minidump: Change the ownership model

minidump/minidump_thread_writer.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // 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.
 
 #ifndef CRASHPAD_MINIDUMP_MINIDUMP_THREAD_WRITER_H_
 #define CRASHPAD_MINIDUMP_MINIDUMP_THREAD_WRITER_H_
 
 #include <dbghelp.h>
 #include <stdint.h>
 
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "minidump/minidump_stream_writer.h"
 #include "minidump/minidump_writable.h"
+#include "util/stdlib/pointer_container.h"
 
 namespace crashpad {
 
 class MinidumpContextWriter;
 class MinidumpMemoryListWriter;
 class MinidumpMemoryWriter;
 
 //! \brief The writer for a MINIDUMP_THREAD object in a minidump file.
 //!
 //! Because MINIDUMP_THREAD objects only appear as elements of
@@ skipping 10 matching lines @@
   //! This method is expected to be called by a MinidumpThreadListWriter in
   //! order to obtain a MINIDUMP_THREAD to include in its list.
   //!
   //! \note Valid in #kStateWritable.
   const MINIDUMP_THREAD* MinidumpThread() const;
 
   //! \brief Returns a MinidumpMemoryWriter that will write the memory region
   //!     corresponding to this object’s stack.
   //!
   //! If the thread does not have a stack, or its stack could not be determined,
-  //! this will return nullptr.
+  //! this will return `nullptr`.
   //!
   //! This method is provided so that MinidumpThreadListWriter can obtain thread
   //! stack memory regions for the purposes of adding them to a
   //! MinidumpMemoryListWriter (configured by calling
   //! MinidumpThreadListWriter::SetMemoryListWriter()) by calling
   //! MinidumpMemoryListWriter::AddExtraMemory().
   //!
   //! \note Valid in any state.
-  MinidumpMemoryWriter* Stack() const { return stack_; }
+  MinidumpMemoryWriter* Stack() const { return stack_.get(); }
 
   //! \brief Arranges for MINIDUMP_THREAD::Stack to point to the MINIDUMP_MEMORY
   //!     object to be written by \a stack.
   //!
-  //! \a stack will become a child of this object in the overall tree of
-  //! internal::MinidumpWritable objects.
+  //! This object takes ownership of \a stack and becomes its parent in the
+  //! overall tree of internal::MinidumpWritable objects.
   //!
   //! \note Valid in #kStateMutable.
-  void SetStack(MinidumpMemoryWriter* stack);
+  void SetStack(scoped_ptr<MinidumpMemoryWriter> stack);
 
   //! \brief Arranges for MINIDUMP_THREAD::ThreadContext to point to the CPU
   //!     context to be written by \a context.
   //!
   //! A context is required in all MINIDUMP_THREAD objects.
   //!
-  //! \a context will become a child of this object in the overall tree of
-  //! internal::MinidumpWritable objects.
+  //! This object takes ownership of \a context and becomes its parent in the
+  //! overall tree of internal::MinidumpWritable objects.
   //!
   //! \note Valid in #kStateMutable.
-  void SetContext(MinidumpContextWriter* context);
+  void SetContext(scoped_ptr<MinidumpContextWriter> context);
 
   //! \brief Sets MINIDUMP_THREAD::ThreadId.
   void SetThreadID(uint32_t thread_id) { thread_.ThreadId = thread_id; }
 
   //! \brief Sets MINIDUMP_THREAD::SuspendCount.
   void SetSuspendCount(uint32_t suspend_count) {
     thread_.SuspendCount = suspend_count;
   }
 
   //! \brief Sets MINIDUMP_THREAD::PriorityClass.
   void SetPriorityClass(uint32_t priority_class) {
     thread_.PriorityClass = priority_class;
   }
 
   //! \brief Sets MINIDUMP_THREAD::Priority.
   void SetPriority(uint32_t priority) { thread_.Priority = priority; }
 
   //! \brief Sets MINIDUMP_THREAD::Teb.
   void SetTEB(uint64_t teb) { thread_.Teb = teb; }
 
  protected:
   // MinidumpWritable:
   bool Freeze() override;
   size_t SizeOfObject() override;
   std::vector<MinidumpWritable*> Children() override;
   bool WriteObject(FileWriterInterface* file_writer) override;
 
  private:
   MINIDUMP_THREAD thread_;
-  MinidumpMemoryWriter* stack_;  // weak
-  MinidumpContextWriter* context_;  // weak
+  scoped_ptr<MinidumpMemoryWriter> stack_;
+  scoped_ptr<MinidumpContextWriter> context_;
 
   DISALLOW_COPY_AND_ASSIGN(MinidumpThreadWriter);
 };
 
 //! \brief The writer for a MINIDUMP_THREAD_LIST stream in a minidump file,
 //!     containing a list of MINIDUMP_THREAD objects.
 class MinidumpThreadListWriter final : public internal::MinidumpStreamWriter {
  public:
   MinidumpThreadListWriter();
-  ~MinidumpThreadListWriter();
+  ~MinidumpThreadListWriter() override;
 
   //! \brief Sets the MinidumpMemoryListWriter that each thread’s stack memory
   //!     region should be added to as extra memory.
   //!
   //! Each MINIDUMP_THREAD object can contain a reference to a
   //! MinidumpMemoryWriter object that contains a snapshot of its stack memory.
   //! In the overall tree of internal::MinidumpWritable objects, these
   //! MinidumpMemoryWriter objects are considered children of their
   //! MINIDUMP_THREAD, and are referenced by a MINIDUMP_MEMORY_DESCRIPTOR
   //! contained in the MINIDUMP_THREAD. It is also possible for the same memory
@@ skipping 10 matching lines @@
   //! of the memory’s contents.
   //!
   //! \note This method must be called before AddThread() is called. Threads
   //!     added by AddThread() prior to this method being called will not have
   //!     their stacks added to \a memory_list_writer as extra memory.
   //! \note Valid in #kStateMutable.
   void SetMemoryListWriter(MinidumpMemoryListWriter* memory_list_writer);
 
   //! \brief Adds a MinidumpThreadWriter to the MINIDUMP_THREAD_LIST.
   //!
-  //! \a thread will become a child of this object in the overall tree of
-  //! internal::MinidumpWritable objects.
+  //! This object takes ownership of \a thread and becomes its parent in the
+  //! overall tree of internal::MinidumpWritable objects.
   //!
   //! \note Valid in #kStateMutable.
-  void AddThread(MinidumpThreadWriter* thread);
+  void AddThread(scoped_ptr<MinidumpThreadWriter> thread);
 
  protected:
   // MinidumpWritable:
   bool Freeze() override;
   size_t SizeOfObject() override;
   std::vector<MinidumpWritable*> Children() override;
   bool WriteObject(FileWriterInterface* file_writer) override;
 
   // MinidumpStreamWriter:
   MinidumpStreamType StreamType() const override;
 
  private:
   MINIDUMP_THREAD_LIST thread_list_base_;
-  std::vector<MinidumpThreadWriter*> threads_;  // weak
+  PointerVector<MinidumpThreadWriter> threads_;
   MinidumpMemoryListWriter* memory_list_writer_;  // weak
 
   DISALLOW_COPY_AND_ASSIGN(MinidumpThreadListWriter);
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_MINIDUMP_MINIDUMP_THREAD_WRITER_H_