[PATCH RFC] AIX thread support

[PATCH RFC] AIX thread support

[Kevin Buettner]

The patch below implements thread support for AIX.  Nick Duffek
deserves the lion's share of the credit for this work.  Martin Hunt,
Louis Hamilton, and I also worked on this code.  Martin and Louis
fixed some bugs and I adapted the code to build and work with the
current sources.

I'll wait several days for comments / objections before committing it.

Kevin

	From Nicholas Duffek (with minor changes by Martin Hunt, 
	Louis Hamilton, and Kevin Buettner):
	* aix-thread.c: New file.
	* Makefile.in (ALLDEPFILES): Add aix-thread.c.
	(aix-thread.o): New rule.
	* configure.host (gdb_host): Set to aix432 on AIX 4.3.2+.
	* config/powerpc/aix432.mh: New file.

Index: Makefile.in
===================================================================
RCS file: /cvs/src/src/gdb/Makefile.in,v
retrieving revision 1.219
diff -u -p -r1.219 Makefile.in
--- Makefile.in	12 Jul 2002 15:23:10 -0000	1.219
+++ Makefile.in	12 Jul 2002 19:05:00 -0000
@@ -1200,6 +1200,7 @@ MAKEOVERRIDES=
 unexport CHILLFLAGS CHILL_LIB CHILL_FOR_TARGET :
 
 ALLDEPFILES = a68v-nat.c \
+	aix-thread.c \
 	alpha-nat.c alphabsd-nat.c \
 	alpha-tdep.c alpha-linux-tdep.c alphabsd-tdep.c alphanbsd-tdep.c \
 	alpha-osf1-tdep.c alphafbsd-tdep.c \
@@ -1259,6 +1260,9 @@ ALLDEPFILES = a68v-nat.c \
 
 a68v-nat.o: a68v-nat.c $(defs_h) $(gdbcore_h) $(inferior_h) \
 	$(regcache_h)
+
+aix-thread.o: aix-thread.c $(defs_h) $(gdbcore_h) $(gdbthread_h) \
+	$(inferior_h) $(target_h) $(regcache_h)
 
