icinga2/base/application.cpp

442 lines
11 KiB
C++

/******************************************************************************
* Icinga 2 *
* Copyright (C) 2012 Icinga Development Team (http://www.icinga.org/) *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License *
* as published by the Free Software Foundation; either version 2 *
* of the License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU General Public License for more details. *
* *
* You should have received a copy of the GNU General Public License *
* along with this program; if not, write to the Free Software Foundation *
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. *
******************************************************************************/
#include "i2-base.h"
#ifndef _WIN32
# include <ltdl.h>
#endif
using namespace icinga;
Application::Ptr Application::m_Instance;
bool Application::m_ShuttingDown = false;
bool Application::m_Debugging = false;
boost::thread::id Application::m_MainThreadID;
/**
* Constructor for the Application class.
*/
Application::Application(void)
: m_PidFile(NULL)
{
#ifdef _WIN32
WSADATA wsaData;
if (WSAStartup(MAKEWORD(1, 1), &wsaData) != 0)
throw Win32Exception("WSAStartup failed", WSAGetLastError());
#else /* _WIN32 */
lt_dlinit();
#endif /* _WIN32 */
char *debugging = getenv("_DEBUG");
m_Debugging = (debugging && strtol(debugging, NULL, 10) != 0);
#ifdef _WIN32
if (IsDebuggerPresent())
m_Debugging = true;
#endif /* _WIN32 */
}
/**
* Destructor for the application class.
*/
Application::~Application(void)
{
m_ShuttingDown = true;
/* stop all components */
BOOST_FOREACH(const Component::Ptr& component, m_Components | map_values) {
component->Stop();
}
m_Components.clear();
#ifdef _WIN32
WSACleanup();
#endif /* _WIN32 */
ClosePidFile();
}
/**
* Retrieves a pointer to the application singleton object.
*
* @returns The application object.
*/
Application::Ptr Application::GetInstance(void)
{
return m_Instance;
}
/**
* Processes events for registered sockets and timers and calls whatever
* handlers have been set up for these events.
*/
void Application::RunEventLoop(void)
{
while (!m_ShuttingDown) {
Object::ClearHeldObjects();
long sleep = Timer::ProcessTimers();
if (m_ShuttingDown)
break;
Event::ProcessEvents(boost::get_system_time() + boost::posix_time::seconds(sleep));
}
}
/**
* Signals the application to shut down during the next
* execution of the event loop.
*/
void Application::Shutdown(void)
{
m_ShuttingDown = true;
}
/**
* Loads a component from a shared library.
*
* @param path The path of the component library.
* @param componentConfig The configuration for the component.
* @returns The component.
*/
Component::Ptr Application::LoadComponent(const string& path,
const ConfigObject::Ptr& componentConfig)
{
Component::Ptr component;
Component *(*pCreateComponent)();
assert(Application::IsMainThread());
Logger::Write(LogInformation, "base", "Loading component '" + path + "'");
#ifdef _WIN32
HMODULE hModule = LoadLibrary(path.c_str());
if (hModule == NULL)
throw Win32Exception("LoadLibrary('" + path + "') failed", GetLastError());
#else /* _WIN32 */
lt_dlhandle hModule = lt_dlopen(path.c_str());
if (hModule == NULL) {
throw runtime_error("Could not load module '" + path + "': " + lt_dlerror());
}
#endif /* _WIN32 */
#ifdef _WIN32
pCreateComponent = (CreateComponentFunction)GetProcAddress(hModule,
"CreateComponent");
#else /* _WIN32 */
# ifdef __GNUC__
/* suppress compiler warning for void * cast */
__extension__
# endif
pCreateComponent = (CreateComponentFunction)lt_dlsym(hModule,
"CreateComponent");
#endif /* _WIN32 */
if (pCreateComponent == NULL)
throw runtime_error("Loadable module does not contain "
"CreateComponent function");
component = Component::Ptr(pCreateComponent());
component->SetConfig(componentConfig);
RegisterComponent(component);
return component;
}
/**
* Registers a component object and starts it.
*
* @param component The component.
*/
void Application::RegisterComponent(const Component::Ptr& component)
{
m_Components[component->GetName()] = component;
component->Start();
}
/**
* Unregisters a component object and stops it.
*
* @param component The component.
*/
void Application::UnregisterComponent(const Component::Ptr& component)
{
string name = component->GetName();
Logger::Write(LogInformation, "base", "Unloading component '" + name + "'");
map<string, Component::Ptr>::iterator i = m_Components.find(name);
if (i != m_Components.end())
m_Components.erase(i);
component->Stop();
}
/**
* Finds a loaded component by name.
*
* @param name The name of the component.
* @returns The component or a null pointer if the component could not be found.
*/
Component::Ptr Application::GetComponent(const string& name) const
{
map<string, Component::Ptr>::const_iterator i = m_Components.find(name);
if (i == m_Components.end())
return Component::Ptr();
return i->second;
}
/**
* Retrieves the full path of the executable.
*
* @returns The path.
