Gaudi::Utils::SignalMonitorSvc Class Reference

Implementation of Gaudi::ISignalMonitor. More...

Inheritance diagram for Gaudi::Utils::SignalMonitorSvc:

Collaboration diagram for Gaudi::Utils::SignalMonitorSvc:

Public Types
typedef struct sigaction	handler_t
Public Types inherited from extends< BASE, Interfaces >
typedef extends	base_class
	Typedef to this class. More...
typedef extend_interfaces< Interfaces...>	extend_interfaces_base
	Typedef to the base of this class. More...
typedef extends	base_class
	Typedef to this class. More...
typedef extend_interfaces< Interfaces...>	extend_interfaces_base
	Typedef to the base of this class. More...
Public Types inherited from extend_interfaces< Interfaces...>
using	ext_iids = typename Gaudi::interface_list_cat< typename Interfaces::ext_iids...>::type
	take union of the ext_iids of all Interfaces... More...
using	ext_iids = typename Gaudi::interface_list_cat< typename Interfaces::ext_iids...>::type
	take union of the ext_iids of all Interfaces... More...

Public Member Functions
void	monitorSignal (int signum, bool propagate)
	Declare a signal to be monitored. More...
void	ignoreSignal (int signum)
	Remove the specific signal handler for the requested signal, restoring the previous signal handler. More...
bool	gotSignal (int signum) const
	Check if the given signal has been received. More...
void	setSignal (int signum)
	Set the flag for the given signal, as if the signal was received. More...
void	clearSignal (int signum)
	Clear the flag for the given signal, so that a new occurrence can be identified. More...
	SignalMonitorSvc (const std::string &name, ISvcLocator *svcLoc)
	Initialize internal variables of the service and set the instance pointer. More...
virtual	~SignalMonitorSvc ()
	Stop monitoring signals and clear the instance pointer. More...
Public Member Functions inherited from extends< BASE, Interfaces >
void *	i_cast (const InterfaceID &tid) const override
	Implementation of IInterface::i_cast. More...
StatusCode	queryInterface (const InterfaceID &ti, void **pp) override
	Implementation of IInterface::queryInterface. More...
std::vector< std::string >	getInterfaceNames () const override
	Implementation of IInterface::getInterfaceNames. More...
	~extends () override=default
	Virtual destructor. More...
void *	i_cast (const InterfaceID &tid) const override
	Implementation of IInterface::i_cast. More...
StatusCode	queryInterface (const InterfaceID &ti, void **pp) override
	Implementation of IInterface::queryInterface. More...
std::vector< std::string >	getInterfaceNames () const override
	Implementation of IInterface::getInterfaceNames. More...
	~extends () override=default
	Virtual destructor. More...
Public Member Functions inherited from extend_interfaces< Interfaces...>
	~extend_interfaces () override=default
	Virtual destructor. More...
	~extend_interfaces () override=default
	Virtual destructor. More...

Private Types
enum	MonitoringMode { ignored, trap, propagate }
	Possible monitoring modes. More...

Private Member Functions
void	i_handle (int signum)

Static Private Member Functions
static void	setInstance (SignalMonitorSvc *i)
static SignalMonitorSvc *	instance ()
	Method to get the singleton instance. More...
static void	dispatcher (int signum)
	Signal handler function. More...

Private Attributes
MonitoringMode	m_monitored [NSIG]
	Array of flags to keep track of monitored signals. More...
sig_atomic_t	m_caught [NSIG]
	Array of flags for received signals. More...
handler_t	m_defaultAction
	Helper variable for default signal action. More...
handler_t	m_oldActions [NSIG]
	List of replaced signal actions (for the recovery when disable the monitoring). More...

Static Private Attributes
static SignalMonitorSvc *	s_instance = nullptr
	Pointer to the current instance. More...

Detailed Description

Implementation of Gaudi::ISignalMonitor.

If instantiated, intercepts the system signals and keep track of the recorded ones.

The signal to be monitored have to be declared via the method monitorSignal(). It can be interrogated to check if a signal has been received.

Definition at line 26 of file SignalMonitorSvc.cpp.

Member Typedef Documentation

typedef struct sigaction Gaudi::Utils::SignalMonitorSvc::handler_t

Definition at line 31 of file SignalMonitorSvc.cpp.

Member Enumeration Documentation

enum Gaudi::Utils::SignalMonitorSvc::MonitoringMode

private

Possible monitoring modes.

Enumerator
ignored
trap
propagate

Definition at line 112 of file SignalMonitorSvc.cpp.

                          {
        ignored,  //< the signal is not monitored
        trap,     //< the signal is monitored and not propagated to previously registered handlers
        propagate //< the signal is monitored and propagated to previously registered handlers
      };

Constructor & Destructor Documentation

Gaudi::Utils::SignalMonitorSvc::SignalMonitorSvc ( const std::string &  name, ISvcLocator *  svcLoc  )

inline

Initialize internal variables of the service and set the instance pointer.

Definition at line 85 of file SignalMonitorSvc.cpp.

                                                                  : base_class(name, svcLoc) {
#ifdef _WIN32
        m_defaultAction = SIG_DFL;
#else
        m_defaultAction.sa_handler = SIG_DFL;
        sigemptyset(&m_defaultAction.sa_mask);
        m_defaultAction.sa_flags = 0;
#endif
        for(int i = 0; i < NSIG; ++i){
          m_caught[i] = 0;
          m_monitored[i] = ignored;
          m_oldActions[i] = m_defaultAction;
        }

        setInstance(this);
      }

virtual Gaudi::Utils::SignalMonitorSvc::~SignalMonitorSvc ( )

inlinevirtual

Stop monitoring signals and clear the instance pointer.

