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Unified Diff: mojo/edk/system/watcher.h

Issue 2725133002: Mojo: Armed Watchers (Closed)
Patch Set: rebase Created 3 years, 9 months ago
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Index: mojo/edk/system/watcher.h
diff --git a/mojo/edk/system/watcher.h b/mojo/edk/system/watcher.h
deleted file mode 100644
index b6dc2e4645ad0e8d0d88fa571fedceb78ef97e9f..0000000000000000000000000000000000000000
--- a/mojo/edk/system/watcher.h
+++ /dev/null
@@ -1,88 +0,0 @@
-// Copyright 2016 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.
-
-#ifndef MOJO_EDK_SYSTEM_WATCHER_H_
-#define MOJO_EDK_SYSTEM_WATCHER_H_
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "base/synchronization/lock.h"
-#include "mojo/public/c/system/functions.h"
-#include "mojo/public/c/system/types.h"
-
-namespace mojo {
-namespace edk {
-
-struct HandleSignalsState;
-
-// This object corresponds to a watch added by a single call to |MojoWatch()|.
-//
-// An event may occur at any time which should trigger a Watcher to run its
-// callback, but the callback needs to be deferred until all EDK locks are
-// released. At the same time, a watch may be cancelled at any time by
-// |MojoCancelWatch()| and it is not OK for the callback to be invoked after
-// that happens.
-//
-// Therefore a Watcher needs to have some associated thread-safe state to track
-// its cancellation, which is why it's ref-counted.
-class Watcher : public base::RefCountedThreadSafe<Watcher> {
- public:
- using WatchCallback = base::Callback<void(MojoResult,
- const HandleSignalsState&,
- MojoWatchNotificationFlags)>;
-
- // Constructs a new Watcher which watches for |signals| to be satisfied on a
- // handle and which invokes |callback| either when one such signal is
- // satisfied, or all such signals become unsatisfiable.
- Watcher(MojoHandleSignals signals, const WatchCallback& callback);
-
- // Runs the Watcher's callback with the given arguments if it hasn't been
- // cancelled yet.
- void MaybeInvokeCallback(MojoResult result,
- const HandleSignalsState& state,
- MojoWatchNotificationFlags flags);
-
- // Notifies the Watcher of a state change. This may result in the Watcher
- // adding a finalizer to the current RequestContext to invoke its callback,
- // cancellation notwithstanding.
- void NotifyForStateChange(const HandleSignalsState& signals_state);
-
- // Notifies the Watcher of handle closure. This always results in the Watcher
- // adding a finalizer to the current RequestContext to invoke its callback,
- // cancellation notwithstanding.
- void NotifyClosed();
-
- // Explicitly cancels the watch, guaranteeing that its callback will never be
- // be invoked again.
- void Cancel();
-
- private:
- friend class base::RefCountedThreadSafe<Watcher>;
-
- ~Watcher();
-
- // The set of signals which are watched by this Watcher.
- const MojoHandleSignals signals_;
-
- // The callback to invoke with a result and signal state any time signals in
- // |signals_| are satisfied or become permanently unsatisfiable.
- const WatchCallback callback_;
-
- // Guards |is_cancelled_|.
- base::Lock lock_;
-
- // Indicates whether the watch has been cancelled. A |Watcher| may exist for a
- // brief period of time after being cancelled if it's been attached as a
- // RequestContext finalizer. In such cases the callback must not be invoked,
- // hence this flag.
- bool is_cancelled_ = false;
-
- DISALLOW_COPY_AND_ASSIGN(Watcher);
-};
-
-} // namespace edk
-} // namespace mojo
-
-#endif // MOJO_EDK_SYSTEM_WATCHER_H_

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