base/files/memory_mapped_file_posix.cc

   1 // Copyright 2013 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 "base/files/memory_mapped_file.h"
   6
   7 #include <sys/mman.h>
   8 #include <sys/stat.h>
   9 #include <unistd.h>
  10
  11 #include "base/logging.h"
  12 #include "base/posix/eintr_wrapper.h"
  13 #include "base/threading/thread_restrictions.h"
  14
  15 namespace base {
  16
  17 MemoryMappedFile::MemoryMappedFile()
  18     : file_(kInvalidPlatformFileValue),
  19       data_(NULL),
  20       length_(0) {
  21 }
  22
  23 bool MemoryMappedFile::MapFileToMemoryInternal() {
  24   ThreadRestrictions::AssertIOAllowed();
  25
  26   struct stat file_stat;
  27   if (fstat(file_, &file_stat) == kInvalidPlatformFileValue) {
  28     DLOG(ERROR) << "Couldn't fstat " << file_ << ", errno " << errno;
  29     return false;
  30   }
  31   length_ = file_stat.st_size;
  32
  33   data_ = static_cast<uint8*>(
  34       mmap(NULL, length_, PROT_READ, MAP_SHARED, file_, 0));
  35   if (data_ == MAP_FAILED)
  36     DLOG(ERROR) << "Couldn't mmap " << file_ << ", errno " << errno;
  37
  38   return data_ != MAP_FAILED;
  39 }
  40
  41 void MemoryMappedFile::CloseHandles() {
  42   ThreadRestrictions::AssertIOAllowed();
  43
  44   if (data_ != NULL)
  45     munmap(data_, length_);
  46   if (file_ != kInvalidPlatformFileValue)
  47     ignore_result(HANDLE_EINTR(close(file_)));
  48
  49   data_ = NULL;
  50   length_ = 0;
  51   file_ = kInvalidPlatformFileValue;
  52 }
  53
  54 }  // namespace base