src/runtime/runtime-atomics.cc

// 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/arguments-inl.h"
#include "src/base/macros.h"
#include "src/base/platform/mutex.h"
#include "src/conversions-inl.h"
#include "src/heap/factory.h"
#include "src/objects/js-array-buffer-inl.h"
#include "src/runtime/runtime-utils.h"

// Implement Atomic accesses to SharedArrayBuffers as defined in the
// SharedArrayBuffer draft spec, found here
// https://github.com/tc39/ecmascript_sharedmem

namespace v8 {
namespace internal {

namespace {

#if V8_CC_GNU

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);
}

#elif V8_CC_MSVC

#define InterlockedExchange32 _InterlockedExchange
#define InterlockedCompareExchange32 _InterlockedCompareExchange
#define InterlockedCompareExchange8 _InterlockedCompareExchange8
#define InterlockedExchangeAdd32 _InterlockedExchangeAdd
#define InterlockedExchangeAdd16 _InterlockedExchangeAdd16
#define InterlockedExchangeAdd8 _InterlockedExchangeAdd8
#define InterlockedAnd32 _InterlockedAnd
#define InterlockedOr32 _InterlockedOr
#define InterlockedXor32 _InterlockedXor

#define ATOMIC_OPS(type, suffix, vctype)                                    \
  inline type ExchangeSeqCst(type* p, type value) {                         \
    return InterlockedExchange##suffix(reinterpret_cast<vctype*>(p),        \
                                       bit_cast<vctype>(value));            \
  }                                                                         \
  inline type CompareExchangeSeqCst(type* p, type oldval, type newval) {    \
    return InterlockedCompareExchange##suffix(reinterpret_cast<vctype*>(p), \
                                              bit_cast<vctype>(newval),     \
                                              bit_cast<vctype>(oldval));    \
  }                                                                         \
  inline type AddSeqCst(type* p, type value) {                              \
    return InterlockedExchangeAdd##suffix(reinterpret_cast<vctype*>(p),     \
                                          bit_cast<vctype>(value));         \
  }                                                                         \
  inline type SubSeqCst(type* p, type value) {                              \
    return InterlockedExchangeAdd##suffix(reinterpret_cast<vctype*>(p),     \
                                          -bit_cast<vctype>(value));        \
  }                                                                         \
  inline type AndSeqCst(type* p, type value) {                              \
    return InterlockedAnd##suffix(reinterpret_cast<vctype*>(p),             \
                                  bit_cast<vctype>(value));                 \
  }                                                                         \
  inline type OrSeqCst(type* p, type value) {                               \
    return InterlockedOr##suffix(reinterpret_cast<vctype*>(p),              \
                                 bit_cast<vctype>(value));                  \
  }                                                                         \
  inline type XorSeqCst(type* p, type value) {                              \
    return InterlockedXor##suffix(reinterpret_cast<vctype*>(p),             \
                                  bit_cast<vctype>(value));                 \
  }

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) */

#undef ATOMIC_OPS

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

#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);
}


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

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

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

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

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

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

template <typename T>
inline Object* DoExchange(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 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>
inline Object* DoAdd(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>
inline Object* DoSub(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>
inline Object* DoAnd(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>
inline Object* DoOr(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>
inline Object* DoXor(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(V)       \
  V(Uint8, uint8, UINT8, uint8_t)     \
  V(Int8, int8, INT8, int8_t)         \
  V(Uint16, uint16, UINT16, uint16_t) \
  V(Int16, int16, INT16, int16_t)     \
  V(Uint32, uint32, UINT32, uint32_t) \
  V(Int32, int32, INT32, int32_t)

RUNTIME_FUNCTION(Runtime_AtomicsExchange) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoExchange<ctype>(isolate, source, index, value);

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

RUNTIME_FUNCTION(Runtime_AtomicsCompareExchange) {
  HandleScope scope(isolate);
  DCHECK_EQ(4, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(oldobj, 2);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(newobj, 3);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoCompareExchange<ctype>(isolate, source, index, oldobj, newobj);

    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) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoAdd<ctype>(isolate, source, index, value);

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

// ES #sec-atomics.sub
// Atomics.sub( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsSub) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoSub<ctype>(isolate, source, index, value);

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

// ES #sec-atomics.and
// Atomics.and( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsAnd) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoAnd<ctype>(isolate, source, index, value);

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

// ES #sec-atomics.or
// Atomics.or( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsOr) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoOr<ctype>(isolate, source, index, value);

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

// ES #sec-atomics.xor
// Atomics.xor( typedArray, index, value )
RUNTIME_FUNCTION(Runtime_AtomicsXor) {
  HandleScope scope(isolate);
  DCHECK_EQ(3, args.length());
  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
  CONVERT_SIZE_ARG_CHECKED(index, 1);
  CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);
  CHECK(sta->GetBuffer()->is_shared());
  CHECK_LT(index, NumberToSize(sta->length()));

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

  switch (sta->type()) {
#define TYPED_ARRAY_CASE(Type, typeName, TYPE, ctype) \
  case kExternal##Type##Array:                        \
    return DoXor<ctype>(isolate, source, index, value);

    INTEGER_TYPED_ARRAYS(TYPED_ARRAY_CASE)
#undef TYPED_ARRAY_CASE

    default:
      break;
  }

  UNREACHABLE();
}

#undef INTEGER_TYPED_ARRAYS

}  // namespace internal
}  // namespace v8