Fix memory leak:

Direct leak of 24 byte(s) in 1 object(s) allocated from:
    #0 0xffff8dfed43b in malloc (/usr/lib/aarch64-linux-gnu/libasan.so.5+0xcf43b)
    #1 0xffff81eb8f4f in __cxa_thread_atexit_impl /home/circleci/datadog/tmp/build_extension/ext/ddtrace.c:560
    #2 0xffff82ed7c8b in std::sys::unix::thread_local_dtor::register_dtor::ha7abe21b2e8f0491 library/std/src/sys/unix/thread_local_dtor.rs:31
    #3 0xffff81ec332b in _dd_writer_loop /home/circleci/datadog/tmp/build_extension/ext/coms.c:1053
    #4 0xffff8db7a7e3 in start_thread /build/glibc-tVuo8E/glibc-2.28/nptl/pthread_create.c:486
    #5 0xffff8b16a70b  (/lib/aarch64-linux-gnu/libc.so.6+0xcf70b)

SUMMARY: AddressSanitizer: 24 byte(s) leaked in 1 allocation(s).

ext/coms.c

@@ -33,6 +33,7 @@
 #include "compatibility.h"
 #include "configuration.h"
 #include "ddshared.h"
+#include "ddtrace.h"
 #include "ext/version.h"
 #include "logging.h"
 #include "mpack/mpack.h"
@@ -935,7 +936,12 @@ static void _dd_signal_data_processed(struct _writer_loop_data_t *writer) {
 #define TIMEOUT_SIG SIGPROF
 #endif
 
-static void _dd_writer_loop_cleanup(void *ctx) { _dd_signal_writer_finished((struct _writer_loop_data_t *)ctx); }
+static void _dd_writer_loop_cleanup(void *ctx) {
+    _dd_signal_writer_finished((struct _writer_loop_data_t *)ctx);
+#ifdef CXA_THREAD_ATEXIT_WRAPPER
+    dd_run_rust_thread_destructors(NULL);
+#endif
+}
 
 static void *_dd_writer_loop(void *_) {
     UNUSED(_);

ext/ddtrace.c

@@ -506,9 +506,6 @@ static PHP_GINIT_FUNCTION(ddtrace) {
 // This prevents us from a) having the weak symbols updated to the new locations and b) having ddtrace updates going live without hard restart.
 // Thus, we need to intercept it: define it ourselves so that the linker will force the rust code to call our code here.
 // Then we can collect the callbacks and invoke them ourselves right at thread shutdown, i.e. GSHUTDOWN.
-#if defined(COMPILE_DL_DDTRACE) && defined(__GLIBC__) && __GLIBC_MINOR__
-#define CXA_THREAD_ATEXIT_WRAPPER 1
-#endif
 #ifdef CXA_THREAD_ATEXIT_WRAPPER
 #define CXA_THREAD_ATEXIT_PHP ((void *)0)
 #define CXA_THREAD_ATEXIT_UNINITIALIZED ((void *)1)
@@ -526,7 +523,7 @@ struct dd_rust_thread_destructor {
 static __thread struct dd_rust_thread_destructor *dd_rust_thread_destructors = NULL;
 ZEND_TLS bool dd_is_main_thread = false;
 
-static void dd_run_rust_thread_destructors(void *unused) {
+void dd_run_rust_thread_destructors(void *unused) {
     UNUSED(unused);
     struct dd_rust_thread_destructor *entry = dd_rust_thread_destructors;
     dd_rust_thread_destructors = NULL; // destructors _may_ be invoked multiple times. We need to reset thus.

ext/ddtrace.h

@@ -1,5 +1,8 @@
 #ifndef DDTRACE_H
 #define DDTRACE_H
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 #include <Zend/zend_types.h>
 #include <stdbool.h>
 #include <stdint.h>
@@ -41,6 +44,10 @@ static inline zend_array *ddtrace_property_array(zval *zv) {
     return Z_ARR_P(zv);
 }
 
+#if defined(COMPILE_DL_DDTRACE) && defined(__GLIBC__) && __GLIBC_MINOR__
+#define CXA_THREAD_ATEXIT_WRAPPER 1
+#endif
+
 bool ddtrace_tracer_is_limited(void);
 // prepare the tracer state to start handling a new trace
 void dd_prepare_for_new_trace(void);
@@ -53,6 +60,9 @@ bool ddtrace_alter_dd_env(zval *old_value, zval *new_value);
 bool ddtrace_alter_dd_version(zval *old_value, zval *new_value);
 void dd_force_shutdown_tracing(void);
 void dd_internal_handle_fork(void);
+#ifdef CXA_THREAD_ATEXIT_WRAPPER
+void dd_run_rust_thread_destructors(void *unused);
+#endif
 
 typedef struct {
     int type;