Re: [PATCH with testcase] Bug 11568 - delete thread-specific breakpoint on the thread exit

[Muhammad Waqas <mwaqas at codesourcery dot com>]

On 08/05/2013 06:57 PM, Tom Tromey wrote:
> > > > > > "Muhammad" == Muhammad Waqas <mwaqas@codesourcery.com> writes:
> Muhammad>  insertion_state_t;
> Muhammad>  +static void remove_threaded_breakpoints (struct thread_info *tp, int
> Muhammad> silent);
> Muhammad> +
>
> Your patch got mangled by your mailer.  This makes it hard to check the
> formatting, so please fix that.
>
> Muhammad>  +static void
> Muhammad> +remove_threaded_breakpoints(struct thread_info *tp, int silent)
> Muhammad> +{
>
> Needs an intro comment.
>
> Muhammad> +
> Muhammad> +  if (b->thread > 0)
> Muhammad> +    {
> Muhammad> +      observer_attach_thread_exit (remove_threaded_breakpoints);
> Muhammad> +    }
>
> It seems odd to re-register the observer each time.
> Why not just do it once, at initialization time?
>
> Muhammad> 2013-07-24  Muhammad Waqas  <mwaqas@codesourccery.com>
> Muhammad> 	    Jan Kratochvil  <jan.kartochvil@redhat.com>
>
> Muhammad> 	PR gdb/11568
> Muhammad> 	*gdb.thread/thread-specific-bp.c: Newfile.
> Muhammad> 	*gdb.thread/thread-specific-bp.exp: Newfile.
>
> Space after "*" and in "New file".
>
> Muhammad> +set mode "All stop"
> Muhammad> +
> Muhammad> +if {[gdb_compile_pthreads \
> Muhammad> +	 "${srcdir}/${subdir}/${srcfile}" \
> Muhammad> +	 "${binfile}" executable {debug} ] != "" } {
> Muhammad> +    return -1
> Muhammad> +}
> Muhammad> +
> Muhammad> +clean_restart ${binfile}
> Muhammad> +
> Muhammad> +proc check_threaded_breakpoint {} {
> Muhammad> +    global gdb_prompt mode
>
> Make "mode" a parameter.
> Use with_test_prefix, since otherwise the new .exp will have repeated
> test names, an gdb anti-pattern.
>
> Muhammad> +# Testing in non-stop+async mode.
> Muhammad> +set mode "non-stop\\async"
>
> It's better to simply not use an unusual character.
>
> Tom

Thanks for reviewing patch.

Changlog

2013-08-05  Muhammad Waqas  <mwaqas@codesourcery.com>

	PR gdb/11568
	* breakpoint.c (remove_threaded_breakpoints): New function.
	* breakpoint.c (_initialize_breakpoint): function
	remove_threaded_breakpoints registerd with thread_exit.

Added intro comments for new function.
Fix with re-register the observer each time now it register
at inilization time only once.


Index: ./../../breakpoint.c
===================================================================
RCS file: /cvs/src/src/gdb/breakpoint.c,v
retrieving revision 1.773
diff -u -p -r1.773 breakpoint.c
--- ./../../breakpoint.c	24 Jul 2013 19:50:32 -0000	1.773
+++ ./../../breakpoint.c	6 Aug 2013 05:56:35 -0000
@@ -200,6 +200,9 @@ typedef enum
   }
 insertion_state_t;
 
+static void remove_threaded_breakpoints (struct thread_info *tp,
+					 int silent);
+
 static int remove_breakpoint (struct bp_location *, insertion_state_t);
 static int remove_breakpoint_1 (struct bp_location *, insertion_state_t);
 
@@ -2928,6 +2931,24 @@ remove_breakpoints (void)
   return val;
 }
 
+/* Used when a thread exits, it will remove breakpoints which
+   are related to that thread.  */
+
+static void
+remove_threaded_breakpoints (struct thread_info *tp, int silent)
+{
+  struct breakpoint *b, *b_tmp;
+
+  ALL_BREAKPOINTS_SAFE (b, b_tmp)
+    {
+      if (b->thread == tp->num)
+	{
+	  b->disposition = disp_del_at_next_stop;
+	  b->number = 0;
+	}
+    }
+}
+
 /* Remove breakpoints of process PID.  */
 
 int
@@ -16568,4 +16589,5 @@ agent-printf \"printf format string\", a
   automatic_hardware_breakpoints = 1;
 
   observer_attach_about_to_proceed (breakpoint_about_to_proceed);
+  observer_attach_thread_exit (remove_threaded_breakpoints);
 }

Changlog

2013-07-24  Muhammad Waqas  <mwaqas@codesourccery.com>
	    Jan Kratochvil  <jan.kartochvil@redhat.com>

	PR gdb/11568
	* gdb.thread/thread-specific-bp.c: New file.
	* gdb.thread/thread-specific-bp.exp: New file.

