Mojo: Move waiting APIs to public library

mojo/public/cpp/system/tests/wait_unittest.cc

+// Copyright 2017 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/public/cpp/system/wait.h"
+
+#include <string>
+#include <vector>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/strings/string_piece.h"
+#include "base/threading/platform_thread.h"
+#include "base/threading/simple_thread.h"
+#include "base/time/time.h"
+#include "mojo/public/c/system/types.h"
+#include "mojo/public/cpp/system/handle_signals_state.h"
+#include "mojo/public/cpp/system/message_pipe.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace {
+
+using WaitTest = testing::Test;
+using WaitManyTest = testing::Test;
+
+void WriteMessage(const ScopedMessagePipeHandle& handle,
+                  const base::StringPiece& message) {
+  MojoResult rv = WriteMessageRaw(handle.get(), message.data(),
+                                  static_cast<uint32_t>(message.size()),
+                                  nullptr, 0, MOJO_WRITE_MESSAGE_FLAG_NONE);
+  CHECK_EQ(MOJO_RESULT_OK, rv);
+}
+
+std::string ReadMessage(const ScopedMessagePipeHandle& handle) {
+  uint32_t num_bytes = 0;
+  uint32_t num_handles = 0;
+  MojoResult rv = ReadMessageRaw(handle.get(), nullptr, &num_bytes, nullptr,
+                                 &num_handles, MOJO_READ_MESSAGE_FLAG_NONE);
+  CHECK_EQ(MOJO_RESULT_RESOURCE_EXHAUSTED, rv);
+  CHECK_EQ(0u, num_handles);
+
+  std::vector<char> buffer(num_bytes);
+  rv = ReadMessageRaw(handle.get(), buffer.data(), &num_bytes, nullptr,
+                      &num_handles, MOJO_READ_MESSAGE_FLAG_NONE);
+  CHECK_EQ(MOJO_RESULT_OK, rv);
+  return std::string(buffer.data(), buffer.size());
+}
+
+class ThreadedRunner : public base::SimpleThread {
+ public:
+  explicit ThreadedRunner(const base::Closure& callback)
+      : SimpleThread("ThreadedRunner"), callback_(callback) {}
+  ~ThreadedRunner() override { Join(); }
+
+  void Run() override { callback_.Run(); }
+
+ private:
+  const base::Closure callback_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadedRunner);
+};
+
+TEST_F(WaitTest, InvalidArguments) {
+  Handle invalid_handle;
+
+  EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            Wait(invalid_handle, MOJO_HANDLE_SIGNAL_READABLE));
+
+  MessagePipe p;
+  Handle valid_handles[2] = {p.handle0.get(), p.handle1.get()};
+  Handle invalid_handles[2];
+  MojoHandleSignals signals[2] = {MOJO_HANDLE_SIGNAL_NONE,
+                                  MOJO_HANDLE_SIGNAL_NONE};
+  size_t result_index = 0;
+  EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            WaitMany(invalid_handles, signals, 2, &result_index));
+  EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            WaitMany(nullptr, signals, 2, &result_index));
+  EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            WaitMany(valid_handles, nullptr, 2, &result_index));
+}
+
+TEST_F(WaitTest, Basic) {
+  MessagePipe p;
+
+  // Write to one end of the pipe and wait on the other.
+  const char kTestMessage1[] = "how about a nice game of chess?";
+  WriteMessage(p.handle0, kTestMessage1);
+  EXPECT_EQ(MOJO_RESULT_OK, Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_READABLE));
+
+  // And make sure we can also grab the handle signals state (with both the C
+  // and C++ library structs.)
+
+  MojoHandleSignalsState c_hss = {0, 0};
+  EXPECT_EQ(MOJO_RESULT_OK,
+            Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_READABLE, &c_hss));
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
+            c_hss.satisfied_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE |
+                MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            c_hss.satisfiable_signals);
+
+  HandleSignalsState hss;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_READABLE, &hss));
+  EXPECT_TRUE(hss.readable() && hss.writable() && !hss.peer_closed());
+  EXPECT_FALSE(hss.never_readable() || hss.never_writable() ||
+               hss.never_peer_closed());
+
+  // Now close the writing end and wait for peer closure.
+
+  p.handle0.reset();
+  EXPECT_EQ(MOJO_RESULT_OK,
+            Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_PEER_CLOSED, &hss));
+
+  // Still readable as there's still a message queued. No longer writable as
+  // peer closure has been detected.
