Get pending events in random

[deliverable/binutils-gdb.git] / gdb / gdbserver / inferiors.c

diff --git a/gdb/gdbserver/inferiors.c b/gdb/gdbserver/inferiors.c
index 7888f3c18525682555acda2019361f3c06054122..574a7ba7d57082534589f78b9232a5233bb6f312 100644 (file)
--- a/gdb/gdbserver/inferiors.c
+++ b/gdb/gdbserver/inferiors.c
@@ -248,6 +248,51 @@ find_inferior (struct inferior_list *list,
   return NULL;
 }
 
+/* Find the random inferior_list_entry E in LIST for which FUNC (E, ARG)
+   returns non-zero.  If no entry is found then return NULL.  */
+
+struct inferior_list_entry *
+find_inferior_in_random (struct inferior_list *list,
+                        int (*func) (struct inferior_list_entry *, void *),
+                        void *arg)
+{
+  struct inferior_list_entry *inf = list->head;
+  int count = 0;
+  int random_selector;
+
+  /* First count how many interesting entries we have.  */
+  while (inf != NULL)
+    {
+      struct inferior_list_entry *next;
+
+      next = inf->next;
+      if ((*func) (inf, arg))
+       count++;
+      inf = next;
+    }
+
+  if (count == 0)
+    return NULL;
+
+  /* Now randomly pick an entry out of those.  */
+  random_selector = (int)
+    ((count * (double) rand ()) / (RAND_MAX + 1.0));
+
+  inf = list->head;
+  while (inf != NULL)
+    {
+      struct inferior_list_entry *next;
+
+      next = inf->next;
+      if ((*func) (inf, arg) && (random_selector-- == 0))
+       return inf;
+      inf = next;
+    }
+
+  gdb_assert_not_reached ("failed to find an inferior in random.");
+  return NULL;
+}
+
 struct inferior_list_entry *
 find_inferior_id (struct inferior_list *list, ptid_t id)
 {