[PATCH][fix for gdb/15853] 'thread apply all inetrrupt&' shows inefficiency on remote targets

[Muhammad Bilal]

On 08/27/2013 07:00 PM, Muhammad Bilal wrote:
> Hi,
> While I was playing with non-stop thread debugging, I have observed that.
>
> In the case of 'interrupt -a&' command gdb sends only one packet to
> stop all  threads as $vCont;t#b9...
>
> But in case of 'thread apply all interrupt&' GDB issues individual 
> packet for each thread.I think that In non-stop mode
> 'interrupt -a&' and 'thread apply all interrupt&' commands are equals 
> but time efficiency of later command is less.
>
> Also,
>
> If user issues a command like 'thread apply all interrupt -a&'
> GDB accepts it and GDB will stop all threads on first vcount;t 
> packets  but due to loops iteration on all threads,
> GDB sends vcount;t packet for all remaining threads although GDB has 
> already stop all thread so IMO it is a bug.
>
>
> 2013-08-28  Muhammad Bilal  <mbilal@codesourcery.com>
>
>     PR gdb/15853
>     * thread.c (thread_apply_all_command): Lookup 'interrupt' command
>     using 'lookup_cmd_composition', 'find_command_name_length'
>     functions and execute single command for all threads.
>     * infcmd.c (interrupt_target_command): Issue a warning on
>     'thread apply all interrupt -a&' command.
>     (interrupt_all_threads): Define as global.
>     (all_threads): Removed.
>     * inferior.h (interrupt_all_threads): Declare.
>     * cli/cli-decode.c (find_cmd): Change definition from
>     static to global.
>     (lookup_cmd_composition): Check command ambiguousness
>     with 'nfound' instead of CMD_LIST_AMBIGUOUS.
>     * command.h (find_command_name_length): Declare.
> ---
>  gdb/cli/cli-decode.c |    4 ++--
>  gdb/command.h        |    2 ++
>  gdb/infcmd.c         |   13 +++++++++----
>  gdb/inferior.h       |    3 +++
>  gdb/thread.c         |   15 +++++++++++++++
>  5 files changed, 31 insertions(+), 6 deletions(-)
>
> diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
> index 2fdd9e4..a1a3510 100644
> --- a/gdb/cli/cli-decode.c
> +++ b/gdb/cli/cli-decode.c
> @@ -1232,7 +1232,7 @@ find_cmd (const char *command, int len, struct 
> cmd_list_element *clist,
>    return found;
>  }
>
> -static int
> +int
>  find_command_name_length (const char *text)
>  {
>    const char *p = text;
> @@ -1729,7 +1729,7 @@ lookup_cmd_composition (const char *text,
>        *cmd = find_cmd (command, len, cur_list, 1, &nfound);
>      }
>
> -      if (*cmd == CMD_LIST_AMBIGUOUS)
> +      if (nfound > 1)CMD_LIST_AMBIGUOUS
>      {
>        return 0;              /* ambiguous */
>      }
> diff --git a/gdb/command.h b/gdb/command.h
> index 81edc43..83040a3 100644
> --- a/gdb/command.h
> +++ b/gdb/command.h
> @@ -397,4 +397,6 @@ extern int cmd_func_p (struct cmd_list_element *cmd);
>  extern void cmd_func (struct cmd_list_element *cmd,
>                char *args, int from_tty);
>
> +extern int find_command_name_length (const char *text);
> +
>  #endif /* !defined (COMMAND_H) */
> diff --git a/gdb/infcmd.c b/gdb/infcmd.c
> index 154cde2..9bc0999 100644
> --- a/gdb/infcmd.c
> +++ b/gdb/infcmd.c
> @@ -2776,23 +2776,28 @@ interrupt_target_1 (int all_threads)
>     if the `-a' switch is used.  */
>
>  /* interrupt [-a]  */
> +int interrupt_all_threads = 0;
>  static void
>  interrupt_target_command (char *args, int from_tty)
>  {
>    if (target_can_async_p ())
>      {
> -      int all_threads = 0;
>
>        dont_repeat ();        /* Not for the faint of heart.  */
>
>        if (args != NULL
>        && strncmp (args, "-a", sizeof ("-a") - 1) == 0)
> -    all_threads = 1;
> +    {
> +          if (interrupt_all_threads)
> +        error (_("-a is meaningless in thread apply all command."));
> +      interrupt_all_threads = 1;
> +    }
>
> -      if (!non_stop && all_threads)
> +      if (!non_stop && interrupt_all_threads)
>      error (_("-a is meaningless in all-stop mode."));
>
> -      interrupt_target_1 (all_threads);
> +      interrupt_target_1 (interrupt_all_threads);
> +      interrupt_all_threads = 0;
>      }
>  }
>
> diff --git a/gdb/inferior.h b/gdb/inferior.h
> index 2a5770d..464511a 100644
> --- a/gdb/inferior.h
> +++ b/gdb/inferior.h
> @@ -128,6 +128,9 @@ extern int detach_fork;
>     system's address space randomization feature when starting an 
> inferior.  */
>  extern int disable_randomization;
>
> +/* If set, in non_stop 'interrupt' command will be apply on all 
> threads.  */
> +extern int interrupt_all_threads;
> +
>  extern void generic_mourn_inferior (void);
>
>  extern void terminal_save_ours (void);
> diff --git a/gdb/thread.c b/gdb/thread.c
> index 78851e4..fea6aed 100644
> --- a/gdb/thread.c
> +++ b/gdb/thread.c
> @@ -1216,6 +1216,9 @@ thread_apply_all_command (char *cmd, int from_tty)
>    char *saved_cmd;
>    int tc;
>    struct thread_array_cleanup ta_cleanup;
> +  struct cmd_list_element *alias = NULL;
> +  struct cmd_list_element *prefix_cmd = NULL;
> +  struct cmd_list_element *command = NULL;
>
>    if (cmd == NULL || *cmd == '\000')
>      error (_("Please specify a command following the thread ID list"));
> @@ -1224,6 +1227,18 @@ thread_apply_all_command (char *cmd, int from_tty)
>
>    old_chain = make_cleanup_restore_current_thread ();
>
> +  /* If there is 'interrupt' command in non-stop mode.  */
> +  if (non_stop
> +      && lookup_cmd_composition (cmd, &alias, &prefix_cmd, &command)
> +      && !strncmp (cmd, "interrupt", find_command_name_length(cmd)))
> +    {
> +      interrupt_all_threads = 1;
> +      execute_command (cmd, from_tty);
> +      do_cleanups (old_chain);
> +      interrupt_all_threads = 0;
> +      return;
> +    }
> +
>    /* Save a copy of the command in case it is clobbered by
>       execute_command.  */
>    saved_cmd = xstrdup (cmd);
ping


Thanks,
-Bilal