* thread-db.c (attach_thread): Prototype.

	(struct private_thread_info): Remove lwpid.  Add thread handle (th),
	thread information (ti), and valid flags (th_valid, ti_valid).
	(attach_thread): Move target_pid_to_str call to after the thread
	is added to GDB's list.  Initialize the cache.
	(thread_get_info_callback, thread_db_map_id2thr)
	(thread_db_get_info): New functions.
	(thread_from_lwp, lwp_from_thread, thread_db_fetch_registers)
	(thread_db_store_registers, thread_db_thread_alive)
	(thread_db_get_thread_local_address): Use them.
	(thread_db_pid_to_str): Likewise.  Return "Missing" instead
	of calling error() for threads in unknown state.

	(clear_lwpid_callback): New function.
	(thread_db_resume): Use it to clear the cache.

1 files changed, 170 insertions, 67 deletions

diff --git a/gdb/thread-db.c b/gdb/thread-db.c
index 9f4cde7ad75..08c29ccbad7 100644
--- a/gdb/thread-db.c
+++ b/gdb/thread-db.c
@@ -126,6 +126,8 @@ 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);
 
 
 /* Building process ids.  */
@@ -141,10 +143,17 @@ static void thread_db_find_new_threads (void);
 #define BUILD_THREAD(tid, pid)	ptid_build (pid, 0, tid)
 
 
+/* Use "struct private_thread_info" to cache thread state.  This is
+   a substantial optimization.  */
+
 struct private_thread_info
 {
-  /* Cached LWP id.  Must come first, see lin-lwp.c.  */
-  lwpid_t lwpid;
+  /* Cached thread state.  */
+  unsigned int th_valid : 1;
+  unsigned int ti_valid : 1;
+
+  td_thrhandle_t th;
+  td_thrinfo_t ti;
 };
 
 
@@ -228,15 +237,100 @@ thread_db_state_str (td_thr_state_e state)
     }
 }
 
+/* A callback function for td_ta_thr_iter, which we use to map all
+   threads to LWPs.  
+
+   THP is a handle to the current thread; if INFOP is not NULL, the
+   struct thread_info associated with this thread is returned in
+   *INFOP.  */
+
+static int
+thread_get_info_callback (const td_thrhandle_t *thp, void *infop)
+{
+  td_thrinfo_t ti;
+  td_err_e err;
+  struct thread_info *thread_info;
+  ptid_t thread_ptid;
+
+  err = td_thr_get_info_p (thp, &ti);
+  if (err != TD_OK)
+    error ("thread_get_info_callback: cannot get thread info: %s", 
+	   thread_db_err_str (err));
+
+  /* Fill the cache.  */
+  thread_ptid = BUILD_THREAD (ti.ti_tid, GET_PID (inferior_ptid));
+  thread_info = find_thread_pid (thread_ptid);
+
+  if (thread_info == NULL)
+    {
+      /* New thread.  Attach to it now (why wait?).  */
+      attach_thread (thread_ptid, thp, &ti, 1);
+      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;
+}
+
+static td_thrinfo_t *
+thread_db_get_info (struct thread_info *thread_info)
+{
+  td_err_e err;
+
+  if (thread_info->private->ti_valid)
+    return &thread_info->private->ti;
+
+  if (! thread_info->private->th_valid)
+    thread_db_map_id2thr (thread_info, 1);
+
+  err = td_thr_get_info_p (&thread_info->private->th, &thread_info->private->ti);
+  if (err != TD_OK)
+    error ("thread_db_get_info: cannot get thread info: %s", 
+	   thread_db_err_str (err));
+
+  thread_info->private->ti_valid = 1;
+  return &thread_info->private->ti;
+}
+
 /* Convert between user-level thread ids and LWP ids.  */
 
 static ptid_t
 thread_from_lwp (ptid_t ptid)
 {
-  td_thrinfo_t ti;
   td_thrhandle_t th;
   td_err_e err;
+  struct thread_info *thread_info;
+  ptid_t thread_ptid;
 
   if (GET_LWP (ptid) == 0)
     ptid = BUILD_LWP (GET_PID (ptid), GET_PID (ptid));
@@ -248,35 +342,26 @@ thread_from_lwp (ptid_t ptid)
     error ("Cannot find user-level thread for LWP %ld: %s",
 	   GET_LWP (ptid), thread_db_err_str (err));
 
-  err = td_thr_get_info_p (&th, &ti);
-  if (err != TD_OK)
-    error ("thread_from_lwp: cannot get thread info: %s", 
-	   thread_db_err_str (err));
+  thread_info = NULL;
+  thread_get_info_callback (&th, &thread_info);
+  gdb_assert (thread_info && thread_info->private->ti_valid);
 