 alpha-nat.o: alpha-nat.c $(defs_h) $(gdbcore_h) $(inferior_h) $(target_h) \
 	$(regcache_h) $(alpha_tdep_h)
Index: aix-thread.c
===================================================================
RCS file: aix-thread.c
diff -N aix-thread.c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ aix-thread.c	12 Jul 2002 19:05:00 -0000
@@ -0,0 +1,1492 @@
+/* Low level interface for debugging AIX 4.3+ pthreads.
+
+   Copyright 1999, 2000, 2002 Free Software Foundation, Inc.
+   Written by Nick Duffek <nsd@redhat.com>.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+
+/* This module uses the libpthdebug.a library provided by AIX 4.3+ for
+   debugging pthread applications.
+
+   Some name prefix conventions:
+     pthdb_	provided by libpthdebug.a
+     pdc_	callbacks that this module provides to libpthdebug.a
+     pd_	variables or functions interfacing with libpthdebug.a
+
+   libpthdebug peculiarities:
+
+     - pthdb_ptid_pthread() is prototyped in <sys/pthdebug.h>, but it's not
+       documented, and after several calls it stops working and causes other
+       libpthdebug functions to fail.
+
+     - pthdb_tid_pthread() doesn't always work after pthdb_session_update(),
+       but it does work after cycling through all threads using
+       pthdb_pthread().
+
+     */
+
+#include "defs.h"
+#include "gdbthread.h"
+#include "target.h"
+#include "inferior.h"
+#include "regcache.h"
+
+#if 0
+#include "coff/internal.h"	/* for libcoff.h */
+#include "bfd/libcoff.h"	/* for xcoff_data */
+#endif
+
+#include <procinfo.h>
+#include <sys/types.h>
+#include <sys/ptrace.h>
+#include <sys/reg.h>
+#if 0
+#include <pthread.h>
+#endif
+#include <sched.h>
+#include <sys/pthdebug.h>
+
+/* Whether to emit debugging output. */
+
+#define DEBUG 0
+
+/* Default debugging output file, overridden by envvar UWTHR_DEBUG. */
+
+#define DEBUG_FILE "/dev/tty"
+
+/* #if DEBUG, write string S to the debugging output channel. */
+
+#if !DEBUG
+# define DBG(fmt_and_args)
+# define DBG2(fmt_and_args)
+#else
+# define DBG(fmt_and_args) dbg fmt_and_args
+# define DBG2(fmt_and_args) dbg fmt_and_args
+#endif
+
+/* in AIX 5.1, functions use pthdb_tid_t instead of tid_t */
+#ifndef PTHDB_VERSION_3
+#define pthdb_tid_t	tid_t
+#endif
+
+/* Return whether to treat PID as a debuggable thread id. */
+
+#define PD_TID(ptid)	(pd_active && ptid_get_tid (ptid) != 0)
+
+/* Build a thread ptid.  */
+#define BUILD_THREAD(TID, PID) ptid_build (PID, 0, TID)
+
+/* Build and lwp ptid.  */
+#define BUILD_LWP(LWP, PID) MERGEPID (PID, LWP)
+
+/* Call error() with a message indicating that libpthdebug FUNC failed with
+   STATUS. */
+
+#define PD_ERROR(func, status) \
+  error ("aix-thread: %s returned %s", func, pd_status2str (status))
+
+/* pthdb_user_t value that we pass to pthdb functions.  0 causes
+   PTHDB_BAD_USER errors, so use 1. */
+
+#define PD_USER	1
+
+/* Success and failure values returned by pthdb callbacks. */
+
+#define PDC_SUCCESS	PTHDB_SUCCESS
+#define PDC_FAILURE	PTHDB_CALLBACK
+
+/* Convert composite process/thread inferior_ptid to a process id, evaluate
+   base_ops function CALL, and then restore inferior_ptid. */
+
+#define CALL_BASE(call)					\
+  do {							\
+    struct cleanup *cleanup = save_inferior_ptid ();	\
+    inferior_ptid = pid_to_ptid (PIDGET (inferior_ptid)); \
+    call;						\
+    do_cleanups (cleanup);				\
+  } while (0)
+
+/* Private data attached to each element in GDB's thread list. */
+
+struct private_thread_info {
+  pthdb_pthread_t pdtid;	/* thread's libpthdebug id */
+  pthdb_tid_t tid;			/* kernel thread id */
+};
+
+/* Information about a thread of which libpthdebug is aware. */
+
+struct pd_thread {
+  pthdb_pthread_t pdtid;
+  pthread_t pthid;
+  pthdb_tid_t tid;
+};
+
+/* This module's target-specific operations, active while pd_able is true. */
+
+static struct target_ops ops;
+
+/* Copy of the target over which ops is pushed.  This is
+   more convenient than a pointer to child_ops or core_ops, because
+   they lack current_target's default callbacks. */
+
+static struct target_ops base_ops;
+
+/* Address of the function that libpthread will call when libpthdebug is
+   ready to be initialized. */
+
+static CORE_ADDR pd_brk_addr;
+
+/* Whether the current application is debuggable by pthdb. */
+
+static int pd_able = 0;
+
+/* Whether a threaded application is being debugged. */
+
+static int pd_active = 0;
+
+/* Whether the current architecture is 64-bit.  Only valid when pd_able is
+   true. */
+
+static int arch64;
+
+/* Saved pointer to previous owner of target_new_objfile_hook. */
+
+static void (*target_new_objfile_chain)(struct objfile *);
+
+/* Forward declarations for pthdb callbacks. */
+
+static int pdc_symbol_addrs (pthdb_user_t, pthdb_symbol_t *, int);
+static int pdc_read_data (pthdb_user_t, void *, pthdb_addr_t, size_t);
+static int pdc_write_data (pthdb_user_t, void *, pthdb_addr_t, size_t);
+static int pdc_read_regs (pthdb_user_t user, pthdb_tid_t tid,
+			  unsigned long long flags, pthdb_context_t *context);
+static int pdc_write_regs (pthdb_user_t user, pthdb_tid_t tid,
+			   unsigned long long flags, pthdb_context_t *context);
+static int pdc_alloc (pthdb_user_t, size_t, void **);
+static int pdc_realloc (pthdb_user_t, void *, size_t, void **);
+static int pdc_dealloc (pthdb_user_t, void *);
+
+/* pthdb callbacks. */
+
+static pthdb_callbacks_t pd_callbacks = {
+  pdc_symbol_addrs,
+  pdc_read_data,
+  pdc_write_data,
+  pdc_read_regs,
+  pdc_write_regs,
+  pdc_alloc,
+  pdc_realloc,
+  pdc_dealloc,
+  NULL
+};
+
+/* Current pthdb session. */
+
+static pthdb_session_t pd_session;
+
+#if DEBUG
+/* DBG() helper: if printf-style FMT is non-null, format it with args and
+   display the result on the debugging output channel. */
+
+static void
+dbg (char *fmt, ...)
+{
+  static int fd = -1, len;
+  va_list args;
+  char buf[1024];
+  char *path;
+
+  if (!fmt)
+    return;
+
+  if (fd < 0)
+    {
+      path = getenv ("UWTHR_DEBUG");
+      if (!path)
+	path = DEBUG_FILE;
+      if ((fd = open (path, O_WRONLY | O_CREAT | O_TRUNC, 0664)) < 0)
+	error ("can't open %s\n", path);
+    }
+
+  va_start (args, fmt);
+  vsprintf (buf, fmt, args);
+  va_end (args);
+
+  len = strlen (buf);
+  buf[len] = '\n';
+  (void)write (fd, buf, len + 1);
+}
+#endif   /* DEBUG */
+
+/* Return a printable representation of pthdebug function return STATUS. */
+
+static char *
+pd_status2str (int status)
+{
+  switch (status)
+    {
+    case PTHDB_SUCCESS:		return "SUCCESS";
+    case PTHDB_NOSYS:		return "NOSYS";
+    case PTHDB_NOTSUP:		return "NOTSUP";
+    case PTHDB_BAD_VERSION:	return "BAD_VERSION";
+    case PTHDB_BAD_USER:	return "BAD_USER";
+    case PTHDB_BAD_SESSION:	return "BAD_SESSION";
+    case PTHDB_BAD_MODE:	return "BAD_MODE";
+    case PTHDB_BAD_FLAGS:	return "BAD_FLAGS";
+    case PTHDB_BAD_CALLBACK:	return "BAD_CALLBACK";
+    case PTHDB_BAD_POINTER:	return "BAD_POINTER";
+    case PTHDB_BAD_CMD:		return "BAD_CMD";
+    case PTHDB_BAD_PTHREAD:	return "BAD_PTHREAD";
+    case PTHDB_BAD_ATTR:	return "BAD_ATTR";
+    case PTHDB_BAD_MUTEX:	return "BAD_MUTEX";
+    case PTHDB_BAD_MUTEXATTR:	return "BAD_MUTEXATTR";
+    case PTHDB_BAD_COND:	return "BAD_COND";
+    case PTHDB_BAD_CONDATTR:	return "BAD_CONDATTR";
+    case PTHDB_BAD_RWLOCK:	return "BAD_RWLOCK";
+    case PTHDB_BAD_RWLOCKATTR:	return "BAD_RWLOCKATTR";
+    case PTHDB_BAD_KEY:		return "BAD_KEY";
+    case PTHDB_BAD_PTID:	return "BAD_PTID";
+    case PTHDB_BAD_TID:		return "BAD_TID";
+    case PTHDB_CALLBACK:	return "CALLBACK";
+    case PTHDB_CONTEXT:		return "CONTEXT";
+    case PTHDB_HELD:		return "HELD";
+    case PTHDB_NOT_HELD:	return "NOT_HELD";
+    case PTHDB_MEMORY:		return "MEMORY";
+    case PTHDB_NOT_PTHREADED:	return "NOT_PTHREADED";
+    case PTHDB_SYMBOL:		return "SYMBOL";
+    case PTHDB_NOT_AVAIL:	return "NOT_AVAIL";
+    case PTHDB_INTERNAL:	return "INTERNAL";
+    default:			return "UNKNOWN";
+    }
+}
+
+/* A call to ptrace(REQ, ID, ...) just returned RET.  Check for exceptional
+   conditions and either return nonlocally or else return 1 for success and 0
+   for failure. */
+
+static int
+ptrace_check (int req, int id, int ret)
+{
+  if (ret == 0 && !errno)
+    return 1;
+
+  /* According to ptrace(2), ptrace may fail with EPERM if "the Identifier
