Remove redundant global variable: SIGG(reset)

This global variable controls whether the Zend deferred signal handlers are installed
at the beginning of each request or not. Interestingly, it is set to 1 on
initialization, and there is only *one* place where the value is modified.

This is in OPCache, where the global is temporarily set to 0 while preloading.
Why is this? Discussion on GitHub revealed that the purpose was so that what happens
during preloading would not affect subsequent requests... but the fact is, as long
as Zend signal handling is enabled, the Zend signal handlers will always be installed
on each subsequent request, so installing them during preloading will not affect
anything.

Author: alexdowad

Zend/zend_signal.c

@@ -320,10 +320,8 @@ void zend_signal_activate(void)
 
 	memcpy(&SIGG(handlers), &global_orig_handlers, sizeof(global_orig_handlers));
 
-	if (SIGG(reset)) {
-		for (x = 0; x < sizeof(zend_sigs) / sizeof(*zend_sigs); x++) {
-			zend_signal_register(zend_sigs[x], zend_signal_handler_defer);
-		}
+	for (x = 0; x < sizeof(zend_sigs) / sizeof(*zend_sigs); x++) {
+		zend_signal_register(zend_sigs[x], zend_signal_handler_defer);
 	}
 
 	SIGG(active) = 1;
@@ -376,7 +374,6 @@ static void zend_signal_globals_ctor(zend_signal_globals_t *zend_signal_globals)
 	size_t x;
 
 	memset(zend_signal_globals, 0, sizeof(*zend_signal_globals));
-	zend_signal_globals->reset = 1;
 
 	for (x = 0; x < sizeof(zend_signal_globals->pstorage) / sizeof(*zend_signal_globals->pstorage); ++x) {
 		zend_signal_queue_t *queue = &zend_signal_globals->pstorage[x];

Zend/zend_signal.h

@@ -57,7 +57,6 @@ typedef struct _zend_signal_globals_t {
 	int running;            /* in signal handler execution */
 	int active;             /* internal signal handling is enabled */
 	zend_bool check;        /* check for replaced handlers on shutdown */
-	zend_bool reset;        /* reset signal handlers on each request */
 	zend_signal_entry_t handlers[NSIG];
 	zend_signal_queue_t pstorage[ZEND_SIGNAL_QUEUE_SIZE], *phead, *ptail, *pavail; /* pending queue */
 } zend_signal_globals_t;

ext/opcache/ZendAccelerator.c

@@ -4802,9 +4802,6 @@ static int accel_finish_startup(void)
 		size_t (*orig_ub_write)(const char *str, size_t str_length) = sapi_module.ub_write;
 		void (*orig_flush)(void *server_context) = sapi_module.flush;
 		uint32_t orig_compiler_options = CG(compiler_options);
-#ifdef ZEND_SIGNALS
-		zend_bool old_reset_signals = SIGG(reset);
-#endif
 
 		if (UNEXPECTED(file_cache_only)) {
 			zend_accel_error(ACCEL_LOG_WARNING, "Preloading doesn't work in \"file_cache_only\" mode");
@@ -4907,10 +4904,6 @@ static int accel_finish_startup(void)
 
 		zend_interned_strings_switch_storage(1);
 
-#ifdef ZEND_SIGNALS
-		SIGG(reset) = 0;
-#endif
-
 		orig_error_reporting = EG(error_reporting);
 		EG(error_reporting) = 0;
 
@@ -4943,20 +4936,12 @@ static int accel_finish_startup(void)
 
 			orig_report_memleaks = PG(report_memleaks);
 			PG(report_memleaks) = 0;
-#ifdef ZEND_SIGNALS
-			/* We may not have registered signal handlers due to SIGG(reset)=0, so
-			 * also disable the check that they are registered. */
-			SIGG(check) = 0;
-#endif
 			php_request_shutdown(NULL); /* calls zend_shared_alloc_unlock(); */
 			PG(report_memleaks) = orig_report_memleaks;
 		} else {
 			zend_shared_alloc_unlock();
 			ret = FAILURE;
 		}
-#ifdef ZEND_SIGNALS
-		SIGG(reset) = old_reset_signals;
-#endif
 
 		CG(compiler_options) = orig_compiler_options;