Mojo: Add multiprocess shared memory passing test.

mojo/system/multiprocess_message_pipe_unittest.cc

Index: mojo/system/multiprocess_message_pipe_unittest.cc
diff --git a/mojo/system/multiprocess_message_pipe_unittest.cc b/mojo/system/multiprocess_message_pipe_unittest.cc
index beaa38a3b5759530f03c5515f742e3f5966fd8ae..0e2e44502053583bc2de2b58165e2770a09f4cc5 100644
--- a/mojo/system/multiprocess_message_pipe_unittest.cc
+++ b/mojo/system/multiprocess_message_pipe_unittest.cc
@@ -4,6 +4,7 @@
 
 #include <stdint.h>
 #include <stdio.h>
+#include <string.h>
 
 #include <string>
 #include <vector>
@@ -27,6 +28,8 @@
 #include "mojo/system/platform_handle_dispatcher.h"
 #include "mojo/system/proxy_message_pipe_endpoint.h"
 #include "mojo/system/raw_channel.h"
+#include "mojo/system/raw_shared_buffer.h"
+#include "mojo/system/shared_buffer_dispatcher.h"
 #include "mojo/system/test_utils.h"
 #include "mojo/system/waiter.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -280,6 +283,176 @@ TEST_F(MultiprocessMessagePipeTest, QueueMessages) {
             helper()->WaitForChildShutdown());
 }
 
