Add functions in the GC interface to get object hash

Author: qinsoon

src/builtins.c

@@ -344,13 +344,10 @@ static uintptr_t type_object_id_(jl_value_t *v, jl_varidx_t *env) JL_NOTSAFEPOIN
             i++;
             pe = pe->prev;
         }
-        // FIXME: Pinning objects that get hashed
-        // until we implement address space hashing.
-        OBJ_PIN(v);
         uintptr_t bits = jl_astaggedvalue(v)->header;
         if (bits & GC_IN_IMAGE)
             return ((uintptr_t*)v)[-2];
-        return inthash((uintptr_t)v);
+        return inthash(jl_gc_get_obj_hash(v));
     }
     if (tv == jl_uniontype_type) {
         return bitmix(bitmix(jl_object_id((jl_value_t*)tv),
@@ -403,12 +400,7 @@ static uintptr_t immut_id_(jl_datatype_t *dt, jl_value_t *v, uintptr_t h) JL_NOT
         // a few select pointers (notably symbol) also have special hash values
         // which may affect the stability of the objectid hash, even though
         // they don't affect egal comparison
-
-        // FIXME: Pinning objects that get hashed
-        // until we implement address space hashing.
-        PTR_PIN(v); // This has to be a pointer pin -- v could be an internal pointer
-
-        return bits_hash(v, sz) ^ h;
+        return bits_hash((const void*)jl_gc_get_ptr_hash(v), sz) ^ h;
     }
     if (dt == jl_unionall_type)
         return type_object_id_(v, NULL);
@@ -469,10 +461,7 @@ static uintptr_t NOINLINE jl_object_id__cold(uintptr_t tv, jl_value_t *v) JL_NOT
         if (bits & GC_IN_IMAGE)
             return ((uintptr_t*)v)[-2];
 
-        // FIXME: Pinning objects that get hashed
-        // until we implement address space hashing.
-        OBJ_PIN(v);
-        return inthash((uintptr_t)v);
+        return inthash(jl_gc_get_obj_hash(v));
     }
     return immut_id_(dt, v, dt->hash);
 }

src/gc-interface.h

@@ -123,6 +123,9 @@ JL_DLLEXPORT void jl_gc_preserve_begin_hook(int n, ...) JL_NOTSAFEPOINT;
 // Runtime hook for gc preserve end. The GC needs to make sure that the preserved objects and its children stay alive and won't move.
 JL_DLLEXPORT void jl_gc_preserve_end_hook(void) JL_NOTSAFEPOINT;
 
+JL_DLLEXPORT uintptr_t jl_gc_get_obj_hash(void* obj) JL_NOTSAFEPOINT;
+JL_DLLEXPORT uintptr_t jl_gc_get_ptr_hash(void* ptr) JL_NOTSAFEPOINT;
+
 // ========================================================================= //
 // Metrics
 // ========================================================================= //

src/gc-mmtk.c

@@ -1623,6 +1623,14 @@ JL_DLLEXPORT void jl_gc_preserve_end_hook(void) JL_NOTSAFEPOINT
     JL_GC_POP_PRESERVE_ROOT_OBJS();
 }
 
+JL_DLLEXPORT uintptr_t jl_gc_get_obj_hash(void* obj) JL_NOTSAFEPOINT {
+    return mmtk_get_object_hash(obj);
+}
+
+JL_DLLEXPORT uintptr_t jl_gc_get_ptr_hash(void* ptr) JL_NOTSAFEPOINT {
+    return mmtk_get_ptr_hash(ptr);
+}
+
 #ifdef __cplusplus
 }
 #endif

src/gc-stock.c

@@ -4127,6 +4127,14 @@ JL_DLLEXPORT void jl_gc_notify_thread_yield(jl_ptls_t ptls, void* ctx) {
     // Do nothing before a thread yields
 }
 
+JL_DLLEXPORT uintptr_t jl_gc_get_obj_hash(void* obj) JL_NOTSAFEPOINT {
+    return (uintptr_t)obj;
+}
+
+JL_DLLEXPORT uintptr_t jl_gc_get_ptr_hash(void* ptr) JL_NOTSAFEPOINT {
+    return (uintptr_t)ptr;
+}
+
 #ifdef __cplusplus
 }
 #endif