Reland: Add code to deal with serial device disconnection detection on Windows

device/serial/serial_io_handler_win.cc

 // Copyright 2014 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 "device/serial/serial_io_handler_win.h"
+
 #include <windows.h>
+#include <setupapi.h>
 
-#include "device/serial/serial_io_handler_win.h"
+#include "base/bind.h"
+#include "base/scoped_observer.h"
+#include "base/threading/thread_checker.h"
+#include "device/core/device_monitor_win.h"
+#include "device/core/scoped_device_info_list.h"
+#include "device/core/scoped_device_info_object.h"
+#include "third_party/re2/re2/re2.h"
 
 namespace device {
 
 namespace {
 
 int BitrateToSpeedConstant(int bitrate) {
 #define BITRATE_TO_SPEED_CASE(x) \
   case x:                        \
     return CBR_##x;
   switch (bitrate) {
@@ skipping 105 matching lines @@
 serial::StopBits StopBitsConstantToEnum(int stop_bits) {
   switch (stop_bits) {
     case TWOSTOPBITS:
       return serial::STOP_BITS_TWO;
     case ONESTOPBIT:
     default:
       return serial::STOP_BITS_ONE;
   }
 }
 
+// Searches for the COM port in the device's friendly name, assigns its value to
+// com_port, and returns whether the operation was successful.
+bool GetCOMPort(const std::string friendly_name, std::string* com_port) {
+  return RE2::PartialMatch(friendly_name, ".* \\((COM[0-9]+)\\)", com_port);
+}
+
 }  // namespace
 
 // static
 scoped_refptr<SerialIoHandler> SerialIoHandler::Create(
     scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner) {
   return new SerialIoHandlerWin(file_thread_task_runner, ui_thread_task_runner);
 }
 
+class SerialIoHandlerWin::UiThreadHelper : public DeviceMonitorWin::Observer {
+ public:
+  UiThreadHelper(
+      base::WeakPtr<SerialIoHandlerWin> io_handler,
+      scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner)
+      : device_observer_(this),
+        io_handler_(io_handler),
+        io_thread_task_runner_(io_thread_task_runner) {}
+
+  ~UiThreadHelper() { DCHECK(thread_checker_.CalledOnValidThread()); }
+
+  static void Start(UiThreadHelper* self) {
+    self->thread_checker_.DetachFromThread();
+    DeviceMonitorWin* device_monitor = DeviceMonitorWin::GetForAllInterfaces();
+    if (device_monitor)
+      self->device_observer_.Add(device_monitor);
+  }
+
+ private:
+  // DeviceMonitorWin::Observer
+  void OnDeviceRemoved(const GUID& class_guid,
+                       const std::string& device_path) override {
+    DCHECK(thread_checker_.CalledOnValidThread());
+    io_thread_task_runner_->PostTask(
+        FROM_HERE, base::Bind(&SerialIoHandlerWin::OnDeviceRemoved, io_handler_,
+                              device_path));
+  }
+
+  base::ThreadChecker thread_checker_;
+  ScopedObserver<DeviceMonitorWin, DeviceMonitorWin::Observer> device_observer_;
+
+  // This weak pointer is only valid when checked on this task runner.
+  base::WeakPtr<SerialIoHandlerWin> io_handler_;
+  scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(UiThreadHelper);
+};
+
+void SerialIoHandlerWin::OnDeviceRemoved(const std::string& device_path) {
+  DCHECK(CalledOnValidThread());
+  base::win::ScopedDeviceInfoList dev_info_list(
+      SetupDiCreateDeviceInfoList(NULL, NULL));
+  if (!dev_info_list.IsValid()) {
+    VPLOG(1) << "Failed to create a device information set";

[grt (UTC plus 2), 2015/11/13 19:40:05]

can these be debug-only logs? do you really need these strings in every shipping
build?

[juncai, 2015/11/14 01:51:24]

Done.

