1    :  // Copyright 2012 Google Inc. All Rights Reserved.
   2    :  //
   3    :  // Licensed under the Apache License, Version 2.0 (the "License");
   4    :  // you may not use this file except in compliance with the License.
   5    :  // You may obtain a copy of the License at
   6    :  //
   7    :  //     http://www.apache.org/licenses/LICENSE-2.0
   8    :  //
   9    :  // Unless required by applicable law or agreed to in writing, software
  10    :  // distributed under the License is distributed on an "AS IS" BASIS,
  11    :  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12    :  // See the License for the specific language governing permissions and
  13    :  // limitations under the License.
  14    :  //
  15    :  // This file implements the trace::service::Buffer and BufferPool
  16    :  // structures, which are used to represent the shared memory buffers
  17    :  // used by the call_trace service.
  18    :  
  19    :  #include "syzygy/trace/service/buffer_pool.h"
  20    :  
  21    :  #include "base/logging.h"
  22    :  #include "syzygy/common/com_utils.h"
  23    :  
  24    :  namespace trace {
  25    :  namespace service {
  26    :  
  27  E :  BufferPool::BufferPool() {
  28  E :  }
  29    :  
  30  E :  BufferPool::~BufferPool() {
  31  E :  }
  32    :  
  33    :  bool BufferPool::Init(Session* session,
  34    :                        size_t num_buffers,
  35  E :                        size_t buffer_size) {
  36  E :    DCHECK(num_buffers != 0);
  37  E :    DCHECK(buffer_size != 0);
  38  E :    DCHECK(!handle_.IsValid());
  39    :  
  40  E :    size_t mapping_size = num_buffers * buffer_size;
  41    :  
  42  E :    VLOG(1) << "Creating " << (mapping_size >> 20) << "MB memory pool.";
  43    :  
  44    :    // Create a pagefile backed memory mapped file. This will be cut up into a
  45    :    // pool of buffers.
  46    :    base::win::ScopedHandle new_handle(
  47  E :        ::CreateFileMapping(NULL, NULL, PAGE_READWRITE, 0, mapping_size, NULL));
  48  E :    if (!new_handle.IsValid()) {
  49  i :      DWORD error = ::GetLastError();
  50  i :      LOG(ERROR) << "Failed to allocate buffer: " << ::common::LogWe(error)
  51    :                 << ".";
  52  i :      return false;
  53    :    }
  54    :  
  55    :    // Take ownership of the newly created resources.
  56  E :    handle_.Set(new_handle.Take());
  57    :  
  58    :    // Create records for each buffer in the pool.
  59  E :    buffers_.resize(num_buffers);
  60  E :    for (size_t i = 0; i < num_buffers; ++i) {
  61  E :      Buffer& cb = buffers_[i];
  62  E :      size_t offset = i * buffer_size;
  63  E :      cb.shared_memory_handle = NULL;
  64  E :      cb.mapping_size = mapping_size;
  65  E :      cb.buffer_offset = offset;
  66  E :      cb.buffer_size = buffer_size;
  67  E :      cb.session = session;
  68  E :      cb.pool = this;
  69  E :      cb.state = Buffer::kAvailable;
  70  E :    }
  71    :  
  72  E :    return true;
  73  E :  }
  74    :  
  75  E :  void BufferPool::SetClientHandle(HANDLE client_handle) {
  76  E :    DCHECK(client_handle != NULL);
  77    :  
  78  E :    for (size_t i = 0; i < buffers_.size(); ++i) {
  79  E :      Buffer& cb = buffers_[i];
  80  E :      DCHECK_EQ(Buffer::kAvailable, cb.state);
  81  E :      DCHECK(cb.shared_memory_handle == NULL);
  82  E :      cb.shared_memory_handle = reinterpret_cast<unsigned long>(client_handle);
  83  E :    }
  84  E :  }
  85    :  
  86    :  }  // namespace service
  87    :  }  // namespace trace