+/* Returns true if INF has any resumed thread with a status
+ pending. */
+
+static bool
+threads_are_resumed_pending_p (inferior *inf)
+{
+ for (thread_info *tp : inf->non_exited_threads ())
+ if (tp->resumed
+ && tp->suspend.waitstatus_pending_p)
+ return true;
+
+ return false;
+}
+
+/* Wrapper for target_wait that first checks whether threads have
+ pending statuses to report before actually asking the target for
+ more events. Polls for events from all inferiors/targets. */
+
+static bool
+do_target_wait (ptid_t wait_ptid, execution_control_state *ecs, int options)
+{
+ int num_inferiors = 0;
+ int random_selector;
+
+ /* For fairness, we pick the first inferior/target to poll at
+ random, and then continue polling the rest of the inferior list
+ starting from that one in a circular fashion until the whole list
+ is polled once. */
+
+ auto inferior_matches = [&wait_ptid] (inferior *inf)
+ {
+ return (inf->process_target () != NULL
+ && (threads_are_executing (inf->process_target ())
+ || threads_are_resumed_pending_p (inf))
+ && ptid_t (inf->pid).matches (wait_ptid));
+ };
+
+ /* First see how many resumed inferiors we have. */
+ for (inferior *inf : all_inferiors ())
+ if (inferior_matches (inf))
+ num_inferiors++;
+
+ if (num_inferiors == 0)
+ {
+ ecs->ws.kind = TARGET_WAITKIND_IGNORE;
+ return false;
+ }
+
+ /* Now randomly pick an inferior out of those that were resumed. */
+ random_selector = (int)
+ ((num_inferiors * (double) rand ()) / (RAND_MAX + 1.0));
+
+ if (debug_infrun && num_inferiors > 1)
+ fprintf_unfiltered (gdb_stdlog,
+ "infrun: Found %d inferiors, starting at #%d\n",
+ num_inferiors, random_selector);
+
+ /* Select the Nth inferior that was resumed. */
+
+ inferior *selected = nullptr;
+
+ for (inferior *inf : all_inferiors ())
+ if (inferior_matches (inf))
+ if (random_selector-- == 0)
+ {
+ selected = inf;
+ break;
+ }
+
+ /* Now poll for events out of each of the resumed inferior's
+ targets, starting from the selected one. */
+
+ auto do_wait = [&] (inferior *inf)
+ {
+ switch_to_inferior_no_thread (inf);
+
+ ecs->ptid = do_target_wait_1 (inf, wait_ptid, &ecs->ws, options);
+ ecs->target = inf->process_target ();
+ return (ecs->ws.kind != TARGET_WAITKIND_IGNORE);
+ };
+
+ /* Needed in all-stop+target-non-stop mode, because we end up here
+ spuriously after the target is all stopped and we've already
+ reported the stop to the user, polling for events. */
+ scoped_restore_current_thread restore_thread;
+
+ int inf_num = selected->num;
+ for (inferior *inf = selected; inf != NULL; inf = inf->next)
+ if (inferior_matches (inf))
+ if (do_wait (inf))
+ return true;
+
+ for (inferior *inf = inferior_list;
+ inf != NULL && inf->num < inf_num;
+ inf = inf->next)
+ if (inferior_matches (inf))
+ if (do_wait (inf))
+ return true;
+
+ ecs->ws.kind = TARGET_WAITKIND_IGNORE;
+ return false;
+}
+
projects / deliverable / binutils-gdb.git / blobdiff