Mojo: Armed Watchers

mojo/public/cpp/system/tests/watcher_unittest.cc

 // 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.
 
 #include "mojo/public/cpp/system/watcher.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 30 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(WatcherTest);
 };
 
 TEST_F(WatcherTest, WatchBasic) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
 
   bool notified = false;
   base::RunLoop run_loop;
-  Watcher b_watcher(FROM_HERE);
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
   EXPECT_EQ(MOJO_RESULT_OK,
             b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                             OnReady([&] (MojoResult result) {
                               EXPECT_EQ(MOJO_RESULT_OK, result);
                               notified = true;
                               run_loop.Quit();
                             })));
   EXPECT_TRUE(b_watcher.IsWatching());
 
   EXPECT_EQ(MOJO_RESULT_OK, WriteMessageRaw(a.get(), "hello", 5, nullptr, 0,
                                             MOJO_WRITE_MESSAGE_FLAG_NONE));
   run_loop.Run();
   EXPECT_TRUE(notified);
 
   b_watcher.Cancel();
 }
 
 TEST_F(WatcherTest, WatchUnsatisfiable) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
   a.reset();
 
-  Watcher b_watcher(FROM_HERE);
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
             b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                             NotReached()));
   EXPECT_FALSE(b_watcher.IsWatching());
 }
 
 TEST_F(WatcherTest, WatchInvalidHandle) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
   a.reset();
   b.reset();
 
-  Watcher b_watcher(FROM_HERE);
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
   EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
             b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                             NotReached()));
   EXPECT_FALSE(b_watcher.IsWatching());
 }
 
 TEST_F(WatcherTest, Cancel) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
 
   base::RunLoop run_loop;
-  Watcher b_watcher(FROM_HERE);
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
   EXPECT_EQ(MOJO_RESULT_OK,
             b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                             NotReached()));
   EXPECT_TRUE(b_watcher.IsWatching());
   b_watcher.Cancel();
   EXPECT_FALSE(b_watcher.IsWatching());
 
   // This should never trigger the watcher.
   EXPECT_EQ(MOJO_RESULT_OK, WriteMessageRaw(a.get(), "hello", 5, nullptr, 0,
                                             MOJO_WRITE_MESSAGE_FLAG_NONE));
 
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, run_loop.QuitClosure());
   run_loop.Run();
 }
 
 TEST_F(WatcherTest, CancelOnClose) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
 
   base::RunLoop run_loop;
-  Watcher b_watcher(FROM_HERE);
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
   EXPECT_EQ(MOJO_RESULT_OK,
             b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                             OnReady([&] (MojoResult result) {
                               EXPECT_EQ(MOJO_RESULT_CANCELLED, result);
                               run_loop.Quit();
                             })));
   EXPECT_TRUE(b_watcher.IsWatching());
 
   // This should trigger the watcher above.
   b.reset();
 
   run_loop.Run();
 
   EXPECT_FALSE(b_watcher.IsWatching());
 }
 
 TEST_F(WatcherTest, CancelOnDestruction) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
   base::RunLoop run_loop;
   {
-    Watcher b_watcher(FROM_HERE);
+    Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
     EXPECT_EQ(MOJO_RESULT_OK,
               b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                               NotReached()));
     EXPECT_TRUE(b_watcher.IsWatching());
 
     // |b_watcher| should be cancelled when it goes out of scope.
   }
 
   // This should never trigger the watcher above.
   EXPECT_EQ(MOJO_RESULT_OK, WriteMessageRaw(a.get(), "hello", 5, nullptr, 0,
                                             MOJO_WRITE_MESSAGE_FLAG_NONE));
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, run_loop.QuitClosure());
   run_loop.Run();
 }
 
 TEST_F(WatcherTest, CloseAndCancel) {
   ScopedMessagePipeHandle a, b;
   CreateMessagePipe(nullptr, &a, &b);
 
-  Watcher b_watcher(FROM_HERE);
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::AUTOMATIC);
   EXPECT_EQ(MOJO_RESULT_OK,
             b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
                             OnReady([](MojoResult result) { FAIL(); })));
   EXPECT_TRUE(b_watcher.IsWatching());
 
