Add some sleeps to gnutls_try_handshake

* admin/merge-gnulib (GNULIB_MODULES): Add the nanosleep module.
* m4/gnulib-comp.m4 (gl_EARLY):
* lib/gnulib.mk.in: Automatic update.

* m4/nanosleep.m4:
* lib/nanosleep.c: New module.

* nt/mingw-cfg.site (gl_cv_func_free_preserves_errno):
* nt/gnulib-cfg.mk (OMIT_GNULIB_MODULE_nanosleep): Omit nanosleep,
since mingw has it.

* src/gnutls.c (gnutls_try_handshake): Add some sleeping to the
busy-wait loop so that we don't use 100% CPU here (bug#32452).

1 files changed, 4 insertions, 0 deletions

diff --git a/src/gnutls.c b/src/gnutls.c
index 3ec38370679..09590ca005c 100644
--- a/src/gnutls.c
+++ b/src/gnutls.c
@@ -616,6 +616,9 @@ gnutls_try_handshake (struct Lisp_Process *proc)
   gnutls_session_t state = proc->gnutls_state;
   int ret;
   bool non_blocking = proc->is_non_blocking_client;
+  /* Sleep for ten milliseconds when busy-looping in
+     gnutls_handshake.  */
+  struct timespec delay = { 0, 1000 * 1000 * 10 };
 
   if (proc->gnutls_complete_negotiation_p)
     non_blocking = false;
@@ -630,6 +633,7 @@ gnutls_try_handshake (struct Lisp_Process *proc)
       maybe_quit ();
       if (non_blocking && ret != GNUTLS_E_INTERRUPTED)
         break;
+      nanosleep (&delay, NULL);
     }
 
   proc->gnutls_initstage = GNUTLS_STAGE_HANDSHAKE_TRIED;