-  return BUILD_THREAD (ti.ti_tid, GET_PID (ptid));
+  return BUILD_THREAD (thread_info->private->ti.ti_tid, GET_PID (ptid));
 }
 
 static ptid_t
 lwp_from_thread (ptid_t ptid)
 {
-  td_thrinfo_t ti;
-  td_thrhandle_t th;
-  td_err_e err;
+  struct thread_info *thread_info;
+  ptid_t thread_ptid;
 
   if (!is_thread (ptid))
     return ptid;
 
-  err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
-  if (err != TD_OK)
-    error ("Cannot find thread %ld: %s",
-	   (long) GET_THREAD (ptid), thread_db_err_str (err));
-
-  err = td_thr_get_info_p (&th, &ti);
-  if (err != TD_OK)
-    error ("lwp_from_thread: cannot get thread info: %s", 
-	   thread_db_err_str (err));
+  thread_info = find_thread_pid (ptid);
+  thread_db_get_info (thread_info);
 
-  return BUILD_LWP (ti.ti_lid, GET_PID (ptid));
+  return BUILD_LWP (thread_info->private->ti.ti_lid, GET_PID (ptid));
 }
 
 
@@ -581,13 +666,13 @@ attach_thread (ptid_t ptid, const td_thrhandle_t *th_p,
 
   check_thread_signals ();
 
-  if (verbose)
-    printf_unfiltered ("[New %s]\n", target_pid_to_str (ptid));
-
   /* Add the thread to GDB's thread list.  */
   tp = add_thread (ptid);
   tp->private = xmalloc (sizeof (struct private_thread_info));
-  tp->private->lwpid = ti_p->ti_lid;
+  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.  */
@@ -644,6 +729,19 @@ thread_db_detach (char *args, int from_tty)
   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)
 {
@@ -654,6 +752,9 @@ thread_db_resume (ptid_t ptid, int step, enum target_signal signo)
   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);
@@ -787,7 +888,7 @@ thread_db_xfer_memory (CORE_ADDR memaddr, char *myaddr, int len, int write,
 static void
 thread_db_fetch_registers (int regno)
 {
-  td_thrhandle_t th;
+  struct thread_info *thread_info;
   prgregset_t gregset;
   gdb_prfpregset_t fpregset;
   td_err_e err;
@@ -799,17 +900,15 @@ thread_db_fetch_registers (int regno)
       return;
     }
 
-  err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (inferior_ptid), &th);
-  if (err != TD_OK)
-    error ("Cannot find thread %ld: %s",
-	   (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
+  thread_info = find_thread_pid (inferior_ptid);
+  thread_db_map_id2thr (thread_info, 1);
 
-  err = td_thr_getgregs_p (&th, gregset);
+  err = td_thr_getgregs_p (&thread_info->private->th, gregset);
   if (err != TD_OK)
     error ("Cannot fetch general-purpose registers for thread %ld: %s",
 	   (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
 
-  err = td_thr_getfpregs_p (&th, &fpregset);
+  err = td_thr_getfpregs_p (&thread_info->private->th, &fpregset);
   if (err != TD_OK)
     error ("Cannot get floating-point registers for thread %ld: %s",
 	   (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
@@ -824,10 +923,10 @@ thread_db_fetch_registers (int regno)
 static void
 thread_db_store_registers (int regno)
 {
-  td_thrhandle_t th;
   prgregset_t gregset;
   gdb_prfpregset_t fpregset;
   td_err_e err;
+  struct thread_info *thread_info;
 
   if (!is_thread (inferior_ptid))
     {
@@ -836,10 +935,8 @@ thread_db_store_registers (int regno)
       return;
     }
 
-  err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (inferior_ptid), &th);
-  if (err != TD_OK)
-    error ("Cannot find thread %ld: %s",
-	   (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
+  thread_info = find_thread_pid (inferior_ptid);
+  thread_db_map_id2thr (thread_info, 1);
 
   if (regno != -1)
     {
@@ -853,11 +950,11 @@ thread_db_store_registers (int regno)
   fill_gregset ((gdb_gregset_t *) gregset, -1);
   fill_fpregset (&fpregset, -1);
 
