thread.c (consume_communication_pipe): disarm UBF_TIMER before consume

Same reasoning as the disarm in rb_sigwait_fd_get, the current
thread is already processing signals, so we do not need
UBF_TIMER to continually kick the process, anymore.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64390 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

thread.c

@@ -4269,6 +4269,14 @@ consume_communication_pipe(int fd)
     ssize_t result;
     int ret = FALSE; /* for rb_sigwait_sleep */
 
+    /*
+     * disarm UBF_TIMER before we read, because it can become
+     * re-armed at any time via sighandler and the pipe will refill
+     * We can disarm it because this thread is now processing signals
+     * and we do not want unnecessary SIGVTALRM
+     */
+    ubf_timer_disarm();
+
     while (1) {
 	result = read(fd, buff, sizeof(buff));
 	if (result > 0) {

thread_win32.c

@@ -22,6 +22,7 @@
 #define unregister_ubf_list(th)
 #define ubf_wakeup_all_threads() do {} while (0)
 #define ubf_threads_empty() (1)
+#define ubf_timer_disarm() do {} while (0)
 
 static volatile DWORD ruby_native_thread_key = TLS_OUT_OF_INDEXES;