X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Flinux-thread-db.c;h=83632d060c543e147dcba236335a02aa633e84b6;hb=ebd3bcc1327e6a7de6daf6536134cb20be9c2cfd;hp=d91a894166d5cbc6bc84840d133e34c99e4f414b;hpb=3f64f7b1c773929215cd1284c891f371e4fc625f;p=deliverable%2Fbinutils-gdb.git

diff --git a/gdb/linux-thread-db.c b/gdb/linux-thread-db.c
index d91a894166..83632d060c 100644
--- a/gdb/linux-thread-db.c
+++ b/gdb/linux-thread-db.c
@@ -1,13 +1,13 @@
 /* libthread_db assisted debugging support, generic parts.
 
-   Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006
+   Copyright (C) 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2008
    Free Software Foundation, Inc.
 
    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
+   the Free Software Foundation; either version 3 of the License, or
    (at your option) any later version.
 
    This program is distributed in the hope that it will be useful,
@@ -16,9 +16,7 @@
    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., 51 Franklin Street, Fifth Floor,
-   Boston, MA 02110-1301, USA.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
 
@@ -37,8 +35,11 @@
 #include "regcache.h"
 #include "solib-svr4.h"
 #include "gdbcore.h"
+#include "observer.h"
 #include "linux-nat.h"
 
+#include <signal.h>
+
 #ifdef HAVE_GNU_LIBC_VERSION_H
 #include <gnu/libc-version.h>
 #endif
@@ -47,23 +48,41 @@
 #define LIBTHREAD_DB_SO "libthread_db.so.1"
 #endif
 
+/* GNU/Linux libthread_db support.
+
+   libthread_db is a library, provided along with libpthread.so, which
+   exposes the internals of the thread library to a debugger.  It
+   allows GDB to find existing threads, new threads as they are
+   created, thread IDs (usually, the result of pthread_self), and
+   thread-local variables.
+
+   The libthread_db interface originates on Solaris, where it is
+   both more powerful and more complicated.  This implementation
+   only works for LinuxThreads and NPTL, the two glibc threading
+   libraries.  It assumes that each thread is permanently assigned
+   to a single light-weight process (LWP).
+
+   libthread_db-specific information is stored in the "private" field
+   of struct thread_info.  When the field is NULL we do not yet have
+   information about the new thread; this could be temporary (created,
+   but the thread library's data structures do not reflect it yet)
+   or permanent (created using clone instead of pthread_create).
+
+   Process IDs managed by linux-thread-db.c match those used by
+   linux-nat.c: a common PID for all processes, an LWP ID for each
+   thread, and no TID.  We save the TID in private.  Keeping it out
+   of the ptid_t prevents thread IDs changing when libpthread is
+   loaded or unloaded.  */
+
 /* If we're running on GNU/Linux, we must explicitly attach to any new
    threads.  */
 
-/* FIXME: There is certainly some room for improvements:
-   - Cache LWP ids.
-   - Bypass libthread_db when fetching or storing registers for
-   threads bound to a LWP.  */
-
 /* This module's target vector.  */
 static struct target_ops thread_db_ops;
 
 /* The target vector that we call for things this module can't handle.  */
 static struct target_ops *target_beneath;
 
-/* Pointer to the next function on the objfile event chain.  */
-static void (*target_new_objfile_chain) (struct objfile * objfile);
-
 /* Non-zero if we're using this module's target vector.  */
 static int using_thread_db;
 
@@ -125,20 +144,8 @@ static CORE_ADDR td_death_bp_addr;
 /* Prototypes for local functions.  */
 static void thread_db_find_new_threads (void);
 static void attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
-			   const td_thrinfo_t *ti_p, int verbose);
-static void detach_thread (ptid_t ptid, int verbose);
-
-
-/* Building process ids.  */
-
-#define GET_PID(ptid)		ptid_get_pid (ptid)
-#define GET_LWP(ptid)		ptid_get_lwp (ptid)
-#define GET_THREAD(ptid)	ptid_get_tid (ptid)
-
-#define is_lwp(ptid)		(GET_LWP (ptid) != 0)
-#define is_thread(ptid)		(GET_THREAD (ptid) != 0)
-
-#define BUILD_LWP(lwp, pid)	ptid_build (pid, lwp, 0)
+			   const td_thrinfo_t *ti_p);
+static void detach_thread (ptid_t ptid);
 