*/
string Application::GetExePath(void) const
{
static string result;
if (!result.empty())
return result;
string executablePath;
#ifndef _WIN32
string argv0 = m_Arguments[0];
char buffer[MAXPATHLEN];
if (getcwd(buffer, sizeof(buffer)) == NULL)
throw PosixException("getcwd failed", errno);
string workingDirectory = buffer;
if (argv0[0] != '/')
executablePath = workingDirectory + "/" + argv0;
else
executablePath = argv0;
if (argv0.find_first_of('/') == string::npos) {
const char *pathEnv = getenv("PATH");
if (pathEnv != NULL) {
vector<string> paths;
boost::algorithm::split(paths, pathEnv, boost::is_any_of(":"));
bool foundPath = false;
BOOST_FOREACH(string& path, paths) {
string pathTest = path + "/" + argv0;
if (access(pathTest.c_str(), X_OK) == 0) {
executablePath = pathTest;
foundPath = true;
break;
}
}
if (!foundPath) {
executablePath.clear();
throw runtime_error("Could not determine executable path.");
}
}
}
if (realpath(executablePath.c_str(), buffer) == NULL)
throw PosixException("realpath failed", errno);
result = buffer;
#else /* _WIN32 */
char FullExePath[MAXPATHLEN];
if (!GetModuleFileName(NULL, FullExePath, sizeof(FullExePath)))
throw Win32Exception("GetModuleFileName() failed", GetLastError());
result = FullExePath;
#endif /* _WIN32 */
return result;
}
/**
* Adds a directory to the component search path.
*
* @param componentDirectory The directory.
*/
void Application::AddComponentSearchDir(const string& componentDirectory)
{
#ifdef _WIN32
SetDllDirectory(componentDirectory.c_str());
#else /* _WIN32 */
lt_dladdsearchdir(componentDirectory.c_str());
#endif /* _WIN32 */
}
/**
* Retrieves the debugging mode of the application.
*
* @returns true if the application is being debugged, false otherwise
*/
bool Application::IsDebugging(void)
{
return m_Debugging;
}
bool Application::IsMainThread(void)
{
return (boost::this_thread::get_id() == m_MainThreadID);
}
#ifndef _WIN32
/**
* Signal handler for SIGINT. Prepares the application for cleanly
* shutting down during the next execution of the event loop.
*
* @param signum The signal number.
*/
void Application::SigIntHandler(int signum)
{
assert(signum == SIGINT);
Application::Ptr instance = Application::GetInstance();
if (!instance)
return;
instance->Shutdown();
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = SIG_DFL;
sigaction(SIGINT, &sa, NULL);
}
#else /* _WIN32 */
/**
* Console control handler. Prepares the application for cleanly
* shutting down during the next execution of the event loop.
*/
BOOL WINAPI Application::CtrlHandler(DWORD type)
{
Application::Ptr instance = Application::GetInstance();
if (!instance)
return TRUE;
instance->GetInstance()->Shutdown();
SetConsoleCtrlHandler(NULL, FALSE);
return TRUE;
}
#endif /* _WIN32 */
/**
* Runs the application.
*
* @param argc The number of arguments.
* @param argv The arguments that should be passed to the application.
* @returns The application's exit code.
*/
int Application::Run(int argc, char **argv)
{
int result;
assert(!Application::m_Instance);
m_MainThreadID = boost::this_thread::get_id();
Application::m_Instance = GetSelf();
#ifndef _WIN32
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = &Application::SigIntHandler;
sigaction(SIGINT, &sa, NULL);
sa.sa_handler = SIG_IGN;
sigaction(SIGPIPE, &sa, NULL);
#else
SetConsoleCtrlHandler(&Application::CtrlHandler, TRUE);
#endif /* _WIN32 */
m_Arguments.clear();
for (int i = 0; i < argc; i++)
m_Arguments.push_back(string(argv[i]));
if (IsDebugging()) {
result = Main(m_Arguments);
Application::m_Instance.reset();
} else {
try {
result = Main(m_Arguments);
} catch (const exception& ex) {
Application::m_Instance.reset();
Logger::Write(LogCritical, "base", "---");
Logger::Write(LogCritical, "base", "Exception: " + Utility::GetTypeName(typeid(ex)));
Logger::Write(LogCritical, "base", "Message: " + string(ex.what()));
return EXIT_FAILURE;
}
}
return result;
}
void Application::UpdatePidFile(const string& filename)
{
ClosePidFile();
/* There's just no sane way of getting a file descriptor for a
* C++ ofstream which is why we're using FILEs here. */
m_PidFile = fopen(filename.c_str(), "w");
if (m_PidFile == NULL)
throw runtime_error("Could not open PID file '" + filename + "'");
#ifndef _WIN32
if (flock(fileno(m_PidFile), LOCK_EX | LOCK_NB) < 0) {
ClosePidFile();
throw runtime_error("Another instance of the application is "
"already running. Remove the '" + filename + "' file if "
"you're certain that this is not the case.");
}
#endif /* _WIN32 */
#ifndef _WIN32
pid_t pid = getpid();
#else /* _WIN32 */
DWORD pid = GetCurrentProcessId();
#endif /* _WIN32 */
fprintf(m_PidFile, "%d", pid);
fflush(m_PidFile);
}
void Application::ClosePidFile(void)
{
if (m_PidFile != NULL)
fclose(m_PidFile);
m_PidFile = NULL;
}