[PATCH 3/5] gdb/doc: Clarify vCont packet description

Pedro Alves
2016-02-17T02:44:58Z

Specifically, what happens with multiple actions that could match a
thread, and what happens when we get a vCont action that matches a
thread that was already running. E.g., what does:

"vCont;s:2"
"vCont;s:1;c"

mean for thread 2.

(Thread 2 continues stepping.)

gdb/doc/ChangeLog:
2016-02-16 Pedro Alves <palves@redhat.com>

* gdb.texinfo (Packets): Clarify vCont packets with multiple
actions that match a thread, and what happens when an action
matches a thread that is already running.
---
gdb/doc/gdb.texinfo | 32 +++++++++++++++++++++-----------
1 file changed, 21 insertions(+), 11 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 9db234e..d936176 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -35321,13 +35321,17 @@ for success in non-stop mode (@pxref{Remote Non-Stop})
@cindex @samp{vCont} packet
@anchor{vCont packet}
Resume the inferior, specifying different actions for each thread.
-If an action is specified with no @var{thread-id}, then it is applied to any
-threads that don't have a specific action specified; if no default action is
-specified then other threads should remain stopped in all-stop mode and
-in their current state in non-stop mode.
-Specifying multiple
-default actions is an error; specifying no actions is also an error.
-Thread IDs are specified using the syntax described in @ref{thread-id syntax}.
+
+For each inferior thread, the leftmost action with a matching
+@var{thread-id} is applied. Threads that don't match any action
+remain in their current state. Thread IDs are specified using the
+syntax described in @ref{thread-id syntax}. If multiprocess
+extensions (@pxref{multiprocess extensions}) are supported, actions
+can be specified to match all threads in a process by using the
+@samp{p@var{pid}.-1} form of the @var{thread-id}. An action with no
+@var{thread-id} is called the default action and matches all threads.
+Specifying multiple default actions is an error; specifying no actions
+is also an error.

Currently supported actions are:

@@ -35372,11 +35376,17 @@ the corresponding stop reply should indicate that the thread has stopped with
signal @samp{0}, regardless of whether the target uses some other signal
as an implementation detail.

+The server must ignore @samp{c}, @samp{C}, @samp{s}, @samp{S}, and
+@samp{r} actions for threads that are already running. Conversely,
+the server must ignore @samp{t} actions for threads that are already
+stopped.
+
+@emph{Note:} In non-stop mode, a thread is considered running until
+@value{GDBN} acknowleges an asynchronous stop notification for it with
+the @samp{vStopped} packet (@pxref{Remote Non-Stop}).
+
The stub must support @samp{vCont} if it reports support for
-multiprocess extensions (@pxref{multiprocess extensions}). Note that in
-this case @samp{vCont} actions can be specified to apply to all threads
-in a process by using the @samp{p@var{pid}.-1} form of the
-@var{thread-id}.
+multiprocess extensions (@pxref{multiprocess extensions}).

Reply:
@xref{Stop Reply Packets}, for the reply specifications.
--
1.9.3