 
 /* Use "struct private_thread_info" to cache thread state.  This is
@@ -150,11 +157,8 @@ struct private_thread_info
   unsigned int dying:1;
 
   /* Cached thread state.  */
-  unsigned int th_valid:1;
-  unsigned int ti_valid:1;
-
   td_thrhandle_t th;
-  td_thrinfo_t ti;
+  thread_t tid;
 };
 
 
@@ -207,12 +211,39 @@ thread_db_err_str (td_err_e err)
       return "only part of register set was written/read";
     case TD_NOXREGS:
       return "X register set not available for this thread";
+#ifdef THREAD_DB_HAS_TD_NOTALLOC
+    case TD_NOTALLOC:
+      return "thread has not yet allocated TLS for given module";
+#endif
+#ifdef THREAD_DB_HAS_TD_VERSION
+    case TD_VERSION:
+      return "versions of libpthread and libthread_db do not match";
+#endif
+#ifdef THREAD_DB_HAS_TD_NOTLS
+    case TD_NOTLS:
+      return "there is no TLS segment in the given module";
+#endif
     default:
       snprintf (buf, sizeof (buf), "unknown thread_db error '%d'", err);
       return buf;
     }
 }
 
+/* Return 1 if any threads have been registered.  There may be none if
+   the threading library is not fully initialized yet.  */
+
+static int
+have_threads_callback (struct thread_info *thread, void *dummy)
+{
+  return thread->private != NULL;
+}
+
+static int
+have_threads (void)
+{
+  return iterate_over_threads (have_threads_callback, NULL) != NULL;
+}
+
 /* A callback function for td_ta_thr_iter, which we use to map all
    threads to LWPs.
 
@@ -237,7 +268,7 @@ thread_get_info_callback (const td_thrhandle_t *thp, void *infop)
 	   thread_db_err_str (err));
 
   /* Fill the cache.  */
-  thread_ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
+  thread_ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, 0);
   thread_info = find_thread_pid (thread_ptid);
 
   /* In the case of a zombie thread, don't continue.  We don't want to
@@ -246,57 +277,22 @@ thread_get_info_callback (const td_thrhandle_t *thp, void *infop)
     {
       if (infop != NULL)
         *(struct thread_info **) infop = thread_info;
-      if (thread_info != NULL)
-	{
-	  memcpy (&thread_info->private->th, thp, sizeof (*thp));
-	  thread_info->private->th_valid = 1;
-	  memcpy (&thread_info->private->ti, &ti, sizeof (ti));
-	  thread_info->private->ti_valid = 1;
-	}
       return TD_THR_ZOMBIE;
     }
 
   if (thread_info == NULL)
     {
       /* New thread.  Attach to it now (why wait?).  */
-      attach_thread (thread_ptid, thp, &ti, 1);
+      attach_thread (thread_ptid, thp, &ti);
       thread_info = find_thread_pid (thread_ptid);
       gdb_assert (thread_info != NULL);
     }
 
-  memcpy (&thread_info->private->th, thp, sizeof (*thp));
-  thread_info->private->th_valid = 1;
-  memcpy (&thread_info->private->ti, &ti, sizeof (ti));
-  thread_info->private->ti_valid = 1;
-
   if (infop != NULL)
     *(struct thread_info **) infop = thread_info;
 
   return 0;
 }
-
-/* Accessor functions for the thread_db information, with caching.  */
-
-static void
-thread_db_map_id2thr (struct thread_info *thread_info, int fatal)
-{
-  td_err_e err;
-
-  if (thread_info->private->th_valid)
-    return;
-
-  err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (thread_info->ptid),
-			    &thread_info->private->th);
-  if (err != TD_OK)
-    {
-      if (fatal)
-	error (_("Cannot find thread %ld: %s"),
-	       (long) GET_THREAD (thread_info->ptid),
-	       thread_db_err_str (err));
-    }
-  else
-    thread_info->private->th_valid = 1;
-}
 
 /* Convert between user-level thread ids and LWP ids.  */
 
@@ -308,10 +304,9 @@ thread_from_lwp (ptid_t ptid)
   struct thread_info *thread_info;
   ptid_t thread_ptid;
 
-  if (GET_LWP (ptid) == 0)
-    ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid));
-
-  gdb_assert (is_lwp (ptid));
+  /* This ptid comes from linux-nat.c, which should always fill in the
+     LWP.  */
+  gdb_assert (GET_LWP (ptid) != 0);
 
   err = td_ta_map_lwp2thr_p (thread_agent, GET_LWP (ptid), &th);
   if (err != TD_OK)
@@ -332,16 +327,8 @@ thread_from_lwp (ptid_t ptid)
       && thread_info == NULL)
     return pid_to_ptid (-1);
 
