refactor(agent): optimize user function instrumentation lookup for PHPs 8.0+

agent/php_execute.c

@@ -93,6 +93,12 @@
  * conditions wherever possible.
  */
 
+static inline nruserfn_t* nr_php_get_wraprec_from_op_array_extension(const char* fn, zend_function* zf) {
+  nruserfn_t* wraprec = (nruserfn_t*)ZEND_OP_ARRAY_EXTENSION(&zf->op_array, NR_PHP_PROCESS_GLOBALS(op_array_extension_handle));
+  nrl_verbosedebug(NRL_AGENT, "%s from %s, op_array_extension=%p, wraprec=%p, wraprec->pid=%d", __func__, fn, ZEND_OP_ARRAY_EXTENSION(&zf->op_array, NR_PHP_PROCESS_GLOBALS(op_array_extension_handle)), wraprec, wraprec->pid);
+  return wraprec;
+}
+
 static void nr_php_show_exec_return(NR_EXECUTE_PROTO TSRMLS_DC);
 static int nr_php_show_exec_indentation(TSRMLS_D);
 static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC);
@@ -598,6 +604,7 @@ static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
   char argstr[NR_EXECUTE_DEBUG_STRBUFSZ];
   const char* filename = nr_php_op_array_file_name(NR_OP_ARRAY);
   const char* function_name = nr_php_op_array_function_name(NR_OP_ARRAY);
+  nruserfn_t* wr = nr_php_get_wraprec_from_op_array_extension(__func__, execute_data->func);
 
   argstr[0] = '\0';
 
@@ -621,7 +628,7 @@ static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
 #if ZEND_MODULE_API_NO < ZEND_7_4_X_API_NO
         nr_php_op_array_get_wraprec(NR_OP_ARRAY TSRMLS_CC) ? " *" : "",
 #else
-        nr_php_get_wraprec(execute_data->func) ? " *" : "",
+        wr ? " *" : "",
 #endif
         NRP_FILENAME(filename), NR_OP_ARRAY->line_start);
   } else if (NR_OP_ARRAY->function_name) {
@@ -642,7 +649,7 @@ static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
 #if ZEND_MODULE_API_NO < ZEND_7_4_X_API_NO
         nr_php_op_array_get_wraprec(NR_OP_ARRAY TSRMLS_CC) ? " *" : "",
 #else
-        nr_php_get_wraprec(execute_data->func) ? " *" : "",
+        wr ? " *" : "",
 #endif
         NRP_FILENAME(filename), NR_OP_ARRAY->line_start);
   } else if (NR_OP_ARRAY->filename) {
@@ -1928,7 +1935,7 @@ static void nr_php_instrument_func_begin(NR_EXECUTE_PROTO) {
      */
     nr_php_observer_attempt_call_cufa_handler(NR_EXECUTE_ORIG_ARGS);
   }
-  wraprec = nr_php_get_wraprec(execute_data->func);
+  wraprec = nr_php_get_wraprec_from_op_array_extension(__func__, execute_data->func);
 
   segment = nr_segment_start(NRPRG(txn), NULL, NULL);
 

agent/php_globals.h

@@ -49,12 +49,10 @@ typedef struct _nrphpglobals_t {
                       * variable with the key `NEW_RELIC_LABELS`	 */
 #if ZEND_MODULE_API_NO >= ZEND_8_1_X_API_NO /* PHP 8.1+ */
   zend_long zend_offset;                    /* Zend extension offset */
-  zend_long
-      zend_op_array_offset; /* Zend extension op_array to modify reserved */
 #else
   int zend_offset;          /* Zend extension offset */
-  int zend_op_array_offset; /* Zend extension op_array to modify reserved */
 #endif
+  int op_array_extension_handle; /* Zend op_array extension handle to attach agent's data to function */
   int done_instrumentation;  /* Set to true if we have installed instrumentation
                                 handlers */
   nrtime_t expensive_min;    /* newrelic.special.expensive_node_min */