+     parameter corresponds to a kernel thread which is stopped in kernel mode
+     and whose computational state cannot be read or written."  This happens
+     quite often with register reads. */
+
+  switch (req)
+    {
+    case PTT_READ_GPRS:
+    case PTT_READ_FPRS:
+    case PTT_READ_SPRS:
+      if (ret == -1 && errno == EPERM)
+	goto strange;
+      break;
+    }
+  error ("aix-thread: ptrace (%d, %d) returned %d (errno = %d %s)",
+	 req, id, ret, errno, strerror (errno));
+
+ strange:
+  DBG2(("ptrace (%d, %d) = %d (errno = %d)", req, id, ret, errno));
+  return ret == -1 ? 0 : 1;
+}
+
+/* Call ptracex(REQ, ID, ADDR, DATA, BUF).  Return success. */
+
+static int
+ptrace64aix (int req, int id, long long addr, int data, int *buf)
+{
+  errno = 0;
+  return ptrace_check (req, id, ptracex (req, id, addr, data, buf));
+}
+
+/* Call ptrace(REQ, ID, ADDR, DATA, BUF).  Return success. */
+
+static int
+ptrace32 (int req, int id, int *addr, int data, int *buf)
+{
+  errno = 0;
+  return ptrace_check (req, id, ptrace (req, id, (int *)addr, data, buf));
+}
+
+/* If *PIDP is a composite process/thread id, convert it to a process id. */
+
+static void
+pid_to_prc (ptid_t *ptidp)
+{
+  ptid_t ptid;
+
+  ptid = *ptidp;
+  if (PD_TID (ptid))
+    *ptidp = pid_to_ptid (PIDGET (ptid));
+}
+
+/* pthdb callback: for <i> from 0 to COUNT, set SYMBOLS[<i>].addr to the
+   address of SYMBOLS[<i>].name. */
+
+static int
+pdc_symbol_addrs (pthdb_user_t user, pthdb_symbol_t *symbols, int count)
+{
+  struct minimal_symbol *ms;
+  int i;
+  char *name;
+
+  DBG2(("pdc_symbol_addrs (user = %ld, symbols = 0x%x, count = %d)",
+	user, symbols, count));
+
+  for (i = 0; i < count; i++)
+    {
+      name = symbols[i].name;
+      DBG2(("  symbols[%d].name = \"%s\"", i, name));
+
+      if (!*name)
+	symbols[i].addr = 0;
+      else
+	{
+	  if (!(ms = lookup_minimal_symbol (name, NULL, NULL)))
+	    {
+	      DBG2((" returning PDC_FAILURE"));
+	      return PDC_FAILURE;
+	    }
+	  symbols[i].addr = SYMBOL_VALUE_ADDRESS (ms);
+	}
+      DBG2(("  symbols[%d].addr = 0x%llx", i, symbols[i].addr));
+    }
+  DBG2((" returning PDC_SUCCESS"));
+  return PDC_SUCCESS;
+}
+
+/* Read registers call back function should be able to read the context */
+/* information of a debuggee kernel thread from an active process or from */
+/* a core file. The information should be formatted in context64 form for */
+/* both 32-bit and 64-bit process. If successful return 0, else non-zero */
+/* is returned. */
+static int
+pdc_read_regs (pthdb_user_t user, 
+	       pthdb_tid_t tid,
+	       unsigned long long flags,
+	       pthdb_context_t *context)
+{
+  /* this function doesn't appear to be used, so we could probably just */
+  /* return 0 here.  HOWEVER, if it is not defined, the OS will complain */
+  /* and several thread debug functions will fail. In case this is needed, */
+  /* I have implemented what I think it should do, however this code is */
+  /* untested. */
+  uint64_t gprs64[32];
+  uint32_t gprs32[32];
+  double fprs[32];
+  struct ptxsprs sprs64;
+  struct ptsprs sprs32;
+  
+  DBG2(("pdc_read_regs tid=%d flags=%llx\n", (int)tid, flags));
+
+  /* General-purpose registers. */
+  if (flags & PTHDB_FLAG_GPRS)
+    {
+      if (arch64)
+	{
+	  if (!ptrace64aix (PTT_READ_GPRS, tid, (unsigned long) gprs64, 0, NULL))
+	    memset (gprs64, 0, sizeof (gprs64));
+	  memcpy (context->gpr, gprs64, sizeof(gprs64));
+	}
+      else
+	{
+	  if (!ptrace32 (PTT_READ_GPRS, tid, gprs32, 0, NULL))
+	    memset (gprs32, 0, sizeof (gprs32));
+	  memcpy (context->gpr, gprs32, sizeof(gprs32));
+	}
+    }
+
+  /* Floating-point registers. */
+  if (flags & PTHDB_FLAG_FPRS)
+    {
+      if (!ptrace32 (PTT_READ_FPRS, tid, (int *) fprs, 0, NULL))
+	memset (fprs, 0, sizeof (fprs));
+      	  memcpy (context->fpr, fprs, sizeof(fprs));
+    }
+
+  /* Special-purpose registers. */
+  if (flags & PTHDB_FLAG_SPRS)
+    {
+      if (arch64)
+	{
+	  if (!ptrace64aix (PTT_READ_SPRS, tid, (unsigned long) &sprs64, 0, NULL))
+	    memset (&sprs64, 0, sizeof (sprs64));
+      	  memcpy (&context->msr, &sprs64, sizeof(sprs64));
+	}
+      else
+	{
+	  if (!ptrace32 (PTT_READ_SPRS, tid, (int *) &sprs32, 0, NULL))
+	    memset (&sprs32, 0, sizeof (sprs32));
+      	  memcpy (&context->msr, &sprs32, sizeof(sprs32));
+	}
+    }  
+  return 0;
+}
+
+/* Write register function should be able to write requested context */
+/* information to specified debuggee's kernel thread id. If successful */
+/* return 0, else non-zero is returned. */
+static int
+pdc_write_regs (pthdb_user_t user,
+		pthdb_tid_t tid,
+		unsigned long long flags,
+		pthdb_context_t *context)
+{ 
+  /* this function doesn't appear to be used, so we could probably just */
+  /* return 0 here.  HOWEVER, if it is not defined, the OS will complain */
+  /* and several thread debug functions will fail. In case this is needed, */
+  /* I have implemented what I think it should do, however this code is */
+  /* untested. */
+
+  DBG2(("pdc_write_regs tid=%d flags=%llx\n", (int)tid, flags));
+
+  /* General-purpose registers. */
+  if (flags & PTHDB_FLAG_GPRS)
+    {
+      if (arch64)
+	ptrace64aix (PTT_WRITE_GPRS, tid, (unsigned long)context->gpr, 0, NULL);
+      else
+	ptrace32 (PTT_WRITE_GPRS, tid, (int *)context->gpr, 0, NULL);
+    }
+
+ /* Floating-point registers. */
+  if (flags & PTHDB_FLAG_FPRS)
+    {
+      ptrace32 (PTT_WRITE_FPRS, tid, (int *)context->fpr, 0, NULL);
+    }
+
+  /* Special-purpose registers. */
+  if (flags & PTHDB_FLAG_SPRS)
+    {
+      if (arch64)
+	{
+	  ptrace64aix (PTT_WRITE_SPRS, tid, (unsigned long) &context->msr, 0, NULL);
+	}
+      else
+	{
+	  ptrace32 (PTT_WRITE_SPRS, tid, (int *)&context->msr, 0, NULL);
+	}
+    }
+  return 0;
+}
+
+/* pthdb callback: read LEN bytes from process ADDR into BUF. */
+
+static int
+pdc_read_data (pthdb_user_t user, void *buf, pthdb_addr_t addr, size_t len)
+{
+  int status, ret;
+
+  DBG2(("pdc_read_data (user = %ld, buf = 0x%x, addr = 0x%llx, len = %d)",
+	user, buf, addr, len));
+
+  status = target_read_memory (addr, buf, len);
+  ret = status == 0 ? PDC_SUCCESS : PDC_FAILURE;
+
+  DBG2(("  status=%d, returning %s", status, pd_status2str (ret)));
+  return ret;
+}
+
+/* pthdb callback: write LEN bytes from BUF to process ADDR. */
+
+static int
+pdc_write_data (pthdb_user_t user, void *buf, pthdb_addr_t addr, size_t len)
+{
+  int status, ret;
+
+  DBG2(("pdc_write_data (user = %ld, buf = 0x%x, addr = 0x%llx, len = %d)",
+	user, buf, addr, len));
+
+  status = target_write_memory (addr, buf, len);
+  ret = status == 0 ? PDC_SUCCESS : PDC_FAILURE;
+
+  DBG2(("  status=%d, returning %s", status, pd_status2str (ret)));
+  return ret;
+}
+
+/* pthdb callback: allocate a LEN-byte buffer and store a pointer to it in
+   BUFP. */
+
+static int
+pdc_alloc (pthdb_user_t user, size_t len, void **bufp)
+{
+  DBG2(("pdc_alloc (user = %ld, len = %d, bufp = 0x%x)", user, len, bufp));
+  *bufp = xmalloc (len);
+  DBG2(("  malloc returned 0x%x", *bufp));
+  /* Note: xmalloc() can't return 0; therefore PDC_FAILURE will never be
+     returned.  */
+  return *bufp ? PDC_SUCCESS : PDC_FAILURE;
+}
+
+/* pthdb callback: reallocate BUF, which was allocated by the alloc or realloc
+   callback, so that it contains LEN bytes, and store a pointer to the result
+   in BUFP. */
+
+static int
+pdc_realloc (pthdb_user_t user, void *buf, size_t len, void **bufp)
+{
+  DBG2(("pdc_realloc (user = %ld, buf = 0x%x, len = %d, bufp = 0x%x)",
+	user, buf, len, bufp));
+  *bufp = realloc (buf, len);
+  DBG2(("  realloc returned 0x%x", *bufp));
+  return *bufp ? PDC_SUCCESS : PDC_FAILURE;
+}
+
+/* pthdb callback: free BUF, which was allocated by the alloc or realloc
+   callback. */
+
+static int
+pdc_dealloc (pthdb_user_t user, void *buf)
+{
+  DBG2(("pdc_free (user = %ld, buf = 0x%x)", user, buf));
+  xfree (buf);
+  return PDC_SUCCESS;
+}
+
+/* Return a printable representation of pthread STATE. */
+
+static char *
+state2str (pthdb_state_t state)
+{
+  switch (state)
+    {
+    case PST_IDLE:	return "idle";		/* being created */
+    case PST_RUN:	return "running";	/* running */
+    case PST_SLEEP:	return "sleeping";	/* awaiting an event */
+    case PST_READY:	return "ready";		/* runnable */
+    case PST_TERM:	return "finished";	/* awaiting a join/detach */