+MOJO_MULTIPROCESS_TEST_CHILD_MAIN(CheckSharedBuffer) {
+  ChannelThread channel_thread;
+  embedder::ScopedPlatformHandle client_platform_handle =
+      mojo::test::MultiprocessTestHelper::client_platform_handle.Pass();
+  CHECK(client_platform_handle.is_valid());
+  scoped_refptr<MessagePipe> mp(new MessagePipe(
+      scoped_ptr<MessagePipeEndpoint>(new LocalMessagePipeEndpoint()),
+      scoped_ptr<MessagePipeEndpoint>(new ProxyMessagePipeEndpoint())));
+  channel_thread.Start(client_platform_handle.Pass(), mp);
+
+  // Wait for the first message from our parent.
+  CHECK_EQ(WaitIfNecessary(mp, MOJO_WAIT_FLAG_READABLE), MOJO_RESULT_OK);
+
+  // It should have a shared buffer.
+  std::string read_buffer(100, '\0');
+  uint32_t num_bytes = static_cast<uint32_t>(read_buffer.size());
+  DispatcherVector dispatchers;
+  uint32_t num_dispatchers = 10;  // Maximum number to receive.
+  CHECK_EQ(mp->ReadMessage(0,
+                           &read_buffer[0], &num_bytes,
+                           &dispatchers, &num_dispatchers,
+                           MOJO_READ_MESSAGE_FLAG_NONE),
+           MOJO_RESULT_OK);
+  read_buffer.resize(num_bytes);
+  CHECK_EQ(read_buffer, std::string("go 1"));
+  CHECK_EQ(num_dispatchers, 1u);
+
+  CHECK_EQ(dispatchers[0]->GetType(), Dispatcher::kTypeSharedBuffer);
+
+  scoped_refptr<SharedBufferDispatcher> dispatcher(
+      static_cast<SharedBufferDispatcher*>(dispatchers[0].get()));
+
+  // Make a mapping.
+  scoped_ptr<RawSharedBufferMapping> mapping;
+  CHECK_EQ(dispatcher->MapBuffer(0, 100, MOJO_MAP_BUFFER_FLAG_NONE, &mapping),
+           MOJO_RESULT_OK);
+  CHECK(mapping);
+  CHECK(mapping->base());
+  CHECK_EQ(mapping->length(), 100u);
+
+  // Write some stuff to the shared buffer.
+  static const char kHello[] = "hello";
+  memcpy(mapping->base(), kHello, sizeof(kHello));
+
+  // We should be able to close the dispatcher now.
+  dispatcher->Close();
+
+  // And send a message to signal that we've written stuff.
+  const std::string go2("go 2");
+  CHECK_EQ(mp->WriteMessage(0,
+                            &go2[0],
+                            static_cast<uint32_t>(go2.size()),
+                            NULL,
+                            MOJO_WRITE_MESSAGE_FLAG_NONE),
+           MOJO_RESULT_OK);
+
+  // Now wait for our parent to send us a message.
+  CHECK_EQ(WaitIfNecessary(mp, MOJO_WAIT_FLAG_READABLE), MOJO_RESULT_OK);
+
+  read_buffer = std::string(100, '\0');
+  num_bytes = static_cast<uint32_t>(read_buffer.size());
+  CHECK_EQ(mp->ReadMessage(0,
+                           &read_buffer[0], &num_bytes,
+                           NULL, NULL,
+                           MOJO_READ_MESSAGE_FLAG_NONE),
+           MOJO_RESULT_OK);
+  read_buffer.resize(num_bytes);
+  CHECK_EQ(read_buffer, std::string("go 3"));
+
+  // It should have written something to the shared buffer.
+  static const char kWorld[] = "world!!!";
+  CHECK_EQ(memcmp(mapping->base(), kWorld, sizeof(kWorld)), 0);
+
+  // And we're done.
+  mp->Close(0);
+
+  return 0;
+}
+
+#if defined(OS_POSIX)
+#define MAYBE_SharedBufferPassing SharedBufferPassing
+#else
+// Not yet implemented (on Windows).
+#define MAYBE_SharedBufferPassing DISABLED_SharedBufferPassing
+#endif
+TEST_F(MultiprocessMessagePipeTest, MAYBE_SharedBufferPassing) {
+  helper()->StartChild("CheckSharedBuffer");
+
+  scoped_refptr<MessagePipe> mp(new MessagePipe(
+      scoped_ptr<MessagePipeEndpoint>(new LocalMessagePipeEndpoint()),
+      scoped_ptr<MessagePipeEndpoint>(new ProxyMessagePipeEndpoint())));
+  Init(mp);
+
+  // Make a shared buffer.
+  scoped_refptr<SharedBufferDispatcher> dispatcher;
+  MojoCreateSharedBufferOptions validated_options = {};
+  EXPECT_EQ(MOJO_RESULT_OK,
+            SharedBufferDispatcher::ValidateOptions(NULL, &validated_options));
+  EXPECT_EQ(MOJO_RESULT_OK,
+            SharedBufferDispatcher::Create(validated_options, 100,
+                                           &dispatcher));
+  ASSERT_TRUE(dispatcher);
+
+  // Make a mapping.
+  scoped_ptr<RawSharedBufferMapping> mapping;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            dispatcher->MapBuffer(0, 100, MOJO_MAP_BUFFER_FLAG_NONE, &mapping));
+  ASSERT_TRUE(mapping);
+  ASSERT_TRUE(mapping->base());
+  ASSERT_EQ(100u, mapping->length());
+
+  // Send the shared buffer.
+  const std::string go1("go 1");
+  DispatcherTransport transport(
+      test::DispatcherTryStartTransport(dispatcher.get()));
+  ASSERT_TRUE(transport.is_valid());
+
+  std::vector<DispatcherTransport> transports;
+  transports.push_back(transport);
+  EXPECT_EQ(MOJO_RESULT_OK,
+            mp->WriteMessage(0,
+                             &go1[0],
+                             static_cast<uint32_t>(go1.size()),
+                             &transports,
+                             MOJO_WRITE_MESSAGE_FLAG_NONE));
+  transport.End();
+
+  EXPECT_TRUE(dispatcher->HasOneRef());
+  dispatcher = NULL;
+
+  // Wait for a message from the child.
+  EXPECT_EQ(MOJO_RESULT_OK, WaitIfNecessary(mp, MOJO_WAIT_FLAG_READABLE));
+
+  std::string read_buffer(100, '\0');
+  uint32_t num_bytes = static_cast<uint32_t>(read_buffer.size());
+  EXPECT_EQ(MOJO_RESULT_OK,
+            mp->ReadMessage(0,
+                            &read_buffer[0], &num_bytes,
+                            NULL, NULL,
+                            MOJO_READ_MESSAGE_FLAG_NONE));
+  read_buffer.resize(num_bytes);
+  EXPECT_EQ(std::string("go 2"), read_buffer);
+
+  // After we get it, the child should have written something to the shared
+  // buffer.
+  static const char kHello[] = "hello";
+  EXPECT_EQ(0, memcmp(mapping->base(), kHello, sizeof(kHello)));
+
+  // Now we'll write some stuff to the shared buffer.
+  static const char kWorld[] = "world!!!";
+  memcpy(mapping->base(), kWorld, sizeof(kWorld));
+
+  // And send a message to signal that we've written stuff.
+  const std::string go3("go 3");
+  EXPECT_EQ(MOJO_RESULT_OK,
+            mp->WriteMessage(0,
+                             &go3[0],
+                             static_cast<uint32_t>(go3.size()),
+                             NULL,
+                             MOJO_WRITE_MESSAGE_FLAG_NONE));
+
+  // Wait for |mp| to become readable, which should fail.
+  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
+            WaitIfNecessary(mp, MOJO_WAIT_FLAG_READABLE));
+
+  mp->Close(0);
+
+  EXPECT_EQ(0, helper()->WaitForChildShutdown());
+}
+
 MOJO_MULTIPROCESS_TEST_CHILD_MAIN(CheckPlatformHandleFile) {
   ChannelThread channel_thread;
   embedder::ScopedPlatformHandle client_platform_handle =