agent/php_minit.c

@@ -722,6 +722,11 @@ PHP_MINIT_FUNCTION(newrelic) {
   nrl_debug(NRL_INIT, "MINIT processing done");
 #if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO /* PHP 7.4+ */
   NR_PHP_PROCESS_GLOBALS(zend_offset) = zend_get_resource_handle(dummy);
+#if ZEND_MODULE_API_NO >= ZEND_8_4_X_API_NO /* PHP 7.4+ */
+  NR_PHP_PROCESS_GLOBALS(op_array_extension_handle) = zend_get_internal_function_extension_handle("newrelic");
+#else
+  NR_PHP_PROCESS_GLOBALS(op_array_extension_handle) = zend_get_op_array_extension_handle("newrelic");
+#endif
 #else
   NR_PHP_PROCESS_GLOBALS(zend_offset) = zend_get_resource_handle(&dummy);
 #endif

agent/php_observer.c

@@ -75,13 +75,27 @@
 static zend_observer_fcall_handlers nr_php_fcall_register_handlers(
     zend_execute_data* execute_data) {
   zend_observer_fcall_handlers handlers = {NULL, NULL};
+  nruserfn_t* wr;
   if (NULL == execute_data) {
     return handlers;
   }
   if ((NULL == execute_data->func)
       || (ZEND_INTERNAL_FUNCTION == execute_data->func->type)) {
     return handlers;
   }
+
+  if (!OP_ARRAY_IS_A_FILE(NR_OP_ARRAY)) {
+    nrl_verbosedebug(NRL_AGENT, "Registering Observer API handlers for user function %s",
+            NRSAFESTR(nr_php_op_array_function_name(NR_OP_ARRAY)));
+  } else {
+    nrl_verbosedebug(NRL_AGENT, "Registering Observer API handlers for file %s",
+            NRSAFESTR(nr_php_op_array_file_name(NR_OP_ARRAY)));
+  }
+
+  wr = nr_php_get_wraprec(execute_data->func);
+  // store the wraprec in the op_array extension for the duration of the request for later lookup
+  ZEND_OP_ARRAY_EXTENSION(&execute_data->func->op_array, NR_PHP_PROCESS_GLOBALS(op_array_extension_handle)) = wr;
+
   handlers.begin = nr_php_observer_fcall_begin;
   handlers.end = nr_php_observer_fcall_end;
   return handlers;

agent/php_user_instrument.c

@@ -130,6 +130,10 @@ static nr_php_wraprec_hashmap_t* user_function_wrappers;
 static inline void nr_php_wraprec_lookup_set(nruserfn_t* wr,
                                              zend_function* zf) {
   nr_php_wraprec_hashmap_update(user_function_wrappers, zf, wr);
+  // store the wraprec in the op_array extension for the duration of the request for later lookup
+  // for situation when wraprec is added after first execution of the function
+  ZEND_OP_ARRAY_EXTENSION(&zf->op_array, NR_PHP_PROCESS_GLOBALS(op_array_extension_handle)) = wr;
+
 }
 static inline nruserfn_t* nr_php_wraprec_lookup_get(zend_function* zf) {
   nruserfn_t* wraprec = NULL;
@@ -291,7 +295,9 @@ static void nr_php_wrap_user_function_internal(nruserfn_t* wraprec TSRMLS_DC) {
 }
 
 static nruserfn_t* nr_php_user_wraprec_create(void) {
-  return (nruserfn_t*)nr_zalloc(sizeof(nruserfn_t));
+  nruserfn_t* wr = (nruserfn_t*)nr_zalloc(sizeof(nruserfn_t));
+  wr->pid = nr_getpid();
+  return wr;
 }
 
 static nruserfn_t* nr_php_user_wraprec_create_named(const char* full_name,

agent/php_user_instrument.h

@@ -108,6 +108,7 @@ typedef struct _nruserfn_t {
 #if ZEND_MODULE_API_NO >= ZEND_7_4_X_API_NO
   char* wordpress_plugin_theme;
 #endif
+  int pid; /* pid of a process that created this wraprec */
 } nruserfn_t;
 
 extern nruserfn_t* nr_wrapped_user_functions; /* a singly linked list */