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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* Copyright 2016 Mozilla Foundation
* Copyright 2023 Moonchild Productions
*
* 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef wasm_instance_h
#define wasm_instance_h
#include "gc/Barrier.h"
#include "wasm/WasmCode.h"
#include "wasm/WasmTable.h"
namespace js {
namespace wasm {
// Instance represents a wasm instance and provides all the support for runtime
// execution of code in the instance. Instances share various immutable data
// structures with the Module from which they were instantiated and other
// instances instantiated from the same Module. However, an Instance has no
// direct reference to its source Module which allows a Module to be destroyed
// while it still has live Instances.
class Instance
{
JSCompartment* const compartment_;
ReadBarrieredWasmInstanceObject object_;
const UniqueCode code_;
GCPtrWasmMemoryObject memory_;
SharedTableVector tables_;
TlsData tlsData_;
// Internal helpers:
const void** addressOfSigId(const SigIdDesc& sigId) const;
FuncImportTls& funcImportTls(const FuncImport& fi);
TableTls& tableTls(const TableDesc& td) const;
// Import call slow paths which are called directly from wasm code.
friend void* AddressOf(SymbolicAddress, ExclusiveContext*);
static int32_t callImport_void(Instance*, int32_t, int32_t, uint64_t*);
static int32_t callImport_i32(Instance*, int32_t, int32_t, uint64_t*);
static int32_t callImport_i64(Instance*, int32_t, int32_t, uint64_t*);
static int32_t callImport_f64(Instance*, int32_t, int32_t, uint64_t*);
static uint32_t growMemory_i32(Instance* instance, uint32_t delta);
static uint32_t currentMemory_i32(Instance* instance);
bool callImport(JSContext* cx, uint32_t funcImportIndex, unsigned argc, const uint64_t* argv,
MutableHandleValue rval);
// Only WasmInstanceObject can call the private trace function.
friend class js::WasmInstanceObject;
void tracePrivate(JSTracer* trc);
public:
Instance(JSContext* cx,
HandleWasmInstanceObject object,
UniqueCode code,
HandleWasmMemoryObject memory,
SharedTableVector&& tables,
Handle<FunctionVector> funcImports,
const ValVector& globalImports);
~Instance();
bool init(JSContext* cx);
void trace(JSTracer* trc);
JSContext* cx() const { return tlsData_.cx; }
JSCompartment* compartment() const { return compartment_; }
Code& code() { return *code_; }
const Code& code() const { return *code_; }
const CodeSegment& codeSegment() const { return code_->segment(); }
uint8_t* codeBase() const { return code_->segment().base(); }
const Metadata& metadata() const { return code_->metadata(); }
bool isAsmJS() const { return metadata().isAsmJS(); }
const SharedTableVector& tables() const { return tables_; }
SharedMem<uint8_t*> memoryBase() const;
size_t memoryLength() const;
size_t memoryMappedSize() const;
bool memoryAccessInGuardRegion(uint8_t* addr, unsigned numBytes) const;
TlsData& tlsData() { return tlsData_; }
// This method returns a pointer to the GC object that owns this Instance.
// Instances may be reached via weak edges (e.g., Compartment::instances_)
// so this perform a read-barrier on the returned object unless the barrier
// is explicitly waived.
WasmInstanceObject* object() const;
WasmInstanceObject* objectUnbarriered() const;
// Execute the given export given the JS call arguments, storing the return
// value in args.rval.
[[nodiscard]] bool callExport(JSContext* cx, uint32_t funcIndex, CallArgs args);
// Initially, calls to imports in wasm code call out through the generic
// callImport method. If the imported callee gets JIT compiled and the types
// match up, callImport will patch the code to instead call through a thunk
// directly into the JIT code. If the JIT code is released, the Instance must
// be notified so it can go back to the generic callImport.
void deoptimizeImportExit(uint32_t funcImportIndex);
// Called by simulators to check whether accessing 'numBytes' starting at
// 'addr' would trigger a fault and be safely handled by signal handlers.
bool memoryAccessWouldFault(uint8_t* addr, unsigned numBytes);
// Called by Wasm(Memory|Table)Object when a moving resize occurs:
void onMovingGrowMemory(uint8_t* prevMemoryBase);
void onMovingGrowTable();
// See Code::ensureProfilingState comment.
[[nodiscard]] bool ensureProfilingState(JSContext* cx, bool enabled);
// about:memory reporting:
void addSizeOfMisc(MallocSizeOf mallocSizeOf,
Metadata::SeenSet* seenMetadata,
ShareableBytes::SeenSet* seenBytes,
Table::SeenSet* seenTables,
size_t* code,
size_t* data) const;
};
typedef UniquePtr<Instance> UniqueInstance;
bool InitInstanceStaticData();
void ShutDownInstanceStaticData();
} // namespace wasm
} // namespace js
#endif // wasm_instance_h
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