minix/lib/libsys/sef_signal.c
2012-03-25 21:58:14 +02:00

196 lines
6.3 KiB
C

#include "syslib.h"
#include <assert.h>
#include <signal.h>
#include <minix/sysutil.h>
/* SEF Signal callbacks. */
static struct sef_cbs {
sef_cb_signal_handler_t sef_cb_signal_handler;
sef_cb_signal_manager_t sef_cb_signal_manager;
} sef_cbs = {
SEF_CB_SIGNAL_HANDLER_DEFAULT,
SEF_CB_SIGNAL_MANAGER_DEFAULT
};
/* SEF Signal prototypes for sef_receive(). */
int do_sef_signal_request(message *m_ptr);
/* Debug. */
EXTERN char* sef_debug_header(void);
/* Information about SELF. */
EXTERN endpoint_t sef_self_endpoint;
/*===========================================================================*
* process_sigmgr_signals *
*===========================================================================*/
static void process_sigmgr_signals(void)
{
/* A signal manager has pending signals in the kernel. Process them. */
endpoint_t target;
sigset_t sigset;
int signo, r;
while (TRUE) {
/* Get an arbitrary pending signal. */
if((r=sys_getksig(&target, &sigset)) != OK)
panic("SEF: sys_getksig failed: %d", r);
if (target == NONE) {
/* Stop if there are no more pending signals. */
break;
} else {
/* Process every signal in the signal set. */
r = OK;
for (signo = SIGS_FIRST; signo <= SIGS_LAST; signo++) {
if(sigismember(&sigset, signo)) {
/* Let the callback code process the signal. */
r = sef_cbs.sef_cb_signal_manager(target, signo);
/* Stop if process is gone. */
if(r == EDEADSRCDST) {
break;
}
}
}
/* Tell the kernel we are done if the target is still alive. */
if(r == OK) {
if((r=sys_endksig(target)) != OK)
panic("SEF: sys_endksig failed :%d", r);
}
}
}
}
/*===========================================================================*
* process_sigmgr_self_signals *
*===========================================================================*/
static void process_sigmgr_self_signals(sigset_t sigset)
{
/* A signal manager has pending signals for itself. Process them. */
int signo;
for (signo = SIGS_FIRST; signo <= SIGS_LAST; signo++) {
if(sigismember(&sigset, signo)) {
/* Let the callback code process the signal. */
sef_cbs.sef_cb_signal_handler(signo);
}
}
}
/*===========================================================================*
* do_sef_signal_request *
*===========================================================================*/
int do_sef_signal_request(message *m_ptr)
{
/* Handle a SEF Signal request. */
int signo;
sigset_t sigset;
if(m_ptr->m_source == SYSTEM) {
/* Handle kernel signals. */
sigset = m_ptr->NOTIFY_ARG;
for (signo = SIGK_FIRST; signo <= SIGK_LAST; signo++) {
if (sigismember(&sigset, signo)) {
/* Let the callback code handle the kernel signal. */
sef_cbs.sef_cb_signal_handler(signo);
/* Handle SIGKSIG for a signal manager. */
if(signo == SIGKSIG) {
process_sigmgr_signals();
}
/* Handle SIGKSIGSM for a signal manager. */
else if(signo == SIGKSIGSM) {
process_sigmgr_self_signals(sigset);
}
}
}
}
else {
/* Handle system signals from a signal manager. */
signo = m_ptr->SIGS_SIG_NUM;
/* Debug. */
#if SEF_SIGNAL_DEBUG
sef_signal_debug_begin();
sef_signal_dprint("%s. Got a SEF Signal request for signal %d! About to handle signal.\n",
sef_debug_header(), signo);
sef_signal_debug_end();
#endif
/* Let the callback code handle the signal. */
sef_cbs.sef_cb_signal_handler(signo);
}
/* Return OK not to let anybody else intercept the request. */
return OK;
}
/*===========================================================================*
* sef_setcb_signal_handler *
*===========================================================================*/
void sef_setcb_signal_handler(sef_cb_signal_handler_t cb)
{
assert(cb != NULL);
sef_cbs.sef_cb_signal_handler = cb;
}
/*===========================================================================*
* sef_setcb_signal_manager *
*===========================================================================*/
void sef_setcb_signal_manager(sef_cb_signal_manager_t cb)
{
assert(cb != NULL);
sef_cbs.sef_cb_signal_manager = cb;
}
/*===========================================================================*
* sef_cb_signal_handler_null *
*===========================================================================*/
void sef_cb_signal_handler_null(int signo)
{
}
/*===========================================================================*
* sef_cb_signal_manager_null *
*===========================================================================*/
int sef_cb_signal_manager_null(endpoint_t target, int signo)
{
return OK;
}
/*===========================================================================*
* sef_cb_signal_handler_term *
*===========================================================================*/
void sef_cb_signal_handler_term(int signo)
{
/* Terminate in case of SIGTERM, ignore other signals. */
if(signo == SIGTERM) {
sef_exit(1);
}
}
/*===========================================================================*
* sef_cb_signal_handler_posix_default *
*===========================================================================*/
void sef_cb_signal_handler_posix_default(int signo)
{
switch(signo) {
/* Ignore when possible. */
case SIGCHLD:
case SIGWINCH:
case SIGCONT:
case SIGTSTP:
case SIGTTIN:
case SIGTTOU:
break;
/* Terminate in any other case unless it is a kernel signal. */
default:
if(!IS_SIGK(signo)) {
sef_exit(1);
}
break;
}
}