+    default:		return "unknown";
+    }
+}
+
+/* qsort() comparison function for sorting pd_thread structs by pthid. */
+
+static int
+pcmp (const void *p1v, const void *p2v)
+{
+  struct pd_thread *p1 = (struct pd_thread *) p1v;
+  struct pd_thread *p2 = (struct pd_thread *) p2v;
+  return p1->pthid < p2->pthid ? -1 : p1->pthid > p2->pthid;
+}
+
+/* iterate_over_threads() callback for counting GDB threads. */
+
+static int
+giter_count (struct thread_info *thread, void *countp)
+{
+  (*(int *) countp)++;
+  return 0;
+}
+
+/* iterate_over_threads() callback for accumulating GDB thread pids. */
+
+static int
+giter_accum (struct thread_info *thread, void *bufp)
+{
+  **(struct thread_info ***) bufp = thread;
+  (*(struct thread_info ***) bufp)++;
+  return 0;
+}
+
+/* ptid comparison function */
+static int
+ptid_cmp (ptid_t ptid1, ptid_t ptid2)
+{
+  int pid1, pid2;
+
+  if (ptid_get_pid (ptid1) < ptid_get_pid (ptid2))
+    return -1;
+  else if (ptid_get_pid (ptid1) > ptid_get_pid (ptid2))
+    return 1;
+  else if (ptid_get_tid (ptid1) < ptid_get_tid (ptid2))
+    return -1;
+  else if (ptid_get_tid (ptid1) > ptid_get_tid (ptid2))
+    return 1;
+  else if (ptid_get_lwp (ptid1) < ptid_get_lwp (ptid2))
+    return -1;
+  else if (ptid_get_lwp (ptid1) > ptid_get_lwp (ptid2))
+    return 1;
+  else
+    return 0;
+}
+
+/* qsort() comparison function for sorting thread_info structs by pid. */
+
+static int
+gcmp (const void *t1v, const void *t2v)
+{
+  struct thread_info *t1 = *(struct thread_info **) t1v;
+  struct thread_info *t2 = *(struct thread_info **) t2v;
+  return ptid_cmp (t1->ptid, t2->ptid);
+}
+
+/* Synchronize GDB's thread list with libpthdebug's.
+
+   There are some benefits of doing this every time the inferior stops:
+
+     - allows users to run thread-specific commands without needing to run
+       "info threads" first
+
+     - helps pthdb_tid_pthread() work properly (see "libpthdebug
+       peculiarities" at the top of this module)
+
+     - simplifies the demands placed on libpthdebug, which seems to have
+       difficulty with certain call patterns */
+
+static void
+sync_threadlists (void)
+{
+  int cmd, status, infpid;
+  int pcount, psize, pi, gcount, gi;
+  struct pd_thread *pbuf;
+  struct thread_info **gbuf, **g, *thread;
+  pthdb_pthread_t pdtid;
+  pthread_t pthid;
+  pthdb_tid_t tid;
+  ptid_t pptid, gptid;
+
+  /* Accumulate an array of libpthdebug threads sorted by pthread id. */
+
+  pcount = 0;
+  psize = 1;
+  pbuf = (struct pd_thread *) xmalloc (psize * sizeof *pbuf);
+
+  for (cmd = PTHDB_LIST_FIRST;; cmd = PTHDB_LIST_NEXT)
+    {
+      status = pthdb_pthread (pd_session, &pdtid, cmd);
+      if (status != PTHDB_SUCCESS || pdtid == PTHDB_INVALID_PTHREAD)
+	break;
+
+      status = pthdb_pthread_ptid (pd_session, pdtid, &pthid);
+      if (status != PTHDB_SUCCESS || pthid == PTHDB_INVALID_PTID)
+	continue;
+
+      if (pcount == psize)
+	{
+	  psize *= 2;
+	  pbuf = (struct pd_thread *) xrealloc (pbuf, psize * sizeof *pbuf);
+	}
+      pbuf[pcount].pdtid = pdtid;
+      pbuf[pcount].pthid = pthid;
+      pcount++;
+    }
+
+  for (pi = 0; pi < pcount; pi++)
+    {
+      status = pthdb_pthread_tid (pd_session, pbuf[pi].pdtid, &tid);
+      if (status != PTHDB_SUCCESS)
+	tid = PTHDB_INVALID_TID;
+      pbuf[pi].tid = tid;
+    }
+
+  qsort (pbuf, pcount, sizeof *pbuf, pcmp);
+
+  /* Accumulate an array of GDB threads sorted by pid. */
+
+  gcount = 0;
+  iterate_over_threads (giter_count, &gcount);
+  g = gbuf = (struct thread_info **) xmalloc (gcount * sizeof *gbuf);
+  iterate_over_threads (giter_accum, &g);
+  qsort (gbuf, gcount, sizeof *gbuf, gcmp);
+
+  /* Apply differences between the two arrays to GDB's thread list. */
+
+  infpid = PIDGET (inferior_ptid);
+  for (pi = gi = 0; pi < pcount || gi < gcount;)
+    {
+      pptid = BUILD_THREAD (pbuf[pi].pthid, infpid);
+      gptid = gbuf[gi]->ptid;
+      pdtid = pbuf[pi].pdtid;
+      tid = pbuf[pi].tid;
+
+      if (pi == pcount)
+	goto del;
+      if (gi == gcount)
+	goto add;
+
+      if (ptid_equal (pptid, gptid))
+	{
+	  gbuf[gi]->private->pdtid = pdtid;
+	  gbuf[gi]->private->tid = tid;
+	  pi++;
+	  gi++;
+	}
+      else if (ptid_cmp (pptid, gptid) > 0)
+	{
+	del:
+	  delete_thread (gptid);
+	  gi++;
+	}
+      else
+	{
+	add:
+	  thread = add_thread (pptid);
+	  thread->private = xmalloc (sizeof (struct private_thread_info));
+	  thread->private->pdtid = pdtid;
+	  thread->private->tid = tid;
+	  pi++;
+	}
+
+    }
+
+  xfree (pbuf);
+  xfree (gbuf);
+}
+
+/* iterate_over_threads() callback for locating a thread whose kernel thread
+   just received a trap signal. */
+
+static int
+iter_trap (struct thread_info *thread, void *unused)
+{
+  struct thrdsinfo64 thrinf;
+  pthdb_tid_t tid;
+
+  /* getthrds(3) isn't prototyped in any AIX 4.3.3 #include file. */
+  extern int getthrds (pid_t, struct thrdsinfo64 *, int, pthdb_tid_t *, int);
+
+  tid = thread->private->tid;
+  if (tid == PTHDB_INVALID_TID)
+    return 0;
+
+  if (getthrds (PIDGET (inferior_ptid), &thrinf, sizeof (thrinf), &tid, 1) != 1)
+    return 0;
+
+  return thrinf.ti_cursig == SIGTRAP;
+}
+
+/* Synchronize libpthdebug's state with the inferior and with GDB, generate a
+   composite process/thread <pid> for the current thread, set inferior_ptid to
+   <pid> if SET_INFPID, and return <pid>. */
+
+static ptid_t
+pd_update (int set_infpid)
+{
+  int status;
+  ptid_t ptid;
+  struct thread_info *thread;
+
+  if (!pd_active)
+    return inferior_ptid;
+
+  status = pthdb_session_update (pd_session);
+  if (status != PTHDB_SUCCESS)
+    return inferior_ptid;
+
+  sync_threadlists ();
+
+  /* Define "current thread" as one that just received a trap signal. */
+
+  thread = iterate_over_threads (iter_trap, NULL);
+  if (!thread)
+    ptid = inferior_ptid;
+  else
+    {
+      ptid = thread->ptid;
+      if (set_infpid)
+	inferior_ptid = ptid;
+    }
+  return ptid;
+}
+
+/* Try to start debugging threads in the current process.  If successful and
+   SET_INFPID, set inferior_ptid to reflect the current thread. */
+
+static ptid_t
+pd_activate (int set_infpid)
+{
+  int status;
+		
+  status = pthdb_session_init (PD_USER, arch64 ? PEM_64BIT : PEM_32BIT,
+			       PTHDB_FLAG_REGS, &pd_callbacks, &pd_session);
+  if (status != PTHDB_SUCCESS)
+    {
+      return inferior_ptid;
+    }
+  pd_active = 1;
+  return pd_update (set_infpid);
+}
+
+/* Undo the effects of pd_activate(). */
+
+static void
+pd_deactivate (void)
+{
+  if (!pd_active)
+    return;
+  pthdb_session_destroy (pd_session);
+  
+  pid_to_prc (&inferior_ptid);
+  pd_active = 0;
+}
+
+/* An object file has just been loaded.  Check whether the current application
+   is pthreaded, and if so, prepare for thread debugging. */
+
+static void
+pd_enable (void)
+{
+  int status;
+  char *stub_name;
+  struct minimal_symbol *ms;
+
+  /* Don't initialize twice. */
+  if (pd_able)
+    return;
+
+  /* Check application word size. */
+  arch64 = REGISTER_RAW_SIZE (0) == 8;
+
+  /* Check whether the application is pthreaded. */
+  stub_name = NULL;
+  status = pthdb_session_pthreaded (PD_USER, PTHDB_FLAG_REGS, &pd_callbacks,
+				    &stub_name);
+  if ((status != PTHDB_SUCCESS && status != PTHDB_NOT_PTHREADED) || !stub_name)
+    return;
+
+  /* Set a breakpoint on the returned stub function. */
+  if (!(ms = lookup_minimal_symbol (stub_name, NULL, NULL)))
+    return;
+  pd_brk_addr = SYMBOL_VALUE_ADDRESS (ms);
+  if (!create_thread_event_breakpoint (pd_brk_addr))
+    return;
+
+  /* Prepare for thread debugging. */
+  base_ops = current_target;
+  push_target (&ops);
+  pd_able = 1;
+
+  /* If we're debugging a core file or an attached inferior, the pthread
+     library may already have been initialized, so try to activate thread
+     debugging. */
+  pd_activate (1);
+}
+
+/* Undo the effects of pd_enable(). */
+
+static void
+pd_disable (void)
+{
+  if (!pd_able)
+    return;
+  if (pd_active)
+    pd_deactivate ();
+  pd_able = 0;
+  unpush_target (&ops);
+}
+
+/* target_new_objfile_hook callback.
+
+   If OBJFILE is non-null, check whether a threaded application is being
+   debugged, and if so, prepare for thread debugging.
+
+   If OBJFILE is null, stop debugging threads. */
+
+static void
+new_objfile (struct objfile *objfile)
+{
+  if (objfile)
+    pd_enable ();
