MINOR: debug: copy the thread info into the post_mortem struct

The last starting thread now copies the pthread ID and stack top of
each thread into post_mortem. That way it's as easy as issuing
"p post_mortem" in gdb to see all thread IDs and stack frames and more
easily map them to the threads met in a core.

diff --git a/src/debug.c b/src/debug.c
index 78d913696f352787b78fe6adfd28e50a0024a5b1..837061505df788a29c358e1008084176621c3780 100644 (file)
--- a/src/debug.c
+++ b/src/debug.c
@@ -98,6 +98,13 @@ struct post_mortem {
                gid_t boot_gid;
                struct rlimit limit_fd;  // RLIMIT_NOFILE
                struct rlimit limit_ram; // RLIMIT_AS or RLIMIT_DATA
+
+#if defined(USE_THREAD)
+               struct {
+                       ullong pth_id;   // pthread_t cast to a ullong
+                       void *stack_top; // top of the stack
+               } thread_info[MAX_THREADS];
+#endif
        } process;
 } post_mortem ALIGNED(256) = { };
 
@@ -2145,6 +2152,28 @@ static int feed_post_mortem()
 
 REGISTER_POST_CHECK(feed_post_mortem);
 
+#ifdef USE_THREAD
+/* init code is called one at a time so let's collect all per-thread info on
+ * the last starting thread. These info are not critical anyway and there's no
+ * problem if we get them slightly late.
+ */
+static int feed_post_mortem_late()
+{
+       static int per_thread_info_collected;
+
+       if (HA_ATOMIC_ADD_FETCH(&per_thread_info_collected, 1) == global.nbthread) {
+               int i;
+               for (i = 0; i < global.nbthread; i++) {
+                       post_mortem.process.thread_info[i].pth_id = ha_thread_info[i].pth_id;
+                       post_mortem.process.thread_info[i].stack_top = ha_thread_info[i].stack_top;
+               }
+       }
+       return 1;
+}
+
+REGISTER_PER_THREAD_INIT(feed_post_mortem_late);
+#endif
+
 /* register cli keywords */
 static struct cli_kw_list cli_kws = {{ },{
        {{ "debug", "dev", "bug", NULL },      "debug dev bug                           : call BUG_ON() and crash",                 debug_parse_cli_bug,   NULL, NULL, NULL, ACCESS_EXPERT },