// Signal.cpp // $Id$ #define ACE_BUILD_DLL #include "ace/Synch_T.h" #include "ace/Signal.h" #if !defined (__ACE_INLINE__) #include "ace/Signal.i" #endif /* __ACE_INLINE__ */ // Static definitions. #if defined (ACE_HAS_SIG_C_FUNC) extern "C" void ace_sig_handler_dispatch (int signum, siginfo_t *info, ucontext_t *context) { ACE_TRACE ("ace_signal_handler_dispatch"); ACE_Sig_Handler::dispatch (signum, info, context); } static ACE_SignalHandler ace_signal_handler_dispatcher = ACE_SignalHandler (ace_sig_handler_dispatch); #if !defined (ACE_HAS_BROKEN_HPUX_TEMPLATES) extern "C" void ace_sig_handlers_dispatch (int signum, siginfo_t *info, ucontext_t *context) { ACE_TRACE ("ace_signal_handlers_dispatch"); ACE_Sig_Handlers::dispatch (signum, info, context); } static ACE_SignalHandler ace_signal_handlers_dispatcher = ACE_SignalHandler (ace_sig_handlers_dispatch); #endif /* ACE_HAS_BROKEN_HPUX_TEMPLATES */ #else static ACE_SignalHandler ace_signal_handler_dispatcher = ACE_SignalHandler (ACE_Sig_Handler::dispatch); #if !defined (ACE_HAS_BROKEN_HPUX_TEMPLATES) static ACE_SignalHandler ace_signal_handlers_dispatcher = ACE_SignalHandler (ACE_Sig_Handlers::dispatch); #endif /* ACE_HAS_BROKEN_HPUX_TEMPLATES */ #endif /* ACE_HAS_SIG_C_FUNC */ #if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) ACE_Recursive_Thread_Mutex ACE_Sig_Handler::ace_sig_handler_lock_; #endif /* ACE_MT_SAFE */ // Array of Event_Handlers that will handle the signals. ACE_Event_Handler *ACE_Sig_Handler::signal_handlers_[NSIG]; // Remembers if a signal has occurred. sig_atomic_t ACE_Sig_Handler::sig_pending_ = 0; ACE_ALLOC_HOOK_DEFINE(ACE_Sig_Action) void ACE_Sig_Action::dump (void) const { ACE_TRACE ("ACE_Sig_Action::dump"); } ACE_ALLOC_HOOK_DEFINE(ACE_Sig_Set) void ACE_Sig_Set::dump (void) const { ACE_TRACE ("ACE_Sig_Set::dump"); } ACE_ALLOC_HOOK_DEFINE(ACE_Sig_Guard) void ACE_Sig_Guard::dump (void) const { ACE_TRACE ("ACE_Sig_Guard::dump"); } ACE_Sig_Action::ACE_Sig_Action (void) { // ACE_TRACE ("ACE_Sig_Action::ACE_Sig_Action"); this->sa_.sa_flags = 0; // Since Service_Config::signal_handler_ is static and has an // ACE_Sig_Action instance, Win32 will get errno set unless this is // commented out. #if !defined (ACE_WIN32) ACE_OS::sigemptyset (&this->sa_.sa_mask); #endif /* ACE_WIN32 */ this->sa_.sa_handler = 0; } ACE_Sig_Action::ACE_Sig_Action (ACE_SignalHandler sig_handler, sigset_t *sig_mask, int sig_flags) { // ACE_TRACE ("ACE_Sig_Action::ACE_Sig_Action"); this->sa_.sa_flags = sig_flags; if (sig_mask == 0) ACE_OS::sigemptyset (&this->sa_.sa_mask); else this->sa_.sa_mask = *sig_mask; // Structure assignment... #if !defined(ACE_HAS_TANDEM_SIGNALS) this->sa_.sa_handler = ACE_SignalHandlerV (sig_handler); #else this->sa_.sa_handler = (void (*)()) ACE_SignalHandlerV (sig_handler); #endif /* !ACE_HAS_TANDEM_SIGNALS */ } ACE_Sig_Action::ACE_Sig_Action (ACE_SignalHandler sig_handler, int signum, sigset_t *sig_mask, int sig_flags) { // ACE_TRACE ("ACE_Sig_Action::ACE_Sig_Action"); this->sa_.sa_flags = sig_flags; if (sig_mask == 0) ACE_OS::sigemptyset (&this->sa_.sa_mask); else this->sa_.sa_mask = *sig_mask; // Structure assignment... #if !defined(ACE_HAS_TANDEM_SIGNALS) this->sa_.sa_handler = ACE_SignalHandlerV (sig_handler); #else this->sa_.sa_handler = (void (*)()) ACE_SignalHandlerV (sig_handler); #endif /* !ACE_HAS_TANDEM_SIGNALS */ ACE_OS::sigaction (signum, &this->sa_, 0); } ACE_ALLOC_HOOK_DEFINE(ACE_Sig_Handler) void ACE_Sig_Handler::dump (void) const { ACE_TRACE ("ACE_Sig_Handler::dump"); } sig_atomic_t