Add basic code for binding partition revalidation

base/Base_compiler.jl

@@ -253,6 +253,7 @@ include("ordering.jl")
 using .Order
 
 include("coreir.jl")
+include("invalidation.jl")
 
 # For OS specific stuff
 # We need to strcat things here, before strings are really defined

base/invalidation.jl

@@ -0,0 +1,112 @@
+# This file is a part of Julia. License is MIT: https://julialang.org/license
+
+struct GlobalRefIterator
+    mod::Module
+end
+IteratorSize(::Type{GlobalRefIterator}) = SizeUnknown()
+globalrefs(mod::Module) = GlobalRefIterator(mod)
+
+function iterate(gri::GlobalRefIterator, i = 1)
+    m = gri.mod
+    table = ccall(:jl_module_get_bindings, Ref{SimpleVector}, (Any,), m)
+    i == length(table) && return nothing
+    b = table[i]
+    b === nothing && return iterate(gri, i+1)
+    return ((b::Core.Binding).globalref, i+1)
+end
+
+const TYPE_TYPE_MT = Type.body.name.mt
+const NONFUNCTION_MT = Core.MethodTable.name.mt
+function foreach_module_mtable(visit, m::Module, world::UInt)
+    for gb in globalrefs(m)
+        binding = gb.binding
+        bpart = lookup_binding_partition(world, binding)
+        if is_some_const_binding(binding_kind(bpart))
+            isdefined(bpart, :restriction) || continue
+            v = partition_restriction(bpart)
+            uw = unwrap_unionall(v)
+            name = gb.name
+            if isa(uw, DataType)
+                tn = uw.name
+                if tn.module === m && tn.name === name && tn.wrapper === v && isdefined(tn, :mt)
+                    # this is the original/primary binding for the type (name/wrapper)
+                    mt = tn.mt
+                    if mt !== nothing && mt !== TYPE_TYPE_MT && mt !== NONFUNCTION_MT
+                        @assert mt.module === m
+                        visit(mt) || return false
+                    end
+                end
+            elseif isa(v, Module) && v !== m && parentmodule(v) === m && _nameof(v) === name
+                # this is the original/primary binding for the submodule
+                foreach_module_mtable(visit, v, world) || return false
+            elseif isa(v, Core.MethodTable) && v.module === m && v.name === name
+                # this is probably an external method table here, so let's
+                # assume so as there is no way to precisely distinguish them
+                visit(v) || return false
+            end
+        end
+    end
+    return true
+end
+
+function foreach_reachable_mtable(visit, world::UInt)
+    visit(TYPE_TYPE_MT) || return
+    visit(NONFUNCTION_MT) || return
+    for mod in loaded_modules_array()
+        foreach_module_mtable(visit, mod, world)
+    end
+end
+
+function should_invalidate_code_for_globalref(gr::GlobalRef, src::CodeInfo)
+    found_any = false
+    labelchangemap = nothing
+    stmts = src.code
+    isgr(g::GlobalRef) = gr.mod == g.mod && gr.name === g.name
+    isgr(g) = false
+    for i = 1:length(stmts)
+        stmt = stmts[i]
+        if isgr(stmt)
+            found_any = true
+            continue
+        end
+        for ur in Compiler.userefs(stmt)
+            arg = ur[]
+            # If any of the GlobalRefs in this stmt match the one that
+            # we are about, we need to move out all GlobalRefs to preserve
+            # effect order, in case we later invalidate a different GR
+            if isa(arg, GlobalRef)
+                if isgr(arg)
+                    @assert !isa(stmt, PhiNode)
+                    found_any = true
+                    break
+                end
+            end
+        end
+    end
+    return found_any
+end
+
+function invalidate_code_for_globalref!(gr::GlobalRef, new_max_world::UInt)
+    valid_in_valuepos = false
+    foreach_reachable_mtable(new_max_world) do mt::Core.MethodTable
+        for method in MethodList(mt)
+            if isdefined(method, :source)
+                src = _uncompressed_ir(method)
+                old_stmts = src.code
+                if should_invalidate_code_for_globalref(gr, src)
+                    for mi in specializations(method)
+                        ci = mi.cache
+                        while true
+                            if ci.max_world > new_max_world
+                                ccall(:jl_invalidate_code_instance, Cvoid, (Any, UInt), ci, new_max_world)
+                            end
+                            isdefined(ci, :next) || break
+                            ci = ci.next
+                        end
+                    end
+                end
+            end
+        end
+        return true
+    end
+end

src/gf.c

@@ -1785,6 +1785,11 @@ static void invalidate_code_instance(jl_code_instance_t *replaced, size_t max_wo
     JL_UNLOCK(&replaced->def->def.method->writelock);
 }
 
