解决方法
我使用这个类在C控制台应用程序中捕获信号.不过Qt并不具体.它在Windows平台上使用SetConsoleCtrlHandler(),并由< signal.h>在其他平台上棘手的一点是,“信号”不是跨平台术语 – Windows和POSIX对它们有不同的定义.无论如何,这个类试图将它们映射到一个常见的词汇. Ctrl ^ C是在两个平台上映射良好的C ^ C.
我希望这可以适应你的具体情况.请注意,错误检查很小,应该可以改进.
用法(main.cpp)
#include "SignalHandler.h"
class Application : public SignalHandler
{
public:
Application() : SignalHandler(SignalHandler::SIG_INT),myThread(NULL) {}
int Application::main(int argc,char *argv[])
{
// Main program instructions here (e.g. start a thread)
myThread = new Thread(...);
myThread->start();
myThread->join();
delete myThread;
return 0;
}
bool handleSignal(int signal)
{
std::cout << "Handling signal " << signal << std::endl;
if (_myThread && _myThread->isRunning())
{
_myThread->stop();
// The thread is going to stop soon,so don't propagate this signal further
return true;
}
// Let the signal propagate as though we had not been there
return false;
}
private:
Thread* myThread;
};
int main(int argc,char* argv[])
{
Application app;
return app.main(argc,argv);
}
SignalHandler.h
class SignalHandler
{
public:
SignalHandler(int mask = DEFAULT_SIGNALS);
virtual ~SignalHandler();
enum SIGNALS
{
SIG_UNHANDLED = 0,// Physical signal not supported by this class
SIG_NOOP = 1,// The application is requested to do a no-op (only a target that platform-specific signals map to when they can't be raised anyway)
SIG_INT = 2,// Control+C (should terminate but consider that it's a normal way to do so; can delay a bit)
SIG_TERM = 4,// Control+Break (should terminate now without regarding the consquences)
SIG_CLOSE = 8,// Container window closed (should perform normal termination,like Ctrl^C) [Windows only; on Linux it maps to SIG_TERM]
SIG_RELOAD = 16,// Reload the configuration [Linux only,physical signal is SIGHUP; on Windows it maps to SIG_NOOP]
DEFAULT_SIGNALS = SIG_INT | SIG_TERM | SIG_CLOSE,};
static const int numSignals = 6;
virtual bool handleSignal(int signal) = 0;
private:
int _mask;
};
SignalHandler.cpp
#include "SignalHandler.h"
#include <assert.h>
#ifndef _WIN32
#include <signal.h>
#else
#include <windows.h>
#endif //!_WIN32
// There can be only ONE SignalHandler per process
SignalHandler* g_handler(NULL);
#ifdef _WIN32
BOOL WINAPI WIN32_handleFunc(DWORD);
int WIN32_physicalToLogical(DWORD);
DWORD WIN32_logicalToPhysical(int);
std::set<int> g_registry;
#else //_WIN32
void POSIX_handleFunc(int);
int POSIX_physicalToLogical(int);
int POSIX_logicalToPhysical(int);
#endif //_WIN32
SignalHandler::SignalHandler(int mask) : _mask(mask)
{
assert(g_handler == NULL);
g_handler = this;
#ifdef _WIN32
SetConsoleCtrlHandler(WIN32_handleFunc,TRUE);
#endif //_WIN32
for (int i=0;i<numSignals;i++)
{
int logical = 0x1 << i;
if (_mask & logical)
{
#ifdef _WIN32
g_registry.insert(logical);
#else
int sig = POSIX_logicalToPhysical(logical);
bool Failed = signal(sig,POSIX_handleFunc) == SIG_ERR;
assert(!Failed);
(void)Failed; // Silence the warning in non _DEBUG; TODO: something better
#endif //_WIN32
}
}
}
SignalHandler::~SignalHandler()
{
#ifdef _WIN32
SetConsoleCtrlHandler(WIN32_handleFunc,FALSE);
#else
for (int i=0;i<numSignals;i++)
{
int logical = 0x1 << i;
if (_mask & logical)
{
signal(POSIX_logicalToPhysical(logical),SIG_DFL);
}
}
#endif //_WIN32
}
#ifdef _WIN32
DWORD WIN32_logicalToPhysical(int signal)
{
switch (signal)
{
case SignalHandler::SIG_INT: return CTRL_C_EVENT;
case SignalHandler::SIG_TERM: return CTRL_BREAK_EVENT;
case SignalHandler::SIG_CLOSE: return CTRL_CLOSE_EVENT;
default:
return ~(unsigned int)0; // SIG_ERR = -1
}
}
#else
int POSIX_logicalToPhysical(int signal)
{
switch (signal)
{
case SignalHandler::SIG_INT: return SIGINT;
case SignalHandler::SIG_TERM: return SIGTERM;
// In case the client asks for a SIG_CLOSE handler,accept and
// bind it to a SIGTERM. Anyway the signal will never be raised
case SignalHandler::SIG_CLOSE: return SIGTERM;
case SignalHandler::SIG_RELOAD: return SIGHUP;
default:
return -1; // SIG_ERR = -1
}
}
#endif //_WIN32
#ifdef _WIN32
int WIN32_physicalToLogical(DWORD signal)
{
switch (signal)
{
case CTRL_C_EVENT: return SignalHandler::SIG_INT;
case CTRL_BREAK_EVENT: return SignalHandler::SIG_TERM;
case CTRL_CLOSE_EVENT: return SignalHandler::SIG_CLOSE;
default:
return SignalHandler::SIG_UNHANDLED;
}
}
#else
int POSIX_physicalToLogical(int signal)
{
switch (signal)
{
case SIGINT: return SignalHandler::SIG_INT;
case SIGTERM: return SignalHandler::SIG_TERM;
case SIGHUP: return SignalHandler::SIG_RELOAD;
default:
return SignalHandler::SIG_UNHANDLED;
}
}
#endif //_WIN32
#ifdef _WIN32
BOOL WINAPI WIN32_handleFunc(DWORD signal)
{
if (g_handler)
{
int signo = WIN32_physicalToLogical(signal);
// The std::set is thread-safe in const reading access and we never
// write to it after the program has started so we don't need to
// protect this search by a mutex
std::set<int>::const_iterator found = g_registry.find(signo);
if (signo != -1 && found != g_registry.end())
{
return g_handler->handleSignal(signo) ? TRUE : FALSE;
}
else
{
return FALSE;
}
}
else
{
return FALSE;
}
}
#else
void POSIX_handleFunc(int signal)
{
if (g_handler)
{
int signo = POSIX_physicalToLogical(signal);
g_handler->handleSignal(signo);
}
}
#endif //_WIN32
