Signal handling.

runtime/bin/process_win.cc

 // Copyright (c) 2012, 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.
 
 #include "platform/globals.h"
 #if defined(TARGET_OS_WINDOWS)
 
 #include <process.h>  // NOLINT
 
 #include "bin/builtin.h"
 #include "bin/process.h"
 #include "bin/eventhandler.h"
 #include "bin/log.h"
+#include "bin/socket.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
 #include "bin/utils_win.h"
 
 
 namespace dart {
 namespace bin {
 
 static const int kReadHandle = 0;
 static const int kWriteHandle = 1;
@@ skipping 818 matching lines @@
 
 void Process::TerminateExitCodeHandler() {
   // Nothing needs to be done on Windows.
 }
 
 
 intptr_t Process::CurrentProcessId() {
   return static_cast<intptr_t>(GetCurrentProcessId());
 }
 
+
+class SignalInfo {
+ public:
+  SignalInfo(intptr_t fd, int signal, SignalInfo* prev = NULL)
+      : fd_(fd),
+        signal_(signal),
+        port_(Dart_GetMainPortId()),
+        next_(NULL),
+        prev_(prev) {
+    if (prev_ != NULL) {
+      prev_->next_ = this;
+    }
+  }
+
+  ~SignalInfo() {
+    reinterpret_cast<FileHandle*>(fd_)->Close();
+  }
+
+  void Unlink() {
+    if (prev_ != NULL) {
+      prev_->next_ = next_;
+    }
+    if (next_ != NULL) {
+      next_->prev_ = prev_;
+    }
+  }
+
+  intptr_t fd() const { return fd_; }
+  int signal() const { return signal_; }
+  Dart_Port port() const { return port_; }
+  SignalInfo* next() const { return next_; }
+
+ private:
+  intptr_t fd_;
+  int signal_;
+  Dart_Port port_;
+  SignalInfo* next_;
+  SignalInfo* prev_;
+};
+
+
+static SignalInfo* signal_handlers = NULL;
+static Mutex* signal_mutex = new Mutex();
+
+
+BOOL WINAPI SignalHandler(DWORD signal) {
+  MutexLocker lock(signal_mutex);
+  const SignalInfo* handler = signal_handlers;
+  bool handled = false;
+  while (handler != NULL) {
+    if (handler->signal() == signal) {
+      int value = 0;
+      Socket::Write(handler->fd(), &value, 1);
+      handled = true;
+    }
+    handler = handler->next();
+  }
+  return handled;
+}
+
+
+intptr_t GetWinSignal(intptr_t signal) {
+  switch (signal) {
+    case 1:  // SIGHUP
+      return CTRL_CLOSE_EVENT;
+    case 2:  // SIGINT
+      return CTRL_C_EVENT;
+    default:
+      return -1;
+  }
+}
+
+
+intptr_t Process::SetSignalHandler(intptr_t signal) {
+  signal = GetWinSignal(signal);
+  if (signal == -1) return -1;

[Søren Gjesse, 2013/12/18 08:07:14]

Throw here?

Dart_ThrowException(DartUtils::NewDartArgumentError("Illegal argument to
SetSignalHandler"));

The Dart code should check this anyway, but is an unsupported value gets through
I think it is better to throw.

[Anders Johnsen, 2013/12/18 21:20:29]

Returning -1 will throw as well (in process.cc). While it's not a 'correct'
exception, it's fine as it's not supposed to happen, but will guide us to the
right fix.

+  // Generate a unique pipe name for the named pipe.

[Søren Gjesse, 2013/12/18 08:07:14]

Please factor out this named pipe name generation to avoid code duplication.

[Anders Johnsen, 2013/12/18 21:20:29]

Done.

+  static const int kMaxPipeNameSize = 80;
+  wchar_t pipe_name[kMaxPipeNameSize];
+  UUID uuid;
+  RPC_STATUS status = UuidCreateSequential(&uuid);
+  if (status != RPC_S_OK && status != RPC_S_UUID_LOCAL_ONLY) {
+    int error_code = GetLastError();
+    Log::PrintErr("UuidCreateSequential failed %d\n", status);
+    SetLastError(error_code);
+    return -1;
+  }
+  RPC_WSTR uuid_string;
+  status = UuidToStringW(&uuid, &uuid_string);
+  if (status != RPC_S_OK) {
+    int error_code = GetLastError();
+    Log::PrintErr("UuidToString failed %d\n", status);
+    SetLastError(error_code);
+    return -1;
+  }
+  static const wchar_t* prefix = L"\\\\.\\Pipe\\dart";
+  _snwprintf(pipe_name,
+             kMaxPipeNameSize,
+             L"%s_%s", prefix, uuid_string);
+  status = RpcStringFreeW(&uuid_string);
+  if (status != RPC_S_OK) {
+    int error_code = GetLastError();
+    Log::PrintErr("RpcStringFree failed %d\n", status);
+    SetLastError(error_code);
+    return -1;
+  }
+  HANDLE fds[2];
+  if (!CreateProcessPipe(fds, pipe_name, kInheritNone)) {
+    int error_code = GetLastError();
+    CloseProcessPipe(fds);
+    SetLastError(error_code);
+    return -1;
+  }
+  MutexLocker lock(signal_mutex);
+  FileHandle* write_handle = new FileHandle(fds[kWriteHandle]);
+  write_handle->EnsureInitialized(EventHandler::delegate());
+  intptr_t write_fd = reinterpret_cast<intptr_t>(write_handle);
+  if (signal_handlers == NULL) {
+    if (SetConsoleCtrlHandler(SignalHandler, true) == 0) {
+      int error_code = GetLastError();
+      delete write_handle;
+      CloseProcessPipe(fds);
+      SetLastError(error_code);
+      return -1;
+    }
+    signal_handlers = new SignalInfo(write_fd, signal);
+  } else {
+    new SignalInfo(write_fd, signal, signal_handlers);
+  }
+  return reinterpret_cast<intptr_t>(new FileHandle(fds[kReadHandle]));
+}
+
+
+void Process::ClearSignalHandler(intptr_t signal) {
+  signal = GetWinSignal(signal);
+  if (signal == -1) return;
+  MutexLocker lock(signal_mutex);
+  SignalInfo* handler = signal_handlers;
+  while (handler != NULL) {
+    if (handler->port() == Dart_GetMainPortId() &&
+        handler->signal() == signal) {
+      handler->Unlink();
+      break;
+    }
+    handler = handler->next();
+  }
+  if (handler != NULL) {
+    if (signal_handlers == handler) {
+      signal_handlers = handler->next();
+    }
+    if (signal_handlers == NULL) {
+      USE(SetConsoleCtrlHandler(SignalHandler, false));
+    }
+  }
+  delete handler;
+}
+
 }  // namespace bin
 }  // namespace dart
 
 #endif  // defined(TARGET_OS_WINDOWS)