Ajout de l'exo3 TP4

TP4/Exo3/helpers.c

@@ -0,0 +1,19 @@
+#include "helpers.h"
+#include <signal.h>
+#include <time.h>
+
+int set_signal_handler(int signo, void (*handler)(int)) {
+    struct sigaction sa;
+    sa.sa_handler = handler;    // call `handler` on signal
+    sigemptyset(&sa.sa_mask);   // don't block other signals in handler
+    sa.sa_flags = SA_RESTART;            //  restart system calls
+    return sigaction(signo, &sa, NULL);
+}
+
+double tstamp(void) {                                                                                    
+	struct timespec tv;
+	clock_gettime(CLOCK_REALTIME, &tv);
+	return tv.tv_sec + tv.tv_nsec * 1.0e-9;
+}
+
+

TP4/Exo3/helpers.h

@@ -0,0 +1,7 @@
+#ifndef _HELPERS_H
+#define _HELPERS_H
+
+int set_signal_handler(int signo, void (*handler)(int));
+double tstamp(void);
+
+#endif

TP4/Exo3/section_critique.c

@@ -0,0 +1,44 @@
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <stdint.h>
+#include <assert.h>
+#include "helpers.h"
+#include "helpers.c"
+
+int x = 2, y = 3;
+
+sigset_t quitset;
+
+int swap(int *x, int *y)
+{
+	sigemptyset(&quitset);
+	sigaddset(&quitset, SIGQUIT);
+	sigprocmask(SIG_BLOCK, &quitset, NULL);
+
+	int tmp = *x;
+	*x = *y;
+	*y = tmp;
+
+	sigprocmask(SIG_UNBLOCK, &quitset, NULL);
+}
+
+void sig_handler(int signo)
+{
+	switch (signo)
+	{
+	case SIGQUIT:
+		printf("x=%d y=%d\n", x, y);
+		break;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	assert(set_signal_handler(SIGQUIT, sig_handler) == 0);
+	while (1)
+	{
+		swap(&x, &y);
+	}
+}