content/child/web_process_memory_dump_impl.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/child/web_process_memory_dump_impl.h"
   6
   7 #include "base/trace_event/process_memory_dump.h"
   8 #include "content/child/web_memory_allocator_dump_impl.h"
   9
  10 namespace content {
  11
  12 WebProcessMemoryDumpImpl::WebProcessMemoryDumpImpl()
  13     : owned_process_memory_dump_(
  14           new base::trace_event::ProcessMemoryDump(nullptr)),
  15       process_memory_dump_(owned_process_memory_dump_.get()) {
  16 }
  17
  18 WebProcessMemoryDumpImpl::WebProcessMemoryDumpImpl(
  19     base::trace_event::ProcessMemoryDump* process_memory_dump)
  20     : process_memory_dump_(process_memory_dump) {
  21 }
  22
  23 WebProcessMemoryDumpImpl::~WebProcessMemoryDumpImpl() {
  24 }
  25
  26 blink::WebMemoryAllocatorDump*
  27 WebProcessMemoryDumpImpl::createMemoryAllocatorDump(
  28     const blink::WebString& absolute_name) {
  29   // Get a MemoryAllocatorDump from the base/ object.
  30   base::trace_event::MemoryAllocatorDump* mad =
  31       process_memory_dump_->CreateAllocatorDump(absolute_name.utf8());
  32   if (!mad)
  33     return nullptr;
  34
  35   // Wrap it and return to blink.
  36   WebMemoryAllocatorDumpImpl* web_mad_impl =
  37       new WebMemoryAllocatorDumpImpl(mad);
  38
  39   // memory_allocator_dumps_ will take ownership of |web_mad_impl|.
  40   memory_allocator_dumps_.push_back(web_mad_impl);
  41   return web_mad_impl;
  42 }
  43
  44 void WebProcessMemoryDumpImpl::clear() {
  45   // Clear all the WebMemoryAllocatorDump wrappers.
  46   memory_allocator_dumps_.clear();
  47
  48   // Clear the actual MemoryAllocatorDump objects from the underlying PMD.
  49   process_memory_dump_->Clear();
  50 }
  51
  52 void WebProcessMemoryDumpImpl::takeAllDumpsFrom(
  53     blink::WebProcessMemoryDump* other) {
  54   auto other_impl = static_cast<WebProcessMemoryDumpImpl*>(other);
  55   // WebProcessMemoryDumpImpl is a container of WebMemoryAllocatorDump(s) which
  56   // in turn are wrappers of base::trace_event::MemoryAllocatorDump(s).
  57   // In order to expose the move and ownership transfer semantics of the
  58   // underlying ProcessMemoryDump, we need to
  59
  60   // 1) Move and transfer the ownership of the wrapped
  61   // base::trace_event::MemoryAllocatorDump(s) instances.
  62   process_memory_dump_->TakeAllDumpsFrom(other_impl->process_memory_dump_);
  63
  64   // 2) Move and transfer the ownership of the WebMemoryAllocatorDump wrappers.
  65   memory_allocator_dumps_.insert(memory_allocator_dumps_.end(),
  66                                  other_impl->memory_allocator_dumps_.begin(),
  67                                  other_impl->memory_allocator_dumps_.end());
  68   other_impl->memory_allocator_dumps_.weak_clear();
  69 }
  70
  71 }  // namespace content