refactor(agent): optimize user function instrumentation lookup for PHPs 8.0+ (#1042)

Reduce agent’s CPU overhead when observer API is used to hook
into Zend Engine. This is achieved by:
* Simplifying the checks the agent needs to perform to determine if
special instrumentation for user function is provided. Before this
change, on every function execution the agent used a hashmap to check if
special instrumentation for user function is provided. However, when the
observer API is used to hook into Zend Engine, this can be done only
once per user function execution at the time when the user function is
executed for the first time.
* Reducing the number of times the name of the file is compared with the
list of ‘magic files’ to detect package and/or framework used. Before
this change on every file execution the agent scanned the list of magic
files twice. However, when the observer API is used to hook into Zend
Engine, this can be done only once per file execution.

---------

Co-authored-by: Amber Sistla <[email protected]>

Author: lavarou

agent/Makefile.frag

@@ -117,6 +117,7 @@ TEST_BINARIES = \
 	tests/test_txn_private \
 	tests/test_user_instrument \
 	tests/test_user_instrument_hashmap \
+	tests/test_user_instrument_wraprec_hashmap \
 	tests/test_zval
 
 .PHONY: unit-tests

agent/config.m4

@@ -220,6 +220,7 @@ if test "$PHP_NEWRELIC" = "yes"; then
   php_pdo_mysql.c php_pdo_pgsql.c php_pgsql.c php_psr7.c php_redis.c \
   php_rinit.c php_rshutdown.c php_samplers.c php_stack.c \
   php_stacked_segment.c php_txn.c php_user_instrument.c \
+  php_user_instrument_wraprec_hashmap.c \
   php_user_instrument_hashmap.c php_vm.c php_wrapper.c"
   FRAMEWORKS="fw_cakephp.c fw_codeigniter.c fw_drupal8.c \
   fw_drupal.c fw_drupal_common.c fw_joomla.c fw_kohana.c \

agent/fw_drupal8.c

@@ -140,14 +140,17 @@ static void nr_drupal8_add_method_callback_before_after_clean(
     nrspecialfn_t after_callback,
     nrspecialfn_t clean_callback) {
   zend_function* function = NULL;
+  char* methodLC = NULL;
 
   if (NULL == ce) {
     nrl_verbosedebug(NRL_FRAMEWORK, "Drupal 8: got NULL class entry in %s",
                      __func__);
     return;
   }
 
-  function = nr_php_find_class_method(ce, method);
+  methodLC = nr_string_to_lowercase(method);
+  function = nr_php_find_class_method(ce, methodLC);
+  nr_free(methodLC);
   if (NULL == function) {
     nrl_verbosedebug(NRL_FRAMEWORK,
                      "Drupal 8+: cannot get zend_function entry for %.*s::%.*s",
@@ -640,7 +643,7 @@ NR_PHP_WRAPPER(nr_drupal8_module_handler) {
 #if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO \
     && !defined OVERWRITE_ZEND_EXECUTE_DATA
   nr_drupal8_add_method_callback_before_after_clean(
-      ce, NR_PSTR("invokeallwith"), nr_drupal94_invoke_all_with,
+      ce, NR_PSTR("invokeAllWith"), nr_drupal94_invoke_all_with,
       nr_drupal94_invoke_all_with_after, nr_drupal94_invoke_all_with_clean);
 #else
   nr_drupal8_add_method_callback(ce, NR_PSTR("invokeallwith"),

agent/fw_laminas3.c

@@ -155,7 +155,7 @@ void nr_laminas3_enable(TSRMLS_D) {
    */
 
   nr_php_wrap_user_function(
-      NR_PSTR("Laminas\\Router\\HTTP\\RouteMatch::setMatchedRouteName"),
+      NR_PSTR("Laminas\\Router\\Http\\RouteMatch::setMatchedRouteName"),
       nr_laminas3_name_the_wt TSRMLS_CC);
   nr_php_wrap_user_function(
       NR_PSTR("Laminas\\Router\\RouteMatch::setMatchedRouteName"),

