fix(remote-config): late shutdown crash

ext/datadog.c

@@ -652,10 +652,6 @@ static PHP_RSHUTDOWN_FUNCTION(datadog) {
     bool fast_shutdown = is_zend_mm() && !EG(full_tables_cleanup);
 #endif
 
-    if (DATADOG_G(remote_config_state)) {
-        datadog_rshutdown_remote_config();
-    }
-
     if (!datadog_disable) {
         dd_shutdown_observer();
     }
@@ -666,6 +662,11 @@ static PHP_RSHUTDOWN_FUNCTION(datadog) {
 
     datadog_sidecar_finalize(true);
     DATADOG_G(request_initialized) = false;
+    /* A signal may have queued a Remote Config reread during RSHUTDOWN. */
+    DATADOG_G(reread_remote_configuration) = 0;
+    if (DATADOG_G(remote_config_state)) {
+        datadog_rshutdown_remote_config();
+    }
 
     datadog_telemetry_rshutdown();
     datadog_sidecar_rshutdown();

ext/remote_config.c

@@ -21,10 +21,12 @@ static void dd_vm_interrupt(zend_execute_data *execute_data) {
     if (dd_prev_interrupt_function) {
         dd_prev_interrupt_function(execute_data);
     }
-    if (DATADOG_G(remote_config_state) && DATADOG_G(reread_remote_configuration)) {
-        LOG(INFO, "Rereading remote configurations after interrupt");
+    if (DATADOG_G(reread_remote_configuration)) {
         DATADOG_G(reread_remote_configuration) = 0;
-        ddog_process_remote_configs(DATADOG_G(remote_config_state));
+        if (DATADOG_G(request_initialized) && DATADOG_G(remote_config_state)) {
+            LOG(INFO, "Rereading remote configurations after interrupt");
+            ddog_process_remote_configs(DATADOG_G(remote_config_state));
+        }
     }
 }
 
@@ -53,7 +55,9 @@ DATADOG_PUBLIC void datadog_set_all_thread_vm_interrupt(void) {
 }
 
 void datadog_check_for_new_config_now(void) {
-    if (DATADOG_G(remote_config_state) && !DATADOG_G(reread_remote_configuration) && ddog_process_remote_configs(DATADOG_G(remote_config_state))) {
+    if (DATADOG_G(request_initialized) && DATADOG_G(remote_config_state) &&
+        !DATADOG_G(reread_remote_configuration) &&
+        ddog_process_remote_configs(DATADOG_G(remote_config_state))) {
         // If we blocked the signal, notify the other threads too
         datadog_set_all_thread_vm_interrupt();
     }

ext/sidecar.c

@@ -815,7 +815,7 @@ void ddtrace_sidecar_submit_span_data_direct(ddog_SidecarTransport **transport,
     const ddog_Vec_Tag *process_tags = datadog_process_tags_get_vec();
 
     bool changed = true;
-    if (DATADOG_G(remote_config_state)) {
+    if (DATADOG_G(request_initialized) && DATADOG_G(remote_config_state)) {
         changed = ddog_remote_configs_service_env_change(DATADOG_G(remote_config_state), service_slice, env_slice, version_slice, &DATADOG_G(active_global_tags), process_tags);
     }
 
@@ -853,7 +853,7 @@ void ddtrace_sidecar_submit_span_data_direct(ddog_SidecarTransport **transport,
             ddog_sidecar_telemetry_filter_flush(transport, datadog_sidecar_instance_id, &DATADOG_G(sidecar_queue_id), datadog_telemetry_buffer(), datadog_telemetry_cache(), service_slice, env_slice));
     }
 
-    if (DATADOG_G(remote_config_state)) {
+    if (DATADOG_G(request_initialized) && DATADOG_G(remote_config_state)) {
         // Must happen after ddog_sidecar_set_universal_service_tags (session state fully initialized)
         ddog_process_remote_configs(DATADOG_G(remote_config_state));
     }

