*
* Author: S. Piccardi Dec. 2002
*
- * $Id: SigHand.c,v 1.5 2003/05/02 09:55:14 piccardi Exp $
- *
*****************************************************************************/
-#include <errno.h> /* error simbol definitions */
-#include <stdio.h> /* standard I/O functions */
-#include <signal.h> /* signal handling declarations */
-#include <sys/types.h>
-#include <sys/wait.h>
+#include <errno.h> /* error definitions and routines */
+#include <stdio.h> /* standard I/O library */
+#include <signal.h> /* signal constants, types and functions */
+#include <sys/types.h> /* primitive system data types */
+#include <sys/wait.h> /* process termination constants and functions */
#include "Gapil.h"
#include "macros.h"
* Initialize a signal handler.
* To enable the signal handling a process we need to tell it to
* kernel; this is done writing all needed info to a sigaction structure
- * named sigact, and then callind sigaction() system call passing the
+ * named sigact, and then calling sigaction() system call passing the
+ * information stored in the sigact structure variable.
+ *
+ * Input: the signal to handle
+ * the signal handler function
+ * Return: the previous signal handler
+ */
+inline SigHandler * Signal(int signo, SigHandler *func)
+{
+ struct sigaction new_handl, old_handl;
+ new_handl.sa_flags=0; /* init to 0 all flags */
+ new_handl.sa_handler = func; /* set signal handler */
+ /* clear signal mask: no signal blocked during execution of func */
+ if (sigemptyset(&new_handl.sa_mask)!=0){ /* initialize signal set */
+ return SIG_ERR;
+ }
+ /* change action for signo signal */
+ if (sigaction(signo, &new_handl, &old_handl)){
+ return SIG_ERR;
+ }
+ return (old_handl.sa_handler);
+}
+
+/*
+ * Function SignalRestart
+ * Initialize a signal handler.
+ * To enable the signal handling a process we need to tell it to
+ * kernel; this is done writing all needed info to a sigaction structure
+ * named sigact, and then calling sigaction() system call passing the
* information stored in the sigact structure variable.
+ * This version enable BSD semantics with SA_RESTART
*
* Input: the signal to handle
* the signal handler function
- * Return: the previous sigaction structure
+ * Return: the previous signal handler
*/
-inline SigFunc * Signal(int signo, SigFunc *func)
+inline SigHandler * SignalRestart(int signo, SigHandler *func)
{
struct sigaction new_handl, old_handl;
- new_handl.sa_handler = func; /* set signal handler */
+ new_handl.sa_flags = SA_RESTART; /* restart system call */
+ new_handl.sa_handler = func; /* set signal handler */
/* clear signal mask: no signal blocked during execution of func */
- if (sigemptyset(&new_handl.sa_mask)!=0){ /* initialize signal set */
+ if (sigemptyset(&new_handl.sa_mask)!=0){ /* initialize signal set */
return SIG_ERR;
}
- new_handl.sa_flags=0; /* init to 0 all flags */
/* change action for signo signal */
- if (sigaction(signo,&new_handl,&old_handl)){
+ if (sigaction(signo, &new_handl, &old_handl)){
return SIG_ERR;
}
return (old_handl.sa_handler);
}
+
+/*
+ * Function Action
+ * Initialize a sa_sigaction signal handler.
+ * To enable the signal handling a process we need to tell it to
+ * kernel; this is done writing all needed info to a sigaction structure
+ * named sigact, and then calling sigaction() system call passing the
+ * information stored in the sigact structure variable.
+ *
+ * Input: the signal to handle
+ * the signal handler function (sa_sigaction type)
+ * Return: the previous signal handler
+ */
+inline SigAction * Action(int signo, SigAction *func)
+{
+ struct sigaction new_handl, old_handl;
+ new_handl.sa_flags=SA_SIGINFO; /* we use sa_sigaction handler */
+ new_handl.sa_sigaction = func; /* set signal handler */
+ /* clear signal mask: no signal blocked during execution of func */
+ if (sigemptyset(&new_handl.sa_mask)!=0){ /* initialize signal set */
+ return NULL;
+ }
+ /* change action for signo signal */
+ if (sigaction(signo, &new_handl, &old_handl)){
+ return NULL;
+ }
+ return (old_handl.sa_sigaction);
+}
+/*
+ * Function Action
+ * Initialize a sa_sigaction signal handler.
+ * To enable the signal handling a process we need to tell it to
+ * kernel; this is done writing all needed info to a sigaction structure
+ * named sigact, and then calling sigaction() system call passing the
+ * information stored in the sigact structure variable.
+ *
+ * Input: the signal to handle
+ * the signal handler function (sa_sigaction type)
+ * Return: the previous signal handler
+ */
+inline SigAction * ActionRestart(int signo, SigAction *func)
+{
+ struct sigaction new_handl, old_handl;
+ new_handl.sa_flags=SA_SIGINFO|SA_RESTART;/* flag setup */
+ new_handl.sa_sigaction = func; /* set signal handler */
+ /* clear signal mask: no signal blocked during execution of func */
+ if (sigemptyset(&new_handl.sa_mask)!=0){ /* initialize signal set */
+ return NULL;
+ }
+ /* change action for signo signal */
+ if (sigaction(signo, &new_handl, &old_handl)){
+ return NULL;
+ }
+ return (old_handl.sa_sigaction);
+}
+
/*
* Functions: HandSigCHLD
- * Generic handler for SIGCHLD signal
+ * Generic simple handler for SIGCHLD signal
*
* Simone Piccardi Dec. 2002
- * $Id: SigHand.c,v 1.5 2003/05/02 09:55:14 piccardi Exp $
*/
void HandSigCHLD(int sig)
{
do {
errno = 0;
pid = waitpid(WAIT_ANY, &status, WNOHANG);
- if (pid > 0) {
- debug("child %d terminated with status %x\n", pid, status);
- }
- } while ((pid > 0) && (errno == EINTR));
+// if (pid > 0) {
+// debug("child %d terminated with status %x\n", pid, status);
+// }
+ } while (pid > 0);
/* restore errno value*/
errno = errno_save;
/* return */
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