-  gdb_assert (thread_info && thread_info->private->ti_valid);
-
-  return ptid_build (GET_PID (ptid), GET_LWP (ptid),
-		     thread_info->private->ti.ti_tid);
-}
-
-static ptid_t
-lwp_from_thread (ptid_t ptid)
-{
-  return BUILD_LWP (GET_LWP (ptid), GET_PID (ptid));
+  gdb_assert (ptid_get_tid (ptid) == 0);
+  return ptid;
 }
 
 
@@ -472,9 +459,9 @@ enable_thread_event_reporting (void)
   td_event_addset (&events, TD_CREATE);
 
 #ifdef HAVE_GNU_LIBC_VERSION_H
-  /* FIXME: kettenis/2000-04-23: The event reporting facility is
-     broken for TD_DEATH events in glibc 2.1.3, so don't enable it for
-     now.  */
+  /* The event reporting facility is broken for TD_DEATH events in
+     glibc 2.1.3, so don't enable it if we have glibc but a lower
+     version.  */
   libc_version = gnu_get_libc_version ();
   if (sscanf (libc_version, "%d.%d", &libc_major, &libc_minor) == 2
       && (libc_major > 2 || (libc_major == 2 && libc_minor > 1)))
@@ -567,6 +554,10 @@ check_for_thread_db (void)
   td_err_e err;
   static int already_loaded;
 
+  /* Do nothing if we couldn't load libthread_db.so.1.  */
+  if (td_ta_new_p == NULL)
+    return;
+
   /* First time through, report that libthread_db was successfuly
      loaded.  Can't print this in in thread_db_load as, at that stage,
      the interpreter and it's console haven't started.  */
@@ -584,8 +575,9 @@ check_for_thread_db (void)
 	/* Paranoid - don't let a NULL path slip through.  */
 	library = LIBTHREAD_DB_SO;
 
-      printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
-			 library);
+      if (info_verbose)
+	printf_unfiltered (_("Using host libthread_db library \"%s\".\n"),
+			   library);
       already_loaded = 1;
     }
 
@@ -599,6 +591,10 @@ check_for_thread_db (void)
   if (!target_has_execution)
     return;
 
+  /* Don't attempt to use thread_db for remote targets.  */
+  if (!target_can_run (&current_target))
+    return;
+
   /* Initialize the structure that identifies the child process.  */
   proc_handle.pid = GET_PID (inferior_ptid);
 
@@ -633,9 +629,6 @@ thread_db_new_objfile (struct objfile *objfile)
 {
   if (objfile != NULL)
     check_for_thread_db ();
-
-  if (target_new_objfile_chain)
-    target_new_objfile_chain (objfile);
 }
 
 /* Attach to a new thread.  This function is called when we receive a
@@ -644,9 +637,10 @@ thread_db_new_objfile (struct objfile *objfile)
 
 static void
 attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
-	       const td_thrinfo_t *ti_p, int verbose)
+	       const td_thrinfo_t *ti_p)
 {
-  struct thread_info *tp;
+  struct private_thread_info *private;
+  struct thread_info *tp = NULL;
   td_err_e err;
 
   /* If we're being called after a TD_CREATE event, we may already
@@ -664,29 +658,51 @@ attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
       tp = find_thread_pid (ptid);
       gdb_assert (tp != NULL);
 
-      if (!tp->private->dying)
-        return;
+      /* If tp->private is NULL, then GDB is already attached to this
+	 thread, but we do not know anything about it.  We can learn
+	 about it here.  This can only happen if we have some other
+	 way besides libthread_db to notice new threads (i.e.
+	 PTRACE_EVENT_CLONE); assume the same mechanism notices thread
+	 exit, so this can not be a stale thread recreated with the
+	 same ID.  */
+      if (tp->private != NULL)
+	{
+	  if (!tp->private->dying)
+	    return;
 
-      delete_thread (ptid);
+	  delete_thread (ptid);
+	  tp = NULL;
+	}
     }
 
   check_thread_signals ();
 