ACE_Sig_Handler::sig_pending (void) { ACE_TRACE ("ACE_Sig_Handler::sig_pending"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); return ACE_Sig_Handler::sig_pending_; } void ACE_Sig_Handler::sig_pending (sig_atomic_t pending) { ACE_TRACE ("ACE_Sig_Handler::sig_pending"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); ACE_Sig_Handler::sig_pending_ = pending; } ACE_Event_Handler * ACE_Sig_Handler::handler (int signum) { ACE_TRACE ("ACE_Sig_Handler::handler"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); if (ACE_Sig_Handler::in_range (signum)) return ACE_Sig_Handler::signal_handlers_[signum]; else return 0; } ACE_Event_Handler * ACE_Sig_Handler::handler (int signum, ACE_Event_Handler *new_sh) { ACE_TRACE ("ACE_Sig_Handler::handler"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); if (ACE_Sig_Handler::in_range (signum)) { ACE_Event_Handler *sh = ACE_Sig_Handler::signal_handlers_[signum]; ACE_Sig_Handler::signal_handlers_[signum] = new_sh; return sh; } else return 0; } // Register an ACE_Event_Handler along with the corresponding SIGNUM. int ACE_Sig_Handler::register_handler (int signum, ACE_Event_Handler *new_sh, ACE_Sig_Action *new_disp, ACE_Event_Handler **old_sh, ACE_Sig_Action *old_disp) { ACE_TRACE ("ACE_Sig_Handler::register_handler"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); if (ACE_Sig_Handler::in_range (signum)) { ACE_Sig_Action sa; // Define a "null" action. ACE_Event_Handler *sh = this->handler (signum, new_sh); // Stack the old ACE_Sig_Handler if the user gives us a pointer // to a object. if (old_sh != 0) *old_sh = sh; // Make sure that new_disp points to a valid location if the // user doesn't care... if (new_disp == 0) new_disp = &sa; new_disp->handler (ace_signal_handler_dispatcher); new_disp->flags (new_disp->flags () | SA_SIGINFO); return new_disp->register_action (signum, old_disp); } else return -1; } // Remove an ACE_Event_Handler. int ACE_Sig_Handler::remove_handler (int signum, ACE_Sig_Action *new_disp, ACE_Sig_Action *old_disp, int) { ACE_TRACE ("ACE_Sig_Handler::remove_handler"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); if (ACE_Sig_Handler::in_range (signum)) { ACE_Sig_Action sa (SIG_DFL); // Define the default disposition. if (new_disp == 0) new_disp = &sa; ACE_Sig_Handler::signal_handlers_[signum] = 0; // Register either the new disposition or restore the default. return new_disp->register_action (signum, old_disp); } else return -1; } // Master dispatcher function that gets called by a signal handler and // dispatches one handler... void ACE_Sig_Handler::dispatch (int signum, siginfo_t *siginfo, ucontext_t *ucontext) { ACE_TRACE ("ACE_Sig_Handler::dispatch"); ACE_MT (ACE_TSS_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); // Preserve errno across callbacks! int old_errno = errno; ACE_Sig_Handler::sig_pending (1); // Darn well better be in range since the OS dispatched this... ACE_ASSERT (ACE_Sig_Handler::in_range (signum)); ACE_Event_Handler *eh = ACE_Sig_Handler::signal_handlers_[signum]; if (eh != 0 && eh->handle_signal (signum, siginfo, ucontext) == -1) { // Define the default disposition. ACE_Sig_Action sa (SIG_DFL); ACE_Sig_Handler::signal_handlers_[signum] = 0; // Remove the current disposition by registering the default // disposition. sa.register_action (signum); } // Restore error when callback completes. errno = old_errno; } ACE_Sig_Adapter::ACE_Sig_Adapter (ACE_Sig_Action &sa, int sigkey) : sigkey_ (sigkey), type_ (SIG_ACTION), sa_ (sa) { // ACE_TRACE ("ACE_Sig_Adapter::ACE_Sig_Adapter"); } ACE_Sig_Adapter::ACE_Sig_Adapter (ACE_Event_Handler *eh, int sigkey) : sigkey_ (sigkey), type_ (ACE_HANDLER), eh_ (eh) { // ACE_TRACE ("ACE_Sig_Adapter::ACE_Sig_Adapter"); } ACE_Sig_Adapter::ACE_Sig_Adapter (ACE_Sig_Handler_Ex sig_func, int sigkey) : sigkey_ (sigkey), type_ (C_FUNCTION), sig_func_ (sig_func) { // ACE_TRACE ("ACE_Sig_Adapter::ACE_Sig_Adapter"); } int ACE_Sig_Adapter::sigkey (void) { ACE_TRACE ("ACE_Sig_Adapter::sigkey"); return this->sigkey_; } int ACE_Sig_Adapter::handle_signal (int signum, siginfo_t *siginfo, ucontext_t *ucontext) { ACE_TRACE ("ACE_Sig_Adapter::handle_signal"); switch (this->type_) { case SIG_ACTION: { // We have to dispatch a handler that was registered by a // third-party library. ACE_Sig_Action old_disp; // Make sure this handler executes in the context it was // expecting... this->sa_.register_action (signum, &old_disp); ACE_Sig_Handler_Ex sig_func = ACE_Sig_Handler_Ex (this->sa_.handler ()); (*sig_func) (signum, siginfo, ucontext); // Restore the original disposition. old_disp.register_action (signum); break; } case ACE_HANDLER: this->eh_->handle_signal (signum, siginfo, ucontext); break; case C_FUNCTION: (*this->sig_func_) (signum, siginfo, ucontext); break; } return 0; } // ---------------------------------------- // The following classes are local to this file. // There are bugs with HP/UX's C++ compiler that prevents this stuff // from compiling... #if !defined (ACE_HAS_BROKEN_HPUX_TEMPLATES) #define ACE_MAX_SIGNAL_HANDLERS ((size_t) 20) // Keeps track of the id that uniquely identifies each registered // signal handler. This id can be used to cancel a timer via the // method. int ACE_Sig_Handlers::sigkey_ = 0; // If this is > 0 then a 3rd party library has registered a // handler... int ACE_Sig_Handlers::third_party_sig_handler_ = 0; // Make life easier by defining typedefs... typedef ACE_Fixed_Set ACE_SIG_HANDLERS_SET; typedef ACE_Fixed_Set_Iterator ACE_SIG_HANDLERS_ITERATOR; class ACE_Sig_Handlers_Set { public: static ACE_SIG_HANDLERS_SET *instance (int signum); private: static ACE_SIG_HANDLERS_SET *sig_handlers_[NSIG]; }; /* static */ ACE_SIG_HANDLERS_SET *ACE_Sig_Handlers_Set::sig_handlers_[NSIG]; /* static */ ACE_SIG_HANDLERS_SET * ACE_Sig_Handlers_Set::instance (int signum) { if (signum <= 0 || signum >= NSIG) return 0; // This will cause problems... else if (ACE_Sig_Handlers_Set::sig_handlers_[signum] == 0) ACE_NEW_RETURN (ACE_Sig_Handlers_Set::sig_handlers_[signum], ACE_SIG_HANDLERS_SET, 0); return ACE_Sig_Handlers_Set::sig_handlers_[signum]; } ACE_ALLOC_HOOK_DEFINE(ACE_Sig_Handlers) void ACE_Sig_Handlers::dump (void) const { ACE_TRACE ("ACE_Sig_Handlers::dump"); } // This is the method that does all the dirty work... The basic // structure of this method was devised by Detlef Becker // (beckerd@erlh.siemens.de). int ACE_Sig_Handlers::register_handler (int signum, ACE_Event_Handler *new_sh, ACE_Sig_Action *new_disp, ACE_Event_Handler **, ACE_Sig_Action *old_disp) { ACE_TRACE ("ACE_Sig_Handlers::register_handler"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); if (ACE_Sig_Handler::in_range (signum)) { ACE_Sig_Adapter *ace_sig_adapter = 0; // Our signal handler. ACE_Sig_Adapter *extern_sh = 0; // An external signal handler. ACE_Sig_Action sa; // Get current signal disposition. sa.retrieve_action (signum); // Check whether we are already in control of the signal // handling disposition... if (!