[mojo-edk] Add explicit message object APIs

mojo/edk/system/message_pipe_unittest.cc

Index: mojo/edk/system/message_pipe_unittest.cc
diff --git a/mojo/edk/system/message_pipe_unittest.cc b/mojo/edk/system/message_pipe_unittest.cc
index bfafbb740d1b97a15171e88e1bf704e24efc80c4..f490b23e760522ecccd957cc1cff9f833d4d0646 100644
--- a/mojo/edk/system/message_pipe_unittest.cc
+++ b/mojo/edk/system/message_pipe_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include <stdint.h>
+#include <string.h>
 
 #include "base/memory/ref_counted.h"
 #include "mojo/edk/system/test_utils.h"
@@ -409,6 +410,75 @@ TEST_F(MessagePipeTest, BasicWaiting) {
   ASSERT_EQ(MOJO_HANDLE_SIGNAL_PEER_CLOSED, hss.satisfiable_signals);
 }
 
+TEST_F(MessagePipeTest, InvalidMessageObjects) {
+  // null message
+  ASSERT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            MojoDestroyMessage(nullptr));
+
+  // null message
+  ASSERT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            MojoGetMessageBuffer(nullptr, nullptr));
+
+  // Non-zero num_handles with null handles array.
+  ASSERT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            MojoCreateMessage(0, nullptr, 1, MOJO_CREATE_MESSAGE_FLAG_NONE,
+                              nullptr));
+}
+
+TEST_F(MessagePipeTest, CreateAndDestroyMessage) {
+  const std::string kMessage = "Hello, world.";
+  void* message = nullptr;
+  ASSERT_EQ(MOJO_RESULT_OK,
+            MojoCreateMessage(static_cast<uint32_t>(kMessage.size()),
+                              nullptr, 0, MOJO_CREATE_MESSAGE_FLAG_NONE,
+                              &message));
+  ASSERT_TRUE(message);
+
+  ASSERT_EQ(MOJO_RESULT_OK, MojoDestroyMessage(message));
+}
+
+TEST_F(MessagePipeTest, WriteAndReadMessageObject) {
+  const std::string kMessage = "Hello, world.";
+  void* message = nullptr;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            MojoCreateMessage(static_cast<uint32_t>(kMessage.size()),
+                              nullptr, 0, MOJO_CREATE_MESSAGE_FLAG_NONE,
+                              &message));
+  ASSERT_TRUE(message);
+
+  void* buffer = nullptr;
+  EXPECT_EQ(MOJO_RESULT_OK, MojoGetMessageBuffer(message, &buffer));
+  ASSERT_TRUE(buffer);
+  memcpy(buffer, kMessage.data(), kMessage.size());
+
+  MojoHandle a, b;
+  CreateMessagePipe(&a, &b);
+  EXPECT_EQ(MOJO_RESULT_OK,
+            MojoWriteMessageNew(a, message, MOJO_WRITE_MESSAGE_FLAG_NONE));
+
+  EXPECT_EQ(MOJO_RESULT_OK,
+            MojoWait(b, MOJO_HANDLE_SIGNAL_READABLE, MOJO_DEADLINE_INDEFINITE,
+                     nullptr));
+  uint32_t num_bytes = 0;
+  uint32_t num_handles = 0;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            MojoReadMessageNew(b, &message, &num_bytes, nullptr, &num_handles,
+                               MOJO_READ_MESSAGE_FLAG_NONE));
+  ASSERT_TRUE(message);
+  EXPECT_EQ(static_cast<uint32_t>(kMessage.size()), num_bytes);
+  EXPECT_EQ(0u, num_handles);
+
+  EXPECT_EQ(MOJO_RESULT_OK, MojoGetMessageBuffer(message, &buffer));
+  ASSERT_TRUE(buffer);
+
+  EXPECT_EQ(0, strncmp(static_cast<const char*>(buffer), kMessage.data(),
+                       num_bytes));
+
+  EXPECT_EQ(MOJO_RESULT_OK, MojoDestroyMessage(message));
+  EXPECT_EQ(MOJO_RESULT_OK, MojoClose(a));
+  EXPECT_EQ(MOJO_RESULT_OK, MojoClose(b));
+}
+
 #if !defined(OS_IOS)
 
 const size_t kPingPongHandlesPerIteration = 50;