-  /* Add the thread to GDB's thread list.  */
-  tp = add_thread (ptid);
-  tp->private = xmalloc (sizeof (struct private_thread_info));
-  memset (tp->private, 0, sizeof (struct private_thread_info));
-
-  if (verbose)
-    printf_unfiltered (_("[New %s]\n"), target_pid_to_str (ptid));
-
   if (ti_p->ti_state == TD_THR_UNKNOWN || ti_p->ti_state == TD_THR_ZOMBIE)
     return;			/* A zombie thread -- do not attach.  */
 
   /* Under GNU/Linux, we have to attach to each and every thread.  */
-#ifdef ATTACH_LWP
-  ATTACH_LWP (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid)), 0);
-#endif
+  if (tp == NULL
+      && lin_lwp_attach_lwp (BUILD_LWP (ti_p->ti_lid, GET_PID (ptid))) < 0)
+    return;
+
+  /* Construct the thread's private data.  */
+  private = xmalloc (sizeof (struct private_thread_info));
+  memset (private, 0, sizeof (struct private_thread_info));
+
+  /* A thread ID of zero may mean the thread library has not initialized
+     yet.  But we shouldn't even get here if that's the case.  FIXME:
+     if we change GDB to always have at least one thread in the thread
+     list this will have to go somewhere else; maybe private == NULL
+     until the thread_db target claims it.  */
+  gdb_assert (ti_p->ti_tid != 0);
+  private->th = *th_p;
+  private->tid = ti_p->ti_tid;
+
+  /* Add the thread to GDB's thread list.  */
+  if (tp == NULL)
+    tp = add_thread_with_info (ptid, private);
+  else
+    tp->private = private;
 
   /* Enable thread event reporting for this thread.  */
   err = td_thr_event_enable_p (th_p, 1);
@@ -696,39 +712,20 @@ attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
 }
 
 static void
-thread_db_attach (char *args, int from_tty)
-{
-  target_beneath->to_attach (args, from_tty);
-
-  /* Destroy thread info; it's no longer valid.  */
-  init_thread_list ();
-
-  /* The child process is now the actual multi-threaded
-     program.  Snatch its process ID...  */
-  proc_handle.pid = GET_PID (inferior_ptid);
-
-  /* ...and perform the remaining initialization steps.  */
-  enable_thread_event_reporting ();
-  thread_db_find_new_threads ();
-}
-
-static void
-detach_thread (ptid_t ptid, int verbose)
+detach_thread (ptid_t ptid)
 {
   struct thread_info *thread_info;
 
-  if (verbose)
-    printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (ptid));
-
   /* Don't delete the thread now, because it still reports as active
      until it has executed a few instructions after the event
      breakpoint - if we deleted it now, "info threads" would cause us
      to re-attach to it.  Just mark it as having had a TD_DEATH
      event.  This means that we won't delete it from our thread list
      until we notice that it's dead (via prune_threads), or until
-     something re-uses its thread ID.  */
+     something re-uses its thread ID.  We'll report the thread exit
+     when the underlying LWP dies.  */
   thread_info = find_thread_pid (ptid);
-  gdb_assert (thread_info != NULL);
+  gdb_assert (thread_info != NULL && thread_info->private != NULL);
   thread_info->private->dying = 1;
 }
 
@@ -737,46 +734,10 @@ thread_db_detach (char *args, int from_tty)
 {
   disable_thread_event_reporting ();
 
-  /* There's no need to save & restore inferior_ptid here, since the
-     inferior is supposed to be survive this function call.  */
-  inferior_ptid = lwp_from_thread (inferior_ptid);
-
-  /* Forget about the child's process ID.  We shouldn't need it
-     anymore.  */
-  proc_handle.pid = 0;
-
   target_beneath->to_detach (args, from_tty);
-}
-
-static int
-clear_lwpid_callback (struct thread_info *thread, void *dummy)
-{
-  /* If we know that our thread implementation is 1-to-1, we could save
-     a certain amount of information; it's not clear how much, so we
-     are always conservative.  */
-
-  thread->private->th_valid = 0;
-  thread->private->ti_valid = 0;
 
-  return 0;
-}
-
-static void
-thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
-{
-  struct cleanup *old_chain = save_inferior_ptid ();
-
-  if (GET_PID (ptid) == -1)
-    inferior_ptid = lwp_from_thread (inferior_ptid);
-  else if (is_thread (ptid))
-    ptid = lwp_from_thread (ptid);
-
-  /* Clear cached data which may not be valid after the resume.  */
-  iterate_over_threads (clear_lwpid_callback, NULL);
-
-  target_beneath->to_resume (ptid, step, signo);
-
-  do_cleanups (old_chain);
+  /* Should this be done by detach_command?  */
+  target_mourn_inferior ();
 }
 
