Fix gc.test "after-gc-hook gets called" failures.

* libguile/scmsigs.c (signal_delivery_thread): Call scm_async_tick to
give any pending asyncs a chance to run before we block indefinitely
waiting for a signal to arrive.

1 files changed, 8 insertions, 0 deletions

diff --git a/libguile/scmsigs.c b/libguile/scmsigs.c
index b4bd380be..1583f4f3e 100644
--- a/libguile/scmsigs.c
+++ b/libguile/scmsigs.c
@@ -182,6 +182,14 @@ signal_delivery_thread (void *data)
     {
       struct signal_pipe_data sigdata;
 
+      /* This tick gives any pending asyncs a chance to run before we
+         block indefinitely waiting for a signal to arrive.  For example
+         it can happen that the garbage collector is triggered while
+         marking the signal handler for future execution.  Due to the
+         way the after-gc-hook is designed, without a call to
+         scm_async_tick, the after-gc-hook will not be triggered. */
+      scm_async_tick ();
+
       scm_without_guile (read_signal_pipe_data, &sigdata);
       
       sig = sigdata.sigbyte;