[GDB 4.18] sol-thread.c sol_detach_thread patch

[Neil Schellenberger <nschelle@crosskeys.com>]

Hi folks,

I had been having trouble convincing gdb 4.17 (and later) to detach
from a multi-threaded process under Solaris 2.5.1.  It seemed that gdb
always locked up as soon as the detach was executed.  Killing the
debugger usually (always?) seemed to have the remedial effect of
forcing a detach via the run-on-close on the procfs.

I finally found some time to figure out what was happening.  Seems
that when sol_thread_detach is called, if the inferior_pid is set to a
user thread id there will be serious grief printing the "detaching"
message.  I won't bother with the details here.

The patch I provide below sets inferior_pid to the process pid before
continuing.  I can't see any serious downside to losing the LWP
information, but someone who really understands this stuff should
decide if this is correct or not.

Of course, once I figured this all of this out, the workaround also
became obvious: switch to a LWP before detaching.

Tue Jun 15 22:32:25 1999  Neil Schellenberger  <nschelle@crosskeys.com>

	* sol-thread.c (sol_thread_detach): Reset inferior_pid so that it
 	is definitely not a thread or LWP id.  The id is used by procfs
 	to_detach to generate the "detaching" message to the tty;
 	unfortunately it can get into an infinite loop inside
 	target_pid_to_str because solaris_pid_to_str cannot properly
 	decode user thread ids without the (just unpushed) sol_thread_ops
 	target.  This also provides better symmetry with the
        inferior_pid manipulation done in sol_thread_attach.

*** sol-thread.c.orig   Tue Jun 15 22:05:31 1999
--- sol-thread.c        Tue Jun 15 22:06:51 1999
*************** sol_thread_detach (args, from_tty)
*** 487,492 ****
--- 487,493 ----
       char *args;
       int from_tty;
  {
+   inferior_pid = PIDGET (main_ph.pid);
    unpush_target (&sol_thread_ops);
    procfs_ops.to_detach (args, from_tty);
  }


Regards,
Neil

-- 
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