+  else
+    pd_disable ();
+
+  if (target_new_objfile_chain)
+    target_new_objfile_chain (objfile);
+}
+
+/* Attach to process specified by ARGS. */
+
+static void
+ops_attach (char *args, int from_tty)
+{
+  base_ops.to_attach (args, from_tty);
+  pd_activate (1);
+}
+
+/* Detach from the process attached to by ops_attach(). */
+
+static void
+ops_detach (char *args, int from_tty)
+{
+  pd_deactivate ();
+  base_ops.to_detach (args, from_tty);
+}
+
+/* Tell the inferior process to continue running thread PID if != -1
+   and all threads otherwise. */
+
+static void
+ops_resume (ptid_t ptid, int step, enum target_signal sig)
+{
+  struct thread_info *thread;
+  pthdb_tid_t tid[2];
+
+  if (!PD_TID (ptid))
+    CALL_BASE (base_ops.to_resume (ptid, step, sig));
+  else
+    {
+      thread = find_thread_pid (ptid);
+      if (!thread)
+	error ("aix-thread resume: unknown pthread %ld", TIDGET (ptid));
+
+      tid[0] = thread->private->tid;
+      if (tid[0] == PTHDB_INVALID_TID)
+	error ("aix-thread resume: no tid for pthread %ld", TIDGET (ptid));
+      tid[1] = 0;
+
+      if (arch64)
+	ptrace64aix (PTT_CONTINUE, tid[0], 1, target_signal_to_host (sig), (int *)tid);
+      else
+	ptrace32 (PTT_CONTINUE, tid[0], (int *) 1,
+		  target_signal_to_host (sig), (int *)tid);
+    }
+}
+
+/* Wait for thread/process ID if != -1 or for any thread otherwise.  If an
+   error occurs, return -1, else return the pid of the stopped thread. */
+
+static ptid_t
+ops_wait (ptid_t ptid, struct target_waitstatus *status)
+{
+  pid_to_prc (&ptid);
+  CALL_BASE (ptid = base_ops.to_wait (ptid, status));
+  if (PIDGET (ptid) == -1)
+    return pid_to_ptid (-1);
+
+  /* Check whether libpthdebug might be ready to be initialized. */
+  if (!pd_active && status->kind == TARGET_WAITKIND_STOPPED &&
+      status->value.sig == TARGET_SIGNAL_TRAP &&
+      read_pc_pid (ptid) - DECR_PC_AFTER_BREAK == pd_brk_addr)
+    return pd_activate (0);
+
+  return pd_update (0);
+}
+
+/* Record that the 64-bit general-purpose registers contain VALS. */
+
+static void
+supply_gprs64 (uint64_t *vals)
+{
+  int regno;
+
+  for (regno = 0; regno < 32; regno++)
+    supply_register (regno, (char *) (vals + regno));
+}
+
+/* Record that 32-bit register REGNO contains VAL. */
+
+static void
+supply_reg32 (int regno, uint32_t val)
+{
+  supply_register (regno, (char *) &val);
+}
+
+/* Record that the floating-point registers contain VALS. */
+
+static void
+supply_fprs (double *vals)
+{
+  int regno;
+
+  for (regno = 0; regno < 32; regno++)
+    supply_register (regno + FP0_REGNUM, (char *) (vals + regno));
+}
+
+/* Record that the special registers contain the specified 64-bit and 32-bit
+   values. */
+
+static void
+supply_sprs64 (uint64_t iar, uint64_t msr, uint32_t cr,
+	       uint64_t lr, uint64_t ctr, uint32_t xer)
+{
+  int regno = FIRST_UISA_SP_REGNUM;
+  supply_register (regno, (char *) &iar);
+  supply_register (regno + 1, (char *) &msr);
+  supply_register (regno + 2, (char *) &cr);
+  supply_register (regno + 3, (char *) &lr);
+  supply_register (regno + 4, (char *) &ctr);
+  supply_register (regno + 5, (char *) &xer);
+}
+
+/* Record that the special registers contain the specified 32-bit values. */
+
+static void
+supply_sprs32 (uint32_t iar, uint32_t msr, uint32_t cr,
+	       uint32_t lr, uint32_t ctr, uint32_t xer)
+{
+  int regno = FIRST_UISA_SP_REGNUM;
+  supply_register (regno, (char *) &iar);
+  supply_register (regno + 1, (char *) &msr);
+  supply_register (regno + 2, (char *) &cr);
+  supply_register (regno + 3, (char *) &lr);
+  supply_register (regno + 4, (char *) &ctr);
+  supply_register (regno + 5, (char *) &xer);
+}
+
+/* Fetch all registers from pthread PDTID, which doesn't have a kernel
+   thread.
+
+   There's no way to query a single register from a non-kernel pthread,
+   so there's no need for a single-register version of this function. */
+
+static void
+fetch_regs_lib (pthdb_pthread_t pdtid)
+{
+  int status, i;
+  pthdb_context_t ctx;
+
+  DBG2 (("fetch_regs_lib %lx\n", (long)pdtid));
+  status = pthdb_pthread_context (pd_session, pdtid, &ctx);
+  if (status != PTHDB_SUCCESS)
+    PD_ERROR ("fetch_registers: pthdb_pthread_context", status);
+
+  /* General-purpose registers. */
+
+  if (arch64)
+    supply_gprs64 (ctx.gpr);
+  else
+    for (i = 0; i < 32; i++)
+      supply_reg32 (i, ctx.gpr[i]);
+
+  /* Floating-point registers. */
+
+  supply_fprs (ctx.fpr);
+
+  /* Special registers. */
+
+  if (arch64)
+    supply_sprs64 (ctx.iar, ctx.msr, ctx.cr, ctx.lr, ctx.ctr, ctx.xer);
+  else
+    supply_sprs32 (ctx.iar, ctx.msr, ctx.cr, ctx.lr, ctx.ctr, ctx.xer);
+}
+
+/* Fetch register REGNO if != -1 or all registers otherwise from kernel thread
+   TID.
+
+   AIX provides a way to query all of a kernel thread's GPRs, FPRs, or SPRs,
+   but there's no way to query individual registers within those groups.
+   Therefore, if REGNO != -1, this function fetches an entire group.
+
+   Unfortunately, kernel thread register queries often fail with EPERM,
+   indicating that the thread is in kernel space.  This breaks backtraces of
+   threads other than the current one.  To make that breakage obvious without
+   throwing an error to top level (which is bad e.g. during "info threads"
+   output), zero registers that can't be retrieved. */
+
+static void
+fetch_regs_kern (int regno, pthdb_tid_t tid)
+{
+  uint64_t gprs64[32];
+  uint32_t gprs32[32];
+  double fprs[32];
+  struct ptxsprs sprs64;
+  struct ptsprs sprs32;
+  int i;
+
+  DBG2 (("fetch_regs_kern tid=%lx regno=%d arch64=%d\n", (long)tid, regno, arch64));
+
+  /* General-purpose registers. */
+  if (regno == -1 || regno < FP0_REGNUM)
+    {
+      if (arch64)
+	{
+	  if (!ptrace64aix (PTT_READ_GPRS, tid, (unsigned long) gprs64, 0, NULL))
+	    memset (gprs64, 0, sizeof (gprs64));
+	  supply_gprs64 (gprs64);
+	}
+      else
+	{
+	  if (!ptrace32 (PTT_READ_GPRS, tid, gprs32, 0, NULL))
+	    memset (gprs32, 0, sizeof (gprs32));
+	  for (i = 0; i < 32; i++)
+	    supply_reg32 (i, gprs32[i]);
+	}
+    }
+
+  /* Floating-point registers. */
+
+  if (regno == -1 || (regno >= FP0_REGNUM && regno <= FPLAST_REGNUM))
+    {
+      if (!ptrace32 (PTT_READ_FPRS, tid, (int *) fprs, 0, NULL))
+	memset (fprs, 0, sizeof (fprs));
+      supply_fprs (fprs);
+    }
+
+  /* Special-purpose registers. */
+
+  if (regno == -1 || (regno > FPLAST_REGNUM && regno <= LAST_UISA_SP_REGNUM))
+    {
+      if (arch64)
+	{
+	  if (!ptrace64aix (PTT_READ_SPRS, tid, (unsigned long) &sprs64, 0, NULL))
+	    memset (&sprs64, 0, sizeof (sprs64));
+	  supply_sprs64 (sprs64.pt_iar, sprs64.pt_msr, sprs64.pt_cr,
+			 sprs64.pt_lr, sprs64.pt_ctr, sprs64.pt_xer);
+	}
+      else
+	{
+	  if (!ptrace32 (PTT_READ_SPRS, tid, (int *) &sprs32, 0, NULL))
+	    memset (&sprs32, 0, sizeof (sprs32));
+	  supply_sprs32 (sprs32.pt_iar, sprs32.pt_msr, sprs32.pt_cr,
+			 sprs32.pt_lr, sprs32.pt_ctr, sprs32.pt_xer);
+
+	  if (REGISTER_RAW_SIZE (LAST_UISA_SP_REGNUM))
+	    supply_register (LAST_UISA_SP_REGNUM, (char *) &sprs32.pt_mq);
+	}
+    }
+}
+
+/* Fetch register REGNO if != -1 or all registers otherwise in the
+   thread/process specified by inferior_ptid. */
+
+static void
+ops_fetch_registers (int regno)
+{
+  struct thread_info *thread;
+  pthdb_tid_t tid;
+
+  if (!PD_TID (inferior_ptid))
+    base_ops.to_fetch_registers (regno);
+  else
+    {
+      thread = find_thread_pid (inferior_ptid);
+      tid = thread->private->tid;
+
+      if (tid == PTHDB_INVALID_TID)
+	fetch_regs_lib (thread->private->pdtid);
+      else
+	fetch_regs_kern (regno, tid);
+    }
+}
+
+/* Store the special registers into the specified 64-bit and 32-bit
+   locations. */
+
+static void
+fill_sprs64 (uint64_t *iar, uint64_t *msr, uint32_t *cr,
+	     uint64_t *lr, uint64_t *ctr, uint32_t *xer)
+{
+  int regno = FIRST_UISA_SP_REGNUM;
+  *iar = read_register (regno);
+  *msr = read_register (regno + 1);
+  *cr = read_register (regno + 2);
+  *lr = read_register (regno + 3);
+  *ctr = read_register (regno + 4);
+  *xer = read_register (regno + 5);
+}
+
+/* Store all registers into pthread PDTID, which doesn't have a kernel
+   thread.
+
+   It's possible to store a single register into a non-kernel pthread, but I
+   doubt it's worth the effort. */
+
+static void
+store_regs_lib (pthdb_pthread_t pdtid)
+{
