Fuchsia: Build standalone VM. Make it run "Hello, World!".

runtime/bin/eventhandler_fuchsia.cc

+// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#if !defined(DART_IO_DISABLED)
+
+#include "platform/globals.h"
+#if defined(TARGET_OS_FUCHSIA)
+
+#include "bin/eventhandler.h"
+#include "bin/eventhandler_fuchsia.h"
+
+#include <magenta/syscalls.h>
+#include <runtime/status.h>
+
+#include "bin/thread.h"
+#include "bin/utils.h"
+
+namespace dart {
+namespace bin {
+
+EventHandlerImplementation::EventHandlerImplementation() {
+  mx_status_t status = mx_message_pipe_create(interrupt_handles_, 0);
+  if (status != NO_ERROR) {
+    FATAL1("mx_message_pipe_create failed: %s\n", mx_strstatus(status));
+  }
+}
+
+
+EventHandlerImplementation::~EventHandlerImplementation() {
+  mx_status_t status = mx_handle_close(interrupt_handles_[0]);
+  if (status != NO_ERROR) {
+    FATAL1("mx_handle_close failed: %s\n", mx_strstatus(status));
+  }
+  status = mx_handle_close(interrupt_handles_[1]);
+  if (status != NO_ERROR) {
+    FATAL1("mx_handle_close failed: %s\n", mx_strstatus(status));
+  }
+}
+
+
+void EventHandlerImplementation::WakeupHandler(intptr_t id,
+                                               Dart_Port dart_port,
+                                               int64_t data) {
+  InterruptMessage msg;
+  msg.id = id;
+  msg.dart_port = dart_port;
+  msg.data = data;
+
+  mx_status_t status =
+    mx_message_write(interrupt_handles_[1], &msg, sizeof(msg), NULL, 0, 0);
+  if (status != NO_ERROR) {
+    FATAL1("mx_message_write failed: %s\n", mx_strstatus(status));
+  }
+}
+
+
+void EventHandlerImplementation::HandleInterruptFd() {
+  InterruptMessage msg;
+  uint32_t bytes = kInterruptMessageSize;
+  mx_status_t status;
+  while (true) {
+    status = mx_message_read(
+        interrupt_handles_[0], &msg, &bytes, NULL, NULL, 0);
+    if (status != NO_ERROR) {
+      break;
+    }
+    ASSERT(bytes == kInterruptMessageSize);
+    if (msg.id == kTimerId) {
+      timeout_queue_.UpdateTimeout(msg.dart_port, msg.data);
+    } else if (msg.id == kShutdownId) {
+      shutdown_ = true;
+    } else {
+      UNIMPLEMENTED();
+    }
+  }
+  if (status != ERR_BAD_STATE) {
+    FATAL1("mx_message_read failed: %s\n", mx_strstatus(status));
+  }

[siva, 2016/07/22 19:18:22]

for status == ERR_BAD_STATE we seem to do nothing, Should we at least log a
message.

[zra, 2016/07/22 20:07:08]

status should be ERR_BAD_STATE when we try to read when there are no messages
available. If status is not ERR_BAD_STATE it means there was some other error
that should be reported. I've added a comment.

+}
+
+
+void EventHandlerImplementation::HandleEvents() {
+  // TODO(zra): Handle events from other handles. At the moment we are only
+  // interrupted when there is a message on interrupt_handles_[0].
+  HandleInterruptFd();
+}
+
+
+int64_t EventHandlerImplementation::GetTimeout() {
+  if (!timeout_queue_.HasTimeout()) {
+    return kInfinityTimeout;
+  }
+  int64_t millis = timeout_queue_.CurrentTimeout() -
+      TimerUtils::GetCurrentMonotonicMillis();
+  return (millis < 0) ? 0 : millis;
+}
+
+
+void EventHandlerImplementation::HandleTimeout() {
+  if (timeout_queue_.HasTimeout()) {
+    int64_t millis = timeout_queue_.CurrentTimeout() -
+        TimerUtils::GetCurrentMonotonicMillis();
+    if (millis <= 0) {
+      DartUtils::PostNull(timeout_queue_.CurrentPort());
+      timeout_queue_.RemoveCurrent();
+    }
+  }
+}
+
+
+void EventHandlerImplementation::Poll(uword args) {
+  EventHandler* handler = reinterpret_cast<EventHandler*>(args);
+  EventHandlerImplementation* handler_impl = &handler->delegate_;
+  ASSERT(handler_impl != NULL);
+
+  while (!handler_impl->shutdown_) {
+    int64_t millis = handler_impl->GetTimeout();
+    ASSERT((millis == kInfinityTimeout) || (millis >= 0));
+
+    mx_time_t timeout =
+        millis * kMicrosecondsPerMillisecond * kNanosecondsPerMicrosecond;
+    mx_signals_state_t signals_state;
+    mx_status_t status = mx_handle_wait_one(
+        handler_impl->interrupt_handles_[0],
+        MX_SIGNAL_READABLE | MX_SIGNAL_PEER_CLOSED,
+        timeout,
+        &signals_state);
+    if ((status != NO_ERROR) && (status != ERR_TIMED_OUT)) {
+      FATAL1("mx_handle_wait_one failed: %s\n", mx_strstatus(status));
+    } else {
+      handler_impl->HandleTimeout();
+      if ((signals_state.satisfied & MX_SIGNAL_READABLE) != 0) {
+        handler_impl->HandleEvents();
+      }
+      if ((signals_state.satisfied & MX_SIGNAL_PEER_CLOSED) != 0) {
+        FATAL("EventHandlerImplementation::Poll: Unexpected peer closed\n");
+      }
+    }
+  }
+  handler->NotifyShutdownDone();
+}
+
+
+void EventHandlerImplementation::Start(EventHandler* handler) {
+  int result = Thread::Start(&EventHandlerImplementation::Poll,
+                             reinterpret_cast<uword>(handler));
+  if (result != 0) {
+    FATAL1("Failed to start event handler thread %d", result);
+  }
+}
+
+
+void EventHandlerImplementation::Shutdown() {
+  SendData(kShutdownId, 0, 0);
+}
+
+
+void EventHandlerImplementation::SendData(intptr_t id,
+                                          Dart_Port dart_port,
+                                          int64_t data) {
+  WakeupHandler(id, dart_port, data);
+}
+
+}  // namespace bin
+}  // namespace dart
+
+#endif  // defined(TARGET_OS_FUCHSIA)
+
+#endif  // !defined(DART_IO_DISABLED)