runtime-atomics.cc | Explore in Territory

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/base/macros.h"
#include "src/base/platform/mutex.h"
#include "src/execution/arguments-inl.h"
#include "src/heap/factory.h"
#include "src/logging/counters.h"
#include "src/numbers/conversions-inl.h"
#include "src/objects/js-array-buffer-inl.h"
#include "src/objects/js-shared-array-inl.h"
#include "src/objects/js-struct-inl.h"
#include "src/runtime/runtime-utils.h"

// Implement Atomic accesses to ArrayBuffers and SharedArrayBuffers.
// https://tc39.es/ecma262/#sec-atomics

namespace v8 {
namespace internal {

// Other platforms have CSA support, see builtins-sharedarraybuffer-gen.h.
#if V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64 || V8_TARGET_ARCH_S390 || \
    V8_TARGET_ARCH_S390X || V8_TARGET_ARCH_LOONG64

namespace {

#if defined(V8_OS_STARBOARD)

template <typename T>
inline T ExchangeSeqCst(T* p, T value) {
  UNIMPLEMENTED();
}

template <typename T>
inline T CompareExchangeSeqCst(T* p, T oldval, T newval) {
  UNIMPLEMENTED();
}

template <typename T>
inline T AddSeqCst(T* p, T value) {
  UNIMPLEMENTED();
}

template <typename T>
inline T SubSeqCst(T* p, T value) {
  UNIMPLEMENTED();
}

template <typename T>
inline T AndSeqCst(T* p, T value) {
  UNIMPLEMENTED();
}

template <typename T>
inline T OrSeqCst(T* p, T value) {
  UNIMPLEMENTED();
}

template <typename T>
inline T XorSeqCst(T* p, T value) {
  UNIMPLEMENTED();
}

#elif V8_CC_GNU

// GCC/Clang helpfully warn us that using 64-bit atomics on 32-bit platforms
// can be slow. Good to know, but we don't have a choice.
#ifdef V8_TARGET_ARCH_32_BIT
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wpragmas"
#pragma GCC diagnostic ignored "-Watomic-alignment"
#endif  // V8_TARGET_ARCH_32_BIT

template <typename T>
inline T LoadSeqCst(T* p) {
  return __atomic_load_n(p, __ATOMIC_SEQ_CST);
}

template <typename T>
inline void StoreSeqCst(T* p, T value) {
  __atomic_store_n(p, value, __ATOMIC_SEQ_CST);
}

template <typename T>
inline T ExchangeSeqCst(T* p, T value) {
  return __atomic_exchange_n(p, value, __ATOMIC_SEQ_CST);
}

template <typename T>
inline T CompareExchangeSeqCst(T* p, T oldval, T newval) {
  (void)__atomic_compare_exchange_n(p, &oldval, newval, 0, __ATOMIC_SEQ_CST,
                                    __ATOMIC_SEQ_CST);
  return oldval;
}

template <typename T>
inline T AddSeqCst(T* p, T value) {
  return __atomic_fetch_add(p, value, __ATOMIC_SEQ_CST);
}

template <typename T>
inline T SubSeqCst(T* p, T value) {
  return __atomic_fetch_sub(p, value, __ATOMIC_SEQ_CST);
}

template <typename T>
inline T AndSeqCst(T* p, T value) {
  return __atomic_fetch_and(p, value, __ATOMIC_SEQ_CST);
}

template <typename T>
inline T OrSeqCst(T* p, T value) {
  return __atomic_fetch_or(p, value, __ATOMIC_SEQ_CST);
}

template <typename T>
inline T XorSeqCst(T* p, T value) {
  return __atomic_fetch_xor(p, value, __ATOMIC_SEQ_CST);
}

#ifdef V8_TARGET_ARCH_32_BIT
#pragma GCC diagnostic pop
#endif  // V8_TARGET_ARCH_32_BIT

#elif V8_CC_MSVC

#define InterlockedExchange32 …
#define InterlockedCompareExchange32 …
#define InterlockedCompareExchange8 …
#define InterlockedExchangeAdd32 …
#define InterlockedExchangeAdd16 …
#define InterlockedExchangeAdd8 …
#define InterlockedAnd32 …
#define InterlockedOr64 …
#define InterlockedOr32 …
#define InterlockedXor32 …

