Implement basic infrastructure for cashew daemon.

src/main.cc

+// Copyright (c) 2010 The Chromium OS 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 <config.h>
+
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <dbus-c++/dbus.h>
+#include <gflags/gflags.h>
+#include <glog/logging.h>
+
+namespace cashew {
+
+typedef int Signal;
+typedef void (*SignalHandler)(Signal signal);
+
+int InstallSignalHandler(const Signal signal,
+                         const SignalHandler signal_handler,
+                         const sigset_t& mask) {
+  DLOG(INFO) << "installing handler for signal " << signal;
+  struct sigaction action;
+  memset(&action, 0, sizeof(action));
+  action.sa_handler = signal_handler;
+  action.sa_mask = mask;
+  return sigaction(signal, &action, NULL);
+}
+
+static DBus::BusDispatcher *g_dispatcher = NULL;
+
+static void OnSignal(int signal) {
+  DLOG(INFO) << "received signal " << signal;
+  if (g_dispatcher) {
+    g_dispatcher->leave();
+  }
+}
+
+int InstallSignalHandlers() {
+  sigset_t mask;
+  if (sigemptyset(&mask) < 0) {
+    PLOG(ERROR) << "sigemptyset failed";
+    return -1;
+  }
+  if (sigaddset(&mask, SIGINT) < 0) {
+    PLOG(ERROR) << "couldn't add SIGINT to mask";
+    return -1;
+  }
+  if (sigaddset(&mask, SIGTERM) < 0) {
+    PLOG(ERROR) << "couldn't add SIGTERM to mask";
+    return -1;
+  }
+  if (InstallSignalHandler(SIGINT, OnSignal, mask) < 0) {
+    PLOG(ERROR) << "couldn't install SIGINT handler";
+    return -1;
+  }
+  if (InstallSignalHandler(SIGTERM, OnSignal, mask) < 0) {
+    PLOG(ERROR) << "couldn't install SIGTERM handler";
+    return -1;
+  }
+  return 0;
+}
+
+// should not be called while event loop is running
+static void CleanUpForExit() {
+  DLOG(INFO) << "cleaning up";
+  DBus::default_dispatcher = NULL;
+  DBus::BusDispatcher *dispatcher_to_delete = g_dispatcher;
+  g_dispatcher = NULL;
+  delete dispatcher_to_delete;
+  // TODO(vlaviano): uncomment when we get a newer version of glog
+  // google::ShutdownGoogleLogging();
+}
+
+}  // namespace cashew
+
+int main(int argc, char *argv[]) {
+  google::SetUsageMessage(argv[0]);
+  google::ParseCommandLineFlags(&argc, &argv, true);
+  google::InitGoogleLogging(argv[0]);
+  google::InstallFailureSignalHandler();
+  LOG(INFO) << PACKAGE_STRING;
+
+  DLOG(INFO) << "creating dbus dispatcher";
+  cashew::g_dispatcher = new(std::nothrow) DBus::BusDispatcher();
+  if (!cashew::g_dispatcher) {
+    LOG(ERROR) << "couldn't create dbus dispatcher";
+    cashew::CleanUpForExit();
+    exit(EXIT_FAILURE);
+  }
+  DBus::default_dispatcher = cashew::g_dispatcher;
+
+  // TODO(vlaviano): policies
+
+  // TODO(vlaviano): back-end carrier apis
+
+  // TODO(vlaviano): front-end dbus api
+
+  if (cashew::InstallSignalHandlers() < 0) {
+    LOG(ERROR) << "couldn't install signal handlers";
+    cashew::CleanUpForExit();
+    exit(EXIT_FAILURE);
+  }
+
+  DLOG(INFO) << "entering event loop";
+  cashew::g_dispatcher->enter();
+  DLOG(INFO) << "exited event loop";
+  cashew::CleanUpForExit();
+  exit(EXIT_SUCCESS);
+}