 /* Check if PID is currently stopped at the location of a thread event
@@ -793,7 +754,7 @@ check_event (ptid_t ptid)
   int loop = 0;
 
   /* Bail out early if we're not at a thread event breakpoint.  */
-  stop_pc = read_pc_pid (ptid) - DECR_PC_AFTER_BREAK;
+  stop_pc = read_pc_pid (ptid) - gdbarch_decr_pc_after_break (current_gdbarch);
   if (stop_pc != td_create_bp_addr && stop_pc != td_death_bp_addr)
     return;
 
@@ -829,14 +790,14 @@ check_event (ptid_t ptid)
       if (err != TD_OK)
 	error (_("Cannot get thread info: %s"), thread_db_err_str (err));
 
-      ptid = ptid_build (GET_PID (ptid), ti.ti_lid, ti.ti_tid);
+      ptid = ptid_build (GET_PID (ptid), ti.ti_lid, 0);
 
       switch (msg.event)
 	{
 	case TD_CREATE:
 	  /* Call attach_thread whether or not we already know about a
 	     thread with this thread ID.  */
-	  attach_thread (ptid, msg.th_p, &ti, 1);
+	  attach_thread (ptid, msg.th_p, &ti);
 
 	  break;
 
@@ -845,7 +806,7 @@ check_event (ptid_t ptid)
 	  if (!in_thread_list (ptid))
 	    error (_("Spurious thread death event."));
 
-	  detach_thread (ptid, 1);
+	  detach_thread (ptid);
 
 	  break;
 
@@ -861,18 +822,13 @@ thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
 {
   extern ptid_t trap_ptid;
 
-  if (GET_PID (ptid) != -1 && is_thread (ptid))
-    ptid = lwp_from_thread (ptid);
-
   ptid = target_beneath->to_wait (ptid, ourstatus);
 
-  if (proc_handle.pid == 0)
-    /* The current child process isn't the actual multi-threaded
-       program yet, so don't try to do any special thread-specific
-       post-processing and bail out early.  */
+  if (ourstatus->kind == TARGET_WAITKIND_IGNORE)
     return ptid;
 
-  if (ourstatus->kind == TARGET_WAITKIND_EXITED)
+  if (ourstatus->kind == TARGET_WAITKIND_EXITED
+    || ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
     return pid_to_ptid (-1);
 
   if (ourstatus->kind == TARGET_WAITKIND_EXECD)
@@ -884,82 +840,33 @@ thread_db_wait (ptid_t ptid, struct target_waitstatus *ourstatus)
       return pid_to_ptid (GET_PID (ptid));
     }
 
+  /* If we do not know about the main thread yet, this would be a good time to
+     find it.  */
+  if (ourstatus->kind == TARGET_WAITKIND_STOPPED && !have_threads ())
+    thread_db_find_new_threads ();
+
   if (ourstatus->kind == TARGET_WAITKIND_STOPPED
       && ourstatus->value.sig == TARGET_SIGNAL_TRAP)
     /* Check for a thread event.  */
     check_event (ptid);
 
-  if (!ptid_equal (trap_ptid, null_ptid))
-    trap_ptid = thread_from_lwp (trap_ptid);
-
-  /* Change the ptid back into the higher level PID + TID format.
-     If the thread is dead and no longer on the thread list, we will 
-     get back a dead ptid.  This can occur if the thread death event
-     gets postponed by other simultaneous events.  In such a case, 
-     we want to just ignore the event and continue on.  */
-  ptid = thread_from_lwp (ptid);
-  if (GET_PID (ptid) == -1)
-    ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
-  
-  return ptid;
-}
-
-static LONGEST
-thread_db_xfer_partial (struct target_ops *ops, enum target_object object,
-			const char *annex, gdb_byte *readbuf,
-			const gdb_byte *writebuf, ULONGEST offset, LONGEST len)
-{
-  struct cleanup *old_chain = save_inferior_ptid ();
-  LONGEST xfer;
-
-  if (is_thread (inferior_ptid))
+  if (have_threads ())
     {
-      /* FIXME: This seems to be necessary to make sure breakpoints
-         are removed.  */
-      if (!target_thread_alive (inferior_ptid))
-	inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid));
-      else
-	inferior_ptid = lwp_from_thread (inferior_ptid);
+      /* Change ptids back into the higher level PID + TID format.  If
+	 the thread is dead and no longer on the thread list, we will
+	 get back a dead ptid.  This can occur if the thread death
+	 event gets postponed by other simultaneous events.  In such a
+	 case, we want to just ignore the event and continue on.  */
+
+      if (!ptid_equal (trap_ptid, null_ptid))
+	trap_ptid = thread_from_lwp (trap_ptid);
+
+      ptid = thread_from_lwp (ptid);
+      if (GET_PID (ptid) == -1)
+	ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
     }
 