+  int status, i;
+  pthdb_context_t ctx;
+
+  DBG2 (("store_regs_lib %lx\n", (long)pdtid));
+
+  /* Retrieve the thread's current context for its non-register values. */
+  status = pthdb_pthread_context (pd_session, pdtid, &ctx);
+  if (status != PTHDB_SUCCESS)
+    PD_ERROR ("store_registers: pthdb_pthread_context", status);
+
+  /* General-purpose registers. */
+
+  for (i = 0; i < 32; i++)
+    ctx.gpr[i] = read_register (i);
+
+  /* Floating-point registers. */
+
+  for (i = 0; i < 32; i++)
+    ctx.fpr[i] = *(double *) &registers[REGISTER_BYTE (FP0_REGNUM + i)];
+
+  /* Special registers. */
+
+  fill_sprs64 (&ctx.iar, &ctx.msr, &ctx.cr, &ctx.lr, &ctx.ctr, &ctx.xer);
+
+  status = pthdb_pthread_setcontext (pd_session, pdtid, &ctx);
+  if (status != PTHDB_SUCCESS)
+    PD_ERROR ("store_registers: pthdb_pthread_setcontext", status);
+}
+
+/* Store register REGNO if != -1 or all registers otherwise into kernel
+   thread TID.
+
+   AIX provides a way to set all of a kernel thread's GPRs, FPRs, or SPRs, but
+   there's no way to set individual registers within those groups.  Therefore,
+   if REGNO != -1, this function stores an entire group. */
+
+static void
+store_regs_kern (int regno, pthdb_tid_t tid)
+{
+  struct ptxsprs sprs64;
+  struct ptsprs sprs32;
+  char *regp;
+
+  DBG2 (("store_regs_kern tid=%lx regno=%d\n", (long)tid, regno));
+
+  /* General-purpose registers. */
+  if (regno == -1 || regno < FP0_REGNUM)
+    {
+      regp = &registers[REGISTER_BYTE (0)];
+      if (arch64)
+	ptrace64aix (PTT_WRITE_GPRS, tid, (unsigned long) regp, 0, NULL);
+      else
+	ptrace32 (PTT_WRITE_GPRS, tid, (int *) regp, 0, NULL);
+    }
+
+  /* Floating-point registers. */
+
+  if (regno == -1 || (regno >= FP0_REGNUM && regno <= FPLAST_REGNUM))
+    {
+      regp = &registers[REGISTER_BYTE (FP0_REGNUM)];
+      ptrace32 (PTT_WRITE_FPRS, tid, (int *) regp, 0, NULL);
+    }
+
+  /* Special-purpose registers. */
+
+  if (regno == -1 || (regno > FPLAST_REGNUM && regno <= LAST_UISA_SP_REGNUM))
+    {
+      if (arch64)
+	{
+	  ptrace64aix (PTT_READ_SPRS, tid, (unsigned long) &sprs64, 0, NULL);
+	  fill_sprs64 (&sprs64.pt_iar, &sprs64.pt_msr, &sprs64.pt_cr,
+		       &sprs64.pt_lr, &sprs64.pt_ctr, &sprs64.pt_xer);
+	  ptrace64aix (PTT_WRITE_SPRS, tid, (unsigned long) &sprs64, 0, NULL);
+	}
+      else
+	{
+	  ptrace32 (PTT_READ_SPRS, tid, (int *) &sprs32, 0, NULL);
+
+	  regno = FIRST_UISA_SP_REGNUM;
+	  sprs32.pt_iar = read_register (regno);
+	  sprs32.pt_msr = read_register (regno + 1);
+	  sprs32.pt_cr = read_register (regno + 2);
+	  sprs32.pt_lr = read_register (regno + 3);
+	  sprs32.pt_ctr = read_register (regno + 4);
+	  sprs32.pt_xer = read_register (regno + 5);
+
+	  if (REGISTER_RAW_SIZE (LAST_UISA_SP_REGNUM))
+	    sprs32.pt_mq = read_register (LAST_UISA_SP_REGNUM);
+
+	  ptrace32 (PTT_WRITE_SPRS, tid, (int *) &sprs32, 0, NULL);
+	}
+    }
+}
+
+/* Store gdb's current view of the register set into the thread/process
+   specified by inferior_ptid. */
+
+static void
+ops_store_registers (int regno)
+{
+  struct thread_info *thread;
+  pthdb_tid_t tid;
+
+  if (!PD_TID (inferior_ptid))
+    base_ops.to_store_registers (regno);
+  else
+    {
+      thread = find_thread_pid (inferior_ptid);
+      tid = thread->private->tid;
+
+      if (tid == PTHDB_INVALID_TID)
+	store_regs_lib (thread->private->pdtid);
+      else
+	store_regs_kern (regno, tid);
+    }
+}
+
+/* Prepare to modify the registers array. */
+
+static void
+ops_prepare_to_store (void)
+{
+  if (!PD_TID (inferior_ptid))
+    base_ops.to_prepare_to_store ();
+  else
+    read_register_bytes (0, NULL, REGISTER_BYTES);
+}
+
+/* Transfer LEN bytes of memory from GDB address MYADDR to target address
+   MEMADDR if WRITE and vice versa otherwise. */
+
+static int
+ops_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
+                 struct mem_attrib *attrib,
+		 struct target_ops *target)
+{
+  int n;
+
+  CALL_BASE (n = base_ops.to_xfer_memory (memaddr, myaddr, len, write,
+					  attrib, &base_ops));
+  return n;
+}
+
+/* Kill and forget about the inferior process. */
+
+static void
+ops_kill (void)
+{
+  CALL_BASE (base_ops.to_kill ());
+}
+
+/* Clean up after the inferior exits. */
+
+static void
+ops_mourn_inferior (void)
+{
+  pd_deactivate ();
+  base_ops.to_mourn_inferior ();
+}
+
+/* Return whether thread PID is still valid. */
+
+static int
+ops_thread_alive (ptid_t ptid)
+{
+  if (!PD_TID (ptid))
+    return base_ops.to_thread_alive (ptid);
+
+  /* We update the thread list every time the child stops, so all valid
+     threads should be in the thread list. */
+  return in_thread_list (ptid);
+}
+
+/* Return a printable representation of composite PID for use in "info
+   threads" output. */
+
+static char *
+ops_pid_to_str (ptid_t ptid)
+{
+  static char *ret = NULL;
+
+  if (!PD_TID (ptid))
+    return base_ops.to_pid_to_str (ptid);
+
+  /* Free previous return value; a new one will be allocated by
+     xasprintf().  */
+  xfree (ret);
+
+  xasprintf (&ret, "Thread %ld", ptid_get_tid (ptid));
+  return ret;
+}
+
+/* Return a printable representation of extra information about THREAD, for
+   use in "info threads" output. */
+
+static char *
+ops_extra_thread_info (struct thread_info *thread)
+{
+  struct ui_file *buf;
+  int status;
+  pthdb_pthread_t pdtid;
+  pthdb_tid_t tid;
+  pthdb_state_t state;
+  pthdb_suspendstate_t suspendstate;
+  pthdb_detachstate_t detachstate;
+  int cancelpend;
+  long length;
+  static char *ret = NULL;
+
+  if (!PD_TID (thread->ptid))
+    return NULL;
+
+  buf = mem_fileopen ();
+
+  pdtid = thread->private->pdtid;
+  tid = thread->private->tid;
+
+  if (tid != PTHDB_INVALID_TID)
+    fprintf_unfiltered (buf, "tid %d", tid);
+
+  status = pthdb_pthread_state (pd_session, pdtid, &state);
+  if (status != PTHDB_SUCCESS)
+    state = PST_NOTSUP;
+  fprintf_unfiltered (buf, ", %s", state2str (state));
+
+  status = pthdb_pthread_suspendstate (pd_session, pdtid, &suspendstate);
+  if (status == PTHDB_SUCCESS && suspendstate == PSS_SUSPENDED)
+    fprintf_unfiltered (buf, ", suspended");
+
+  status = pthdb_pthread_detachstate (pd_session, pdtid, &detachstate);
+  if (status == PTHDB_SUCCESS && detachstate == PDS_DETACHED)
+    fprintf_unfiltered (buf, ", detached");
+
+  pthdb_pthread_cancelpend (pd_session, pdtid, &cancelpend);
+  if (status == PTHDB_SUCCESS && cancelpend)
+    fprintf_unfiltered (buf, ", cancel pending");
+
+  ui_file_write (buf, "", 1);
+
+  xfree (ret);			/* Free old buffer.  */
+
+  ret = ui_file_xstrdup (buf, &length);
+  ui_file_delete (buf);
+
+  return ret;
+}
+
+/* Initialize target ops. */
+
+static void
+init_ops (void)
+{
+  ops.to_shortname          = "aix-threads";
+  ops.to_longname           = "AIX pthread support";
+  ops.to_doc                = "AIX pthread support";
+
+  ops.to_attach             = ops_attach;
+  ops.to_detach             = ops_detach;
+  ops.to_resume             = ops_resume;
+  ops.to_wait               = ops_wait;
+  ops.to_fetch_registers    = ops_fetch_registers;
+  ops.to_store_registers    = ops_store_registers;
+  ops.to_prepare_to_store   = ops_prepare_to_store;
+  ops.to_xfer_memory        = ops_xfer_memory;
+  /* No need for ops.to_create_inferior, because we activate thread debugging
+     when the inferior reaches pd_brk_addr. */
+  ops.to_kill               = ops_kill;
+  ops.to_mourn_inferior     = ops_mourn_inferior;
+  ops.to_thread_alive       = ops_thread_alive;
+  ops.to_pid_to_str         = ops_pid_to_str;
+  ops.to_extra_thread_info  = ops_extra_thread_info;
+  ops.to_stratum            = thread_stratum;
+  ops.to_magic              = OPS_MAGIC;
+}
+
+/* Module startup initialization function, automagically called by
+   init.c. */
+
+void
+_initialize_aix_thread (void)
+{
+  init_ops ();
+  add_target (&ops);
+
+  /* Notice when object files get loaded and unloaded. */
+  target_new_objfile_chain = target_new_objfile_hook;
+  target_new_objfile_hook = new_objfile;
+}
Index: configure.host
===================================================================
RCS file: /cvs/src/src/gdb/configure.host,v
retrieving revision 1.39
diff -u -p -r1.39 configure.host
--- configure.host	31 May 2002 00:59:13 -0000	1.39
+++ configure.host	12 Jul 2002 19:05:00 -0000
@@ -129,7 +129,10 @@ none-*-*)		gdb_host=none ;;
 
