tools: acrntrace: Add option -t for max capture time

If option -t is configured, a timer will be set with configured timeout when
launching acrntrace. When timer fired, acrntrace will exit.

Signed-off-by: Kaige Fu <kaige.fu@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
Reviewed-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>

tools/acrntrace/Makefile

@@ -2,7 +2,7 @@
 OUT_DIR ?= .
 
 all:
-	$(CC) -o $(OUT_DIR)/acrntrace acrntrace.c sbuf.c -I. -lpthread
+	$(CC) -o $(OUT_DIR)/acrntrace acrntrace.c sbuf.c -I. -lpthread -lrt
 
 clean:
 	rm -f $(OUT_DIR)/acrntrace

tools/acrntrace/README.rst

@@ -19,6 +19,7 @@ Options:
 
 -h			print this message
 -i period		specify polling interval in milliseconds [1-999]
+-t			max time to capture trace data (in second)
 -c			clear the buffered old data
 -r			minimal amount (in MB) of free space kept on the disk
 			before acrntrace stops

tools/acrntrace/acrntrace.c

@@ -15,16 +15,21 @@
 #include <errno.h>
 #include <pthread.h>
 #include <string.h>
+#include <signal.h>
 
 #include "acrntrace.h"
 
 /* default minimal amount free space (in MB) left on the disk */
 static uint64_t disk_reserved = 512;
+
+#define TIMER_ID	(128)
+static uint32_t timeout = 0;
+
 static int exiting = 0;
 
 /* for opt */
 static uint64_t period = 10000;
-static const char optString[] = "i:hcr:";
+static const char optString[] = "i:hcr:t:";
 static const char dev_name[] = "/dev/acrn_trace";
 
 static uint32_t flags;
@@ -42,9 +47,50 @@ static void display_usage(void)
 	       "\t-r: minimal amount (in MB) of free space kept on the disk\n"
 	       "\t    before acrntrace stops\n"
 	       "\t-i: period_in_ms: specify polling interval [1-999]\n"
+	       "\t-t: max time to capture trace data (in second)\n"
 	       "\t-c: clear the buffered old data\n");
 }
 
+static void timer_handler(union sigval sv)
+{
+	exiting = 1;
+	exit(0);
+}
+
+static int init_timer(int timeout)
+{
+	struct sigevent event;
+	struct itimerspec it;
+	timer_t tm_id;
+	int err;
+
+	memset(&event, 0, sizeof(struct sigevent));
+
+	event.sigev_value.sival_int = TIMER_ID;
+	event.sigev_notify = SIGEV_THREAD;
+	event.sigev_notify_function = timer_handler;
+
+	err = timer_create(CLOCK_MONOTONIC, &event, &tm_id);
+	if (err < 0) {
+		pr_err("Error to create timer, errno(%d)\n", err);
+		return err;
+	}
+
+	it.it_interval.tv_sec = timeout;
+	it.it_interval.tv_nsec = 0;
+	it.it_value.tv_sec = timeout;
+	it.it_value.tv_nsec = 0;
+
+	err = timer_settime(tm_id, 0, &it, NULL);
+	if (err < 0) {
+		pr_err("Error to set timer, errno(%d)\n", err);
+		return err;
+	}
+
+	pr_info("Capture trace data for about %ds and exit\n", timeout);
+	return 0;
+}
+
 static int parse_opt(int argc, char *argv[])
 {
 	int opt, ret;
@@ -69,6 +115,15 @@ static int parse_opt(int argc, char *argv[])
 			disk_reserved = ret;
 			pr_dbg("Keeping %dMB of space on the disk\n", ret);
 			break;
+		case 't':
+			ret = atoi(optarg);
+			if (ret <= 0) {
+				pr_err("'-t' require integer greater than 0\n");
+				return -EINVAL;
+			}
+			timeout = ret;
+			pr_dbg("Capture trace data for at most %ds\n", ret);
+			break;
 		case 'c':
 			flags |= FLAG_CLEAR_BUF;
 			break;
@@ -331,6 +386,7 @@ static void signal_exit_handler(int sig)
 int main(int argc, char *argv[])
 {
 	uint32_t cpu = 0;
+	int err;
 
 	/* parse options */
 	if (parse_opt(argc, argv))
@@ -350,6 +406,15 @@ int main(int argc, char *argv[])
 		exit(EXIT_FAILURE);
 	}
 
+	/* Set timer if timeout configured */
+	if (timeout) {
+		err = init_timer(timeout);
+		if (err < 0) {
+			pr_err("Failed to set timer\n");
+			exit(EXIT_FAILURE);
+		}
+	}
+
 	atexit(handle_on_exit);
 
 	/* acquair res for each trace dev */