[Emacs-diffs] emacs-26 f7fdaea: A better solution for bug#29347

[Eli Zaretskii]

branch: emacs-26
commit f7fdaea4c0a2f4285d974a2870c4f6b465b40500
Author: Eli Zaretskii <address@hidden>
Commit: Eli Zaretskii <address@hidden>

    A better solution for bug#29347
    
    * src/thread.c (really_call_select): Don't try to take the global
    lock if the same thread is already holding it.  (Bug#29347)
---
 src/thread.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/thread.c b/src/thread.c
index 9e799ce..dd46681 100644
--- a/src/thread.c
+++ b/src/thread.c
@@ -97,12 +97,7 @@ post_acquire_global_lock (struct thread_state *self)
 static void
 acquire_global_lock (struct thread_state *self)
 {
-  /* If some Lisp was interrupted by C-g while inside pselect, the
-     signal handler could have called maybe_reacquire_global_lock, in
-     which case we are already holding the lock and shouldn't try
-     taking it again, or else we will hang forever.  */
-  if (!(self && !self->not_holding_lock))
-    sys_mutex_lock (&global_lock);
+  sys_mutex_lock (&global_lock);
   post_acquire_global_lock (self);
 }
 
@@ -578,8 +573,15 @@ really_call_select (void *arg)
                           sa->timeout, sa->sigmask);
 
   block_interrupt_signal (&oldset);
-  acquire_global_lock (self);
-  self->not_holding_lock = 0;
+  /* If we were interrupted by C-g while inside sa->func above, the
+     signal handler could have called maybe_reacquire_global_lock, in
+     which case we are already holding the lock and shouldn't try
+     taking it again, or else we will hang forever.  */
+  if (self->not_holding_lock)
+    {
+      acquire_global_lock (self);
+      self->not_holding_lock = 0;
+    }
   restore_signal_mask (&oldset);
 }