#if defined(V8_HOST_ARCH_ARM64)
#define InterlockedExchange8 …
#endif

#define ATOMIC_OPS …

ATOMIC_OPS(int8_t, 8, char)
ATOMIC_OPS(uint8_t, 8, char)
ATOMIC_OPS(int16_t, 16, short)  /* NOLINT(runtime/int) */
ATOMIC_OPS(uint16_t, 16, short) /* NOLINT(runtime/int) */
ATOMIC_OPS(int32_t, 32, long)   /* NOLINT(runtime/int) */
ATOMIC_OPS(uint32_t, 32, long)  /* NOLINT(runtime/int) */
ATOMIC_OPS(int64_t, 64, __int64)
ATOMIC_OPS(uint64_t, 64, __int64)

template <typename T>
inline T LoadSeqCst(T* p) {
  UNREACHABLE();
}

template <typename T>
inline void StoreSeqCst(T* p, T value) {
  UNREACHABLE();
}

#undef ATOMIC_OPS

#undef InterlockedExchange32
#undef InterlockedCompareExchange32
#undef InterlockedCompareExchange8
#undef InterlockedExchangeAdd32
#undef InterlockedExchangeAdd16
#undef InterlockedExchangeAdd8
#undef InterlockedAnd32
#undef InterlockedOr64
#undef InterlockedOr32
#undef InterlockedXor32

#if defined(V8_HOST_ARCH_ARM64)
#undef InterlockedExchange8
#endif

#else

#error Unsupported platform!

#endif

template <typename T>
T FromObject(Handle<Object> number);

template <>
inline uint8_t FromObject<uint8_t>(Handle<Object> number) {
  return NumberToUint32(*number);
}

template <>
inline int8_t FromObject<int8_t>(Handle<Object> number) {
  return NumberToInt32(*number);
}

template <>
inline uint16_t FromObject<uint16_t>(Handle<Object> number) {
  return NumberToUint32(*number);
}

template <>
inline int16_t FromObject<int16_t>(Handle<Object> number) {
  return NumberToInt32(*number);
}

template <>
inline uint32_t FromObject<uint32_t>(Handle<Object> number) {
  return NumberToUint32(*number);
}

template <>
inline int32_t FromObject<int32_t>(Handle<Object> number) {
  return NumberToInt32(*number);
}

template <>
inline uint64_t FromObject<uint64_t>(Handle<Object> bigint) {
  return Cast<BigInt>(bigint)->AsUint64();
}

template <>
inline int64_t FromObject<int64_t>(Handle<Object> bigint) {
  return Cast<BigInt>(bigint)->AsInt64();
}

inline Tagged<Object> ToObject(Isolate* isolate, int8_t t) {
  return Smi::FromInt(t);
}

inline Tagged<Object> ToObject(Isolate* isolate, uint8_t t) {
  return Smi::FromInt(t);
}

inline Tagged<Object> ToObject(Isolate* isolate, int16_t t) {
  return Smi::FromInt(t);
}

inline Tagged<Object> ToObject(Isolate* isolate, uint16_t t) {
  return Smi::FromInt(t);
}

inline Tagged<Object> ToObject(Isolate* isolate, int32_t t) {
  return *isolate->factory()->NewNumber(t);
}

inline Tagged<Object> ToObject(Isolate* isolate, uint32_t t) {
  return *isolate->factory()->NewNumber(t);
}

inline Tagged<Object> ToObject(Isolate* isolate, int64_t t) {
  return *BigInt::FromInt64(isolate, t);
}

inline Tagged<Object> ToObject(Isolate* isolate, uint64_t t) {
  return *BigInt::FromUint64(isolate, t);
}

template <typename T>
struct Load {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer,
                                  size_t index) {
    T result = LoadSeqCst(static_cast<T*>(buffer) + index);
    return ToObject(isolate, result);
  }
};

template <typename T>
struct Store {
  static inline void Do(Isolate* isolate, void* buffer, size_t index,
                        Handle<Object> obj) {
    T value = FromObject<T>(obj);
    StoreSeqCst(static_cast<T*>(buffer) + index, value);
  }
};

template <typename T>
struct Exchange {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> obj) {
    T value = FromObject<T>(obj);
    T result = ExchangeSeqCst(static_cast<T*>(buffer) + index, value);
    return ToObject(isolate, result);
  }
};

template <typename T>
inline Tagged<Object> DoCompareExchange(Isolate* isolate, void* buffer,
                                        size_t index, Handle<Object> oldobj,
                                        Handle<Object> newobj) {
  T oldval = FromObject<T>(oldobj);
  T newval = FromObject<T>(newobj);
  T result =
      CompareExchangeSeqCst(static_cast<T*>(buffer) + index, oldval, newval);
  return ToObject(isolate, result);
}

