1 files changed, 33 insertions, 64 deletions

diff --git a/gdb/thread.c b/gdb/thread.c
index 02672f0..f0722d3 100644
--- a/gdb/thread.c
+++ b/gdb/thread.c
@@ -55,6 +55,9 @@
 
 static int highest_thread_num;
 
+/* The current/selected thread.  */
+static thread_info *current_thread_;
+
 /* RAII type used to increase / decrease the refcount of each thread
    in a given list of threads.  */
 
@@ -78,13 +81,19 @@ private:
   const std::vector<thread_info *> &m_thrds;
 };
 
+/* Returns true if THR is the current thread.  */
+
+static bool
+is_current_thread (const thread_info *thr)
+{
+  return thr == current_thread_;
+}
 
 struct thread_info*
 inferior_thread (void)
 {
-  struct thread_info *tp = find_thread_ptid (current_inferior (), inferior_ptid);
-  gdb_assert (tp);
-  return tp;
+  gdb_assert (current_thread_ != nullptr);
+  return current_thread_;
 }
 
 /* Delete the breakpoint pointed at by BP_P, if there's one.  */
@@ -194,7 +203,7 @@ clear_thread_inferior_resources (struct thread_info *tp)
 /* Set the TP's state as exited.  */
 
 static void
-set_thread_exited (thread_info *tp, int silent)
+set_thread_exited (thread_info *tp, bool silent)
 {
   /* Dead threads don't need to step-over.  Remove from queue.  */
   if (tp->step_over_next != NULL)
@@ -245,7 +254,12 @@ new_thread (struct inferior *inf, ptid_t ptid)
       struct thread_info *last;
 
       for (last = inf->thread_list; last->next != NULL; last = last->next)
-	;
+	gdb_assert (ptid != last->ptid
+		    || last->state == THREAD_EXITED);
+
+      gdb_assert (ptid != last->ptid
+		  || last->state == THREAD_EXITED);
+
       last->next = tp;
     }
 
@@ -255,51 +269,15 @@ new_thread (struct inferior *inf, ptid_t ptid)
 struct thread_info *
 add_thread_silent (process_stratum_target *targ, ptid_t ptid)
 {
-  inferior *inf;
-
-  thread_info *tp = find_thread_ptid (targ, ptid);
-  if (tp)
-    /* Found an old thread with the same id.  It has to be dead,
-       otherwise we wouldn't be adding a new thread with the same id.
-       The OS is reusing this id --- delete it, and recreate a new
-       one.  */
-    {
-      /* In addition to deleting the thread, if this is the current
-	 thread, then we need to take care that delete_thread doesn't
-	 really delete the thread if it is inferior_ptid.  Create a
-	 new template thread in the list with an invalid ptid, switch
-	 to it, delete the original thread, reset the new thread's
-	 ptid, and switch to it.  */
-
-      if (inferior_ptid == ptid)
-	{
-	  thread_info *new_thr = new_thread (tp->inf, null_ptid);
-
-	  /* Make switch_to_thread not read from the thread.  */
-	  new_thr->state = THREAD_EXITED;
-	  switch_to_no_thread ();
-
-	  /* Now we can delete it.  */
-	  delete_thread (tp);
-
-	  /* Now reset its ptid, and reswitch inferior_ptid to it.  */
-	  new_thr->ptid = ptid;
-	  new_thr->state = THREAD_STOPPED;
-	  switch_to_thread (new_thr);
-
-	  gdb::observers::new_thread.notify (new_thr);
-
-	  /* All done.  */
-	  return new_thr;
-	}
+  inferior *inf = find_inferior_ptid (targ, ptid);
 
-      inf = tp->inf;
-
-      /* Just go ahead and delete it.  */
-      delete_thread (tp);
-    }
-  else
-    inf = find_inferior_ptid (targ, ptid);
+  /* We may have an old thread with the same id in the thread list.
+     If we do, it must be dead, otherwise we wouldn't be adding a new
+     thread with the same id.  The OS is reusing this id --- delete
+     the old thread, and create a new one.  */
+  thread_info *tp = find_thread_ptid (inf, ptid);
+  if (tp != nullptr)
+    delete_thread (tp);
 
   tp = new_thread (inf, ptid);
   gdb::observers::new_thread.notify (tp);
@@ -349,14 +327,6 @@ thread_info::~thread_info ()
   xfree (this->name);
 }
 
-/* Returns true if THR is the current thread.  */
-
-static bool
-is_current_thread (const thread_info *thr)
-{
-  return thr->inf == current_inferior () && thr->ptid == inferior_ptid;
-}
-
 /* See gdbthread.h.  */
 
 bool
@@ -482,10 +452,7 @@ delete_thread_1 (thread_info *thr, bool silent)
   delete tp;
 }
 
-/* Delete thread THREAD and notify of thread exit.  If this is the
-   current thread, don't actually delete it, but tag it as exited and
-   do the notification.  If this is the user selected thread, clear
-   it.  */
+/* See gdbthread.h.  */
 
 void
 delete_thread (thread_info *thread)
@@ -535,7 +502,7 @@ find_thread_ptid (process_stratum_target *targ, ptid_t ptid)
 struct thread_info *
 find_thread_ptid (inferior *inf, ptid_t ptid)
 {
-  for (thread_info *tp : inf->threads ())
+  for (thread_info *tp : inf->non_exited_threads ())
     if (tp->ptid == ptid)
       return tp;
 
@@ -1317,7 +1284,8 @@ switch_to_thread_no_regs (struct thread_info *thread)
   set_current_program_space (inf->pspace);
   set_current_inferior (inf);
 
-  inferior_ptid = thread->ptid;
+  current_thread_ = thread;
+  inferior_ptid = current_thread_->ptid;
 }
 
 /* See gdbthread.h.  */
@@ -1325,9 +1293,10 @@ switch_to_thread_no_regs (struct thread_info *thread)
 void
 switch_to_no_thread ()
 {
-  if (inferior_ptid == null_ptid)
+  if (current_thread_ == nullptr)
     return;
 
+  current_thread_ = nullptr;
   inferior_ptid = null_ptid;
   reinit_frame_cache ();
 }