Definition at line 103 of file SignalMonitorSvc.cpp.

                                  {
        for (int i = 0; i < NSIG; ++i) {
          ignoreSignal(i);
        }
        setInstance(0);
      }

Member Function Documentation

void Gaudi::Utils::SignalMonitorSvc::clearSignal ( int  signum )

inline

Clear the flag for the given signal, so that a new occurrence can be identified.

Definition at line 80 of file SignalMonitorSvc.cpp.

                                   {
        m_caught[signum] = 0;
      }

void Gaudi::Utils::SignalMonitorSvc::dispatcher ( int  signum )

staticprivate

Signal handler function.

Definition at line 161 of file SignalMonitorSvc.cpp.

                                               {
      if (instance()) instance()->i_handle(signum);
    }

bool Gaudi::Utils::SignalMonitorSvc::gotSignal ( int  signum ) const

inline

Check if the given signal has been received.

Definition at line 70 of file SignalMonitorSvc.cpp.

                                       {
        return m_caught[signum] != 0;
      }

void Gaudi::Utils::SignalMonitorSvc::i_handle ( int  signum )

inlineprivate

Definition at line 126 of file SignalMonitorSvc.cpp.

                                {
        m_caught[signum] = 1;
        if ( m_monitored[signum] == propagate &&
#ifdef _WIN32
            m_oldActions[signum] != SIG_DFL
#else
            m_oldActions[signum].sa_handler != SIG_DFL
#endif
        ) {
#ifdef _WIN32
          m_oldActions[signum](signum);
#else
          m_oldActions[signum].sa_handler(signum);
#endif
        }
      }

void Gaudi::Utils::SignalMonitorSvc::ignoreSignal ( int  signum )

inline

Remove the specific signal handler for the requested signal, restoring the previous signal handler.

Definition at line 57 of file SignalMonitorSvc.cpp.

                                    {
        if (m_monitored[signum]) {
#ifdef _WIN32
          (void) signal(signum, m_oldActions[signum]);
#else
          sigaction(signum, &m_oldActions[signum], 0);
#endif
          m_oldActions[signum] = m_defaultAction;
          m_monitored[signum] = ignored;
        }
      }

static SignalMonitorSvc* Gaudi::Utils::SignalMonitorSvc::instance ( )

inlinestaticprivate

Method to get the singleton instance.

Bypass the serviceLocator for efficiency.

Definition at line 152 of file SignalMonitorSvc.cpp.

                                                 {
        return s_instance;
      }

void Gaudi::Utils::SignalMonitorSvc::monitorSignal ( int  signum, bool  propagate  )

inline

Declare a signal to be monitored.

It installs a signal handler for the requested signal.

Definition at line 36 of file SignalMonitorSvc.cpp.

                                                     {
        if (!m_monitored[signum]) {
          handler_t sa;
          handler_t oldact;
#ifdef _WIN32
          sa = SignalMonitorSvc::dispatcher;
          oldact = signal(signum, sa);
#else
          sa.sa_handler = SignalMonitorSvc::dispatcher;
          sigemptyset(&sa.sa_mask);
          sa.sa_flags = 0;
          sigaction(signum, &sa, &oldact);
#endif
          m_oldActions[signum] = oldact;
          m_monitored[signum] = (propagate) ? SignalMonitorSvc::propagate
                                            : SignalMonitorSvc::trap;
        }
      }

static void Gaudi::Utils::SignalMonitorSvc::setInstance ( SignalMonitorSvc *  i )

inlinestaticprivate

Definition at line 146 of file SignalMonitorSvc.cpp.

                                                          {
        s_instance = i;
      }

void Gaudi::Utils::SignalMonitorSvc::setSignal ( int  signum )

inline

Set the flag for the given signal, as if the signal was received.

Definition at line 75 of file SignalMonitorSvc.cpp.

                                 {
        m_caught[signum] = 1;
      }

Member Data Documentation

sig_atomic_t Gaudi::Utils::SignalMonitorSvc::m_caught[NSIG]

private

Array of flags for received signals.

Definition at line 120 of file SignalMonitorSvc.cpp.

handler_t Gaudi::Utils::SignalMonitorSvc::m_defaultAction

private

Helper variable for default signal action.

Definition at line 122 of file SignalMonitorSvc.cpp.

MonitoringMode Gaudi::Utils::SignalMonitorSvc::m_monitored[NSIG]

private

Array of flags to keep track of monitored signals.

Definition at line 118 of file SignalMonitorSvc.cpp.

handler_t Gaudi::Utils::SignalMonitorSvc::m_oldActions[NSIG]

private

List of replaced signal actions (for the recovery when disable the monitoring).

Definition at line 124 of file SignalMonitorSvc.cpp.

Gaudi::Utils::SignalMonitorSvc * Gaudi::Utils::SignalMonitorSvc::s_instance = nullptr

staticprivate

Pointer to the current instance.

Definition at line 144 of file SignalMonitorSvc.cpp.

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The documentation for this class was generated from the following file:

• GaudiUtils/src/component/SignalMonitorSvc.cpp