template <typename T>
struct Add {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> obj) {
    T value = FromObject<T>(obj);
    T result = AddSeqCst(static_cast<T*>(buffer) + index, value);
    return ToObject(isolate, result);
  }
};

template <typename T>
struct Sub {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> obj) {
    T value = FromObject<T>(obj);
    T result = SubSeqCst(static_cast<T*>(buffer) + index, value);
    return ToObject(isolate, result);
  }
};

template <typename T>
struct And {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> obj) {
    T value = FromObject<T>(obj);
    T result = AndSeqCst(static_cast<T*>(buffer) + index, value);
    return ToObject(isolate, result);
  }
};

template <typename T>
struct Or {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> obj) {
    T value = FromObject<T>(obj);
    T result = OrSeqCst(static_cast<T*>(buffer) + index, value);
    return ToObject(isolate, result);
  }
};

template <typename T>
struct Xor {
  static inline Tagged<Object> Do(Isolate* isolate, void* buffer, size_t index,
                                  Handle<Object> obj) {
    T value = FromObject<T>(obj);
    T result = XorSeqCst(static_cast<T*>(buffer) + index, value);
    return ToObject(isolate, result);
  }
};

}  // anonymous namespace

// Duplicated from objects.h
// V has parameters (Type, type, TYPE, C type)
#define INTEGER_TYPED_ARRAYS …

#define THROW_ERROR_RETURN_FAILURE_ON_DETACHED_OR_OUT_OF_BOUNDS …

// This is https://tc39.github.io/ecma262/#sec-getmodifysetvalueinbuffer
// but also includes the ToInteger/ToBigInt conversion that's part of
// https://tc39.github.io/ecma262/#sec-atomicreadmodifywrite
template <template <typename> class Op>
Tagged<Object> GetModifySetValueInBuffer(RuntimeArguments args,
                                         Isolate* isolate,
                                         const char* method_name) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  Handle<JSTypedArray> sta = args.at<JSTypedArray>(0);
  size_t index = NumberToSize(args[1]);
  Handle<Object> value_obj = args.at(2);

  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
                    sta->byte_offset();

  if (sta->type() >= kExternalBigInt64Array) {
    Handle<BigInt> bigint;
    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, bigint,
                                       BigInt::FromObject(isolate, value_obj));

    THROW_ERROR_RETURN_FAILURE_ON_DETACHED_OR_OUT_OF_BOUNDS(isolate, sta, index,
                                                            method_name);

    CHECK_LT(index, sta->GetLength());
    if (sta->type() == kExternalBigInt64Array) {
      return Op<int64_t>::Do(isolate, source, index, bigint);
    }
    DCHECK(sta->type() == kExternalBigUint64Array);
    return Op<uint64_t>::Do(isolate, source, index, bigint);
  }

  Handle<Object> value;
  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, value,
                                     Object::ToInteger(isolate, value_obj));

  THROW_ERROR_RETURN_FAILURE_ON_DETACHED_OR_OUT_OF_BOUNDS(isolate, sta, index,
                                                          method_name);

  CHECK_LT(index, sta->GetLength());

  switch (sta->type()) {
#define TYPED_ARRAY_CASE …

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

RUNTIME_FUNCTION(Runtime_AtomicsLoad64) {
  HandleScope scope(isolate);
  DCHECK_EQ(2, args.length());
  Handle<JSTypedArray> sta = args.at<JSTypedArray>(0);
  size_t index = NumberToSize(args[1]);

  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
                    sta->byte_offset();

  DCHECK(sta->type() == kExternalBigInt64Array ||
         sta->type() == kExternalBigUint64Array);
  DCHECK(!sta->IsDetachedOrOutOfBounds());
  CHECK_LT(index, sta->GetLength());
  if (sta->type() == kExternalBigInt64Array) {
    return Load<int64_t>::Do(isolate, source, index);
  }
  DCHECK(sta->type() == kExternalBigUint64Array);
  return Load<uint64_t>::Do(isolate, source, index);
}

RUNTIME_FUNCTION(Runtime_AtomicsStore64) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  Handle<JSTypedArray> sta = args.at<JSTypedArray>(0);
  size_t index = NumberToSize(args[1]);
  Handle<Object> value_obj = args.at(2);

  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
                    sta->byte_offset();

  Handle<BigInt> bigint;
  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, bigint,
                                     BigInt::FromObject(isolate, value_obj));

  THROW_ERROR_RETURN_FAILURE_ON_DETACHED_OR_OUT_OF_BOUNDS(isolate, sta, index,
                                                          "Atomics.store");

