ape: an implemenation of getitimer setitimer

sys/include/ape/signal.h

@@ -37,9 +37,11 @@ typedef int sig_atomic_t;
 #define SIGTSTP	18	/* interactive stop */
 #define SIGTTIN	19	/* read from ctl tty by member of background */
 #define SIGTTOU	20	/* write to ctl tty by member of background */
+#define SIGVTALRM 21 /* virtual alarm clock */
+#define SIGPROF 22  /* profiling alarm clock */
 
 #ifdef _BSD_EXTENSION
-#define NSIG 21
+#define NSIG 23
 #endif
 
 #ifdef __cplusplus

sys/include/ape/sys/time.h

@@ -9,6 +9,11 @@ struct timeval {
 	long	tv_usec;
 };
 
+struct itimerval {
+	struct timeval it_interval;
+	struct timeval it_value;
+};
+
 #ifdef _BSD_EXTENSION
 struct timezone {
 	int	tz_minuteswest;
@@ -17,6 +22,12 @@ struct timezone {
 #endif
 #endif /* __TIMEVAL__ */
 
+#define ITIMER_REAL 0
+#define ITIMER_VIRTUAL 1
+#define ITIMER_PROF 3
+
 extern int gettimeofday(struct timeval *, struct timezone *);
+int getitimer(int, struct itimerval *);
+int setitimer(int, const struct itimerval *, struct itimerval *);
 
 #endif /* __SYSTIME_H */

sys/src/ape/lib/ap/plan9/signal.c

@@ -28,10 +28,11 @@ static struct {
 	{"sys: trap: address error",		SIGSEGV},
 	{"sys: trap: TLB",			SIGSEGV},
 	{"sys: write on closed pipe",		SIGPIPE},
-	{"alarm",				SIGALRM},
 	{"term",				SIGTERM},
 	{"usr1",				SIGUSR1},
 	{"usr2",				SIGUSR2},
+	{"virtual alarm",			SIGVTALRM},
+	{"profiling alarm",			SIGPROF},
 };
 #define NSIGTAB ((sizeof sigtab)/(sizeof (sigtab[0])))
 

sys/src/ape/lib/bsd/getitimer.c

@@ -0,0 +1,86 @@
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <signal.h>
+#include <errno.h>
+#include <time.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+
+typedef struct Timer Timer;
+struct Timer {
+	int pid, signal;
+	struct itimerval itimer;
+};
+
+Timer timers[3] = {
+	{0, SIGALRM},
+	{0, SIGVTALRM},
+	{0, SIGPROF},
+};
+
+void
+timerloop(Timer *timer, const struct timeval tval)
+{
+	pid_t ppid;
+	struct timespec t, s;
+
+	ppid = getppid();
+	t.tv_sec = tval.tv_sec;
+	t.tv_nsec = tval.tv_usec*1000;
+	for(;;){
+		nanosleep(&t, &s);
+		kill(ppid, timer->signal);
+	}
+}
+
+int
+setitimer(int which, const struct itimerval *new, struct itimerval *curr)
+{
+	pid_t pid;
+	int status;
+	Timer *timer;
+
+	if(which < 0 || which >= 3){
+		errno = EINVAL;
+		return -1;
+	}
+
+	timer = timers+which;
+	if(timer->pid != 0){
+		kill(timer->pid, SIGKILL);
+		waitpid(timer->pid, &status, 0);
+	}
+
+	switch(pid = fork()){
+	default:
+		timer->pid = pid;
+		if(curr != NULL)
+			*curr = timer->itimer;
+		timer->itimer = *new;
+		break;
+	case -1:
+		errno = EFAULT;
+		return -1;
+	case 0:
+		timerloop(timer, new->it_interval);
+		exit(0);
+	}
+	return 0;
+}
+
+int
+getitimer(int which, struct itimerval *curr)
+{
+	Timer *timer;
+
+	if(which < 0 || which >= 3){
+		errno = EINVAL;
+		return -1;
+	}
+
+	timer = timers+which;
+	*curr = timer->itimer;
+	return 0;
+}

sys/src/ape/lib/bsd/mkfile

@@ -15,6 +15,7 @@ OFILES=\
 	gethostbyaddr.$O\
 	gethostbyname.$O\
 	gethostname.$O\
+	getitimer.$O\
 	getnameinfo.$O\
 	getopt.$O\
 	getpeername.$O\