agent/fw_laravel.c

@@ -1232,10 +1232,10 @@ void nr_laravel_enable(TSRMLS_D) {
 #if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO \
     && !defined OVERWRITE_ZEND_EXECUTE_DATA
   nr_php_wrap_user_function_before_after_clean(
-      NR_PSTR("Illuminate\\Console\\Application::doRun"),
+      NR_PSTR("Symfony\\Component\\Console\\Application::doRun"),
       nr_laravel_console_application_dorun, NULL, NULL);
 #else
-  nr_php_wrap_user_function(NR_PSTR("Illuminate\\Console\\Application::doRun"),
+  nr_php_wrap_user_function(NR_PSTR("Symfony\\Component\\Console\\Application::doRun"),
                             nr_laravel_console_application_dorun TSRMLS_CC);
 #endif
   /*

agent/lib_php_amqplib.c

@@ -81,29 +81,6 @@
  * needed to work with MQ_BROKER.
  */
 
-/*
- * Purpose : Ensures the php-amqplib instrumentation gets wrapped.
- *
- * Params  : None
- *
- * Returns : None
- */
-static void nr_php_amqplib_ensure_class() {
-  int result = FAILURE;
-  zend_class_entry* class_entry = NULL;
-
-  class_entry = nr_php_find_class("phpamqplib\\channel\\amqpchannel");
-  if (NULL == class_entry) {
-    result = zend_eval_stringl(
-        NR_PSTR("class_exists('PhpAmqpLib\\Channel\\AMQPChannel');"), NULL,
-        "nr_php_amqplib_class_exists_channel_amqpchannel");
-  }
-  /*
-   * We don't need to check anything else at this point. If this fails, there's
-   * nothing else we can do anyway.
-   */
-}
-
 /*
  * Version information will be pulled from PhpAmqpLib\\Package::VERSION
  * nr_php_amqplib_handle_version will automatically load the class if it isn't
@@ -810,7 +787,6 @@ void nr_php_amqplib_enable() {
 
   /* Extract the version */
   nr_php_amqplib_handle_version();
-  nr_php_amqplib_ensure_class();
 
 #if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO /* less than PHP8.0 */
   nr_php_wrap_user_function_before_after_clean(

agent/php_execute.c

@@ -95,7 +95,6 @@
 
 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);
 
 /*
  * Purpose: Enable monitoring on specific functions in the framework.
@@ -594,11 +593,11 @@ static int nr_php_show_exec_indentation(TSRMLS_D) {
  * Note that this function doesn't handle internal functions, and will crash if
  * you give it one.
  */
-static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
+void nr_php_show_exec(const char* context, 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);
-
+  const char* ctx = context ? context : "execute";
   argstr[0] = '\0';
 
   if (NR_OP_ARRAY->scope) {
@@ -608,12 +607,13 @@ static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
     nr_show_execute_params(NR_EXECUTE_ORIG_ARGS, argstr TSRMLS_CC);
     nrl_verbosedebug(
         NRL_AGENT,
-        "execute: %.*s scope={%.*s} function={" NRP_FMT_UQ
+        NRP_FMT_UQ ": %.*s scope={%.*s} function={" NRP_FMT_UQ
         "}"
         " params={" NRP_FMT_UQ
         "}"
         " %.5s"
         "@ " NRP_FMT_UQ ":%d",
+        NRP_SHOW_EXEC_CONTEXT(ctx),
         nr_php_show_exec_indentation(TSRMLS_C), nr_php_indentation_spaces,
         NRSAFELEN(nr_php_class_entry_name_length(NR_OP_ARRAY->scope)),
         nr_php_class_entry_name(NR_OP_ARRAY->scope),
@@ -631,12 +631,13 @@ static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
     nr_show_execute_params(NR_EXECUTE_ORIG_ARGS, argstr TSRMLS_CC);
     nrl_verbosedebug(
         NRL_AGENT,
-        "execute: %.*s function={" NRP_FMT_UQ
+        NRP_FMT_UQ ": %.*s function={" NRP_FMT_UQ
         "}"
         " params={" NRP_FMT_UQ
         "}"
         " %.5s"
         "@ " NRP_FMT_UQ ":%d",
+        NRP_SHOW_EXEC_CONTEXT(ctx),
         nr_php_show_exec_indentation(TSRMLS_C), nr_php_indentation_spaces,
         NRP_PHP(function_name), NRP_ARGSTR(argstr),
 #if ZEND_MODULE_API_NO < ZEND_7_4_X_API_NO
@@ -649,16 +650,17 @@ static void nr_php_show_exec(NR_EXECUTE_PROTO TSRMLS_DC) {
     /*
      * file
      */
-    nrl_verbosedebug(NRL_AGENT, "execute: %.*s file={" NRP_FMT "}",
+    nrl_verbosedebug(NRL_AGENT, NRP_FMT_UQ ": %.*s file={" NRP_FMT "}",
+                     NRP_SHOW_EXEC_CONTEXT(ctx),
                      nr_php_show_exec_indentation(TSRMLS_C),
                      nr_php_indentation_spaces, NRP_FILENAME(filename));
   } else {
     /*
      * unknown
      */
-    nrl_verbosedebug(NRL_AGENT, "execute: %.*s ?",
-                     nr_php_show_exec_indentation(TSRMLS_C),
-                     nr_php_indentation_spaces);
+    nrl_verbosedebug(NRL_AGENT, NRP_FMT_UQ ": %.*s ?",
+                     NRP_SHOW_EXEC_CONTEXT(ctx),
+                     nr_php_show_exec_indentation(TSRMLS_C), nr_php_indentation_spaces);
   }
 }
 
