Adding MOJO_HANDLE_SIGNAL_PEER_CLOSED to be notified when a peer is closed.

mojo/edk/system/message_pipe_unittest.cc

 // Copyright 2013 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/edk/system/message_pipe.h"
 
 #include "base/memory/ref_counted.h"
 #include "base/threading/platform_thread.h"  // For |Sleep()|.
 #include "base/time/time.h"
 #include "mojo/edk/system/waiter.h"
 #include "mojo/edk/system/waiter_test_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace system {
 namespace {
 
+const MojoHandleSignals kAllSignals = MOJO_HANDLE_SIGNAL_READABLE |
+                                      MOJO_HANDLE_SIGNAL_WRITABLE |
+                                      MOJO_HANDLE_SIGNAL_PEER_CLOSED;
+
 // Tests:
 //  - only default flags
 //  - reading messages from a port
 //    - when there are no/one/two messages available for that port
 //    - with buffer size 0 (and null buffer) -- should get size
 //    - with too-small buffer -- should get size
 //    - also verify that buffers aren't modified when/where they shouldn't be
 //  - writing messages to a port
 //    - in the obvious scenarios (as above)
 //    - to a port that's been closed
@@ skipping 300 matching lines @@
   int32_t buffer[1];
   const uint32_t kBufferSize = static_cast<uint32_t>(sizeof(buffer));
   uint32_t buffer_size;
 
   // Always writable (until the other port is closed).
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
             mp->AddWaiter(0, &waiter, MOJO_HANDLE_SIGNAL_WRITABLE, 0, &hss));
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-            hss.satisfiable_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
             mp->AddWaiter(0, &waiter, MOJO_HANDLE_SIGNAL_READABLE |
                                           MOJO_HANDLE_SIGNAL_WRITABLE,
                           0, &hss));
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-            hss.satisfiable_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
 
   // Not yet readable.
   waiter.Init();
   ASSERT_EQ(MOJO_RESULT_OK,
             mp->AddWaiter(0, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 1, nullptr));
   EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, waiter.Wait(0, nullptr));
   hss = HandleSignalsState();
   mp->RemoveWaiter(0, &waiter, &hss);
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-            hss.satisfiable_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
+
+  // The peer is not closed.
+  waiter.Init();
+  ASSERT_EQ(
+      MOJO_RESULT_OK,
+      mp->AddWaiter(0, &waiter, MOJO_HANDLE_SIGNAL_PEER_CLOSED, 2, nullptr));
+  EXPECT_EQ(MOJO_RESULT_DEADLINE_EXCEEDED, waiter.Wait(0, nullptr));
+  hss = HandleSignalsState();
+  mp->RemoveWaiter(0, &waiter, &hss);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, hss.satisfied_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
 
   // Write from port 0 (to port 1), to make port 1 readable.
   buffer[0] = 123456789;
   EXPECT_EQ(MOJO_RESULT_OK,
             mp->WriteMessage(0, UserPointer<const void>(buffer), kBufferSize,
                              nullptr, MOJO_WRITE_MESSAGE_FLAG_NONE));
 
   // Port 1 should already be readable now.
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
-            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 2, &hss));
+            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 3, &hss));
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
             hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-            hss.satisfiable_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
             mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE |
                                           MOJO_HANDLE_SIGNAL_WRITABLE,
                           0, &hss));
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
             hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-            hss.satisfiable_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
   // ... and still writable.
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
-            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_WRITABLE, 3, &hss));
+            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_WRITABLE, 4, &hss));
   EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
             hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-            hss.satisfiable_signals);
+  EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
 
   // Close port 0.
   mp->Close(0);
 
-  // Now port 1 should not be writable.
+  // Port 1 should be signaled with peer closed.
+  waiter.Init();
+  hss = HandleSignalsState();
+  EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
+            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_PEER_CLOSED, 5, &hss));
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfied_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfiable_signals);
+
+  // Port 1 should not be writable.
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
-            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_WRITABLE, 4, &hss));
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE, hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE, hss.satisfiable_signals);
+            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_WRITABLE, 6, &hss));
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfied_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfiable_signals);
 
   // But it should still be readable.
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_ALREADY_EXISTS,
-            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 5, &hss));
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE, hss.satisfied_signals);
-  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE, hss.satisfiable_signals);
+            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 7, &hss));
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfied_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfiable_signals);
 
   // Read from port 1.
   buffer[0] = 0;
   buffer_size = kBufferSize;
   EXPECT_EQ(MOJO_RESULT_OK,
             mp->ReadMessage(1, UserPointer<void>(buffer),
                             MakeUserPointer(&buffer_size), 0, nullptr,
                             MOJO_READ_MESSAGE_FLAG_NONE));
   EXPECT_EQ(123456789, buffer[0]);
 