(sa.handler () == ace_signal_handlers_dispatcher || sa.handler () == ACE_SignalHandler (SIG_IGN) || sa.handler () == ACE_SignalHandler (SIG_DFL))) { // Drat, a 3rd party library has already installed a signal ;-( // Upto here we never disabled RESTART_MODE. Thus, // RESTART_MODE can only be changed by 3rd party libraries. if (ACE_BIT_DISABLED (sa.flags (), SA_RESTART) && ACE_Sig_Handlers::third_party_sig_handler_) // Toggling is disallowed since we might break 3rd party // code. return -1; // Note that we've seen a 3rd party handler... ACE_Sig_Handlers::third_party_sig_handler_ = 1; // Create a new 3rd party disposition, remembering its // preferred signal blocking etc...; ACE_NEW_RETURN (extern_sh, ACE_Sig_Adapter (sa, ++ACE_Sig_Handlers::sigkey_), -1); // Add the external signal handler to the set of handlers // for this signal. if (ACE_Sig_Handlers_Set::instance (signum)->insert (extern_sh) == -1) { delete extern_sh; return -1; } } // Add our new handler at this point. ACE_NEW_RETURN (ace_sig_adapter, ACE_Sig_Adapter (new_sh, ++ACE_Sig_Handlers::sigkey_), -1); // Add the ACE signal handler to the set of handlers for this // signal (make sure it goes before the external one if there is // one of these). if (ACE_Sig_Handlers_Set::instance (signum)->insert (ace_sig_adapter) == -1) { // We couldn't reinstall our handler, so let's pretend like // none of this happened... if (extern_sh) { ACE_Sig_Handlers_Set::instance (signum)->remove (extern_sh); delete extern_sh; } delete ace_sig_adapter; return -1; } // If ACE_Sig_Handlers::dispatch() was set we're done. else if (sa.handler () == ace_signal_handlers_dispatcher) return ace_sig_adapter->sigkey (); // Otherwise, we need to register our handler function so that // all signals will be dispatched through ACE. else { // Make sure that new_disp points to a valid location if the // user doesn't care... if (new_disp == 0) new_disp = &sa; new_disp->handler (ace_signal_handlers_dispatcher); // Default is to restart signal handlers. new_disp->flags (new_disp->flags () | SA_RESTART); new_disp->flags (new_disp->flags () | SA_SIGINFO); // Finally install (possibly reinstall) the ACE signal // handler disposition with the SA_RESTART mode enabled. if (new_disp->register_action (signum, old_disp) == -1) { // Yikes, lots of roll back at this point... ACE_Sig_Handlers_Set::instance (signum)->remove (ace_sig_adapter); delete ace_sig_adapter; if (extern_sh) { ACE_Sig_Handlers_Set::instance (signum)->remove (extern_sh); delete extern_sh; } return -1; } else // Return the signal key so that programs can cancel this // handler if they want! return ace_sig_adapter->sigkey (); } } else return -1; } // Remove the ACE_Event_Handler currently associated with . // Install the new disposition (if given) and return the previous // disposition (if desired by the caller). Returns 0 on success and // -1 if is invalid. int ACE_Sig_Handlers::remove_handler (int signum, ACE_Sig_Action *new_disp, ACE_Sig_Action *old_disp, int sigkey) { ACE_TRACE ("ACE_Sig_Handlers::remove_handler"); ACE_MT (ACE_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); if (ACE_Sig_Handler::in_range (signum)) { ACE_SIG_HANDLERS_SET *handler_set = ACE_Sig_Handlers_Set::instance (signum); ACE_SIG_HANDLERS_ITERATOR handler_iterator (*handler_set); // Iterate through the set of handlers for this signal. for (ACE_Event_Handler **eh; handler_iterator.next (eh) != 0; handler_iterator.advance ()) { // Type-safe downcast would be nice here... ACE_Sig_Adapter *sh = (ACE_Sig_Adapter *) *eh; // Remove the handler if (1) it's key matches