@@ -982,7 +984,7 @@ static void nr_php_user_instrumentation_from_file(const char* filename,
  */
 #define METRIC_NAME_MAX_LEN 512
 
-static void nr_php_execute_file(const zend_op_array* op_array,
+void nr_php_execute_file(const zend_op_array* op_array,
                                 NR_EXECUTE_PROTO TSRMLS_DC) {
   const char* filename = nr_php_op_array_file_name(op_array);
   size_t filename_len = nr_php_op_array_file_name_len(op_array);
@@ -1007,7 +1009,9 @@ static void nr_php_execute_file(const zend_op_array* op_array,
     return;
   }
 
+#if ZEND_MODULE_API_NO < ZEND_8_0_X_API_NO
   nr_php_add_user_instrumentation(TSRMLS_C);
+#endif
 }
 
 /*
@@ -1519,7 +1523,7 @@ static void nr_php_execute_enabled(NR_EXECUTE_PROTO TSRMLS_DC) {
 
 static void nr_php_execute_show(NR_EXECUTE_PROTO TSRMLS_DC) {
   if (nrunlikely(NR_PHP_PROCESS_GLOBALS(special_flags).show_executes)) {
-    nr_php_show_exec(NR_EXECUTE_ORIG_ARGS TSRMLS_CC);
+    nr_php_show_exec("execute", NR_EXECUTE_ORIG_ARGS TSRMLS_CC);
   }
 
   nr_php_execute_enabled(NR_EXECUTE_ORIG_ARGS TSRMLS_CC);
@@ -1905,16 +1909,7 @@ static void nr_php_instrument_func_begin(NR_EXECUTE_PROTO) {
 
   NRTXNGLOBAL(execute_count) += 1;
   txn_start_time = nr_txn_start_time(NRPRG(txn));
-  /*
-   * Handle here, but be aware the classes might not be loaded yet.
-   */
-  if (nrunlikely(OP_ARRAY_IS_A_FILE(NR_OP_ARRAY))) {
-    const char* filename = nr_php_op_array_file_name(NR_OP_ARRAY);
-    size_t filename_len = nr_php_op_array_file_name_len(NR_OP_ARRAY);
-    nr_execute_handle_framework(all_frameworks, num_all_frameworks,
-                                filename, filename_len TSRMLS_CC);
-    return;
-  }
+
   if (NULL != NRPRG(cufa_callback) && NRPRG(check_cufa)) {
     /*
      * For PHP 7+, call_user_func_array() is flattened into an inline by
@@ -2000,14 +1995,6 @@ static void nr_php_instrument_func_end(NR_EXECUTE_PROTO) {
   }
   txn_start_time = nr_txn_start_time(NRPRG(txn));
 
