fix #33338, race condition in triggering method compilation

Author: JeffBezanson

src/codegen.cpp

@@ -1444,8 +1444,10 @@ void jl_generate_fptr(jl_code_instance_t *output)
                     break;
                 ucache = ucache->next;
             }
-            if (codeinst->invoke)
+            if (codeinst->invoke) {
+                JL_UNLOCK(&codegen_lock);
                 return;
+            }
             if (ucache != NULL) {
                 codeinst->specptr = ucache->specptr;
                 codeinst->rettype_const = ucache->rettype_const;

src/gf.c

@@ -1833,6 +1833,7 @@ jl_code_instance_t *jl_compile_method_internal(jl_method_instance_t *mi, size_t
 {
     jl_code_instance_t *codeinst;
     codeinst = mi->cache;
+    JL_GC_PROMISE_ROOTED(codeinst);
     while (codeinst) {
         if (codeinst->min_world <= world && world <= codeinst->max_world && codeinst->invoke != NULL) {
             return codeinst;
@@ -1869,6 +1870,7 @@ jl_code_instance_t *jl_compile_method_internal(jl_method_instance_t *mi, size_t
         }
     }
 
+    JL_LOCK(&codegen_lock);
     codeinst = mi->cache;
     while (codeinst) {
         if (codeinst->min_world <= world && world <= codeinst->max_world && codeinst->functionObjectsDecls.functionObject != NULL)
@@ -1893,17 +1895,20 @@ jl_code_instance_t *jl_compile_method_internal(jl_method_instance_t *mi, size_t
                 jl_generate_fptr(ucache);
             if (ucache->invoke != jl_fptr_sparam &&
                 ucache->invoke != jl_fptr_interpret_call) {
+                JL_UNLOCK(&codegen_lock);
                 return ucache;
             }
             jl_code_instance_t *codeinst = jl_set_method_inferred(mi, (jl_value_t*)jl_any_type, NULL, NULL,
                 0, 1, ~(size_t)0);
             codeinst->specptr = ucache->specptr;
             codeinst->rettype_const = ucache->rettype_const;
             jl_atomic_store_release(&codeinst->invoke, ucache->invoke);
+            JL_UNLOCK(&codegen_lock);
             return codeinst;
         }
     }
 
+    JL_UNLOCK(&codegen_lock);
     jl_generate_fptr(codeinst);
     return codeinst;
 }