+  EXPECT_TRUE(hss.readable() && hss.peer_closed() && !hss.writable());
+  EXPECT_TRUE(hss.never_writable() && !hss.never_readable() &&
+              !hss.never_peer_closed());
+
+  // Read the message and wait for readable again. Waiting should fail since
+  // there are no more messages and the peer is closed.
+  EXPECT_EQ(kTestMessage1, ReadMessage(p.handle1));
+  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
+            Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_READABLE, &hss));
+
+  // Sanity check the signals state again.
+  EXPECT_TRUE(hss.peer_closed() && !hss.readable() && !hss.writable());
+  EXPECT_TRUE(hss.never_readable() && hss.never_writable() &&
+              !hss.never_peer_closed());
+}
+
+TEST_F(WaitTest, DelayedWrite) {
+  MessagePipe p;
+
+  ThreadedRunner write_after_delay(base::Bind(
+      [](ScopedMessagePipeHandle* handle) {
+        // Wait a little while, then write a message.
+        base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(200));
+        WriteMessage(*handle, "wakey wakey");
+      },
+      &p.handle0));
+  write_after_delay.Start();
+
+  HandleSignalsState hss;
+  EXPECT_EQ(MOJO_RESULT_OK,
+            Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_READABLE, &hss));
+  EXPECT_TRUE(hss.readable() && hss.writable() && !hss.peer_closed());
+  EXPECT_TRUE(!hss.never_readable() && !hss.never_writable() &&
+              !hss.never_peer_closed());
+}
+
+TEST_F(WaitTest, DelayedPeerClosure) {
+  MessagePipe p;
+
+  ThreadedRunner close_after_delay(base::Bind(
+      [](ScopedMessagePipeHandle* handle) {
+        // Wait a little while, then close the handle.
+        base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(200));
+        handle->reset();
+      },
+      &p.handle0));
+  close_after_delay.Start();
+
+  HandleSignalsState hss;
+  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
+            Wait(p.handle1.get(), MOJO_HANDLE_SIGNAL_READABLE, &hss));
+  EXPECT_TRUE(!hss.readable() && !hss.writable() && hss.peer_closed());
+  EXPECT_TRUE(hss.never_readable() && hss.never_writable() &&
+              !hss.never_peer_closed());
+}
+
+TEST_F(WaitTest, CloseWhileWaiting) {
+  MessagePipe p;
+  ThreadedRunner close_after_delay(base::Bind(
+      [](ScopedMessagePipeHandle* handle) {
+        base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(200));
+        handle->reset();
+      },
+      &p.handle0));
+  close_after_delay.Start();
+  EXPECT_EQ(MOJO_RESULT_CANCELLED,
+            Wait(p.handle0.get(), MOJO_HANDLE_SIGNAL_READABLE));
+}
+
+TEST_F(WaitManyTest, Basic) {
+  MessagePipe p;
+
+  const char kTestMessage1[] = "hello";
+  WriteMessage(p.handle0, kTestMessage1);
+
+  // Wait for either handle to become readable. Wait twice, just to verify that
+  // we can use either the C or C++ signaling state structure for the last
+  // argument.
+
+  Handle handles[2] = {p.handle0.get(), p.handle1.get()};
+  MojoHandleSignals signals[2] = {MOJO_HANDLE_SIGNAL_READABLE,
+                                  MOJO_HANDLE_SIGNAL_READABLE};
+  size_t result_index = 0;
+  MojoHandleSignalsState c_hss[2];
+  HandleSignalsState hss[2];
+
+  EXPECT_EQ(MOJO_RESULT_OK,
+            WaitMany(handles, signals, 2, &result_index, c_hss));
+  EXPECT_EQ(1u, result_index);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_WRITABLE, c_hss[0].satisfied_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE |
+                MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            c_hss[0].satisfiable_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE,
+            c_hss[1].satisfied_signals);
+  EXPECT_EQ(MOJO_HANDLE_SIGNAL_READABLE | MOJO_HANDLE_SIGNAL_WRITABLE |
+                MOJO_HANDLE_SIGNAL_PEER_CLOSED,
+            c_hss[1].satisfiable_signals);
+
+  EXPECT_EQ(MOJO_RESULT_OK, WaitMany(handles, signals, 2, &result_index, hss));
+  EXPECT_EQ(1u, result_index);
+  EXPECT_TRUE(!hss[0].readable() && hss[0].writable() && !hss[0].peer_closed());
+  EXPECT_TRUE(!hss[0].never_readable() && !hss[0].never_writable() &&
+              !hss[0].never_peer_closed());
+  EXPECT_TRUE(hss[1].readable() && hss[1].writable() && !hss[1].peer_closed());
+  EXPECT_TRUE(!hss[1].never_readable() && !hss[1].never_writable() &&
+              !hss[1].never_peer_closed());
+
+  // Close the writer and read the message. Try to wait again, and it should
+  // fail due to the conditions being unsatisfiable.
