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/****************************************************************
* *
* Copyright 2001, 2009 Fidelity Information Services, Inc *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#include "mdef.h"
#include "gtm_unistd.h"
#include "gtmci_signals.h"
#include "gtmsiginfo.h"
#include "invocation_mode.h"
/* These routines implement signal handling protocol between gtm and
external user (if C is base the application):
+ by switching the active signal handlers between gtm and external user
+ if signal received in gtm context, it is the responsibility of
gtm to execute external handlers.
+ similary, external user is responsible to save and execute the gtm
signal handlers if signalled in external context.
*/
/* info of the last signal handled by generic_signal_handler */
GBLREF int4 exi_condition;
GBLREF siginfo_t exi_siginfo;
GBLDEF gtm_sigcontext_t exi_context;
static struct sigaction *gtm_sig_h; /* storage for GT.M handlers */
static struct sigaction *ext_sig_h; /* handlers defined in external application */
static boolean_t sig_gtm_ctxt = FALSE; /* if current signal context is of GT.M */
/* initialize all sig handlers to 'act' and save external handlers if C is the
base routine in call-ins. Otherwise, if M is the base routine, don't retain the
old handlers */
void sig_save_ext(struct sigaction* act)
{
int i;
if (MUMPS_CALLIN & invocation_mode)
{ /* C is the base */
gtm_sig_h = (struct sigaction*)malloc(NSIG * SIZEOF(struct sigaction));
ext_sig_h = (struct sigaction*)malloc(NSIG * SIZEOF(struct sigaction));
for (i = 1; i <= NSIG; i++)
sigaction(i, act, &ext_sig_h[i-1]);
} else { /* GT.M is the base */
for (i = 1; i <= NSIG; i++)
sigaction(i, act, 0);
}
}
void sig_save_gtm(void)
{
int i;
if (MUMPS_CALLIN & invocation_mode) {
for (i = 1; i <= NSIG; i++)
sigaction(i, 0, >m_sig_h[i-1]);
sig_gtm_ctxt = TRUE;
}
}
void sig_switch_gtm(void) /* switch to GT.M signal context */
{
int i;
if ((MUMPS_CALLIN & invocation_mode) && !sig_gtm_ctxt) {
for (i = 1; i <= NSIG; i++)
sigaction(i, >m_sig_h[i-1], &ext_sig_h[i-1]);
sig_gtm_ctxt = TRUE;
}
}
void sig_switch_ext(void) /* switch to external signal context */
{
int i;
if ((MUMPS_CALLIN & invocation_mode) && sig_gtm_ctxt) {
for (i = 1; i <= NSIG; i++)
sigaction(i, &ext_sig_h[i-1], >m_sig_h[i-1]);
sig_gtm_ctxt = FALSE;
}
}
/* identify any signal received in GT.M context, and handle them in the context
of external user */
void gtmci_exit_handler(void)
{
static boolean_t handler_active = FALSE;
struct sigaction *act, ignore;
if ((0 >= exi_condition && NSIG < exi_condition) || !(MUMPS_CALLIN & invocation_mode) ||
!(MUMPS_GTMCI & invocation_mode) || handler_active)
return;
handler_active = TRUE;
sig_switch_ext();
act = &ext_sig_h[exi_condition-1];
if (SIG_IGN == act->sa_handler || SIG_DFL == act->sa_handler)
return;
if (act->sa_flags & SA_SIGINFO)
(*act->sa_sigaction)(exi_condition, &exi_siginfo, &exi_context);
else
(*act->sa_handler)(exi_condition);
}
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