sortix--sortix/libc/signal.cpp

/*******************************************************************************

    Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.

    This file is part of the Sortix C Library.

    The Sortix C Library is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or (at your
    option) any later version.

    The Sortix C Library 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 Lesser General Public
    License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.

    signal.cpp
    Handles the good old unix signals.

*******************************************************************************/

#include <sys/types.h>
#include <sys/syscall.h>

#include <signal.h>

const int MAX_SIGNALS = 128;
sighandler_t handlers[MAX_SIGNALS];

extern "C" void SignalHandlerAssembly(int signum);
extern "C" void SignalHandler(int signum)
{
	if ( 0 <= signum && signum < (int) MAX_SIGNALS )
		handlers[signum](signum);
}

DEFN_SYSCALL1(int, sys_register_signal_handler, SYSCALL_REGISTER_SIGNAL_HANDLER, sighandler_t);

extern "C" void init_signal()
{
	for ( int i = 0; i < MAX_SIGNALS; i++ )
		handlers[i] = SIG_DFL;

	// Tell the kernel which function we want called upon signals.
	sys_register_signal_handler(&SignalHandlerAssembly);
}

extern "C" sighandler_t signal(int signum, sighandler_t handler)
{
	if ( signum < 0 || MAX_SIGNALS <= signum ) { return SIG_ERR; }
	return handlers[signum] = handler;
}