MINOR: debug: add "print" to "debug dev sched"

Passing "print=1" for a periodic task will cause it to print the exact
monotonic time at each wakeup to stdout and do nothing else. This is
convenient to watch wakeup delay drifts.

diff --git a/src/debug.c b/src/debug.c
index 35369e1e9496adc3d7063e2e7189859997251cea..afb90429803d681072734c09ebeb32da81c8ae5c 100644 (file)
--- a/src/debug.c
+++ b/src/debug.c
@@ -1671,6 +1671,13 @@ static struct task *debug_task_handler(struct task *t, void *ctx, unsigned int s
 
        t->expire = tick_add(now_ms, inter);
 
+       if (t->state & TASK_F_USR1) {
+               /* This is a time-printing task, we print the precise current time to stdout */
+               ullong time_ns = now_mono_time();
+               printf("task %p: time_ms=%llu.%llu\n", t, time_ns / 1000000ULL, time_ns % 1000000ULL);
+               return t;
+       }
+
        /* half of the calls will wake up another entry */
        rnd = statistical_prng();
        if (rnd & 1) {
@@ -1709,7 +1716,7 @@ static struct task *debug_tasklet_handler(struct task *t, void *ctx, unsigned in
 }
 
 /* parse a "debug dev sched" command
- * debug dev sched {task|tasklet} [count=<count>] [mask=<mask>] [single=<single>] [inter=<inter>]
+ * debug dev sched {task|tasklet} [count=<count>] [mask=<mask>] [single=<single>] [inter=<inter>] [print=<print>]
  */
 static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appctx, void *private)
 {
@@ -1724,6 +1731,7 @@ static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appc
        unsigned long count = 0;
        unsigned long thrid = tid;
        unsigned int inter = 0;
+       unsigned int print = 0;
        unsigned long i;
        int mode = 0; // 0 = tasklet; 1 = task
        unsigned long *tctx; // [0] = #tasks, [1] = inter, [2+] = { tl | (tsk+1) }
@@ -1736,7 +1744,7 @@ static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appc
        if (strcmp(args[3], "task") != 0 && strcmp(args[3], "tasklet") != 0) {
                return cli_err(appctx,
                               "Usage: debug dev sched {task|tasklet} { <obj> = <value> }*\n"
-                              "     <obj>   = {count | tid | inter }\n"
+                              "     <obj>   = {count | tid | inter | print }\n"
                               "     <value> = 64-bit dec/hex integer (0x prefix supported)\n"
                               );
        }
@@ -1755,6 +1763,8 @@ static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appc
                        ptr = &thrid; size = sizeof(thrid);
                } else if (isteq(name, ist("inter"))) {
                        ptr = &inter; size = sizeof(inter);
+               } else if (isteq(name, ist("print"))) {
+                       ptr = &print; size = sizeof(print);
                } else
                        return cli_dynerr(appctx, memprintf(&msg, "Unsupported setting: '%s'.\n", word));
 
@@ -1820,7 +1830,8 @@ static int debug_parse_cli_sched(char **args, char *payload, struct appctx *appc
                unsigned long ctx = tctx[i + 2];
 
                if (ctx & 1)
-                       task_wakeup((struct task *)(ctx - 1), TASK_WOKEN_INIT);
+                       task_wakeup((struct task *)(ctx - 1),
+                                   TASK_WOKEN_INIT | (print ? TASK_F_USR1 : 0));
                else
                        tasklet_wakeup((struct tasklet *)ctx);
        }