fix a couple static variable data-races (#59408)

I used clang-ast to get a list of all static variables in functions and
checked each for possible data races and then had Claude fix them.

Author: vtjnash

src/gc-common.c

@@ -367,10 +367,11 @@ JL_DLLEXPORT void jl_gc_enable_finalizers(jl_task_t *ct, int on)
         JL_CATCH {
             jl_printf((JL_STREAM*)STDERR_FILENO, "WARNING: GC finalizers already enabled on this thread.\n");
             // Only print the backtrace once, to avoid spamming the logs
-            static int backtrace_printed = 0;
-            if (backtrace_printed == 0) {
-                backtrace_printed = 1;
-                jlbacktrace(); // written to STDERR_FILENO
+            static _Atomic(int) backtrace_printed = 0;
+            if (jl_atomic_load_relaxed(&backtrace_printed) == 0) {
+              if (jl_atomic_exchange_relaxed(&backtrace_printed, 1) == 0) {
+                  jlbacktrace(); // written to STDERR_FILENO
+              }
             }
         }
         return;

src/jl_uv.c

@@ -818,7 +818,7 @@ JL_DLLEXPORT int jl_printf(uv_stream_t *s, const char *format, ...)
 
 JL_DLLEXPORT void jl_safe_printf(const char *fmt, ...)
 {
-    static char buf[1000];
+    char buf[1000];
     buf[0] = '\0';
     int last_errno = errno;
 #ifdef _OS_WINDOWS_

src/module.c

@@ -1627,8 +1627,8 @@ JL_DLLEXPORT void jl_set_const(jl_module_t *m JL_ROOTING_ARGUMENT, jl_sym_t *var
 
 void jl_invalidate_binding_refs(jl_globalref_t *ref, jl_binding_partition_t *invalidated_bpart, jl_binding_partition_t *new_bpart, size_t new_world)
 {
-    static jl_value_t *invalidate_code_for_globalref = NULL;
-    if (invalidate_code_for_globalref == NULL && jl_base_module != NULL)
+    jl_value_t *invalidate_code_for_globalref = NULL;
+    if (jl_base_module != NULL)
         invalidate_code_for_globalref = jl_get_global(jl_base_module, jl_symbol("invalidate_code_for_globalref!"));
     if (!invalidate_code_for_globalref)
         jl_error("Binding invalidation is not permitted during bootstrap.");

src/toplevel.c

@@ -83,10 +83,9 @@ void jl_module_run_initializer(jl_module_t *m)
 
 static void jl_register_root_module(jl_module_t *m)
 {
-    static jl_value_t *register_module_func = NULL;
+    jl_value_t *register_module_func = NULL;
     assert(jl_base_module);
-    if (register_module_func == NULL)
-        register_module_func = jl_get_global(jl_base_module, jl_symbol("register_root_module"));
+    register_module_func = jl_get_global(jl_base_module, jl_symbol("register_root_module"));
     assert(register_module_func);
     jl_value_t *args[2];
     args[0] = register_module_func;
@@ -96,8 +95,8 @@ static void jl_register_root_module(jl_module_t *m)
 
 jl_array_t *jl_get_loaded_modules(void)
 {
-    static jl_value_t *loaded_modules_array = NULL;
-    if (loaded_modules_array == NULL && jl_base_module != NULL)
+    jl_value_t *loaded_modules_array = NULL;
+    if (jl_base_module != NULL)
         loaded_modules_array = jl_get_global(jl_base_module, jl_symbol("loaded_modules_array"));
     if (loaded_modules_array != NULL)
         return (jl_array_t*)jl_call0((jl_value_t*)loaded_modules_array);