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 EvictFileFromSystemCache(const FilePath & file)14bool 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 37