Fix with testcase


Index: thread-specific-bp.c
===================================================================
RCS file: thread-specific-bp.c
diff -N thread-specific-bp.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ thread-specific-bp.c	6 Aug 2013 05:56:57 -0000
@@ -0,0 +1,33 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2013 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <pthread.h>
+
+static void *
+start (void *arg)
+{
+  return NULL;
+}
+
+int
+main (void)
+{
+  pthread_t thread;
+  pthread_create (&thread, NULL, start, NULL);
+  pthread_join (thread, NULL);
+  return 0; /*set break here*/
+}
Index: thread-specific-bp.exp
===================================================================
RCS file: thread-specific-bp.exp
diff -N thread-specific-bp.exp
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ thread-specific-bp.exp	6 Aug 2013 05:57:14 -0000
@@ -0,0 +1,98 @@
+# Copyright (C) 2013 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Verify that a thread-specific breakpoint is deleted when the
+# corresponding thread is gone.
+
+standard_testfile
+
+if {[gdb_compile_pthreads \
+	 "${srcdir}/${subdir}/${srcfile}" \
+	 "${binfile}" executable {debug} ] != "" } {
+    return -1
+}
+
+clean_restart ${binfile}
+
+proc check_threaded_breakpoint {mode} { with_test_prefix "$mode" {
+
+    global gdb_prompt
+    gdb_breakpoint "start"
+    gdb_continue_to_breakpoint "start"
+    set thre 0
+
+    gdb_test_multiple "info threads" "get thread 1 id" {
+	-re "(\[0-9\]+)(\[^\n\r\]*Thread\[^\n\r\]*start.*)($gdb_prompt $)" {
+	    pass "thread created"
+	    # get the id of thread
+	    set thre $expect_out(1,string)
+	}
+    }
+    gdb_breakpoint "main thread $thre"
+    gdb_test "info break" ".*breakpoint.*thread $thre" "Breakpoint set"
+    gdb_breakpoint [gdb_get_line_number "set break here"]
+
+    # Force GDB to update its knowledge on existing threads when this
+    # breakpoint is hit.  Otherwise, GDB doesn't realize thread $thre
+    # has exited and doesn't remove the thread specific breakpoint.
+    gdb_test "commands\ninfo threads\nend" "End with.*" "add breakpoint commands"
+    gdb_test "thread $thre" "Switching to thread $thre.*" "Thread $thre selected"
+    set full_name "continue to breakpoint: set break here"
+
+    send_gdb "continue\n"
+    gdb_expect 10 {
+	-re "(?:Breakpoint|Temporary breakpoint) .* (at|in) .*\r\n$gdb_prompt $" {
+	    pass $full_name
+	}
+	-re ".*$gdb_prompt $" {
+	    fail $full_name
+	}
+	timeout {
+	    send_gdb "thread 1\n"
+	    exp_continue
+	}
+    }
+
+    set test "thread-specific breakpoint is deleted"
+    gdb_test_multiple "info breakpoint" $test {
+    	-re "thread $thre.*$gdb_prompt $" {
+	    fail $test
+    	}
+    	-re "$gdb_prompt $" {
+	    pass $test
+    	}
+    }}
+}
+
+if ![runto_main] {
+    untested "could not run to main"
+    return -1
+}
+
+# Testing in all stop mode.
+check_threaded_breakpoint "All stop"
+
+clean_restart ${binfile}
+
+gdb_test "set target-async on" ".*" "Set async mode"
+gdb_test "set non-stop on" ".*" "Set non stop mode"
+
+if ![runto_main] {
+    untested "could not run to main"
+    return -1
+}
+
+# Testing in non-stop with async mode.
+check_threaded_breakpoint "non-stop with async"