  DCHECK(sta->type() == kExternalBigInt64Array ||
         sta->type() == kExternalBigUint64Array);
  CHECK_LT(index, sta->GetLength());
  if (sta->type() == kExternalBigInt64Array) {
    Store<int64_t>::Do(isolate, source, index, bigint);
    return *bigint;
  }
  DCHECK(sta->type() == kExternalBigUint64Array);
  Store<uint64_t>::Do(isolate, source, index, bigint);
  return *bigint;
}

RUNTIME_FUNCTION(Runtime_AtomicsExchange) {
  return GetModifySetValueInBuffer<Exchange>(args, isolate, "Atomics.exchange");
}

RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange) {
  HandleScope scope(isolate);
  DCHECK_EQ(4, args.length());
  Handle<JSTypedArray> sta = args.at<JSTypedArray>(0);
  size_t index = NumberToSize(args[1]);
  Handle<Object> old_value_obj = args.at(2);
  Handle<Object> new_value_obj = args.at(3);

  uint8_t* source = static_cast<uint8_t*>(sta->GetBuffer()->backing_store()) +
                    sta->byte_offset();

  if (sta->type() >= kExternalBigInt64Array) {
    Handle<BigInt> old_bigint;
    Handle<BigInt> new_bigint;
    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
        isolate, old_bigint, BigInt::FromObject(isolate, old_value_obj));
    ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
        isolate, new_bigint, BigInt::FromObject(isolate, new_value_obj));

    THROW_ERROR_RETURN_FAILURE_ON_DETACHED_OR_OUT_OF_BOUNDS(
        isolate, sta, index, "Atomics.compareExchange");

    CHECK_LT(index, sta->GetLength());
    if (sta->type() == kExternalBigInt64Array) {
      return DoCompareExchange<int64_t>(isolate, source, index, old_bigint,
                                        new_bigint);
    }
    DCHECK(sta->type() == kExternalBigUint64Array);
    return DoCompareExchange<uint64_t>(isolate, source, index, old_bigint,
                                       new_bigint);
  }

  Handle<Object> old_value;
  Handle<Object> new_value;
  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, old_value,
                                     Object::ToInteger(isolate, old_value_obj));
  ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, new_value,
                                     Object::ToInteger(isolate, new_value_obj));

  THROW_ERROR_RETURN_FAILURE_ON_DETACHED_OR_OUT_OF_BOUNDS(
      isolate, sta, index, "Atomics.compareExchange");

  switch (sta->type()) {
#define TYPED_ARRAY_CASE …

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

// ES #sec-atomics.add
// Atomics.add( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsAdd) {
  return GetModifySetValueInBuffer<Add>(args, isolate, "Atomics.add");
}

// ES #sec-atomics.sub
// Atomics.sub( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsSub) {
  return GetModifySetValueInBuffer<Sub>(args, isolate, "Atomics.sub");
}

// ES #sec-atomics.and
// Atomics.and( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsAnd) {
  return GetModifySetValueInBuffer<And>(args, isolate, "Atomics.and");
}

// ES #sec-atomics.or
// Atomics.or( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsOr) {
  return GetModifySetValueInBuffer<Or>(args, isolate, "Atomics.or");
}

// ES #sec-atomics.xor
// Atomics.xor( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsXor) {
  return GetModifySetValueInBuffer<Xor>(args, isolate, "Atomics.xor");
}

#undef INTEGER_TYPED_ARRAYS

#else

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

RUNTIME_FUNCTION(…) { …

#endif  // V8_TARGET_ARCH_MIPS64 || V8_TARGET_ARCH_PPC64
        // V8_TARGET_ARCH_S390 || V8_TARGET_ARCH_S390X
        // || V8_TARGET_ARCH_RISCV64 || V8_TARGET_ARCH_LOONG64 ||
        // V8_TARGET_ARCH_RISCV32

RUNTIME_FUNCTION(Runtime_AtomicsLoadSharedStructOrArray) { … }

namespace {

template <typename WriteOperation>
Tagged<Object> AtomicFieldWrite(Isolate* isolate, Handle<JSObject> object,
                                Handle<Name> field_name,
                                DirectHandle<Object> value,
                                WriteOperation write_operation) { … }
}  // namespace

RUNTIME_FUNCTION(Runtime_AtomicsStoreSharedStructOrArray) { … }

RUNTIME_FUNCTION(Runtime_AtomicsExchangeSharedStructOrArray) { … }

RUNTIME_FUNCTION(Runtime_AtomicsCompareExchangeSharedStructOrArray) { … }

}  // namespace internal
}  // namespace v8
chromium/v8/src/runtime/runtime-atomics.cc
