Add OPcache restart hook (php#15590)

This hook will allow observing extensions to observe the actual OPcache restart.

Author: realFlowControl

Zend/zend.c

@@ -94,6 +94,7 @@ ZEND_API char *(*zend_getenv)(const char *name, size_t name_len);
 ZEND_API zend_string *(*zend_resolve_path)(zend_string *filename);
 ZEND_API zend_result (*zend_post_startup_cb)(void) = NULL;
 ZEND_API void (*zend_post_shutdown_cb)(void) = NULL;
+ZEND_API void (*zend_accel_schedule_restart_hook)(int reason) = NULL;
 ZEND_ATTRIBUTE_NONNULL ZEND_API zend_result (*zend_random_bytes)(void *bytes, size_t size, char *errstr, size_t errstr_size) = NULL;
 ZEND_ATTRIBUTE_NONNULL ZEND_API void (*zend_random_bytes_insecure)(zend_random_bytes_insecure_state *state, void *bytes, size_t size) = NULL;
 

Zend/zend.h

@@ -377,6 +377,8 @@ extern ZEND_ATTRIBUTE_NONNULL ZEND_API void (*zend_random_bytes_insecure)(
 extern ZEND_API zend_result (*zend_post_startup_cb)(void);
 extern ZEND_API void (*zend_post_shutdown_cb)(void);
 
+extern ZEND_API void (*zend_accel_schedule_restart_hook)(int reason);
+
 ZEND_API ZEND_COLD void zend_error(int type, const char *format, ...) ZEND_ATTRIBUTE_FORMAT(printf, 2, 3);
 ZEND_API ZEND_COLD ZEND_NORETURN void zend_error_noreturn(int type, const char *format, ...) ZEND_ATTRIBUTE_FORMAT(printf, 2, 3);
 ZEND_API ZEND_COLD ZEND_NORETURN void zend_error_noreturn_unchecked(int type, const char *format, ...);

ext/opcache/ZendAccelerator.c

@@ -3431,6 +3431,11 @@ void zend_accel_schedule_restart(zend_accel_restart_reason reason)
 		/* don't schedule twice */
 		return;
 	}
+
+	if (UNEXPECTED(zend_accel_schedule_restart_hook)) {
+		zend_accel_schedule_restart_hook(reason);
+	}
+
 	zend_accel_error(ACCEL_LOG_DEBUG, "Restart Scheduled! Reason: %s",
 			zend_accel_restart_reason_text[reason]);
 

ext/opcache/ZendAccelerator.h

@@ -311,7 +311,7 @@ extern const char *zps_api_failure_reason;
 BEGIN_EXTERN_C()
 
 void accel_shutdown(void);
-zend_result  accel_activate(INIT_FUNC_ARGS);
+zend_result accel_activate(INIT_FUNC_ARGS);
 zend_result accel_post_deactivate(void);
 void zend_accel_schedule_restart(zend_accel_restart_reason reason);
 void zend_accel_schedule_restart_if_necessary(zend_accel_restart_reason reason);