gdb/

	* infrun.c (sched_multi): New global.
	(resume): If sched_multi is set, resume only threads of the
	current inferior.
	(prepare_to_proceed): Don't switch over to wait_ptid if we're
	resuming a different inferior, and sched_multi is off.
	(show_schedule_multiple): New.
	(_initialize_infrun): Register new "set schedule-multiple" command.
	* inferior.h (sched_multi): Declare.
	* NEWS: Mention new "schedule-multiple" setting.
gdb/doc/
	* gdb.texinfo (All-Stop): Document new 'set schedule-multiple'
	command.

2 files changed, 35 insertions, 0 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index d4c574a..ff1ffd0 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,8 @@
+2009-06-11  Pedro Alves  <pedro@codesourcery.com>
+
+	* gdb.texinfo (All-Stop): Document new 'set schedule-multiple'
+	command.
+
 2009-06-07  Pedro Alves  <pedro@codesourcery.com>
 
 	* gdbint.texinfo (TARGET_HAS_HARDWARE_WATCHPOINTS): Delete all
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 6f5fb9a..c4459e3 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -4650,6 +4650,36 @@ the current thread away from the thread that you are debugging.
 Display the current scheduler locking mode.
 @end table
 
+@cindex resume threads of multiple processes simultaneously
+By default, when you issue one of the execution commands such as
+@code{continue}, @code{next} or @code{step}, @value{GDBN} allows only
+threads of the current inferior to run.  For example, if @value{GDBN}
+is attached to two inferiors, each with two threads, the
+@code{continue} command resumes only the two threads of the current
+inferior.  This is useful, for example, when you debug a program that
+forks and you want to hold the parent stopped (so that, for instance,
+it doesn't run to exit), while you debug the child.  In other
+situations, you may not be interested in inspecting the current state
+of any of the processes @value{GDBN} is attached to, and you may want
+to resume them all until some breakpoint is hit.  In the latter case,
+you can instruct @value{GDBN} to allow all threads of all the
+inferiors to run with the @w{@code{set schedule-multiple}} command.
+
+@table @code
+@kindex set schedule-multiple
+@item set schedule-multiple
+Set the mode for allowing threads of multiple processes to be resumed
+when an execution command is issued.  When @code{on}, all threads of
+all processes are allowed to run.  When @code{off}, only the threads
+of the current process are resumed.  The default is @code{off}.  The
+@code{scheduler-locking} mode takes precedence when set to @code{on},
+or while you are stepping and set to @code{step}.
+
+@item show schedule-multiple
+Display the current mode for resuming the execution of threads of
+multiple processes.
+@end table
+
 @node Non-Stop Mode
 @subsection Non-Stop Mode