diff options
author | mmentovai <mmentovai@4c0a9323-5329-0410-9bdc-e9ce6186880e> | 2006-09-08 18:03:56 +0000 |
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committer | mmentovai <mmentovai@4c0a9323-5329-0410-9bdc-e9ce6186880e> | 2006-09-08 18:03:56 +0000 |
commit | cb9fd5b773b25473770b5ddda53b0a2e9f4c7703 (patch) | |
tree | 63dfc29a69f9528034335a9ac7407fe5d4e59865 /src/processor/linked_ptr.h | |
parent | Change interface for providing files to Minidump (#19). r=bryner (diff) | |
download | breakpad-cb9fd5b773b25473770b5ddda53b0a2e9f4c7703.tar.xz |
Make SourceLineResolver use RangeMap (#13). r=bryner
- Eliminate MemAddrMap from source_line_resolver.cc and adapt it to use
RangeMap, also used by minidump.cc.
- RangeMap operates on both a base address and a size, where MemAddrMap
only used a base address, so the dumped symbol file format is modified
to include size information. dump_syms produces these files and
SourceLineResolver consumes them.
- Provide updated test data conforming to the new dumped symbol format.
http://groups.google.com/group/airbag-dev/browse_thread/thread/e9403cf3ad6336a1
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@21 4c0a9323-5329-0410-9bdc-e9ce6186880e
Diffstat (limited to 'src/processor/linked_ptr.h')
-rw-r--r-- | src/processor/linked_ptr.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/src/processor/linked_ptr.h b/src/processor/linked_ptr.h new file mode 100644 index 00000000..09e4c186 --- /dev/null +++ b/src/processor/linked_ptr.h @@ -0,0 +1,174 @@ +// Copyright (C) 2006 Google Inc. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// 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!). + +#ifndef PROCESSOR_LINKED_PTR_H__ +#define PROCESSOR_LINKED_PTR_H__ + +// 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; + } + + // Join an existing circle. + void join(linked_ptr_internal const* ptr) { + linked_ptr_internal const* p = ptr; + while (p->next_ != ptr) p = p->next_; + p->next_ = this; + next_ = ptr; + } + + // Leave whatever circle we're part of. Returns true iff we were the + // last member of the circle. Once this is done, you can join() another. + bool depart() { + if (next_ == this) return true; + linked_ptr_internal const* p = next_; + while (p->next_ != this) 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 = NULL) { 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) { 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 = NULL) { depart(); capture(ptr); } + T* get() const { return value_; } + T* operator->() const { return value_; } + T& operator*() const { return *value_; } + // Release ownership of the pointed object and returns it. + // Sole ownership by this linked_ptr object is required. + T* release() { + bool last = link_.depart(); + T* v = value_; + value_ = NULL; + return v; + } + + 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); +} + +#endif // PROCESSOR_LINKED_PTR_H__ |