+JL_DLLEXPORT void jl_invalidate_code_instance(jl_code_instance_t *replaced, size_t max_world)
+{
+    invalidate_code_instance(replaced, max_world, 1);
+}
+
 static void _invalidate_backedges(jl_method_instance_t *replaced_mi, size_t max_world, int depth) {
     jl_array_t *backedges = replaced_mi->backedges;
     if (backedges) {

src/module.c

@@ -1025,6 +1025,21 @@ JL_DLLEXPORT void jl_set_const(jl_module_t *m JL_ROOTING_ARGUMENT, jl_sym_t *var
     jl_gc_wb(bpart, val);
 }
 
+void jl_invalidate_binding_refs(jl_globalref_t *ref, size_t new_world)
+{
+    static jl_value_t *invalidate_code_for_globalref = NULL;
+    if (invalidate_code_for_globalref == NULL && 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.");
+    if (jl_generating_output())
+        jl_error("Binding invalidation is not permitted during image generation.");
+    jl_value_t *boxed_world = jl_box_ulong(new_world);
+    JL_GC_PUSH1(&boxed_world);
+    jl_call2((jl_function_t*)invalidate_code_for_globalref, (jl_value_t*)ref, boxed_world);
+    JL_GC_POP();
+}
+
 extern jl_mutex_t world_counter_lock;
 JL_DLLEXPORT void jl_disable_binding(jl_globalref_t *gr)
 {
@@ -1039,9 +1054,16 @@ JL_DLLEXPORT void jl_disable_binding(jl_globalref_t *gr)
 
     JL_LOCK(&world_counter_lock);
     jl_task_t *ct = jl_current_task;
+    size_t last_world = ct->world_age;
     size_t new_max_world = jl_atomic_load_acquire(&jl_world_counter);
-    // TODO: Trigger invalidation here
-    (void)ct;
+    JL_TRY {
+        ct->world_age = jl_typeinf_world;
+        jl_invalidate_binding_refs(gr, new_max_world);
+    } JL_CATCH {
+        JL_UNLOCK(&world_counter_lock);
+        jl_rethrow();
+    }
+    ct->world_age = last_world;
     jl_atomic_store_release(&bpart->max_world, new_max_world);
     jl_atomic_store_release(&jl_world_counter, new_max_world + 1);
     JL_UNLOCK(&world_counter_lock);
@@ -1327,6 +1349,11 @@ JL_DLLEXPORT void jl_add_to_module_init_list(jl_value_t *mod)
     jl_array_ptr_1d_push(jl_module_init_order, mod);
 }
 
+JL_DLLEXPORT jl_svec_t *jl_module_get_bindings(jl_module_t *m)
+{
+    return jl_atomic_load_relaxed(&m->bindings);
+}
+
 JL_DLLEXPORT void jl_init_restored_module(jl_value_t *mod)
 {
     if (!jl_generating_output() || jl_options.incremental) {

test/rebinding.jl

@@ -33,4 +33,11 @@ module Rebinding
     @test Base.@world(Foo, defined_world_age) == typeof(x)
     @test Base.@world(Rebinding.Foo, defined_world_age) == typeof(x)
     @test Base.@world((@__MODULE__).Foo, defined_world_age) == typeof(x)
+
+    # Test invalidation (const -> undefined)
+    const delete_me = 1
+    f_return_delete_me() = delete_me
+    @test f_return_delete_me() == 1
+    Base.delete_binding(@__MODULE__, :delete_me)
+    @test_throws UndefVarError f_return_delete_me()
 end