diff --git a/base/essentials.jl b/base/essentials.jl index 0e7be924c908cc..a07aaa6769ed28 100644 --- a/base/essentials.jl +++ b/base/essentials.jl @@ -1250,6 +1250,50 @@ function isiterable(T)::Bool return hasmethod(iterate, Tuple{T}) end +""" + @world(sym, world) + +Resolve the binding `sym` in world `world`. See [`invoke_in_world`](@ref) for running +arbitrary code in fixed worlds. `world` may be `UnitRange`, in which case the macro +will error unless the binding is valid and has the same value across the entire world +range. + +The `@world` macro is primarily used in the priniting of bindings that are no longer available +in the current world. + +## Example +``` +julia> struct Foo; a::Int; end +Foo + +julia> fold = Foo(1) + +julia> Int(Base.get_world_counter()) +26866 + +julia> struct Foo; a::Int; b::Int end +Foo + +julia> fold +@world(Foo, 26866)(1) +``` + +!!! compat "Julia 1.12" + This functionality requires at least Julia 1.12. +""" +macro world(sym, world) + if isa(sym, Symbol) + return :($(_resolve_in_world)($world, $(QuoteNode(GlobalRef(__module__, sym))))) + elseif isa(sym, GlobalRef) + return :($(_resolve_in_world)($world, $(QuoteNode(sym)))) + else + error("`@world` requires a symbol or GlobalRef") + end +end + +_resolve_in_world(world::Integer, gr::GlobalRef) = + invoke_in_world(UInt(world), Core.getglobal, gr.mod, gr.name) + # Special constprop heuristics for various binary opes typename(typeof(function + end)).constprop_heuristic = Core.SAMETYPE_HEURISTIC typename(typeof(function - end)).constprop_heuristic = Core.SAMETYPE_HEURISTIC diff --git a/base/range.jl b/base/range.jl index 4b5d076dcf4364..33013357858781 100644 --- a/base/range.jl +++ b/base/range.jl @@ -1680,3 +1680,14 @@ function show(io::IO, r::LogRange{T}) where {T} show(io, length(r)) print(io, ')') end + +# Implementation detail of @world +# The rest of this is defined in essentials.jl, but UnitRange is not available +function _resolve_in_world(worlds::UnitRange, gr::GlobalRef) + # Validate that this binding's reference covers the entire world range + bpart = lookup_binding_partition(first(worlds), gr) + if bpart.max_world < last(world) + error("Binding does not cover the full world range") + end + _resolve_in_world(last(world), gr) +end diff --git a/base/runtime_internals.jl b/base/runtime_internals.jl index 645aa55c538b4c..ab867f8fcae6da 100644 --- a/base/runtime_internals.jl +++ b/base/runtime_internals.jl @@ -218,9 +218,10 @@ function _fieldnames(@nospecialize t) return t.name.names end -const BINDING_KIND_GLOBAL = 0x0 -const BINDING_KIND_CONST = 0x1 -const BINDING_KIND_CONST_IMPORT = 0x2 +# N.B.: Needs to be synced with julia.h +const BINDING_KIND_CONST = 0x0 +const BINDING_KIND_CONST_IMPORT = 0x1 +const BINDING_KIND_GLOBAL = 0x2 const BINDING_KIND_IMPLICIT = 0x3 const BINDING_KIND_EXPLICIT = 0x4 const BINDING_KIND_IMPORTED = 0x5 @@ -228,6 +229,8 @@ const BINDING_KIND_FAILED = 0x6 const BINDING_KIND_DECLARED = 0x7 const BINDING_KIND_GUARD = 0x8 +is_some_const_binding(kind::UInt8) = (kind == BINDING_KIND_CONST || kind == BINDING_KIND_CONST_IMPORT) + function lookup_binding_partition(world::UInt, b::Core.Binding) ccall(:jl_get_binding_partition, Ref{Core.BindingPartition}, (Any, UInt), b, world) end @@ -236,9 +239,27 @@ function lookup_binding_partition(world::UInt, gr::Core.GlobalRef) ccall(:jl_get_globalref_partition, Ref{Core.BindingPartition}, (Any, UInt), gr, world) end +partition_restriction(bpart::Core.BindingPartition) = ccall(:jl_bpart_get_restriction_value, Any, (Any,), bpart) + binding_kind(bpart::Core.BindingPartition) = ccall(:jl_bpart_get_kind, UInt8, (Any,), bpart) binding_kind(m::Module, s::Symbol) = binding_kind(lookup_binding_partition(tls_world_age(), GlobalRef(m, s))) +""" + delete_binding(mod::Module, sym::Symbol) + +Force the binding `mod.sym` to be undefined again, allowing it be redefined. +Note that this operation is very expensive, requirinig a full scan of all code in the system, +as well as potential recompilation of any methods that (may) have used binding +information. + +!!! warning + The implementation of this functionality is currently incomplete. Do not use + this method on versions that contain this disclaimer except for testing. +""" +function delete_binding(mod::Module, sym::Symbol) + ccall(:jl_disable_binding, Cvoid, (Any,), GlobalRef(mod, sym)) +end + """ fieldname(x::DataType, i::Integer) diff --git a/base/show.jl b/base/show.jl index a147c2037d70ed..7657ba45face78 100644 --- a/base/show.jl +++ b/base/show.jl @@ -1032,6 +1032,21 @@ function is_global_function(tn::Core.TypeName, globname::Union{Symbol,Nothing}) return false end +function check_world_bounded(tn::Core.TypeName) + bnd = ccall(:jl_get_module_binding, Ref{Core.Binding}, (Any, Any, Cint), tn.module, tn.name, true) + isdefined(bnd, :partitions) || return nothing + partition = @atomic bnd.partitions + while true + if is_some_const_binding(binding_kind(partition)) && partition_restriction(partition) <: tn.wrapper + max_world = @atomic partition.max_world + max_world == typemax(UInt) && return nothing + return Int(partition.min_world):Int(max_world) + end + isdefined(partition, :next) || return nothing + partition = @atomic partition.next + end +end + function show_type_name(io::IO, tn::Core.TypeName) if tn === UnionAll.name # by coincidence, `typeof(Type)` is a valid representation of the UnionAll type. @@ -1060,7 +1075,10 @@ function show_type_name(io::IO, tn::Core.TypeName) end end end + world = check_world_bounded(tn) + world !== nothing && print(io, "@world(") show_sym(io, sym) + world !== nothing && print(io, ", ", world, ")") quo && print(io, ")") globfunc && print(io, ")") nothing diff --git a/src/julia.h b/src/julia.h index f42ac2a23aaebb..e4af79f37e0dc4 100644 --- a/src/julia.h +++ b/src/julia.h @@ -620,6 +620,7 @@ typedef struct _jl_weakref_t { jl_value_t *value; } jl_weakref_t; +// N.B: Needs to be synced with runtime_internals.jl enum jl_partition_kind { // Constant: This binding partition is a constant declared using `const` // ->restriction holds the constant value @@ -684,7 +685,7 @@ typedef struct __attribute__((aligned(8))) _jl_binding_partition_t { _Atomic(jl_ptr_kind_union_t) restriction; size_t min_world; _Atomic(size_t) max_world; - _Atomic(struct _jl_binding_partition_t*) next; + _Atomic(struct _jl_binding_partition_t *) next; size_t reserved; // Reserved for ->kind. Currently this holds the low bits of ->restriction during serialization } jl_binding_partition_t; diff --git a/src/julia_internal.h b/src/julia_internal.h