator==(scoped_array<U> const& p) const;
- template <typename U> bool operator!=(scoped_array<U> const& p) const;
+ // Forbid comparison of different scoped_array types.
+ template <class C2> bool operator==(scoped_array<C2> const& p2) const;
+ template <class C2> bool operator!=(scoped_array<C2> const& p2) const;
+
+ // Disallow evil constructors
+ scoped_array(const scoped_array&);
+ void operator=(const scoped_array&);
};
-template<class T> inline
-void swap(scoped_array<T>& a, scoped_array<T>& b) {
- a.swap(b);
+// Free functions
+template <class C>
+void swap(scoped_array<C>& p1, scoped_array<C>& p2) {
+ p1.swap(p2);
}
-template<typename T> inline
-bool operator==(T* p, const scoped_array<T>& b) {
- return p == b.get();
+template <class C>
+bool operator==(C* p1, const scoped_array<C>& p2) {
+ return p1 == p2.get();
}
-template<typename T> inline
-bool operator!=(T* p, const scoped_array<T>& b) {
- return p != b.get();
+template <class C>
+bool operator!=(C* p1, const scoped_array<C>& 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 {
@@ -238,95 +292,110 @@ class ScopedPtrMallocFree {
// scoped_ptr_malloc<> is similar to scoped_ptr<>, but it accepts a
// second template argument, the functor used to free the object.
-template<typename T, typename FreeProc = ScopedPtrMallocFree>
+template<class C, class FreeProc = ScopedPtrMallocFree>
class scoped_ptr_malloc {
- private:
-
- T* ptr;
-
- scoped_ptr_malloc(scoped_ptr_malloc const &);
- scoped_ptr_malloc & operator=(scoped_ptr_malloc const &);
-
public:
- typedef T element_type;
+ // The element type
+ typedef C element_type;
- explicit scoped_ptr_malloc(T* p = 0): ptr(p) {}
+ // Constructor. Defaults to initializing 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() {
- typedef char type_must_be_complete[sizeof(T)];
- free_((void*) ptr);
+ reset();
}
- void reset(T* p = 0) {
- typedef char type_must_be_complete[sizeof(T)];
-
- if (ptr != p) {
- free_((void*) ptr);
- ptr = p;
+ // 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) {
+ FreeProc free_proc;
+ free_proc(ptr_);
+ ptr_ = p;
}
}
- T& operator*() const {
- assert(ptr != 0);
- return *ptr;
+ // 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_;
}
- T* operator->() const {
- assert(ptr != 0);
- return ptr;
+ C* operator->() const {
+ assert(ptr_ != NULL);
+ return ptr_;
}
- bool operator==(T* p) const {
- return ptr == p;
+ C* get() const {
+ return ptr_;
}
- bool operator!=(T* p) const {
- return ptr != p;
+ // 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 with the boost-derived implementation, these
+ // take non-const arguments.
+ bool operator==(C* p) const {
+ return ptr_ == p;
}
- T* get() const {
- return ptr;
+ bool operator!=(C* p) const {
+ return ptr_ != p;
}
+ // Swap two scoped pointers.
void swap(scoped_ptr_malloc & b) {
- T* tmp = b.ptr;
- b.ptr = ptr;
- ptr = tmp;
+ C* tmp = b.ptr_;
+ b.ptr_ = ptr_;
+ ptr_ = tmp;
}
- T* release() {
- T* tmp = ptr;
- ptr = 0;
+ // 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 <typename U, typename GP>
- bool operator==(scoped_ptr_malloc<U, GP> const& p) const;
- template <typename U, typename GP>
- bool operator!=(scoped_ptr_malloc<U, GP> const& p) const;
-
- static FreeProc const free_;
+ template <class C2, class GP>
+ bool operator==(scoped_ptr_malloc<C2, GP> const& p) const;
+ template <class C2, class GP>
+ bool operator!=(scoped_ptr_malloc<C2, GP> const& p) const;
+
+ // Disallow evil constructors
+ scoped_ptr_malloc(const scoped_ptr_malloc&);
+ void operator=(const scoped_ptr_malloc&);
};
-template<typename T, typename FP>
-FP const scoped_ptr_malloc<T,FP>::free_ = FP();
-
-template<typename T, typename FP> inline
-void swap(scoped_ptr_malloc<T,FP>& a, scoped_ptr_malloc<T,FP>& b) {
+template<class C, class FP> inline
+void swap(scoped_ptr_malloc<C, FP>& a, scoped_ptr_malloc<C, FP>& b) {
a.swap(b);
}
-template<typename T, typename FP> inline
-bool operator==(T* p, const scoped_ptr_malloc<T,FP>& b) {
+template<class C, class FP> inline
+bool operator==(C* p, const scoped_ptr_malloc<C, FP>& b) {
return p == b.get();
}
-template<typename T, typename FP> inline
-bool operator!=(T* p, const scoped_ptr_malloc<T,FP>& b) {
+template<class C, class FP> inline
+bool operator!=(C* p, const scoped_ptr_malloc<C, FP>& b) {
return p != b.get();
}