tests/ext/live-debugger/debugger_rshutdown_remote_config.phpt

@@ -0,0 +1,60 @@
+--TEST--
+Remote Config and live debugger hooks remain valid through tracer request shutdown
+--SKIPIF--
+<?php include __DIR__ . '/../includes/skipif_no_dev_env.inc'; ?>
+--ENV--
+DD_AGENT_HOST=request-replayer
+DD_TRACE_AGENT_PORT=80
+DD_TRACE_GENERATE_ROOT_SPAN=0
+DD_REMOTE_CONFIG_POLL_INTERVAL_SECONDS=0.1
+DD_TRACE_AGENT_TEST_SESSION_TOKEN=live-debugger/rshutdown_remote_config
+--INI--
+datadog.trace.enabled=1
+datadog.autofinish_spans=1
+--FILE--
+<?php
+
+require __DIR__ . "/live_debugger.inc";
+
+reset_request_replayer();
+ini_set('datadog.logs_injection', '0');
+
+function instrumented(): void {}
+
+final class StartSpanDuringShutdown
+{
+    public function __destruct()
+    {
+        $span = \DDTrace\start_span();
+        $span->onClose[] = function () {
+            // The span is closed from tracer RSHUTDOWN. Remote Config and its
+            // live debugger subscriber must still be active.
+            var_dump(count(dd_trace_internal_fn('get_loaded_remote_configs')));
+            echo "onClose completed\n";
+        };
+    }
+}
+
+put_dynamic_config_file([
+    "log_injection_enabled" => true,
+    "dynamic_instrumentation_enabled" => true,
+]);
+
+await_probe_installation(function () {
+    build_span_probe(["where" => ["methodName" => "instrumented"]]);
+});
+
+$trigger = new StartSpanDuringShutdown();
+
+echo "request body complete\n";
+
+?>
+--CLEAN--
+<?php
+require __DIR__ . "/live_debugger.inc";
+reset_request_replayer();
+?>
+--EXPECT--
+request body complete
+int(2)
+onClose completed

tests/ext/remote_config/dynamic_config_late_shutdown.phpt

@@ -0,0 +1,64 @@
+--TEST--
+Remote config is not reapplied after its request shutdown cleanup
+--SKIPIF--
+<?php
+include __DIR__ . '/../includes/skipif_no_dev_env.inc';
+?>
+--ENV--
+DD_AGENT_HOST=request-replayer
+DD_TRACE_AGENT_PORT=80
+DD_TRACE_GENERATE_ROOT_SPAN=0
+DD_REMOTE_CONFIG_POLL_INTERVAL_SECONDS=0.1
+DD_TRACE_AGENT_TEST_SESSION_TOKEN=remote-config/dynamic_config_late_shutdown
+--FILE--
+<?php
+
+require __DIR__ . "/remote_config.inc";
+include __DIR__ . '/../includes/request_replayer.inc';
+
+final class LateRemoteConfigWrapper
+{
+    public $context;
+
+    public function stream_open($path, $mode, $options, &$opened_path)
+    {
+        return true;
+    }
+
+    public function stream_close()
+    {
+        // Resource destruction runs after module RSHUTDOWN. Process Remote
+        // Config synchronously so this lifecycle boundary is deterministic.
+        dd_trace_internal_fn('process_remote_config');
+        echo "late close completed\n";
+    }
+}
+
+reset_request_replayer();
+ini_set('datadog.logs_injection', '0');
+
+$path = put_dynamic_config_file([
+    'log_injection_enabled' => true,
+]);
+
+\DDTrace\start_span();
+if (ini_get('datadog.logs_injection') !== '1') {
+    dd_trace_internal_fn('await_remote_config');
+}
+var_dump(ini_get('datadog.logs_injection'));
+
+stream_wrapper_register('late-remote-config', LateRemoteConfigWrapper::class);
+$trigger = fopen('late-remote-config://trigger', 'r');
+
+echo "request body complete\n";
+
+?>
+--CLEAN--
+<?php
+require __DIR__ . "/remote_config.inc";
+reset_request_replayer();
+?>
+--EXPECT--
+string(1) "1"
+request body complete
+late close completed

tracer/ddtrace.c

@@ -628,7 +628,6 @@ void ddtrace_rshutdown(bool fast_shutdown) {
 
     ddtrace_clean_git_object();
     ddtrace_weak_resources_rshutdown();
-    ddtrace_live_debugger_rshutdown();
 }
 
 void ddtrace_post_deactivate(void) {
@@ -637,6 +636,7 @@ void ddtrace_post_deactivate(void) {
     zai_interceptor_deactivate();
 
     // we can only actually free our hooks hashtables in post_deactivate, as within RSHUTDOWN some user code may still run
+    ddtrace_live_debugger_rshutdown();
     zai_hook_rshutdown();
     zai_uhook_rshutdown();
 }

tracer/functions.c

@@ -2215,6 +2215,10 @@ PHP_FUNCTION(dd_trace_internal_fn) {
             } else {
                 array_init(return_value);
             }
+        } else if (FUNCTION_NAME_MATCHES("process_remote_config")) {
+            // Test/debug helper for exercising Remote Config at precise lifecycle points.
+            datadog_check_for_new_config_now();
+            RETVAL_TRUE;
         } else if (FUNCTION_NAME_MATCHES("await_remote_config")) {
             uint32_t timeout_sec = 10;
             if (params_count == 1) {