 ns32k-*-netbsd*)	gdb_host=nbsdaout ;;
 
-powerpc-*-aix*)		gdb_host=aix ;;
+powerpc-*-aix3*)	gdb_host=aix ;;
+powerpc-*-aix4.[0-2]*)	gdb_host=aix ;;
+powerpc-*-aix4.3.[0-1]*)	gdb_host=aix ;;
+powerpc-*-aix*)		gdb_host=aix432 ;;
 powerpc-*-linux*)	gdb_host=linux ;;
 powerpc-*-netbsd*)	gdb_host=nbsd ;;
 
Index: config/powerpc/aix432.mh
===================================================================
RCS file: config/powerpc/aix432.mh
diff -N config/powerpc/aix432.mh
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ config/powerpc/aix432.mh	12 Jul 2002 19:05:00 -0000
@@ -0,0 +1,19 @@
+# Host: IBM PowerPC running AIX 4.3.2+
+
+XM_FILE= xm-aix.h
+
+NAT_FILE= nm-aix.h
+NATDEPFILES= aix-thread.o fork-child.o infptrace.o inftarg.o corelow.o \
+	     rs6000-nat.o xcoffread.o xcoffsolib.o
+
+# When compiled with cc, for debugging, this argument should be passed.
+# We have no idea who our current compiler is though, so we skip it.
+# MH_CFLAGS = -bnodelcsect
+
+# gdb is too big for all of its external symbols to fit in a small TOC
+# It looks like the GNU linker doesn't understand the -bbigtoc switch.
+# This switch may be needed for some vendor compilers.
+# MH_LDFLAGS = -Wl,-bbigtoc
+
+# pthread debugging support
+NAT_CLIBS = -lpthdebug

