+ shutdown_destructors_async Support for concurrent iteration of the global variable table

Author: EdmondDantes

Zend/zend.c

@@ -1336,7 +1336,7 @@ void zend_call_destructors(void) /* {{{ */
 {
 	zend_try {
 #ifdef PHP_ASYNC_API
-		async_shutdown_destructors();
+		shutdown_destructors_async();
 #else
 		shutdown_destructors();
 #endif

Zend/zend_execute.h

@@ -40,6 +40,9 @@ ZEND_API extern zend_class_entry *(*zend_autoload)(zend_string *name, zend_strin
 void init_executor(void);
 void shutdown_executor(void);
 void shutdown_destructors(void);
+#ifdef PHP_ASYNC_API
+void shutdown_destructors_async(void);
+#endif
 ZEND_API void zend_shutdown_executor_values(bool fast_shutdown);
 
 ZEND_API void zend_init_execute_data(zend_execute_data *execute_data, zend_op_array *op_array, zval *return_value);

Zend/zend_execute_API.c

@@ -199,6 +199,13 @@ void init_executor(void) /* {{{ */
 	EG(filename_override) = NULL;
 	EG(lineno_override) = -1;
 
+#ifdef PHP_ASYNC_API
+	EG(shutdown_context) = (zend_shutdown_context_t) {
+		.coroutine = NULL,
+		.idx = 0
+	};
+#endif
+
 	zend_max_execution_timer_init();
 	zend_fiber_init();
 	zend_weakrefs_init();
@@ -267,6 +274,113 @@ void shutdown_destructors(void) /* {{{ */
 }
 /* }}} */
 
+#ifdef PHP_ASYNC_API
+#include "zend_async_API.h"
+
+static void  shutdown_destructors_coroutine_dtor(zend_coroutine_t *coroutine)
+{
+	zend_shutdown_context_t *shutdown_context = &EG(shutdown_context);
+
+	if (shutdown_context->coroutine == coroutine) {
+		shutdown_context->coroutine = NULL;
+		zend_error(E_CORE_ERROR, "Shutdown destructors coroutine was not finished property");
+		EG(symbol_table).pDestructor = zend_unclean_zval_ptr_dtor;
+		shutdown_destructors();
+	}
+}
+
+static bool shutdown_destructors_context_switch_handler(
+	zend_coroutine_t *coroutine, 
+	bool is_enter, 
+	bool is_finishing
+) {
+	zend_coroutine_t *shutdown_coroutine = ZEND_ASYNC_NEW_COROUTINE(ZEND_ASYNC_MAIN_SCOPE);
+
+	shutdown_coroutine->internal_entry = shutdown_destructors_async;
+	shutdown_coroutine->extended_dispose = shutdown_destructors_coroutine_dtor;
+
+	return false;
+}
+
+void shutdown_destructors_async(void) /* {{{ */
+{
+	zend_coroutine_t *coroutine = ZEND_ASYNC_CURRENT_COROUTINE;
+	bool should_continue = false;
+
+	zend_shutdown_context_t *shutdown_context = &EG(shutdown_context);
+
+	if (coroutine == NULL) {
+		ZEND_ASYNC_ADD_MAIN_COROUTINE_START_HANDLER(shutdown_destructors_context_switch_handler);
+	} else {
+		ZEND_COROUTINE_ADD_SWITCH_HANDLER(coroutine, shutdown_destructors_context_switch_handler);
+	}
+
+	HashTable *symbol_table = &EG(symbol_table);
+
+	if (shutdown_context->coroutine == NULL) {
+		shutdown_context->coroutine = coroutine;
+		shutdown_context->num_elements = zend_hash_num_elements(symbol_table);
+		shutdown_context->idx = symbol_table->nNumUsed;
+	}
+
+	if (CG(unclean_shutdown)) {
+		EG(symbol_table).pDestructor = zend_unclean_zval_ptr_dtor;
+	}
+
+	zend_try {
+		do {
+			if (should_continue) {
+				shutdown_context->num_elements = zend_hash_num_elements(symbol_table);
+				shutdown_context->idx = symbol_table->nNumUsed;
+			} else {
+				should_continue = true;
+			}
+
+			while (shutdown_context->idx > 0) {
+
+				shutdown_context->idx--;
+
+				Bucket *p = symbol_table->arData + shutdown_context->idx;
+
+				if (UNEXPECTED(Z_TYPE(p->val) == IS_UNDEF)) {
+					continue;
+				}
+				
+				zval *zv = &p->val;
+				if (Z_TYPE_P(zv) == IS_INDIRECT) {
+					zv = Z_INDIRECT_P(zv);
+				}
+				
+				if (Z_TYPE_P(zv) == IS_OBJECT && Z_REFCOUNT_P(zv) == 1) {
+					zend_hash_del_bucket(symbol_table, p);
+				}
+				
+				// If the coroutine has changed
+				if (coroutine != ZEND_ASYNC_CURRENT_COROUTINE) {
+					should_continue = false;
+					break;
+				}
+			}
+
+			if (false == should_continue) {
+				break;
+			}
+
+		} while (shutdown_context->num_elements != zend_hash_num_elements(symbol_table));
+
+		if (should_continue) {
+			shutdown_context->coroutine = NULL;
+			zend_objects_store_call_destructors(&EG(objects_store));
+		}
+	} zend_catch {
+		EG(symbol_table).pDestructor = zend_unclean_zval_ptr_dtor;
+		shutdown_destructors();
+		zend_bailout();
+	} zend_end_try();
+}
+/* }}} */
+#endif
+
 /* Free values held by the executor. */
 ZEND_API void zend_shutdown_executor_values(bool fast_shutdown)
 {

Zend/zend_globals.h

@@ -163,6 +163,13 @@ struct _zend_compiler_globals {
 #endif
 };
 
+#ifdef PHP_ASYNC_API
+typedef struct {
+	void *coroutine;
+	uint32_t num_elements;
+	uint32_t idx;
+} zend_shutdown_context_t;
+#endif
 
 struct _zend_executor_globals {
 	zval uninitialized_zval;
@@ -259,6 +266,11 @@ struct _zend_executor_globals {
 	const zend_op *opline_before_exception;
 	zend_op exception_op[3];
 
+#ifdef PHP_ASYNC_API
+	// Used to track the state of shutdown destructors in coroutines
+	zend_shutdown_context_t shutdown_context;
+#endif
+
 	struct _zend_module_entry *current_module;
 
 	bool active;

main/main.c

@@ -1935,6 +1935,10 @@ void php_request_shutdown(void *dummy)
 		zend_call_destructors();
 	} zend_end_try();
 
+#ifdef PHP_ASYNC_API
+	ZEND_ASYNC_RUN_SCHEDULER_AFTER_MAIN();
+#endif
+
 	/* 3. Flush all output buffers */
 	zend_try {
 		php_output_end_all();