1 files changed, 36 insertions, 0 deletions
diff --git a/base/test/test_file_util_mac.cc b/base/test/test_file_util_mac.cc
new file mode 100644
index 0000000..316b5c3
--- /dev/null
+++ b/base/test/test_file_util_mac.cc
@@ -0,0 +1,36 @@
+// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/test/test_file_util.h"
+
+#include <sys/mman.h>
+#include <errno.h>
+#include "base/logging.h"
+#include "base/file_util.h"
+
+namespace file_util {
+
+bool EvictFileFromSystemCache(const FilePath& file) {
+  // There aren't any really direct ways to purge a file from the UBC.  From
+  // talking with Amit Singh, the safest is to mmap the file with MAP_FILE (the
+  // default) + MAP_SHARED, then do an msync to invalidate the memory.  The next
+  // open should then have to load the file from disk.
+
+  file_util::MemoryMappedFile mapped_file;
+  if (!mapped_file.Initialize(file)) {
+    DLOG(WARNING) << "failed to memory map " << file.value();
+    return false;
+  }
+
+  if (msync(const_cast<uint8*>(mapped_file.data()), mapped_file.length(),
+            MS_INVALIDATE) != 0) {
+    DLOG(WARNING) << "failed to invalidate memory map of " << file.value()
+        << ", errno: " << errno;
+    return false;
+  }
+
+  return true;
+}
+
+}  // namespace file_util