Source code

Revision control

Copy as Markdown

Other Tools

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* Copyright 2016 Mozilla Foundation
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* See the License for the specific language governing permissions and
* limitations under the License.
#ifndef wasm_table_h
#define wasm_table_h
#include "gc/Policy.h"
#include "wasm/WasmCode.h"
namespace js {
namespace wasm {
// A Table is an indexable array of opaque values. Tables are first-class
// stateful objects exposed to WebAssembly. asm.js also uses Tables to represent
// its homogeneous function-pointer tables.
// A table of FuncRef holds FunctionTableElems, which are (code*,instance*)
// pairs, where the instance must be traced.
// A table of AnyRef holds pointers, which must be traced.
using TableAnyRefVector = GCVector<HeapPtr<AnyRef>, 0, SystemAllocPolicy>;
class Table : public ShareableBase<Table> {
using InstanceSet =
using FuncRefVector = Vector<FunctionTableElem, 0, SystemAllocPolicy>;
WeakHeapPtr<WasmTableObject*> maybeObject_;
InstanceSet observers_;
FuncRefVector functions_; // either functions_ has data
TableAnyRefVector objects_; // or objects_, but not both
const RefType elemType_;
const bool isAsmJS_;
uint32_t length_;
const Maybe<uint32_t> maximum_;
template <class>
friend struct js::MallocProvider;
Table(JSContext* cx, const TableDesc& desc,
Handle<WasmTableObject*> maybeObject, FuncRefVector&& functions);
Table(JSContext* cx, const TableDesc& desc,
Handle<WasmTableObject*> maybeObject, TableAnyRefVector&& objects);
void tracePrivate(JSTracer* trc);
friend class js::WasmTableObject;
static RefPtr<Table> create(JSContext* cx, const TableDesc& desc,
Handle<WasmTableObject*> maybeObject);
void trace(JSTracer* trc);
RefType elemType() const { return elemType_; }
TableRepr repr() const { return elemType_.tableRepr(); }
bool isAsmJS() const {
return isAsmJS_;
bool isFunction() const { return elemType().isFuncHierarchy(); }
uint32_t length() const { return length_; }
Maybe<uint32_t> maximum() const { return maximum_; }
// Raw pointer to the table for use in TableInstanceData.
uint8_t* instanceElements() const;
// set/get/fillFuncRef is allowed only on table-of-funcref.
// get/fillAnyRef is allowed only on table-of-anyref.
// setNull is allowed on either.
const FunctionTableElem& getFuncRef(uint32_t index) const;
[[nodiscard]] bool getFuncRef(JSContext* cx, uint32_t index,
MutableHandleFunction fun) const;
void setFuncRef(uint32_t index, JSFunction* func);
void setFuncRef(uint32_t index, void* code, Instance* instance);
void fillFuncRef(uint32_t index, uint32_t fillCount, FuncRef ref,
JSContext* cx);
AnyRef getAnyRef(uint32_t index) const;
void setAnyRef(uint32_t index, AnyRef ref);
void fillAnyRef(uint32_t index, uint32_t fillCount, AnyRef ref);
// Sets ref automatically using the correct setter depending on the ref and
// table type (setNull, setFuncRef, or setAnyRef)
void setRef(uint32_t index, AnyRef ref);
// Get the element at index and convert it to a JS value.
[[nodiscard]] bool getValue(JSContext* cx, uint32_t index,
MutableHandleValue result) const;
void setNull(uint32_t index);
// Copy entry from |srcTable| at |srcIndex| to this table at |dstIndex|. Used
// by table.copy. May OOM if it needs to box up a function during an upcast.
[[nodiscard]] bool copy(JSContext* cx, const Table& srcTable,
uint32_t dstIndex, uint32_t srcIndex);
// grow() returns (uint32_t)-1 if it could not grow.
[[nodiscard]] uint32_t grow(uint32_t delta);
[[nodiscard]] bool movingGrowable() const;
[[nodiscard]] bool addMovingGrowObserver(JSContext* cx,
WasmInstanceObject* instance);
void fillUninitialized(uint32_t index, uint32_t fillCount, HandleAnyRef ref,
JSContext* cx);
#ifdef DEBUG
void assertRangeNull(uint32_t index, uint32_t length) const;
void assertRangeNotNull(uint32_t index, uint32_t length) const;
#endif // DEBUG
// about:memory reporting:
size_t sizeOfExcludingThis(MallocSizeOf mallocSizeOf) const;
size_t gcMallocBytes() const;
using SharedTable = RefPtr<Table>;
using SharedTableVector = Vector<SharedTable, 0, SystemAllocPolicy>;
} // namespace wasm
} // namespace js
#endif // wasm_table_h