EDK: Remove mojo::platform::MessageLoopForIO and add PlatformHandleWatcher.

mojo/edk/base_edk/platform_message_loop_for_io_impl_unittest.cc

Index: mojo/edk/base_edk/platform_message_loop_for_io_impl_unittest.cc
diff --git a/mojo/edk/base_edk/platform_message_loop_for_io_impl_unittest.cc b/mojo/edk/base_edk/platform_message_loop_for_io_impl_unittest.cc
index f3d1ca767658a8f8167330aceb518fd85e568fc2..7b5c97ffef8dd498645307b72cc5299062324097 100644
--- a/mojo/edk/base_edk/platform_message_loop_for_io_impl_unittest.cc
+++ b/mojo/edk/base_edk/platform_message_loop_for_io_impl_unittest.cc
@@ -4,11 +4,22 @@
 
 #include "mojo/edk/base_edk/platform_message_loop_for_io_impl.h"
 
+#include <unistd.h>
+
+#include <memory>
+
 #include "base/message_loop/message_loop.h"
+#include "base/posix/eintr_wrapper.h"
 #include "mojo/edk/base_edk/message_loop_test_helper.h"
+#include "mojo/edk/platform/platform_handle.h"
+#include "mojo/edk/platform/platform_handle_watcher.h"
+#include "mojo/edk/platform/scoped_platform_handle.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using mojo::platform::MessageLoop;
+using mojo::platform::PlatformHandle;
+using mojo::platform::PlatformHandleWatcher;
+using mojo::platform::ScopedPlatformHandle;
 
 namespace base_edk {
 namespace {
@@ -20,5 +31,46 @@ TEST(PlatformMessageLoopForIOImplTest, Basic) {
   test::MessageLoopTestHelper(&message_loop_for_io);
 }
 
+TEST(PlatformMessageLoopForIOImplTest, Watch) {
+  const char kHello[] = "hello";
+
+  PlatformMessageLoopForIOImpl message_loop_for_io;
+
+  // TODO(vtl): This is an extremely cursory test. We should test more carefully
+  // (e.g., we should test that the watch callbacks aren't called spuriously,
+  // that the "persist" flag works correctly, and that cancellation works).
+  int pipe_fds[2] = {};
+  ASSERT_EQ(pipe(pipe_fds), 0);
+  // The read end.
+  ScopedPlatformHandle h0((PlatformHandle(pipe_fds[0])));
+  ASSERT_TRUE(h0.is_valid());
+  // The write end.
+  ScopedPlatformHandle h1((PlatformHandle(pipe_fds[1])));
+  ASSERT_TRUE(h1.is_valid());
+
+  // Watch for read on |h1|; it should never trigger.
+  std::unique_ptr<PlatformHandleWatcher::WatchToken> watch1 =
+      message_loop_for_io.Watch(
+          h1.get(), false, []() { EXPECT_TRUE(false); },
+          [&h1, &kHello]() {
+            EXPECT_EQ(static_cast<ssize_t>(sizeof(kHello)),
+                      HANDLE_EINTR(write(h1.get().fd, kHello, sizeof(kHello))));
+          });
+  unsigned h0_read_count = 0u;
+  std::unique_ptr<PlatformHandleWatcher::WatchToken> watch0 =
+      message_loop_for_io.Watch(
+          h0.get(),
+          true, [&h0_read_count, &h0, &kHello, &message_loop_for_io]() {
+            char buf[100] = {};
+            h0_read_count++;
+            EXPECT_EQ(static_cast<ssize_t>(sizeof(kHello)),
+                      HANDLE_EINTR(read(h0.get().fd, buf, sizeof(buf))));
+            EXPECT_STREQ(kHello, buf);
+            message_loop_for_io.QuitWhenIdle();
+          }, nullptr);
+  message_loop_for_io.Run();
+  EXPECT_EQ(1u, h0_read_count);
+}
+
 }  // namespace
 }  // namespace base_edk