Remove usage of find_inferior in iterate_over_lwps

Replace find_inferior with find_thread.  Since it may be useful in the
future, I added another overload to find_thread which filters based on a
ptid (using ptid_t::matches), so now iterate_over_lwps doesn't have to
do the filtering itself.  iterate_over_lwps_filter is removed and
inlined into iterate_over_lwps.

gdb/gdbserver/ChangeLog:

	* gdbthread.h (find_thread): Add overload with ptid_t filter.
	* linux-low.c (struct iterate_over_lwps_args): Remove.
	(iterate_over_lwps_filter): Remove.
	(iterate_over_lwps): Use find_thread.

3 files changed, 25 insertions, 39 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 3a233bb..5183022 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,12 @@
 2017-11-19  Simon Marchi  <simon.marchi@ericsson.com>
 
+	* gdbthread.h (find_thread): Add overload with ptid_t filter.
+	* linux-low.c (struct iterate_over_lwps_args): Remove.
+	(iterate_over_lwps_filter): Remove.
+	(iterate_over_lwps): Use find_thread.
+
+2017-11-19  Simon Marchi  <simon.marchi@ericsson.com>
+
 	* linux-low.c (reset_lwp_ptrace_options_callback): Remove.
 	(linux_handle_new_gdb_connection): Use for_each_thread, inline
 	code from reset_lwp_ptrace_options_callback.
diff --git a/gdb/gdbserver/gdbthread.h b/gdb/gdbserver/gdbthread.h
index b82d5b0..df1e477 100644
--- a/gdb/gdbserver/gdbthread.h
+++ b/gdb/gdbserver/gdbthread.h
@@ -123,6 +123,18 @@ find_thread (int pid, Func func)
     });
 }
 
+/* Find the first thread that matches FILTER for which FUNC returns true.
+   Return NULL if no thread satisfying these conditions is found.  */
+
+template <typename Func>
+static thread_info *
+find_thread (ptid_t filter, Func func)
+{
+  return find_thread ([&] (thread_info *thread) {
+    return thread->id.matches (filter) && func (thread);
+  });
+}
+
 /* Invoke FUNC for each thread.  */
 
 template <typename Func>
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index 628135a..fd8e45e 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -1876,42 +1876,6 @@ num_lwps (int pid)
   return count;
 }
 
-/* The arguments passed to iterate_over_lwps.  */
-
-struct iterate_over_lwps_args
-{
-  /* The FILTER argument passed to iterate_over_lwps.  */
-  ptid_t filter;
-
-  /* The CALLBACK argument passed to iterate_over_lwps.  */
-  iterate_over_lwps_ftype *callback;
-
-  /* The DATA argument passed to iterate_over_lwps.  */
-  void *data;
-};
-
-/* Callback for find_inferior used by iterate_over_lwps to filter
-   calls to the callback supplied to that function.  Returning a
-   nonzero value causes find_inferiors to stop iterating and return
-   the current inferior_list_entry.  Returning zero indicates that
-   find_inferiors should continue iterating.  */
-
-static int
-iterate_over_lwps_filter (thread_info *thread, void *args_p)
-{
-  struct iterate_over_lwps_args *args
-    = (struct iterate_over_lwps_args *) args_p;
-
-  if (thread->id.matches (args->filter))
-    {
-      struct lwp_info *lwp = get_thread_lwp (thread);
-
-      return (*args->callback) (lwp, args->data);
-    }
-
-  return 0;
-}
-
 /* See nat/linux-nat.h.  */
 
 struct lwp_info *
@@ -1919,10 +1883,13 @@ iterate_over_lwps (ptid_t filter,
 		   iterate_over_lwps_ftype callback,
 		   void *data)
 {
-  struct iterate_over_lwps_args args = {filter, callback, data};
+  thread_info *thread = find_thread (filter, [&] (thread_info *thread)
+    {
+      lwp_info *lwp = get_thread_lwp (thread);
+
+      return callback (lwp, data);
+    });
 
-  thread_info *thread = find_inferior (&all_threads, iterate_over_lwps_filter,
-				       &args);
   if (thread == NULL)
     return NULL;