Re: [PATCH RFC] AIX thread support

[Andrew Cagney]

> The patch below implements thread support for AIX.  Nick Duffek
> deserves the lion's share of the credit for this work.  Martin Hunt,
> Louis Hamilton, and I also worked on this code.  Martin and Louis
> fixed some bugs and I adapted the code to build and work with the
> current sources.
> 
> I'll wait several days for comments / objections before committing it.
> 
> Kevin
> 
> 	From Nicholas Duffek (with minor changes by Martin Hunt, 
> 	Louis Hamilton, and Kevin Buettner):
> 	* aix-thread.c: New file.
> 	* Makefile.in (ALLDEPFILES): Add aix-thread.c.
> 	(aix-thread.o): New rule.
> 	* configure.host (gdb_host): Set to aix432 on AIX 4.3.2+.
> 	* config/powerpc/aix432.mh: New file.
> 

Kevin,

A quick glance suggests a review is needed.   For instance, from a 
coding (not thread -> MichaelS) viewpoint ``#define DEBUG 0'' should be 
handled at run-time and should be written to ``gdb_stdlog''.  If 
anything, perhaphs like for ada, this file could be initially commited, 
but not actually included/enabled.  That should at least make the review 
process easier.

Andrew

Re: [PATCH RFC] AIX thread support

[Kevin Buettner]

On Jul 12,  6:59pm, Andrew Cagney wrote:

> > 	From Nicholas Duffek (with minor changes by Martin Hunt, 
> > 	Louis Hamilton, and Kevin Buettner):
> > 	* aix-thread.c: New file.
> > 	* Makefile.in (ALLDEPFILES): Add aix-thread.c.
> > 	(aix-thread.o): New rule.
> > 	* configure.host (gdb_host): Set to aix432 on AIX 4.3.2+.
> > 	* config/powerpc/aix432.mh: New file.
> 
[...]
> A quick glance suggests a review is needed.   For instance, from a 
> coding (not thread -> MichaelS) viewpoint ``#define DEBUG 0'' should be 
> handled at run-time and should be written to ``gdb_stdlog''.  If 
> anything, perhaphs like for ada, this file could be initially commited, 
> but not actually included/enabled.  That should at least make the review 
> process easier.

As suggested, I've commited aix-thread.c to make the review process
easier.

Keep in mind that aix-thread.c will only be used for native AIX
builds.  As such, I think the criteria for including/enabling this
code should be much lower than that for core code or even target
specific code.

I do agree that there are a number of things in this file which should
be cleaned up over time.  However, for the initial review, I suggest
that we focus on issues which might make overall GDB maintenance or
future GDB development more difficult.  Only issues which meet these
criteria should prevent aix-thread.c from being accepted.

I certainly have no objection, however, to reviewers identifying other
cleanups that should occur over time.  I think your comment regarding
``#define DEBUG 0'' is a good example of this.

Kevin

Re: [PATCH RFC] AIX thread support

[Andrew Cagney]

> [...]
> 
>> A quick glance suggests a review is needed.   For instance, from a 
>> coding (not thread -> MichaelS) viewpoint ``#define DEBUG 0'' should be 
>> handled at run-time and should be written to ``gdb_stdlog''.  If 
>> anything, perhaphs like for ada, this file could be initially commited, 
>> but not actually included/enabled.  That should at least make the review 
>> process easier.
> 
> 
> As suggested, I've commited aix-thread.c to make the review process
> easier.
> 
> Keep in mind that aix-thread.c will only be used for native AIX
> builds.  As such, I think the criteria for including/enabling this
> code should be much lower than that for core code or even target
> specific code.

No.

Past history teaches us that once code is in and enabled it is very 
unlikely to be cleaned up or fixed.  Instead the problematic aspects 
tend to be copied leading to a gradual spread.

#define DEBUG is, itself, an example of this problem.  The idea was 
likely (and unfortunatly) picked up from one of the other older modules 
that still uses that and similar techniques.

Andrew