PR gdb/11557

gdb/
	* regcache.c (registers_changed): Rename to ...
	(registers_changed_ptid): ... this, and only delete register cache
	entries matching the ptid filter argument.
	(registers_changed): Reimplement on top of registers_changed_ptid.
	* regcache.h (registers_changed_ptid): Declare.
	* target.c (target_resume): Flush register caches.

	gdb/testsuite/
	* gdb.mi/mi-ns-stale-regcache.exp, gdb.mi/ns-stale-regcache.c: New
	files.

gdb/ChangeLog

@@ -1,3 +1,14 @@
+2010-04-29  Pedro Alves  <pedro@codesourcery.com>
+
+	PR gdb/11557
+
+	* regcache.c (registers_changed): Rename to ...
+	(registers_changed_ptid): ... this, and only delete register cache
+	entries matching the ptid filter argument.
+	(registers_changed): Reimplement on top of registers_changed_ptid.
+	* regcache.h (registers_changed_ptid): Declare.
+	* target.c (target_resume): Flush register caches.
+
 2010-04-29  Phil Muldoon  <pmuldoon@redhat.com>
             Tom Tromey  <tromey@redhat.com>
             Thiago Jung Bauermann  <bauerman@br.ibm.com>

gdb/regcache.c

@@ -518,15 +518,27 @@ regcache_thread_ptid_changed (ptid_t old_ptid, ptid_t new_ptid)
    Indicate that registers may have changed, so invalidate the cache.  */
 
 void
-registers_changed (void)
+registers_changed_ptid (ptid_t ptid)
 {
-  struct regcache_list *list, *next;
+  struct regcache_list *list, **list_link;
 
-  for (list = current_regcache; list; list = next)
+  list = current_regcache;
+  list_link = &current_regcache;
+  while (list)
     {
-      next = list->next;
-      regcache_xfree (list->regcache);
-      xfree (list);
+      if (ptid_match (list->regcache->ptid, ptid))
+	{
+	  struct regcache_list *dead = list;
+
+	  *list_link = list->next;
+	  regcache_xfree (list->regcache);
+	  list = *list_link;
+	  xfree (dead);
+	  continue;
+	}
+
+      list_link = &list->next;
+      list = *list_link;
     }
 
   current_regcache = NULL;
@@ -545,6 +557,11 @@ registers_changed (void)
   alloca (0);
 }
 
+void
+registers_changed (void)
+{
+  registers_changed_ptid (minus_one_ptid);
+}
 
 void
 regcache_raw_read (struct regcache *regcache, int regnum, gdb_byte *buf)

gdb/regcache.h

@@ -159,5 +159,6 @@ extern void regcache_cpy (struct regcache *dest, struct regcache *src);
 extern void regcache_cpy_no_passthrough (struct regcache *dest, struct regcache *src);
 
 extern void registers_changed (void);
+extern void registers_changed_ptid (ptid_t);
 
 #endif /* REGCACHE_H */

gdb/target.c

@@ -2192,6 +2192,7 @@ target_resume (ptid_t ptid, int step, enum target_signal signal)
 				step ? "step" : "continue",
 				target_signal_to_name (signal));
 
+	  registers_changed_ptid (ptid);
 	  set_executing (ptid, 1);
 	  set_running (ptid, 1);
 	  clear_inline_frame_state (ptid);

gdb/testsuite/ChangeLog

@@ -1,3 +1,10 @@
+2010-04-29  Pedro Alves  <pedro@codesourcery.com>
+
+	PR gdb/11557
+
+	* gdb.mi/mi-ns-stale-regcache.exp, gdb.mi/ns-stale-regcache.c: New
+	files.
+
 2010-04-29  Phil Muldoon  <pmuldoon@redhat.com>
 
         * gdb.python/py-param.exp: New File.

gdb/testsuite/gdb.mi/mi-ns-stale-regcache.exp

@@ -0,0 +1,88 @@
+# Copyright 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
+# 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/>.
+
+# Regression test for PR11557.  Make sure we don't end up with a stale
+# register cache just after resuming a thread.
+
+load_lib mi-support.exp
+set MIFLAGS "-i=mi"
+
+gdb_exit
+if {[mi_gdb_start]} {
+    continue
+}
+
+proc mi_nonstop_resume { command test } {
+    if { [mi_send_resuming_command $command $test] != 0 } {
+	# If a resume fails, assume non-stop is broken or unsupported
+	# for this target.  We have logged a FAIL or UNSUPPORTED; skip
+	# the remaining tests to limit timeouts.
+	return -code continue
+    }
+}
+
+#
+# Start here
+#
+set testfile "ns-stale-regcache"
+set srcfile "$testfile.c"
+set binfile "$objdir/$subdir/mi-$testfile"
+
+set options [list debug incdir=$objdir]
+if {[gdb_compile "$srcdir/$subdir/$srcfile" \
+	 $binfile executable $options] != "" } {
+    return -1
+}
+
+mi_gdb_reinitialize_dir $srcdir/$subdir
+mi_gdb_load $binfile
+
+set supported 0
+send_gdb "-gdb-show non-stop\n"
+gdb_expect {
+    -re ".*\\^done,value=\"off\",supported=\"(\[^\"\]+)\"\r\n$mi_gdb_prompt$" {
+	if { $expect_out(1,string) == "1" } {
+	    set supported 1
+	}
+    }
+    -re ".$mi_gdb_prompt$" {
+    }
+}
+
+mi_gdb_test "-gdb-set non-stop 1" ".*"
+mi_gdb_test "-gdb-set target-async 1" ".*"
+detect_async
+
+if { [mi_run_to_main] < 0 } {
+    perror "mi-ns-stale-regcache.exp tests suppressed"
+    continue
+}
+
+# Check that register and stack info don't end up stale after resuming
+# a thread.
+mi_nonstop_resume "exec-continue" "resume thread"
+
+mi_gdb_test "-data-evaluate-expression \$pc" \
+    "\\^error,msg=\".*\"" "no stale register cache of resumed thread"
+
+mi_gdb_test "-stack-info-frame" \
+    "\\^error,msg=\".*\"" "no stale frame info of resumed thread"
+
+# Check that the thread is still running.  If the above tests passed,
+# we want it to be for the right reasons.
+mi_check_thread_states {"running"} "main thread still running"
+
+mi_gdb_exit

gdb/testsuite/gdb.mi/ns-stale-regcache.c

@@ -0,0 +1,30 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2010 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 <unistd.h>
+
+int
+main (int argc, char **argv)
+{
+  volatile int my_number = 1;
+
+  while (my_number > 0)
+    {
+      usleep (1);
+    }
+}