Disabled PHP call tracing by default (it makes significant overhead).

This may be enabled again using envirionment variable USE_ZEND_DTRACE=1.

Author: dstogov

NEWS

@@ -12,6 +12,11 @@ PHP                                                                        NEWS
 - Date:
   . Fixed bug #69587 (DateInterval properties and isset). (jhdxr)
 
+- DTrace:
+  . Disabled PHP call tracing by default (it makes significant overhead).
+    This may be enabled again using envirionment variable USE_ZEND_DTRACE=1.
+    (Dmitry)
+
 - ODBC:
   . Fixed bug #73448 (odbc_errormsg returns trash, always 513 bytes).
     (Anatol)

Zend/zend.c

@@ -678,9 +678,19 @@ int zend_startup(zend_utility_functions *utility_functions, char **extensions) /
 
 #if HAVE_DTRACE
 /* build with dtrace support */
-	zend_compile_file = dtrace_compile_file;
-	zend_execute_ex = dtrace_execute_ex;
-	zend_execute_internal = dtrace_execute_internal;
+	{
+		char *tmp = getenv("USE_ZEND_DTRACE");
+
+		if (tmp && zend_atoi(tmp, 0)) {
+			zend_compile_file = dtrace_compile_file;
+			zend_execute_ex = dtrace_execute_ex;
+			zend_execute_internal = dtrace_execute_internal;
+		} else {
+			zend_compile_file = compile_file;
+			zend_execute_ex = execute_ex;
+			zend_execute_internal = NULL;
+		}
+	}
 #else
 	zend_compile_file = compile_file;
 	zend_execute_ex = execute_ex;