   // Now port 1 should no longer be readable.
   waiter.Init();
   hss = HandleSignalsState();
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
-            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 6, nullptr));
+            mp->AddWaiter(1, &waiter, MOJO_HANDLE_SIGNAL_READABLE, 8, nullptr));
   EXPECT_EQ(0u, hss.satisfied_signals);
   EXPECT_EQ(0u, hss.satisfiable_signals);
 
   mp->Close(1);
 }
 
 TEST(MessagePipeTest, ThreadedWaiting) {
   int32_t buffer[1];
   const uint32_t kBufferSize = static_cast<uint32_t>(sizeof(buffer));
 
@@ skipping 14 matching lines @@
     buffer[0] = 123456789;
     // Write from port 0 (to port 1), which should wake up the waiter.
     EXPECT_EQ(MOJO_RESULT_OK,
               mp->WriteMessage(0, UserPointer<const void>(buffer), kBufferSize,
                                nullptr, MOJO_WRITE_MESSAGE_FLAG_NONE));
 
     HandleSignalsState hss;
     mp->RemoveWaiter(1, thread.waiter(), &hss);
     EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
               hss.satisfied_signals);
-    EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
-              hss.satisfiable_signals);
+    EXPECT_EQ(kAllSignals, hss.satisfiable_signals);
 
     mp->Close(0);
     mp->Close(1);
   }  // Joins |thread|.
   // The waiter should have woken up successfully.
   EXPECT_EQ(MOJO_RESULT_OK, result);
   EXPECT_EQ(1u, context);
 
   // Close to cancel waiter.
   {
@@ skipping 11 matching lines @@
     mp->Close(1);
 
     // Port 1 is closed, so |Dispatcher::RemoveWaiter()| wouldn't call into the
     // |MessagePipe| to remove any waiter.
 
     mp->Close(0);
   }  // Joins |thread|.
   EXPECT_EQ(MOJO_RESULT_CANCELLED, result);
   EXPECT_EQ(2u, context);
 
+  // Close to cancel waiter using peer closed signal.
+  {
+    scoped_refptr<MessagePipe> mp(MessagePipe::CreateLocalLocal());
+    test::SimpleWaiterThread thread(&result, &context);
+
+    thread.waiter()->Init();
+    ASSERT_EQ(MOJO_RESULT_OK,
+              mp->AddWaiter(1, thread.waiter(), MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+                            3, nullptr));
+    thread.Start();
+
+    // Close port 1 first -- this should result in the waiter being cancelled.
+    mp->CancelAllWaiters(1);
+    mp->Close(1);
+
+    // Port 1 is closed, so |Dispatcher::RemoveWaiter()| wouldn't call into the
+    // |MessagePipe| to remove any waiter.
+
+    mp->Close(0);
+  }  // Joins |thread|.
+  EXPECT_EQ(MOJO_RESULT_CANCELLED, result);
+  EXPECT_EQ(3u, context);
+
   // Close to make waiter un-wake-up-able.
   {
     scoped_refptr<MessagePipe> mp(MessagePipe::CreateLocalLocal());
     test::SimpleWaiterThread thread(&result, &context);
 
     thread.waiter()->Init();
     ASSERT_EQ(MOJO_RESULT_OK,
-              mp->AddWaiter(1, thread.waiter(), MOJO_HANDLE_SIGNAL_READABLE, 3,
+              mp->AddWaiter(1, thread.waiter(), MOJO_HANDLE_SIGNAL_READABLE, 4,
                             nullptr));
     thread.Start();
 
     // Close port 0 first -- this should wake the waiter up, since port 1 will
     // never be readable.
     mp->CancelAllWaiters(0);
     mp->Close(0);
 
     HandleSignalsState hss;
     mp->RemoveWaiter(1, thread.waiter(), &hss);
-    EXPECT_EQ(0u, hss.satisfied_signals);
-    EXPECT_EQ(0u, hss.satisfiable_signals);
+    EXPECT_EQ(MOJO_HANDLE_SIGNAL_PEER_CLOSED, hss.satisfied_signals);
+    EXPECT_EQ(MOJO_HANDLE_SIGNAL_PEER_CLOSED, hss.satisfiable_signals);
 
     mp->CancelAllWaiters(1);
     mp->Close(1);
   }  // Joins |thread|.
   EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION, result);
-  EXPECT_EQ(3u, context);
+  EXPECT_EQ(4u, context);
 }
 
 }  // namespace
 }  // namespace system
 }  // namespace mojo