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// -*- c++ -*-
//---------------------------------------------------------------------------
// SigHandler.cpp
//---------------------------------------------------------------------------
// Copyright (C) 1997-2002 Vladislav Grinchenko
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//---------------------------------------------------------------------------
#include <signal.h>
#include "assa/Assure.h"
#include "assa/SigHandler.h"
using namespace ASSA;
#if !defined(WIN32)
/*--- static variables ---*/
EventHandler* SigHandler::m_signal_handlers [NSIG];
int
SigHandler::
in_range (int signum_)
{
trace_with_mask("SigHandler::in_range", SIGHAND);
if ( signum_ >= 1 && signum_ < NSIG) {
return 0;
}
else {
DL((SIGHAND,"signum_ %d is out of range [1;%d]\n", NSIG));
return -1;
}
}
EventHandler *
SigHandler::
handler (int signum_, EventHandler* newh_)
{
trace_with_mask("SigHandler::handler(int, EH*)", SIGHAND);
if (in_range(signum_) == -1)
return 0;
EventHandler* oh = m_signal_handlers[signum_];
m_signal_handlers[signum_] = newh_;
return oh;
}
EventHandler *
SigHandler::
handler (int signum_)
{
trace_with_mask("SigHandler::handler", SIGHAND);
if ( in_range (signum_) == -1 )
return 0;
return m_signal_handlers[signum_];
}
int
SigHandler::
install (int signum_, EventHandler *new_hand_, SigAction *new_disp_,
EventHandler **old_hand_, SigAction *old_disp_)
{
trace_with_mask("SigHandler::install", SIGHAND);
if (in_range (signum_) == -1)
return -1;
/*--- replace old Event Handler ptr with new one in my internal
dispatch table, returning the old one.
---*/
EventHandler* eh = handler(signum_, new_hand_);
/*--- if I am given place to store, save old handler ---*/
if (old_hand_ != 0)
*old_hand_ = eh;
/*--- retrieve old disposition ---*/
if (old_disp_ != 0) {
old_disp_->retrieve_action (signum_);
old_disp_->handler ((C_SIG_HANDLER) SIG_DFL);
}
/*--- if new disposition is NULL, use null action instead ---*/
SigAction null_sa;
if (new_disp_ == 0)
new_disp_ = &null_sa;
/*--- install my dispatcher ---*/
new_disp_->handler((C_SIG_HANDLER) SigHandler::dispatch);
return new_disp_->register_action(signum_, old_disp_);
}
int
SigHandler::
remove (int signum_, EventHandler* /* eh_ */,
SigAction *new_disp_, SigAction *old_disp_)
{
trace_with_mask("SigHandler::remove", SIGHAND);
if (in_range(signum_) == -1)
return -1;
/*---
We need default disposition here if user forgot to give us one.
---*/
SigAction sa ((C_SIG_HANDLER) SIG_DFL);
if (new_disp_ == 0) {
new_disp_ = &sa;
}
m_signal_handlers[signum_] = 0;
return new_disp_->register_action (signum_, old_disp_);
}
void
SigHandler::
dispatch (int signum_)
{
trace_with_mask("SigHandler::dispatch", SIGHAND);
/*--- save errno ---*/
int my_errno = errno;
EventHandler *eh = m_signal_handlers[signum_];
if (eh != 0 && eh->handle_signal(signum_) == -1) {
/*---
we are in trouble, fall back to defaults
---*/
SigAction defact((C_SIG_HANDLER) SIG_DFL);
m_signal_handlers[signum_] = 0;
defact.register_action(signum_);
}
/*--- restore errno ---*/
errno = my_errno;
}
#endif // !defined(WIN32)
|