+    return;
+  }
+
+  // This will add the device to |dev_info_list| so we can query driver info.
+  if (!SetupDiOpenDeviceInterfaceA(dev_info_list.Get(), device_path.c_str(), 0,
+                                   NULL)) {
+    VPLOG(1) << "Failed to get device interface data for " << device_path;
+    return;
+  }
+
+  base::win::ScopedDeviceInfo dev_info;
+  if (!SetupDiEnumDeviceInfo(dev_info_list.Get(), 0, dev_info.get())) {
+    VPLOG(1) << "Failed to get device info for " << device_path;
+    return;
+  }
+
+  dev_info.set_valid(dev_info_list.Get());

[grt (UTC plus 2), 2015/11/13 19:40:05]

this looks like an awkward api that is easy to get wrong. can you instead make
ScopedDeviceInfoList more rich so that it's not just a simple scoper, but rather
provides an API that makes getting the device info you need safe and easy for
callers?

[juncai, 2015/11/14 01:51:24]

Done.

+
+  BYTE friendly_name[512];
+  if (!SetupDiGetDeviceRegistryPropertyA(
+          dev_info_list.Get(), dev_info.get(), SPDRP_FRIENDLYNAME, NULL,
+          friendly_name, sizeof(friendly_name), NULL)) {
+    VPLOG(1) << "Failed to get device service property";
+    return;
+  }
+
+  std::string port;
+  if (!GetCOMPort(reinterpret_cast<const char*>(friendly_name), &port)) {
+    VPLOG(1) << "Failed to get port name from \"" << friendly_name << "\".";
+    return;
+  }
+
+  if (port_ == port)
+    CancelRead(serial::RECEIVE_ERROR_DISCONNECTED);
+}
+
 bool SerialIoHandlerWin::PostOpen() {
   DCHECK(!comm_context_);
   DCHECK(!read_context_);
   DCHECK(!write_context_);
 
   base::MessageLoopForIO::current()->RegisterIOHandler(file().GetPlatformFile(),
                                                        this);
 
   comm_context_.reset(new base::MessageLoopForIO::IOContext());
   comm_context_->handler = this;
   memset(&comm_context_->overlapped, 0, sizeof(comm_context_->overlapped));
 
   read_context_.reset(new base::MessageLoopForIO::IOContext());
   read_context_->handler = this;
   memset(&read_context_->overlapped, 0, sizeof(read_context_->overlapped));
 
   write_context_.reset(new base::MessageLoopForIO::IOContext());
   write_context_->handler = this;
   memset(&write_context_->overlapped, 0, sizeof(write_context_->overlapped));
 
+  scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner =
+      base::ThreadTaskRunnerHandle::Get();
+  helper_ =
+      new UiThreadHelper(weak_factory_.GetWeakPtr(), io_thread_task_runner);
+  ui_thread_task_runner_->PostTask(FROM_HERE,
+                                   base::Bind(&UiThreadHelper::Start, helper_));
+
   // A ReadIntervalTimeout of MAXDWORD will cause async reads to complete
   // immediately with any data that's available, even if there is none.
   // This is OK because we never issue a read request until WaitCommEvent
   // signals that data is available.
   COMMTIMEOUTS timeouts = {0};
   timeouts.ReadIntervalTimeout = MAXDWORD;
   if (!::SetCommTimeouts(file().GetPlatformFile(), &timeouts)) {
     VPLOG(1) << "Failed to set serial timeouts";
     return false;
   }
@@ skipping 92 matching lines @@
     return false;
   }
   return true;
 }
 
 SerialIoHandlerWin::SerialIoHandlerWin(
     scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner)
     : SerialIoHandler(file_thread_task_runner, ui_thread_task_runner),
       event_mask_(0),
-      is_comm_pending_(false) {
-}
+      is_comm_pending_(false),
+      weak_factory_(this) {}
 
 SerialIoHandlerWin::~SerialIoHandlerWin() {
+  ui_thread_task_runner_->DeleteSoon(FROM_HERE, helper_);
 }
 
 void SerialIoHandlerWin::OnIOCompleted(
     base::MessageLoopForIO::IOContext* context,
     DWORD bytes_transferred,
     DWORD error) {
   DCHECK(CalledOnValidThread());
   if (context == comm_context_) {
     DWORD errors;
     COMSTAT status;
@@ skipping 146 matching lines @@
 std::string SerialIoHandler::MaybeFixUpPortName(const std::string& port_name) {
   // For COM numbers less than 9, CreateFile is called with a string such as
   // "COM1". For numbers greater than 9, a prefix of "\\\\.\\" must be added.
   if (port_name.length() > std::string("COM9").length())
     return std::string("\\\\.\\").append(port_name);
 
   return port_name;
 }
 
 }  // namespace device