[mojo] Implement data pipe using a shared buffer.

mojo/edk/system/data_pipe_unittest.cc

Index: mojo/edk/system/data_pipe_unittest.cc
diff --git a/mojo/edk/system/data_pipe_unittest.cc b/mojo/edk/system/data_pipe_unittest.cc
index 27fd9e410af52c64f837924211c15e58d3ef5914..6c02e5d666e0d40ac0d5f7ed80bc299d9190797e 100644
--- a/mojo/edk/system/data_pipe_unittest.cc
+++ b/mojo/edk/system/data_pipe_unittest.cc
@@ -374,6 +374,14 @@ TEST_F(DataPipeTest, BasicProducerWaiting) {
   ASSERT_EQ(123, elements[0]);
   ASSERT_EQ(-1, elements[1]);
 
+  // Wait until we can write.
+  hss = MojoHandleSignalsState();
+  ASSERT_EQ(MOJO_RESULT_OK, MojoWait(producer_, MOJO_HANDLE_SIGNAL_WRITABLE,
+                                     MOJO_DEADLINE_INDEFINITE, &hss));
+  ASSERT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, hss.satisfied_signals);

[Anand Mistry (off Chromium), 2016/01/08 03:28:02]

EXPECT_EQ and next one.

[Eliot Courtney, 2016/01/08 04:44:39]

Done.

+  ASSERT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfiable_signals);
+
   // Try writing, using a two-phase write.
   void* buffer = nullptr;
   num_bytes = static_cast<uint32_t>(3u * sizeof(elements[0]));
@@ -399,6 +407,14 @@ TEST_F(DataPipeTest, BasicProducerWaiting) {
   ASSERT_EQ(MOJO_RESULT_OK, EndReadData(static_cast<uint32_t>(
                                         1u * sizeof(elements[0]))));
 
+  // Wait until we can write.
+  hss = MojoHandleSignalsState();
+  ASSERT_EQ(MOJO_RESULT_OK, MojoWait(producer_, MOJO_HANDLE_SIGNAL_WRITABLE,
+                                     MOJO_DEADLINE_INDEFINITE, &hss));
+  ASSERT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, hss.satisfied_signals);

[Anand Mistry (off Chromium), 2016/01/08 03:28:02]

EXPECT_EQ and next one.

[Eliot Courtney, 2016/01/08 04:44:40]

Done.

+  ASSERT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            hss.satisfiable_signals);
+
   // Write one element.
   elements[0] = 123;
   num_bytes = static_cast<uint32_t>(1u * sizeof(elements[0]));
@@ -569,7 +585,7 @@ TEST_F(DataPipeTest, BasicConsumerWaiting) {
   ASSERT_EQ(MOJO_RESULT_OK,
             MojoWait(consumer_, MOJO_HANDLE_SIGNAL_PEER_CLOSED,
                      MOJO_DEADLINE_INDEFINITE, &hss));
-  ASSERT_TRUE((hss.satisfied_signals & MOJO_HANDLE_SIGNAL_PEER_CLOSED) != 0);
+  ASSERT_NE(hss.satisfied_signals & MOJO_HANDLE_SIGNAL_PEER_CLOSED, 0u);
   ASSERT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_PEER_CLOSED,
             hss.satisfiable_signals);