-  err = td_thr_setgregs_p (&th, gregset);
+  err = td_thr_setgregs_p (&thread_info->private->th, gregset);
   if (err != TD_OK)
     error ("Cannot store general-purpose registers for thread %ld: %s",
 	   (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
-  err = td_thr_setfpregs_p (&th, &fpregset);
+  err = td_thr_setfpregs_p (&thread_info->private->th, &fpregset);
   if (err != TD_OK)
     error ("Cannot store floating-point registers  for thread %ld: %s",
 	   (long) GET_THREAD (inferior_ptid), thread_db_err_str (err));
@@ -915,24 +1012,31 @@ static int
 thread_db_thread_alive (ptid_t ptid)
 {
   td_thrhandle_t th;
-  td_thrinfo_t ti;
   td_err_e err;
 
   if (is_thread (ptid))
     {
-      err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
-      if (err != TD_OK)
-	return 0;
+      struct thread_info *thread_info;
+      thread_info = find_thread_pid (ptid);
 
-      err = td_thr_validate_p (&th);
-      if (err != TD_OK)
+      thread_db_map_id2thr (thread_info, 0);
+      if (! thread_info->private->th_valid)
 	return 0;
 
-      err = td_thr_get_info_p (&th, &ti);
+      err = td_thr_validate_p (&thread_info->private->th);
       if (err != TD_OK)
 	return 0;
 
-      if (ti.ti_state == TD_THR_UNKNOWN || ti.ti_state == TD_THR_ZOMBIE)
+      if (! thread_info->private->ti_valid)
+	{
+	  err = td_thr_get_info_p (&thread_info->private->th, &thread_info->private->ti);
+	  if (err != TD_OK)
+	    return 0;
+	  thread_info->private->ti_valid = 1;
+	}
+
+      if (thread_info->private->ti.ti_state == TD_THR_UNKNOWN
+	  || thread_info->private->ti.ti_state == TD_THR_ZOMBIE)
 	return 0;		/* A zombie thread.  */
 
       return 1;
@@ -986,29 +1090,29 @@ thread_db_pid_to_str (ptid_t ptid)
   if (is_thread (ptid))
     {
       static char buf[64];
-      td_thrhandle_t th;
-      td_thrinfo_t ti;
+      td_thrinfo_t *ti_p;
       td_err_e err;
+      struct thread_info *thread_info;
 
-      err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
-      if (err != TD_OK)
-	error ("Cannot find thread %ld: %s",
-	       (long) GET_THREAD (ptid), thread_db_err_str (err));
+      thread_info = find_thread_pid (ptid);
+      thread_db_map_id2thr (thread_info, 0);
+      if (! thread_info->private->th_valid)
+	{
+	  snprintf (buf, sizeof (buf), "Thread %ld (Missing)", GET_THREAD (ptid));
+	  return buf;
+	}
 
-      err = td_thr_get_info_p (&th, &ti);
-      if (err != TD_OK)
-	error ("thread_db_pid_to_str: cannot get thread info for %ld: %s",
-	       (long) GET_THREAD (ptid), thread_db_err_str (err));
+      ti_p = thread_db_get_info (thread_info);
 
-      if (ti.ti_state == TD_THR_ACTIVE && ti.ti_lid != 0)
+      if (ti_p->ti_state == TD_THR_ACTIVE && ti_p->ti_lid != 0)
 	{
 	  snprintf (buf, sizeof (buf), "Thread %ld (LWP %d)",
-		    (long) ti.ti_tid, ti.ti_lid);
+		    (long) ti_p->ti_tid, ti_p->ti_lid);
 	}
       else
 	{
 	  snprintf (buf, sizeof (buf), "Thread %ld (%s)",
-		    (long) ti.ti_tid, thread_db_state_str (ti.ti_state));
+		    (long) ti_p->ti_tid, thread_db_state_str (ti_p->ti_state));
 	}
 
       return buf;
@@ -1031,9 +1135,9 @@ thread_db_get_thread_local_address (ptid_t ptid, struct objfile *objfile,
     {
       int objfile_is_library = (objfile->flags & OBJF_SHARED);
       td_err_e err;
-      td_thrhandle_t th;
       void *address;
       CORE_ADDR lm;
+      struct thread_info *thread_info;
 
       /* glibc doesn't provide the needed interface.  */
       if (! td_thr_tls_get_addr_p)
@@ -1054,13 +1158,12 @@ thread_db_get_thread_local_address (ptid_t ptid, struct objfile *objfile,
 	}
 
       /* Get info about the thread.  */
-      err = td_ta_map_id2thr_p (thread_agent, GET_THREAD (ptid), &th);
-      if (err != TD_OK)
-	error ("Cannot find thread %ld: %s",
-	       (long) GET_THREAD (ptid), thread_db_err_str (err));
-      
+      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 (&th, (void *) lm, offset, &address);
+      err = td_thr_tls_get_addr_p (&thread_info->private->th, (void *) lm,
+				   offset, &address);
 
 #ifdef THREAD_DB_HAS_TD_NOTALLOC
       /* The memory hasn't been allocated, yet.  */