gdb, btrace, infrun: per-inferior run-control

While recording is already per inferior, run-control isn't.  As soon as
any thread in any inferior is replaying, no other inferior can be resumed.

This is controlled by many calls to record_is_replaying(minus_one_ptid).
Instead of minus_one_ptid, pass the ptid of the inferior to be checked.

gdb/infrun.c

@@ -2400,7 +2400,8 @@ user_visible_resume_ptid (int step)
       resume_ptid = inferior_ptid;
     }
   else if ((scheduler_mode == schedlock_replay)
-	   && target_record_will_replay (minus_one_ptid, execution_direction))
+	   && target_record_will_replay (ptid_t (inferior_ptid.pid ()),
+					 execution_direction))
     {
       /* User-settable 'scheduler' mode requires solo thread resume in replay
 	 mode.  */
@@ -3118,15 +3119,17 @@ clear_proceed_status (int step)
      This is a convenience feature to not require the user to explicitly
      stop replaying the other threads.  We're assuming that the user's
      intent is to resume tracing the recorded process.  */
+  ptid_t resume_ptid = user_visible_resume_ptid (step);
   if (!non_stop && scheduler_mode == schedlock_replay
-      && target_record_is_replaying (minus_one_ptid)
-      && !target_record_will_replay (user_visible_resume_ptid (step),
-				     execution_direction))
-    target_record_stop_replaying ();
+      && target_record_is_replaying (ptid_t (resume_ptid.pid ()))
+      && !target_record_will_replay (resume_ptid, execution_direction))
+    {
+      target_record_stop_replaying ();
+      resume_ptid = user_visible_resume_ptid (step);
+    }
 
   if (!non_stop && inferior_ptid != null_ptid)
     {
-      ptid_t resume_ptid = user_visible_resume_ptid (step);
       process_stratum_target *resume_target
 	= user_visible_resume_target (resume_ptid);
 
@@ -3205,7 +3208,7 @@ schedlock_applies (struct thread_info *tp)
 	  || (scheduler_mode == schedlock_step
 	      && tp->control.stepping_command)
 	  || (scheduler_mode == schedlock_replay
-	      && target_record_will_replay (minus_one_ptid,
+	      && target_record_will_replay (ptid_t (tp->inf->pid),
 					    execution_direction)));
 }
 

gdb/record-btrace.c

@@ -122,7 +122,6 @@ public:
   ptid_t wait (ptid_t, struct target_waitstatus *, target_wait_flags) override;
 
   void stop (ptid_t) override;
-  void update_thread_list () override;
   bool thread_alive (ptid_t ptid) override;
   void goto_record_begin () override;
   void goto_record_end () override;
@@ -2206,7 +2205,7 @@ record_btrace_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
      make progress, we may need to explicitly move replaying threads to the end
      of their execution history.  */
   if ((::execution_direction != EXEC_REVERSE)
-      && !record_is_replaying (minus_one_ptid))
+      && !record_is_replaying (ptid_t (ptid.pid ())))
     {
       this->beneath ()->resume (ptid, step, signal);
       return;
@@ -2625,7 +2624,7 @@ record_btrace_target::wait (ptid_t ptid, struct target_waitstatus *status,
 
   /* As long as we're not replaying, just forward the request.  */
   if ((::execution_direction != EXEC_REVERSE)
-      && !record_is_replaying (minus_one_ptid))
+      && !record_is_replaying (ptid_t (ptid.pid ())))
     {
       return this->beneath ()->wait (ptid, status, options);
     }
@@ -2746,7 +2745,7 @@ record_btrace_target::stop (ptid_t ptid)
 
   /* As long as we're not replaying, just forward the request.  */
   if ((::execution_direction != EXEC_REVERSE)
-      && !record_is_replaying (minus_one_ptid))
+      && !record_is_replaying (ptid_t (ptid.pid ())))
     {
       this->beneath ()->stop (ptid);
     }
@@ -2776,7 +2775,7 @@ record_btrace_target::can_execute_reverse ()
 bool
 record_btrace_target::stopped_by_sw_breakpoint ()
 {
-  if (record_is_replaying (minus_one_ptid))
+  if (record_is_replaying (ptid_t (inferior_ptid.pid ())))
     {
       struct thread_info *tp = inferior_thread ();
 
@@ -2791,7 +2790,7 @@ record_btrace_target::stopped_by_sw_breakpoint ()
 bool
 record_btrace_target::stopped_by_hw_breakpoint ()
 {
-  if (record_is_replaying (minus_one_ptid))
+  if (record_is_replaying (ptid_t (inferior_ptid.pid ())))
     {
       struct thread_info *tp = inferior_thread ();
 
@@ -2801,26 +2800,13 @@ record_btrace_target::stopped_by_hw_breakpoint ()
   return this->beneath ()->stopped_by_hw_breakpoint ();
 }
 
-/* The update_thread_list method of target record-btrace.  */
-
-void
-record_btrace_target::update_thread_list ()
-{
-  /* We don't add or remove threads during replay.  */
-  if (record_is_replaying (minus_one_ptid))
-    return;
-
-  /* Forward the request.  */
-  this->beneath ()->update_thread_list ();
-}
-
 /* The thread_alive method of target record-btrace.  */
 
 bool
 record_btrace_target::thread_alive (ptid_t ptid)
 {
   /* We don't add or remove threads during replay.  */
-  if (record_is_replaying (minus_one_ptid))
+  if (record_is_replaying (ptid_t (ptid.pid ())))
     return true;
 
   /* Forward the request.  */

gdb/testsuite/gdb.btrace/multi-inferior.c

@@ -15,8 +15,16 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
+static int
+fun (void)
+{
+  int x = fun (); /* fun.1 */
+  return x;       /* fun.2 */
+}
+
 int
 main (void)
 {
-  return 0;
+  int x = fun (); /* main.1 */
+  return x;       /* main.2 */
 }

gdb/testsuite/gdb.btrace/multi-inferior.exp

@@ -39,6 +39,8 @@ with_test_prefix "inferior 1" {
     }
 
     gdb_test_no_output "record btrace"
+    gdb_test "step 4" "fun\.1.*"
+    gdb_test "reverse-step" "fun\.1.*"
 }
 
 with_test_prefix "inferior 2" {
@@ -51,4 +53,21 @@ with_test_prefix "inferior 2" {
     }
 
     gdb_test_no_output "record btrace"
+    gdb_test "step 4" "fun\.1.*"
+    gdb_test "reverse-step" "fun\.1.*"
+
+    gdb_test "info record" "Replay in progress.*"
+    gdb_test "record stop" "Process record is stopped.*"
+
+    gdb_test "step" "fun\.1.*"
+}
+
+with_test_prefix "inferior 1" {
+    gdb_test "inferior 1" "Switching to inferior 1.*"
+
+    gdb_test "info record" "Replay in progress.*"
+    gdb_test "reverse-finish" "fun\.1.*"
+    gdb_test "record goto end" "fun\.1.*"
+    gdb_test "step 2" "fun\.1.*"
+    gdb_test "reverse-step 3"
 }