net: Implement canceling of all async operations in FileStream.

Canceling of async operations allows to not wait for their completion
in FileStream's destructor. Other related changes include:

- Got rid of FileStream::Close() and FileStream::CloseSync() methods because
reuse of FileStream object doesn't make much sense, it should be destroyed
instead.

- Changed FileStream to always acquire ownership of the PlatformFile it was
given. Fixed usages of FileStream where no ownership was assumed, introduced
new helper functions in base/platform_file.h on the way.

- FileStream's destructor now always closes the file. If file was opened with
PLATFORM_FILE_ASYNC then actual closing is done asynchronously, destructor
doesn't wait for that and returns immediately. When file was opened without
PLATFORM_FILE_ASYNC closing is done synchronously and the thread doing that
should be allowed to do IO operations.

- Implementation of FileStream is refactored. FileStream is now just a wrapper
around internal object that does all actual work and that can be easily
orphaned in the destructor to not block on the actual file descriptor closing.
All platform-independent code is extracted into a special file and amount of
platform-dependent code is minimized.


BUG=115067, 112474
TEST=net_unittests

Review URL: https://chromiumcodereview.appspot.com/10701050

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166091 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 6 insertions, 6 deletions

diff --git a/chrome/browser/bookmarks/bookmark_html_writer.cc b/chrome/browser/bookmarks/bookmark_html_writer.cc
index fef222f..4cc20ec 100644
--- a/chrome/browser/bookmarks/bookmark_html_writer.cc
+++ b/chrome/browser/bookmarks/bookmark_html_writer.cc
@@ -97,8 +97,7 @@ class Writer : public base::RefCountedThreadSafe<Writer> {
       : bookmarks_(bookmarks),
         path_(path),
         favicons_map_(favicons_map),
-        observer_(observer),
-        file_stream_(NULL) {
+        observer_(observer) {
   }
 
   // Writing bookmarks and favicons data to file.
@@ -149,7 +148,7 @@ class Writer : public base::RefCountedThreadSafe<Writer> {
     Write(kFolderChildrenEnd);
     Write(kNewline);
     // File stream close is forced so that unit test could read it.
-    file_stream_.CloseSync();
+    file_stream_.reset();
 
     NotifyOnFinish();
   }
@@ -172,8 +171,9 @@ class Writer : public base::RefCountedThreadSafe<Writer> {
 
   // Opens the file, returning true on success.
   bool OpenFile() {
+    file_stream_.reset(new net::FileStream(NULL));
     int flags = base::PLATFORM_FILE_CREATE_ALWAYS | base::PLATFORM_FILE_WRITE;
-    return (file_stream_.OpenSync(path_, flags) == net::OK);
+    return (file_stream_->OpenSync(path_, flags) == net::OK);
   }
 
   // Increments the indent.
@@ -197,7 +197,7 @@ class Writer : public base::RefCountedThreadSafe<Writer> {
   // Writes raw text out returning true on success. This does not escape
   // the text in anyway.
   bool Write(const std::string& text) {
-    size_t wrote = file_stream_.WriteSync(text.c_str(), text.length());
+    size_t wrote = file_stream_->WriteSync(text.c_str(), text.length());
     bool result = (wrote == text.length());
     DCHECK(result);
     return result;
@@ -374,7 +374,7 @@ class Writer : public base::RefCountedThreadSafe<Writer> {
   BookmarksExportObserver* observer_;
 
   // File we're writing to.
-  net::FileStream file_stream_;
+  scoped_ptr<net::FileStream> file_stream_;
 
   // How much we indent when writing a bookmark/folder. This is modified
   // via IncrementIndent and DecrementIndent.