[binutils-gdb] btrace, infrun: simplify scheduler-locking replay

[Markus Metzger]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d0844398e2b31632a6a486fc7f103d47d50fb4e4

commit d0844398e2b31632a6a486fc7f103d47d50fb4e4
Author: Markus Metzger <markus.t.metzger@intel.com>
Date:   Fri Oct 25 07:17:05 2024 +0000

    btrace, infrun: simplify scheduler-locking replay
    
    When scheduler-locking is set to replay and we're resuming a thread at the
    end of its execution history, we check whether anything is replaying in
    user_visible_resume_ptid() only to check again in clear_proceed_status()
    before we stop replaying the current process.
    
    What really matters is whether the selected thread is replaying or will
    start replaying.
    
    Simplify this by removing redundant checks.
    
    Also avoid a redundant pass over all threads to check whether anything is
    replaying before stopping replaying.  Make record_stop_replaying() handle
    the case when we're not replaying gracefully.
    
    Approved-By: Tom Tromey <tom@tromey.com>

Diff:
---
 gdb/infrun.c      | 10 ++++------
 gdb/record-full.c |  3 ++-
 2 files changed, 6 insertions(+), 7 deletions(-)

diff --git a/gdb/infrun.c b/gdb/infrun.c
index 81764e6b1a2..99362fe09e9 100644
--- a/gdb/infrun.c
+++ b/gdb/infrun.c
@@ -2397,7 +2397,7 @@ 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 (inferior_ptid, execution_direction))
     {
       /* User-settable 'scheduler' mode requires solo thread resume in replay
 	 mode.  */
@@ -3109,16 +3109,14 @@ notify_about_to_proceed ()
 void
 clear_proceed_status (int step)
 {
-  /* With scheduler-locking replay, stop replaying other threads if we're
-     not replaying the user-visible resume ptid.
+  /* With scheduler-locking replay, stop replaying other threads in the
+     same process if we're not replaying the selected thread.
 
      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.  */
   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_will_replay (inferior_ptid, execution_direction))
     target_record_stop_replaying ();
 
   if (!non_stop && inferior_ptid != null_ptid)
diff --git a/gdb/record-full.c b/gdb/record-full.c
index ff45fcf0343..15d2435ba3c 100644
--- a/gdb/record-full.c
+++ b/gdb/record-full.c
@@ -2074,7 +2074,8 @@ record_full_base_target::goto_record (ULONGEST target_insn)
 void
 record_full_base_target::record_stop_replaying ()
 {
-  goto_record_end ();
+  if (RECORD_FULL_IS_REPLAY)
+    goto_record_end ();
 }
 
 /* "resume" method for prec over corefile.  */