+
+  EXPECT_EQ(kTestMessage1, ReadMessage(p.handle1));
+  p.handle0.reset();
+
+  // handles[0] is invalid.
+  EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT,
+            WaitMany(handles, signals, 2, &result_index, hss));
+  handles[0] = handles[1];
+  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
+            WaitMany(handles, signals, 1, &result_index, hss));
+  EXPECT_EQ(0u, result_index);
+  EXPECT_TRUE(!hss[0].readable() && !hss[0].writable() && hss[0].peer_closed());
+  EXPECT_TRUE(hss[0].never_readable() && hss[0].never_writable() &&
+              !hss[0].never_peer_closed());
+}
+
+TEST_F(WaitManyTest, CloseWhileWaiting) {
+  MessagePipe p, q;
+
+  Handle handles[3] = {q.handle0.get(), q.handle1.get(), p.handle1.get()};
+  MojoHandleSignals signals[3] = {MOJO_HANDLE_SIGNAL_READABLE,
+                                  MOJO_HANDLE_SIGNAL_READABLE,
+                                  MOJO_HANDLE_SIGNAL_READABLE};
+
+  ThreadedRunner close_after_delay(base::Bind(
+      [](ScopedMessagePipeHandle* handle) {
+        base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(200));
+        handle->reset();
+      },
+      &p.handle1));
+  close_after_delay.Start();
+
+  size_t result_index = 0;
+  EXPECT_EQ(MOJO_RESULT_CANCELLED,
+            WaitMany(handles, signals, 3, &result_index));
+  EXPECT_EQ(2u, result_index);
+}
+
+TEST_F(WaitManyTest, DelayedWrite) {
+  MessagePipe p;
+
+  ThreadedRunner write_after_delay(base::Bind(
+      [](ScopedMessagePipeHandle* handle) {
+        // Wait a little while, then write a message.
+        base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(200));
+        WriteMessage(*handle, "wakey wakey");
+      },
+      &p.handle0));
+  write_after_delay.Start();
+
+  Handle handles[2] = {p.handle0.get(), p.handle1.get()};
+  MojoHandleSignals signals[2] = {MOJO_HANDLE_SIGNAL_READABLE,
+                                  MOJO_HANDLE_SIGNAL_READABLE};
+  size_t result_index = 0;
+  HandleSignalsState hss[2];
+  EXPECT_EQ(MOJO_RESULT_OK, WaitMany(handles, signals, 2, &result_index, hss));
+  EXPECT_EQ(1u, result_index);
+  EXPECT_TRUE(!hss[0].readable() && hss[0].writable() && !hss[0].peer_closed());
+  EXPECT_TRUE(!hss[0].never_readable() && !hss[0].never_writable() &&
+              !hss[0].never_peer_closed());
+  EXPECT_TRUE(hss[1].readable() && hss[1].writable() && !hss[1].peer_closed());
+  EXPECT_TRUE(!hss[1].never_readable() && !hss[1].never_writable() &&
+              !hss[1].never_peer_closed());
+}
+
+TEST_F(WaitManyTest, DelayedPeerClosure) {
+  MessagePipe p, q;
+
+  ThreadedRunner close_after_delay(base::Bind(
+      [](ScopedMessagePipeHandle* handle) {
+        // Wait a little while, then close the handle.
+        base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(200));
+        handle->reset();
+      },
+      &p.handle0));
+  close_after_delay.Start();
+
+  Handle handles[3] = {q.handle0.get(), q.handle1.get(), p.handle1.get()};
+  MojoHandleSignals signals[3] = {MOJO_HANDLE_SIGNAL_READABLE,
+                                  MOJO_HANDLE_SIGNAL_READABLE,
+                                  MOJO_HANDLE_SIGNAL_READABLE};
+  size_t result_index = 0;
+  HandleSignalsState hss[3];
+  EXPECT_EQ(MOJO_RESULT_FAILED_PRECONDITION,
+            WaitMany(handles, signals, 3, &result_index, hss));
+  EXPECT_EQ(2u, result_index);
+  EXPECT_TRUE(!hss[2].readable() && !hss[2].writable() && hss[2].peer_closed());
+  EXPECT_TRUE(hss[2].never_readable() && hss[2].never_writable() &&
+              !hss[2].never_peer_closed());
+}
+
+}  // namespace
+}  // namespace mojo