   // This should trigger the watcher above...
   b.reset();
   // ...but the watcher is cancelled first.
   b_watcher.Cancel();
 
   EXPECT_FALSE(b_watcher.IsWatching());
 
   base::RunLoop().RunUntilIdle();
 }
 
+TEST_F(WatcherTest, UnarmedCancel) {
+  ScopedMessagePipeHandle a, b;
+  CreateMessagePipe(nullptr, &a, &b);
+
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::MANUAL);
+  base::RunLoop loop;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
+                            base::Bind(
+                                [](base::RunLoop* loop, MojoResult result) {
+                                  EXPECT_EQ(result, MOJO_RESULT_CANCELLED);
+                                  loop->Quit();
+                                },
+                                &loop)));
+
+  // This message write will not wake up the watcher since the watcher isn't
+  // armed. Instead, the cancellation will dispatch due to the reset below.
+  EXPECT_EQ(MOJO_RESULT_OK, WriteMessageRaw(a.get(), "hello", 5, nullptr, 0,
+                                            MOJO_WRITE_MESSAGE_FLAG_NONE));
+  b.reset();
+  loop.Run();
+}
+
+TEST_F(WatcherTest, ManualArming) {
+  ScopedMessagePipeHandle a, b;
+  CreateMessagePipe(nullptr, &a, &b);
+
+  Watcher b_watcher(FROM_HERE, Watcher::ArmingPolicy::MANUAL);
+  base::RunLoop loop;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            b_watcher.Start(b.get(), MOJO_HANDLE_SIGNAL_READABLE,
+                            base::Bind(
+                                [](base::RunLoop* loop, MojoResult result) {
+                                  EXPECT_EQ(result, MOJO_RESULT_OK);
+                                  loop->Quit();
+                                },
+                                &loop)));
+  EXPECT_EQ(MOJO_RESULT_OK, b_watcher.Arm());
+
+  EXPECT_EQ(MOJO_RESULT_OK, WriteMessageRaw(a.get(), "hello", 5, nullptr, 0,
+                                            MOJO_WRITE_MESSAGE_FLAG_NONE));
+  loop.Run();
+}
+
+TEST_F(WatcherTest, ManualArmOrNotifyWhileSignaled) {
+  ScopedMessagePipeHandle a, b;
+  CreateMessagePipe(nullptr, &a, &b);
+
+  base::RunLoop loop1;
+  Watcher b_watcher1(FROM_HERE, Watcher::ArmingPolicy::MANUAL);
+  bool notified1 = false;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            b_watcher1.Start(
+                b.get(), MOJO_HANDLE_SIGNAL_READABLE,
+                base::Bind(
+                    [](base::RunLoop* loop, bool* notified, MojoResult result) {
+                      EXPECT_EQ(result, MOJO_RESULT_OK);
+                      *notified = true;
+                      loop->Quit();
+                    },
+                    &loop1, &notified1)));
+
+  base::RunLoop loop2;
+  Watcher b_watcher2(FROM_HERE, Watcher::ArmingPolicy::MANUAL);
+  bool notified2 = false;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            b_watcher2.Start(
+                b.get(), MOJO_HANDLE_SIGNAL_READABLE,
+                base::Bind(
+                    [](base::RunLoop* loop, bool* notified, MojoResult result) {
+                      EXPECT_EQ(result, MOJO_RESULT_OK);
+                      *notified = true;
+                      loop->Quit();
+                    },
+                    &loop2, &notified2)));
+
+  // First ensure that |b| is readable.
+  EXPECT_EQ(MOJO_RESULT_OK, b_watcher1.Arm());
+  EXPECT_EQ(MOJO_RESULT_OK, WriteMessageRaw(a.get(), "hello", 5, nullptr, 0,
+                                            MOJO_WRITE_MESSAGE_FLAG_NONE));
+  loop1.Run();
+
+  EXPECT_TRUE(notified1);
+  EXPECT_FALSE(notified2);
+  notified1 = false;
+
+  // Now verify that ArmOrNotify results in a notification.
+  b_watcher2.ArmOrNotify();
+  loop2.Run();
+
+  EXPECT_FALSE(notified1);
+  EXPECT_TRUE(notified2);
+}
+
 }  // namespace
 }  // namespace mojo