Re: Merge of nickrob-async-20060513 to mainline?

[Nick Roberts <nickrob@snap.net.nz>]

 > Just generate the diff between your mergepoint and branch, and then
 > pipe it to diffstat, assuming you've got it installed.

Doing:

cvs diff -r nickrob-async-20060828-mergepoint gdb | diffstat

from the src directory gives the output below.

 > Well, I meant from an internals perspective - like, a patch just
 > summarizing the interface changes, if the whole patch is too big to
 > post at once.

Instead of GDB waiting for the enferior to stop directly, it creates a signal
thread to do that.  This means that the main thread can continue to process the
event loop.  When the inferior does stop, the signal thread writes to a file
which GDB detects through handle_file_event in the event loop. It then calls
inferior_event_handler.

 > > Also it still uses pthreads.  You said previously that it should be done
 > > in one process and, following a remark from Jim Ingham, that ptrace is
 > > non-blocking.  AFAICS the problem is that wait *is* blocking and I can't
 > > see of a way to deal with that without using another thread.
 > 
 > Ah, but wait is non-blocking.  You have to (A) use WNOHANG, and (B) be
 > careful to handle asynchronous SIGCHLD events.  It's not especially
 > difficult, I don't think, but the async event loop in gdb has always
 > confused me; we'll have to figure out how to gather up sigchld/wait
 > events.

The manpage just says:

       WNOHANG
              return immediately if no child has exited.

but what value does it return with?  Does GDB ignore SIGCHLD events so it
can detect state changes through wait?

-- 
Nick                                           http://www.inet.net.nz/~nickrob

New files:

gdb/PROBLEMS.async
gdb/README.async
gdb/TODO.async
gdb/async-nat-inferior.c
gdb/async-nat-inferior.h
gdb/async-nat-sigthread.c
gdb/async-nat-sigthread.h

Makefile.in                |   13 
 gdb-mi.el                  | 2129 ++++++++++++++++++++++++--
 gdb/ChangeLog              | 3645 +--------------------------------------------
 gdb/cli-out.c              |   12 
 gdb/cli-out.h              |    1 
 gdb/cli/cli-interp.c       |   83 -
 gdb/config/i386/nm-linux.h |    3 
 gdb/defs.h                 |   11 
 gdb/event-loop.c           |   72 
 gdb/event-loop.h           |    9 
 gdb/event-top.c            |   93 +
 gdb/event-top.h            |    2 
 gdb/exec.c                 |   52 
 gdb/i386-linux-nat.c       |   21 
 gdb/inf-child.c            |    1 
 gdb/inf-loop.c             |   46 
 gdb/inf-ptrace.c           |   38 
 gdb/infcmd.c               |    9 
 gdb/infrun.c               |   26 
 gdb/interps.c              |   40 
 gdb/interps.h              |    3 
 gdb/linux-nat.c            |  747 ++++-----
 gdb/linux-thread-db.c      |    4 
 gdb/main.c                 |   13 
 gdb/mi/mi-interp.c         |   82 -
 gdb/mi/mi-main.c           |  371 ++++
 gdb/mi/mi-main.h           |   11 
 gdb/remote.c               |   12 
 gdb/target.c               |   31 
 gdb/target.h               |   16 
 gdb/top.c                  |   25 
 gdb/tui/tui-hooks.c        |    4 
 gdb/version.in             |    2 
 gdb/wrapper.h              |    2 
 linux.mh                   |    7 
 35 files changed, 3494 insertions(+), 4142 deletions(-)