-  xfer = target_beneath->to_xfer_partial (ops, object, annex,
-					  readbuf, writebuf, offset, len);
-
-  do_cleanups (old_chain);
-  return xfer;
-}
-
-static void
-thread_db_kill (void)
-{
-  /* There's no need to save & restore inferior_ptid here, since the
-     inferior isn't supposed to survive this function call.  */
-  inferior_ptid = lwp_from_thread (inferior_ptid);
-  target_beneath->to_kill ();
-}
-
-static void
-thread_db_create_inferior (char *exec_file, char *allargs, char **env,
-			   int from_tty)
-{
-  unpush_target (&thread_db_ops);
-  using_thread_db = 0;
-  target_beneath->to_create_inferior (exec_file, allargs, env, from_tty);
-}
-
-static void
-thread_db_post_startup_inferior (ptid_t ptid)
-{
-  if (proc_handle.pid == 0)
-    {
-      /* The child process is now the actual multi-threaded
-         program.  Snatch its process ID...  */
-      proc_handle.pid = GET_PID (ptid);
-
-      /* ...and perform the remaining initialization steps.  */
-      enable_thread_event_reporting ();
-      thread_db_find_new_threads ();
-    }
+  return ptid;
 }
 
 static void
@@ -980,12 +887,38 @@ thread_db_mourn_inferior (void)
   using_thread_db = 0;
 }
 
+static int
+thread_db_can_async_p (void)
+{
+  return target_beneath->to_can_async_p ();
+}
+
+static int
+thread_db_is_async_p (void)
+{
+  return target_beneath->to_is_async_p ();
+}
+
+static void
+thread_db_async (void (*callback) (enum inferior_event_type event_type,
+				   void *context), void *context)
+{
+  return target_beneath->to_async (callback, context);
+}
+
+static int
+thread_db_async_mask (int mask)
+{
+  return target_beneath->to_async_mask (mask);
+}
+
 static int
 find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
 {
   td_thrinfo_t ti;
   td_err_e err;
   ptid_t ptid;
+  struct thread_info *tp;
 
   err = td_thr_get_info_p (th_p, &ti);
   if (err != TD_OK)
@@ -995,10 +928,27 @@ find_new_threads_callback (const td_thrhandle_t *th_p, void *data)
   if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
     return 0;			/* A zombie -- ignore.  */
 
-  ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, ti.ti_tid);
+  ptid = ptid_build (GET_PID (inferior_ptid), ti.ti_lid, 0);
+
+  if (ti.ti_tid == 0)
+    {
+      /* A thread ID of zero means that this is the main thread, but
+	 glibc has not yet initialized thread-local storage and the
+	 pthread library.  We do not know what the thread's TID will
+	 be yet.  Just enable event reporting and otherwise ignore
+	 it.  */
+
+      err = td_thr_event_enable_p (th_p, 1);
+      if (err != TD_OK)
+	error (_("Cannot enable thread event reporting for %s: %s"),
+	       target_pid_to_str (ptid), thread_db_err_str (err));
+
+      return 0;
+    }
 
-  if (!in_thread_list (ptid))
-    attach_thread (ptid, th_p, &ti, 1);
+  tp = find_thread_pid (ptid);
+  if (tp == NULL || tp->private == NULL)
+    attach_thread (ptid, th_p, &ti);
 
   return 0;
 }
@@ -1019,18 +969,17 @@ thread_db_find_new_threads (void)
 static char *
 thread_db_pid_to_str (ptid_t ptid)
 {
-  if (is_thread (ptid))
+  struct thread_info *thread_info = find_thread_pid (ptid);
+
+  if (thread_info != NULL && thread_info->private != NULL)
     {
       static char buf[64];
-      struct thread_info *thread_info;
+      thread_t tid;
 
