[PATCH 0/8, V4] A general notification in GDB RSP

[Yao Qi <yao@codesourcery.com>]

Hi,
We have more and more requirements that remote target wants to notify
GDB via RSP at any time during connection when some states are changed
in remote target.  However, GDB doesn't have such general notification
infrastructure.  This is what this patch set tries to add.

Nowadays, notification mechanism exists in GDB for '%Stop' only,
and works pretty good.  My rationale of this work is 'decouple
%Stop/vStopped from existing notification mechanism so that
notification mechanism can handle other types of notification.

First of all, let us look at how '%Stop' and 'vStopped' works,

    gdb           gdbserver
        <- %Stop         // [1] Send notification
       [after process other packets]
        -> vStopped      // [2] Ack this notification
        <- T05 thread:2  // [3] Reply
        -> vStopped      // [4] Continue to query
        <- OK            // [5] Done

We can generalize this protocol like this,

    gdb           gdbserver
        <- %NOTIF         // [1] Send notification
       [after process other packets]
        -> vACK           // [2] Ack this notification
        <- EVENT          // [3] Event
        -> vACK           // [4] Continue to query
        <- OK             // [5] Done

For each type of notification, we only have to define three things,

   1) NOTIF, the key word of notification, for example, "Stop"
   2) ACK, the command GDB ack to this notification, "vStopped" for
example,
   3) EVENT, the format of event to GDB.  GDBserver should be able to
send packet to comply with EVENT, and GDB is able parse the packet,
and identify the packet is EVENT or not.

This is the V4 of this patch series, there are some changes compared
with V3,

  - Move macros in common/queue.h from the bottom to to top.
    Move the comments of functions to macros, as users should use
macros externally,
  - Don't treat 'Stop' a special notification, and keep the global
queue of stop reply.
  - Move 'ptid' field out of 'struct notif_reply' (it is 'struct notif_event'
now).
  - Rename some struct
  - Add some comments in the code.

This patch series depends on this patch,

  [PATCH] Attach discard_pending_stop_replies to observer inferior_exit
  http://sourceware.org/ml/gdb-patches/2012-12/msg00126.html

All these patches are tested on x86_64-linux {native, gdbserver} x
{sync, async}.  No regression.

 gdb/Makefile.in           |    9 +-
 gdb/NEWS                  |    4 +
 gdb/common/queue.h        |  303 ++++++++++++++++++++++++++++
 gdb/doc/gdb.texinfo       |    6 +
 gdb/gdbserver/Makefile.in |    4 +-
 gdb/gdbserver/linux-low.c |   10 +
 gdb/gdbserver/notif.c     |  180 +++++++++++++++++
 gdb/gdbserver/notif.h     |   68 +++++++
 gdb/gdbserver/server.c    |  164 +++++----------
 gdb/gdbserver/server.h    |    2 -
 gdb/remote-notif.c        |  324 ++++++++++++++++++++++++++++++
 gdb/remote-notif.h        |   85 ++++++++
 gdb/remote.c              |  491 ++++++++++++++++++++++++---------------------
 gdb/remote.h              |    3 +
 14 files changed, 1310 insertions(+), 343 deletions(-)
 create mode 100644 gdb/common/queue.h
 create mode 100644 gdb/gdbserver/notif.c
 create mode 100644 gdb/gdbserver/notif.h
 create mode 100644 gdb/remote-notif.c
 create mode 100644 gdb/remote-notif.h

-- 
1.7.7.6