the key we've // been told to remove or (2) if we've been told to remove // *all* handlers (i.e., == -1). if (sh->sigkey () == sigkey || sigkey == -1) { handler_set->remove (*eh); delete *eh; } } if (handler_set->size () == 0) { // If there are no more handlers left for a signal then // register the new disposition or restore the default // disposition. ACE_Sig_Action sa (SIG_DFL); if (new_disp == 0) new_disp = &sa; return new_disp->register_action (signum, old_disp); } return 0; } else return -1; } // Master dispatcher function that gets called by a signal handler and // dispatches *all* the handlers... void ACE_Sig_Handlers::dispatch (int signum, siginfo_t *siginfo, ucontext_t *ucontext) { ACE_TRACE ("ACE_Sig_Handlers::dispatch"); ACE_MT (ACE_TSS_Guard m (ACE_Sig_Handler::ace_sig_handler_lock_)); // Preserve errno across callbacks! int old_errno = errno; ACE_Sig_Handler::sig_pending (1); // Darn well better be in range since the OS dispatched this... ACE_ASSERT (ACE_Sig_Handler::in_range (signum)); ACE_SIG_HANDLERS_SET *handler_set = ACE_Sig_Handlers_Set::instance (signum); ACE_SIG_HANDLERS_ITERATOR handler_iterator (*handler_set); for (ACE_Event_Handler **eh = 0; handler_iterator.next (eh) != 0; handler_iterator.advance ()) { if ((*eh)->handle_signal (signum, siginfo, ucontext) == -1) { handler_set->remove (*eh); delete *eh; } } // Restore error when callback completes. errno = old_errno; } // Return the first item in the list of handlers. Note that this will // trivially provide the same behavior as the ACE_Sig_Handler // version if there is only 1 handler registered! ACE_Event_Handler * ACE_Sig_Handlers::handler (int signum) { ACE_TRACE ("ACE_Sig_Handlers::handler"); ACE_SIG_HANDLERS_SET *handler_set = ACE_Sig_Handlers_Set::instance (signum); ACE_SIG_HANDLERS_ITERATOR handler_iterator (*handler_set); ACE_Event_Handler **eh = 0; handler_iterator.next (eh); return *eh; } // The following is a strange bit of logic that tries to give the same // semantics as what happens in ACE_Sig_Handler when we replace the // current signal handler with a new one. Note that if there is only // one signal handler the behavior will be identical. If there is // more than one handler then things get weird... ACE_Event_Handler * ACE_Sig_Handlers::handler (int signum, ACE_Event_Handler *new_sh) { ACE_TRACE ("ACE_Sig_Handlers::handler"); ACE_SIG_HANDLERS_SET *handler_set = ACE_Sig_Handlers_Set::instance (signum); ACE_SIG_HANDLERS_ITERATOR handler_iterator (*handler_set); ACE_Event_Handler **eh = 0; // Find the first handler... handler_iterator.next (eh); // ... then remove it from the set ... handler_set->remove (*eh); // ... and then insert the new signal handler into the beginning of // the set (note, this is a bit too tied up in the implementation of // ACE_Unbounded_Set...). ACE_Sig_Adapter *temp; ACE_NEW_RETURN (temp, ACE_Sig_Adapter (new_sh, ++ACE_Sig_Handlers::sigkey_), 0); handler_set->insert (temp); return *eh; } #if defined (ACE_HAS_EXPLICIT_TEMPLATE_INSTANTIATION) ACE_MT (template class ACE_TSS_Guard); ACE_MT (template class ACE_Guard); template class ACE_Fixed_Set; template class ACE_Fixed_Set_Iterator; #elif defined (ACE_HAS_TEMPLATE_INSTANTIATION_PRAGMA) #if defined (ACE_MT_SAFE) && (ACE_MT_SAFE != 0) #pragma instantiate ACE_TSS_Guard #pragma instantiate ACE_Guard #endif /* ACE_MT_SAFE */ #pragma instantiate ACE_Fixed_Set #pragma instantiate ACE_Fixed_Set_Iterator #endif /* ACE_HAS_EXPLICIT_TEMPLATE_INSTANTIATION */ #endif /* ACE_HAS_BROKEN_HPUX_TEMPLATES */