+      tid = thread_info->private->tid;
       thread_info = find_thread_pid (ptid);
-      if (thread_info == NULL)
-	snprintf (buf, sizeof (buf), "Thread %ld (LWP %ld) (Missing)",
-		  GET_THREAD (ptid), GET_LWP (ptid));
-      else
-	snprintf (buf, sizeof (buf), "Thread %ld (LWP %ld)",
-		  GET_THREAD (ptid), GET_LWP (ptid));
+      snprintf (buf, sizeof (buf), "Thread 0x%lx (LWP %ld)",
+		tid, GET_LWP (ptid));
 
       return buf;
     }
@@ -1047,6 +996,9 @@ thread_db_pid_to_str (ptid_t ptid)
 static char *
 thread_db_extra_thread_info (struct thread_info *info)
 {
+  if (info->private == NULL)
+    return NULL;
+
   if (info->private->dying)
     return "Exiting";
 
@@ -1061,11 +1013,19 @@ thread_db_get_thread_local_address (ptid_t ptid,
 				    CORE_ADDR lm,
 				    CORE_ADDR offset)
 {
-  if (is_thread (ptid))
+  struct thread_info *thread_info;
+
+  /* If we have not discovered any threads yet, check now.  */
+  if (!have_threads ())
+    thread_db_find_new_threads ();
+
+  /* Find the matching thread.  */
+  thread_info = find_thread_pid (ptid);
+
+  if (thread_info != NULL && thread_info->private != NULL)
     {
       td_err_e err;
       void *address;
-      struct thread_info *thread_info;
 
       /* glibc doesn't provide the needed interface.  */
       if (!td_thr_tls_get_addr_p)
@@ -1075,12 +1035,9 @@ thread_db_get_thread_local_address (ptid_t ptid,
       /* Caller should have verified that lm != 0.  */
       gdb_assert (lm != 0);
 
-      /* Get info about the thread.  */
-      thread_info = find_thread_pid (ptid);
-      thread_db_map_id2thr (thread_info, 1);
-
       /* Finally, get the address of the variable.  */
-      err = td_thr_tls_get_addr_p (&thread_info->private->th, (void *) lm,
+      err = td_thr_tls_get_addr_p (&thread_info->private->th,
+				   (void *)(size_t) lm,
 				   offset, &address);
 
 #ifdef THREAD_DB_HAS_TD_NOTALLOC
@@ -1119,14 +1076,8 @@ init_thread_db_ops (void)
   thread_db_ops.to_shortname = "multi-thread";
   thread_db_ops.to_longname = "multi-threaded child process.";
   thread_db_ops.to_doc = "Threads and pthreads support.";
-  thread_db_ops.to_attach = thread_db_attach;
   thread_db_ops.to_detach = thread_db_detach;
-  thread_db_ops.to_resume = thread_db_resume;
   thread_db_ops.to_wait = thread_db_wait;
-  thread_db_ops.to_xfer_partial = thread_db_xfer_partial;
-  thread_db_ops.to_kill = thread_db_kill;
-  thread_db_ops.to_create_inferior = thread_db_create_inferior;
-  thread_db_ops.to_post_startup_inferior = thread_db_post_startup_inferior;
   thread_db_ops.to_mourn_inferior = thread_db_mourn_inferior;
   thread_db_ops.to_find_new_threads = thread_db_find_new_threads;
   thread_db_ops.to_pid_to_str = thread_db_pid_to_str;
@@ -1135,6 +1086,10 @@ init_thread_db_ops (void)
   thread_db_ops.to_get_thread_local_address
     = thread_db_get_thread_local_address;
   thread_db_ops.to_extra_thread_info = thread_db_extra_thread_info;
+  thread_db_ops.to_can_async_p = thread_db_can_async_p;
+  thread_db_ops.to_is_async_p = thread_db_is_async_p;
+  thread_db_ops.to_async = thread_db_async;
+  thread_db_ops.to_async_mask = thread_db_async_mask;
   thread_db_ops.to_magic = OPS_MAGIC;
 }
 
@@ -1148,7 +1103,6 @@ _initialize_thread_db (void)
       add_target (&thread_db_ops);
 
       /* Add ourselves to objfile event chain.  */
-      target_new_objfile_chain = deprecated_target_new_objfile_hook;
-      deprecated_target_new_objfile_hook = thread_db_new_objfile;
+      observer_attach_new_objfile (thread_db_new_objfile);
     }
 }