-  /*
-   * Let's get the framework info.
-   */
-  if (nrunlikely(OP_ARRAY_IS_A_FILE(NR_OP_ARRAY))) {
-    nr_php_execute_file(NR_OP_ARRAY, NR_EXECUTE_ORIG_ARGS TSRMLS_CC);
-    return;
-  }
-
   /*
    * Get the current segment and return if null.
    */
@@ -2157,7 +2144,7 @@ void nr_php_observer_fcall_begin(zend_execute_data* execute_data) {
   int show_executes = NR_PHP_PROCESS_GLOBALS(special_flags).show_executes;
 
   if (nrunlikely(show_executes)) {
-    nr_php_show_exec(NR_EXECUTE_ORIG_ARGS);
+    nr_php_show_exec("execute", NR_EXECUTE_ORIG_ARGS);
   }
   nr_php_instrument_func_begin(NR_EXECUTE_ORIG_ARGS);
 

agent/php_execute.h

@@ -27,6 +27,21 @@
 #define OP_ARRAY_IS_METHOD(OP, FNAME) \
   (0 == nr_strcmp(nr_php_op_array_function_name(OP), (FNAME)))
 
+extern void nr_php_execute_file(const zend_op_array* op_array,
+                                NR_EXECUTE_PROTO TSRMLS_DC);
+
+/*
+ * Purpose: Log information about the execute data in a given execution
+ * context - either 'execute' (zend_execute) or 'observe' (fcall_init).
+ * Only first 8 characters of the context are printed.
+ *
+ * Caveat: This function doesn't handle internal functions, and will crash if
+ * you give it one.
+ */
+extern void nr_php_show_exec(const char*, NR_EXECUTE_PROTO TSRMLS_DC);
+/* Limit length of execution context printed in the log file to 8 characters */
+#define NRP_SHOW_EXEC_CONTEXT(C) 8, NRSAFESTR(C)
+
 /*
  * Purpose: Look through the PHP symbol table for special names or symbols
  * that provide additional hints that a specific framework has been loaded.

agent/php_globals.h

@@ -49,11 +49,11 @@ 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
+#if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO /* PHP 8.0+ */
+  int op_array_extension_handle; /* Zend op_array extension handle to attach agent's data to function */
 #endif
   int done_instrumentation;  /* Set to true if we have installed instrumentation
                                 handlers */

agent/php_minit.c

@@ -19,6 +19,7 @@
 #include "php_internal_instrument.h"
 #include "php_samplers.h"
 #include "php_user_instrument.h"
+#include "php_user_instrument_wraprec_hashmap.h"
 #include "php_vm.h"
 #include "php_wrapper.h"
 #include "fw_laravel.h"
@@ -491,6 +492,16 @@ PHP_MINIT_FUNCTION(newrelic) {
    */
   nr_php_generate_internal_wrap_records();
 
+#if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO
+  /* 
+   * The user function wraprec hashmap must be initialized before INI processing
+   * because INI processing adds wraprecs:
+   *  - newrelic.webtransaction.name.functions
+   *  - newrelic.transaction_tracer.custom
+  */
+  nr_php_user_instrument_wraprec_hashmap_init();
+#endif
+
   nr_php_register_ini_entries(module_number TSRMLS_CC);
 
   if (0 == NR_PHP_PROCESS_GLOBALS(enabled)) {
@@ -720,8 +731,16 @@ PHP_MINIT_FUNCTION(newrelic) {
   nr_php_set_opcode_handlers();
 
   nrl_debug(NRL_INIT, "MINIT processing done");
-#if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO /* PHP 7.4+ */
+#if ZEND_MODULE_API_NO >= ZEND_8_0_X_API_NO /* PHP 8.0+ */
   NR_PHP_PROCESS_GLOBALS(zend_offset) = zend_get_resource_handle(dummy);
+  NR_PHP_PROCESS_GLOBALS(op_array_extension_handle) = zend_get_op_array_extension_handle("newrelic");
+#if ZEND_MODULE_API_NO >= ZEND_8_4_X_API_NO /* PHP 8.4+ */
+  /* When observer API is used by an extension, both handles (for user
+   * and internal functions) must be initialized, even when one of them
+   * is not used (as in our case). Observer API was changed in PHP 8.4.
+   * For more details see: https://github.com/php/php-src/pull/14252 */
+  (void) zend_get_internal_function_extension_handle("newrelic");
+#endif
 #else
   NR_PHP_PROCESS_GLOBALS(zend_offset) = zend_get_resource_handle(&dummy);
 #endif