Provide infrastructure for PERL_ASYNC_CHECK() style safe signals.

Provides all the "cost" but no benefit yet - it is to allow cost
to be measured, and implementation experiments (just in mg.c?).

p4raw-id: //depot/perlio@8457

1 files changed, 5 insertions, 0 deletions

diff --git a/perl.h b/perl.h
index 19827a3101..bbea5dddd3 100644
--- a/perl.h
+++ b/perl.h
@@ -3338,6 +3338,11 @@ typedef struct am_table_short AMTS;
  * Keep this check simple, or it may slow down execution
  * massively.
  */
+
+#ifndef PERL_OLD_SIGNALS
+#define PERL_ASYNC_CHECK() if (PL_sig_pending) despatch_signals()
+#endif
+
 #ifndef PERL_ASYNC_CHECK
 #define PERL_ASYNC_CHECK()  NOOP
 #endif