WaitableEvent is the replacement for Windows events. Previously in the code, a HANDLE from CreateEvent was used for signaling, both within a process and across processes.

WaitableEvent is the cross platform replacement for this. To convert:
  * HANDLE -> base::WaitableEvent*
  * ScopedHandle -> scoped_ptr<base::WaitableEvent>
  * CreateEvent -> new base::WaitableEvent
  * SetEvent -> base::WaitableEvent::Signal
  * ResetEvent -> base::WaitableEvent::Reset
  * ObjectWatcher -> base::WaitableEventWatcher
  * WaitForMultipleObjects -> static base::WaitableEvent::WaitMany

ObjectWatcher remains for Windows specific code. WaitableEventWatcher has an identical interface save,
  * It uses WaitableEvents, not HANDLEs
  * It returns void from StartWatching and StopWatcher, rather than errors. System internal errors are fatal to the address space

IMPORTANT: There are semantic differences between the different platforms. WaitableEvents on Windows are implemented on top of events. Windows events work across process and this is used mostly for modal dialog support. Windows events can be duplicated with DuplicateHandle.

On other platforms, WaitableEvent works only within a single process. In the future we shall have to replace the current uses of cross-process events with IPCs.

BEWARE: HANDLE, on Windows, is a void *. Since any pointer type coerces to void *, you can pass a WaitableEvent * where a HANDLE is expected without any build-time errors.

Review URL: http://codereview.chromium.org/16554


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8126 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 2 insertions, 2 deletions

diff --git a/chrome/browser/browser_process_impl.h b/chrome/browser/browser_process_impl.h
index 6f51102..3b8732c 100644
--- a/chrome/browser/browser_process_impl.h
+++ b/chrome/browser/browser_process_impl.h
@@ -167,7 +167,7 @@ class BrowserProcessImpl : public BrowserProcess, public NonThreadSafe {
     return memory_model_;
   }
 
-  virtual HANDLE shutdown_event() { return shutdown_event_; }
+  virtual base::WaitableEvent* shutdown_event() { return shutdown_event_; }
 
  private:
   void CreateResourceDispatcherHost();
@@ -242,7 +242,7 @@ class BrowserProcessImpl : public BrowserProcess, public NonThreadSafe {
   bool using_new_frames_;
 
   // An event that notifies when we are shutting-down.
-  HANDLE shutdown_event_;
+  base::WaitableEvent* shutdown_event_;
 
   DISALLOW_EVIL_CONSTRUCTORS(BrowserProcessImpl);
 };