base/test/test_file_util_mac.cc

   1 // Copyright (c) 2008 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/test/test_file_util.h"
   6
   7 #include <sys/mman.h>
   8 #include <errno.h>
   9 #include "base/logging.h"
  10 #include "base/file_util.h"
  11
  12 namespace file_util {
  13
  14 bool EvictFileFromSystemCache(const FilePath& file) {
  15   // There aren't any really direct ways to purge a file from the UBC.  From
  16   // talking with Amit Singh, the safest is to mmap the file with MAP_FILE (the
  17   // default) + MAP_SHARED, then do an msync to invalidate the memory.  The next
  18   // open should then have to load the file from disk.
  19
  20   file_util::MemoryMappedFile mapped_file;
  21   if (!mapped_file.Initialize(file)) {
  22     DLOG(WARNING) << "failed to memory map " << file.value();
  23     return false;
  24   }
  25
  26   if (msync(const_cast<uint8*>(mapped_file.data()), mapped_file.length(),
  27             MS_INVALIDATE) != 0) {
  28     DLOG(WARNING) << "failed to invalidate memory map of " << file.value()
  29         << ", errno: " << errno;
  30     return false;
  31   }
  32
  33   return true;
  34 }
  35
  36 }  // namespace file_util