Description:
------------
When compiled with #ifdef ZTS, the setitimer calls in zend_unset_timeout show up as a performance hotspot even when 
max_execution_time and max_input_time are set to 0 in php.ini.

(Originally posted to the internals list - http://marc.info/?l=php-internals&m=125689761124706&w=2)

Reproduce code:
---------------
The following patch avoids invoking zend_unset_timeout (and thereby the expensive setitimer call within) when timeouts have been disabled via settings in php.ini


diff -r d0dddebae3a2 main/main.c
--- a/main/main.c	Mon May 04 18:11:50 2009 +0200
+++ b/main/main.c	Fri Aug 28 17:35:25 2009 +0530
@@ -1602,7 +1602,9 @@
 	} zend_end_try();
 
 	zend_try {
-		zend_unset_timeout(TSRMLS_C);
+		if (EG(timeout_seconds) != 0) {
+			zend_unset_timeout(TSRMLS_C);
+		}
 	} zend_end_try();
 }
 
@@ -1702,7 +1704,9 @@
 
 	/* 12. Reset max_execution_time */
 	zend_try {
-		zend_unset_timeout(TSRMLS_C);
+		if (EG(timeout_seconds) != 0) {
+			zend_unset_timeout(TSRMLS_C);
+		}
 	} zend_end_try();
 
 #ifdef PHP_WIN32


Expected result:
----------------
Improved multi-threaded performance.