Exited threads.

	* thread.c (enum thread_state): New.
	(thread_state main_thread_running): Delete, in favor of...
	(thread_state main_thread_state): ... this.  Update throughout.
	(clear_thread_inferior_resources): New, split from free_thread.
	(free_thread): Call clear_thread_inferior_resources.
	(init_thread_list): Set main thread to stopped state.
	(add_thread_silent): Take care of PTID reuses.
	(delete_thread): If deleting inferior_ptid or a thread with
	refcount > 0, mark it as exited, but still keep it in the list.
	Only notify of thread exits, if we haven't done so yet.
	(iterate_over_threads): Make it safe to delete threads while
	iterating over them.
	(do_captured_list_thread_ids): Don't account for exited threads.
	(thread_alive): Check for the THREAD_EXITED state, and don't set
	ptid to -1 on exited threads.
	(set_running): Update to account for extra possible states.
	(is_thread_state): New.
	(is_stopped, is_exited): New.
	(is_running): Implement in terms of is_thread_state.
	(any_running): Update.
	(print_thread_info): Update.  Account for exited threads.  Don't
	warn about missed frame restoring here, its done in the cleanup.
	(switch_to_thread): Don't read from a thread that has gone.
	(restore_current_thread): In non-stop mode, do a full context
	switch.
	(restore_selected_frame): Add a frame_level argument.  Rewrite.
	(struct current_thread_cleanup): Add selected_frame_level and
	was_stopped members.
	(do_restore_current_thread_cleanup): Check if thread was stopped
	and still is, and if the target has registers, stack and memory
	before restoring the selected frame.  Don't delete the cleanup
	argument here.
	(restore_current_thread_cleanup_dtor): New.
	(make_cleanup_restore_current_thread): Remove all arguments.
	Rewrite.
	(thread_apply_all_command): Update.  Prune threads.
	(thread_apply_command): Update.
	(thread_command): Account for currently selected exited thread.
	(do_captured_thread_select): Check for a running thread.  Prune
	threads.
	(_initialize_thread): Make "info threads", "thread", "thread
	apply", and "thread apply all" appliable without a selected thread.
	* gdbthread.h (struct thread_info): Replace running_ by state_.
	Add refcount.
	(is_exited, is_stopped): Declare.
	(make_cleanup_restore_current_thread): Remove all arguments.
	* infrun.c: Include "event-top.h".
	(fetch_inferior_event): In non-stop mode, restore selected thread
	and frame after handling the event and running breakpoint
	commands.  Display GDB prompt if needed.
	(normal_stop): In non-stop mode, don't print thread switching
	notice.
	* cli/cli-decode.c (set_cmd_no_selected_thread_ok)
	(get_cmd_no_selected_thread_ok): New.
	* cli/cli-decode.h (CMD_NO_SELECTED_THREAD_OK): New.
	(set_cmd_no_selected_thread_ok, get_cmd_no_selected_thread_ok):
	Declare.
	* cli/cli-cmds.c: Set "pwd", "help", "info", "show" as
	no-selected-thread ok.
	* top.c (execute_command): Check for non no-selected-thread-ok
	commands.
	* linux-nat.c (struct saved_ptids, threads_to_delete)
	(record_dead_thread, prune_lwps): Delete.
	(exit_lwp): Unconditionally delete thread.
	(linux_nat_resume): Remove prune_lwps call.
	* infcmd.c (proceed_thread_callback): Check if !is_stopped instead
	of is_running.  Adjust to make_cleanup_restore_current_thread
	interface change.
	* mi/mi-main.c (mi_cmd_execute): Only allow a few commands if the
	selected thread has exited.
	* inf-loop.c (inferior_event_handler): Don't display the prompt
	here.
	* varobj.c (c_value_of_root): Update.
	* defs.h (make_cleanup_dtor): Declare.
	* utils.c (make_cleanup_dtor): New.

	* Makefile.in (infrun.o): Depend on $(event_top_h).

3 files changed, 28 insertions, 0 deletions

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index b0f5fa0..efd3137 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -1245,6 +1245,8 @@ The commands below can be used to select other frames by number or address."),
   c = add_com ("pwd", class_files, pwd_command, _("\
 Print working directory.  This is used for your program as well."));
   set_cmd_async_ok (c);
+  set_cmd_no_selected_thread_ok (c);
+
   c = add_cmd ("cd", class_files, cd_command, _("\
 Set working directory to DIR for debugger and program being debugged.\n\
 The change does not take effect for the program being debugged\n\
@@ -1285,6 +1287,7 @@ when GDB is started."), gdbinit);
 	       _("Print list of commands."));
   set_cmd_completer (c, command_completer);
   set_cmd_async_ok (c);
+  set_cmd_no_selected_thread_ok (c);
   add_com_alias ("q", "quit", class_support, 1);
   add_com_alias ("h", "help", class_support, 1);
 
@@ -1314,6 +1317,7 @@ Without an argument, history expansion is enabled."),
 Generic command for showing things about the program being debugged."),
 		      &infolist, "info ", 0, &cmdlist);
   set_cmd_async_ok (c);
+  set_cmd_no_selected_thread_ok (c);
   add_com_alias ("i", "info", class_info, 1);
 
   add_com ("complete", class_obscure, complete_command,
@@ -1323,6 +1327,7 @@ Generic command for showing things about the program being debugged."),
 Generic command for showing things about the debugger."),
 		      &showlist, "show ", 0, &cmdlist);
   set_cmd_async_ok (c);
+  set_cmd_no_selected_thread_ok (c);
   /* Another way to get at the same thing.  */
   add_info ("set", show_command, _("Show all GDB settings."));
 
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index 05a0b27..07bb587 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -117,6 +117,18 @@ get_cmd_async_ok (struct cmd_list_element *cmd)
   return cmd->flags & CMD_ASYNC_OK;
 }
 
+void
+set_cmd_no_selected_thread_ok (struct cmd_list_element *cmd)
+{
+  cmd->flags |= CMD_NO_SELECTED_THREAD_OK;
+}
+
+int
+get_cmd_no_selected_thread_ok (struct cmd_list_element *cmd)
+{
+  return cmd->flags & CMD_NO_SELECTED_THREAD_OK;
+}
+
 enum cmd_types
 cmd_type (struct cmd_list_element *cmd)
 {
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index f133b3d..c790398 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -51,6 +51,10 @@ cmd_types;
 /* This flag is set if the command is allowed during async execution.  */
 #define CMD_ASYNC_OK              0x8
 
+/* This flag is set if the command is allowed to run when the target
+   has execution, but there's no selected thread.  */
+#define CMD_NO_SELECTED_THREAD_OK 0x10
+
 struct cmd_list_element
   {
     /* Points to next command in this list.  */
@@ -253,6 +257,13 @@ extern void set_cmd_async_ok (struct cmd_list_element *);
 /* Return true if command is async-ok.  */
 extern int get_cmd_async_ok (struct cmd_list_element *);
 
+/* Mark command as ok to call when there is no selected thread.  There
+   is no way to disable this once set.  */
+extern void set_cmd_no_selected_thread_ok (struct cmd_list_element *);
+
+/* Return true if command is no-selected-thread-ok.  */
+extern int get_cmd_no_selected_thread_ok (struct cmd_list_element *);
+
 extern struct cmd_list_element *lookup_cmd (char **,
 					    struct cmd_list_element *, char *,
 					    int, int);