index c09bfc5c3eb428..c48d216e0bdc0d 100644 --- a/src/julia_internal.h +++ b/src/julia_internal.h @@ -926,13 +926,7 @@ STATIC_INLINE int jl_bkind_is_some_guard(enum jl_partition_kind kind) JL_NOTSAFE return kind == BINDING_KIND_FAILED || kind == BINDING_KIND_GUARD || kind == BINDING_KIND_DECLARED; } -EXTERN_INLINE_DECLARE jl_binding_partition_t *jl_get_binding_partition(jl_binding_t *b, size_t world) JL_NOTSAFEPOINT { - if (!b) - return NULL; - assert(jl_is_binding(b)); - return jl_atomic_load_relaxed(&b->partitions); -} - +JL_DLLEXPORT jl_binding_partition_t *jl_get_binding_partition(jl_binding_t *b, size_t world); JL_DLLEXPORT jl_binding_partition_t *jl_get_globalref_partition(jl_globalref_t *gr, size_t world); EXTERN_INLINE_DECLARE uint8_t jl_bpart_get_kind(jl_binding_partition_t *bpart) JL_NOTSAFEPOINT { diff --git a/src/module.c b/src/module.c index 36c35f50b44afe..12e7e73aa82481 100644 --- a/src/module.c +++ b/src/module.c @@ -13,10 +13,51 @@ extern "C" { #endif // In this translation unit and this translation unit only emit this symbol `extern` for use by julia -EXTERN_INLINE_DEFINE jl_binding_partition_t *jl_get_binding_partition(jl_binding_t *b, size_t world) JL_NOTSAFEPOINT; EXTERN_INLINE_DEFINE uint8_t jl_bpart_get_kind(jl_binding_partition_t *bpart) JL_NOTSAFEPOINT; extern inline enum jl_partition_kind decode_restriction_kind(jl_ptr_kind_union_t pku) JL_NOTSAFEPOINT; +static jl_binding_partition_t *new_binding_partition(void) +{ + jl_binding_partition_t *bpart = (jl_binding_partition_t*)jl_gc_alloc(jl_current_task->ptls, sizeof(jl_binding_partition_t), jl_binding_partition_type); + jl_atomic_store_relaxed(&bpart->restriction, encode_restriction(NULL, BINDING_KIND_GUARD)); + bpart->min_world = 0; + jl_atomic_store_relaxed(&bpart->max_world, (size_t)-1); + jl_atomic_store_relaxed(&bpart->next, NULL); +#ifdef _P64 + bpart->reserved = 0; +#endif + return bpart; +} + +jl_binding_partition_t *jl_get_binding_partition(jl_binding_t *b, size_t world) { + if (!b) + return NULL; + assert(jl_is_binding(b)); + jl_value_t *parent = (jl_value_t*)b; + _Atomic(jl_binding_partition_t *)*insert = &b->partitions; + jl_binding_partition_t *bpart = jl_atomic_load_relaxed(insert); + size_t max_world = (size_t)-1; + while (1) { + while (bpart && world < bpart->min_world) { + insert = &bpart->next; + max_world = bpart->min_world - 1; + parent = (jl_value_t *)bpart; + bpart = jl_atomic_load_relaxed(&bpart->next); + } + if (bpart && world <= jl_atomic_load_relaxed(&bpart->max_world)) + return bpart; + jl_binding_partition_t *new_bpart = new_binding_partition(); + jl_atomic_store_relaxed(&new_bpart->next, bpart); + if (bpart) + new_bpart->min_world = jl_atomic_load_relaxed(&bpart->max_world) + 1; + new_bpart->max_world = max_world; + if (jl_atomic_cmpswap(insert, &bpart, new_bpart)) { + jl_gc_wb(parent, new_bpart); + return new_bpart; + } + } +} + JL_DLLEXPORT jl_binding_partition_t *jl_get_globalref_partition(jl_globalref_t *gr, size_t world) { if (!gr) @@ -188,19 +229,6 @@ static jl_globalref_t *jl_new_globalref(jl_module_t *mod, jl_sym_t *name, jl_bin return g; } -static jl_binding_partition_t *new_binding_partition(void) -{ - jl_binding_partition_t *bpart = (jl_binding_partition_t*)jl_gc_alloc(jl_current_task->ptls, sizeof(jl_binding_partition_t), jl_binding_partition_type); - jl_atomic_store_relaxed(&bpart->restriction, encode_restriction(NULL, BINDING_KIND_GUARD)); - bpart->min_world = 0; - jl_atomic_store_relaxed(&bpart->max_world, (size_t)-1); - jl_atomic_store_relaxed(&bpart->next, NULL); -#ifdef _P64 - bpart->reserved = 0; -#endif - return bpart; -} - static jl_binding_t *new_binding(jl_module_t *mod, jl_sym_t *name) { jl_task_t *ct = jl_current_task; @@ -215,9 +243,7 @@ static jl_binding_t *new_binding(jl_module_t *mod, jl_sym_t *name) JL_GC_PUSH1(&b); b->globalref = jl_new_globalref(mod, name, b); jl_gc_wb(b, b->globalref); - jl_binding_partition_t *bpart = new_binding_partition(); - jl_atomic_store_relaxed(&b->partitions, bpart); - jl_gc_wb(b, bpart); + jl_atomic_store_relaxed(&b->partitions, NULL); JL_GC_POP(); return b; } @@ -324,6 +350,12 @@ JL_DLLEXPORT jl_value_t *jl_get_binding_value_if_const(jl_binding_t *b) return decode_restriction_value(pku); } +JL_DLLEXPORT jl_value_t *jl_bpart_get_restriction_value(jl_binding_partition_t *bpart) +{ + jl_ptr_kind_union_t pku = jl_atomic_load_relaxed(&bpart->restriction); + return decode_restriction_value(pku); +} + typedef struct _modstack_t { jl_module_t *m; jl_sym_t *var; @@ -952,6 +984,28 @@ JL_DLLEXPORT void jl_set_const(jl_module_t *m JL_ROOTING_ARGUMENT, jl_sym_t *var jl_gc_wb(bpart, val); } +extern jl_mutex_t world_counter_lock; +JL_DLLEXPORT void jl_disable_binding(jl_globalref_t *gr) +{ + jl_binding_t *b = gr->binding; + b = jl_resolve_owner(b, gr->mod, gr->name, NULL); + jl_binding_partition_t *bpart = jl_get_binding_partition(b, jl_current_task->world_age); + + if (decode_restriction_kind(jl_atomic_load_relaxed(&bpart->restriction)) == BINDING_KIND_GUARD) { + // Already guard + return; + } + + JL_LOCK(&world_counter_lock); + jl_task_t *ct = jl_current_task; + size_t new_max_world = jl_atomic_load_acquire(&jl_world_counter); + // TODO: Trigger invalidation here + (void)ct; + 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); +} + JL_DLLEXPORT int jl_globalref_is_const(jl_globalref_t *gr) { jl_binding_t *b = gr->binding; diff --git a/test/choosetests.jl b/test/choosetests.jl index 96d230d185c713..affdee412bd869 100644 --- a/test/choosetests.jl +++ b/test/choosetests.jl @@ -29,7 +29,7 @@ const TESTNAMES = [ "channels", "iostream", "secretbuffer", "specificity", "reinterpretarray", "syntax", "corelogging", "missing", "asyncmap", "smallarrayshrink", "opaque_closure", "filesystem", "download", - "scopedvalues", "compileall" + "scopedvalues", "compileall", "rebinding" ] const INTERNET_REQUIRED_LIST = [ diff --git a/test/rebinding.jl b/test/rebinding.jl new file mode 100644 index 00000000000000..4066d91bc4b9b9 --- /dev/null +++ b/test/rebinding.jl @@ -0,0 +1,18 @@ +# This file is a part of Julia. License is MIT: https://julialang.org/license + +module Rebinding + using Test + + @test Base.binding_kind(@__MODULE__, :Foo) == Base.BINDING_KIND_GUARD + struct Foo + x::Int + end + x = Foo(1) + + @test Base.binding_kind(@__MODULE__, :Foo) == Base.BINDING_KIND_CONST + @test !contains(repr(x), "@world") + Base.delete_binding(@__MODULE__, :Foo) + + @test Base.binding_kind(@__MODULE__, :Foo) == Base.BINDING_KIND_GUARD + @test contains(repr(x), "@world") +end