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1 // Copyright 2015 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #include "src/runtime/runtime-utils.h"
6 
7 #include "src/arguments.h"
8 #include "src/base/platform/time.h"
9 #include "src/conversions-inl.h"
10 #include "src/futex-emulation.h"
11 #include "src/globals.h"
12 
13 // Implement Futex API for SharedArrayBuffers as defined in the
14 // SharedArrayBuffer draft spec, found here:
15 // https://github.com/lars-t-hansen/ecmascript_sharedmem
16 
17 namespace v8 {
18 namespace internal {
19 
RUNTIME_FUNCTION(Runtime_AtomicsFutexWait)20 RUNTIME_FUNCTION(Runtime_AtomicsFutexWait) {
21   HandleScope scope(isolate);
22   DCHECK(args.length() == 4);
23   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
24   CONVERT_SIZE_ARG_CHECKED(index, 1);
25   CONVERT_INT32_ARG_CHECKED(value, 2);
26   CONVERT_DOUBLE_ARG_CHECKED(timeout, 3);
27   RUNTIME_ASSERT(sta->GetBuffer()->is_shared());
28   RUNTIME_ASSERT(index < NumberToSize(isolate, sta->length()));
29   RUNTIME_ASSERT(sta->type() == kExternalInt32Array);
30   RUNTIME_ASSERT(timeout == V8_INFINITY || !std::isnan(timeout));
31 
32   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
33   size_t addr = (index << 2) + NumberToSize(isolate, sta->byte_offset());
34 
35   return FutexEmulation::Wait(isolate, array_buffer, addr, value, timeout);
36 }
37 
38 
RUNTIME_FUNCTION(Runtime_AtomicsFutexWake)39 RUNTIME_FUNCTION(Runtime_AtomicsFutexWake) {
40   HandleScope scope(isolate);
41   DCHECK(args.length() == 3);
42   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
43   CONVERT_SIZE_ARG_CHECKED(index, 1);
44   CONVERT_INT32_ARG_CHECKED(count, 2);
45   RUNTIME_ASSERT(sta->GetBuffer()->is_shared());
46   RUNTIME_ASSERT(index < NumberToSize(isolate, sta->length()));
47   RUNTIME_ASSERT(sta->type() == kExternalInt32Array);
48 
49   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
50   size_t addr = (index << 2) + NumberToSize(isolate, sta->byte_offset());
51 
52   return FutexEmulation::Wake(isolate, array_buffer, addr, count);
53 }
54 
55 
RUNTIME_FUNCTION(Runtime_AtomicsFutexWakeOrRequeue)56 RUNTIME_FUNCTION(Runtime_AtomicsFutexWakeOrRequeue) {
57   HandleScope scope(isolate);
58   DCHECK(args.length() == 5);
59   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
60   CONVERT_SIZE_ARG_CHECKED(index1, 1);
61   CONVERT_INT32_ARG_CHECKED(count, 2);
62   CONVERT_INT32_ARG_CHECKED(value, 3);
63   CONVERT_SIZE_ARG_CHECKED(index2, 4);
64   RUNTIME_ASSERT(sta->GetBuffer()->is_shared());
65   RUNTIME_ASSERT(index1 < NumberToSize(isolate, sta->length()));
66   RUNTIME_ASSERT(index2 < NumberToSize(isolate, sta->length()));
67   RUNTIME_ASSERT(sta->type() == kExternalInt32Array);
68 
69   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
70   size_t addr1 = (index1 << 2) + NumberToSize(isolate, sta->byte_offset());
71   size_t addr2 = (index2 << 2) + NumberToSize(isolate, sta->byte_offset());
72 
73   return FutexEmulation::WakeOrRequeue(isolate, array_buffer, addr1, count,
74                                        value, addr2);
75 }
76 
77 
RUNTIME_FUNCTION(Runtime_AtomicsFutexNumWaitersForTesting)78 RUNTIME_FUNCTION(Runtime_AtomicsFutexNumWaitersForTesting) {
79   HandleScope scope(isolate);
80   DCHECK(args.length() == 2);
81   CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, sta, 0);
82   CONVERT_SIZE_ARG_CHECKED(index, 1);
83   RUNTIME_ASSERT(sta->GetBuffer()->is_shared());
84   RUNTIME_ASSERT(index < NumberToSize(isolate, sta->length()));
85   RUNTIME_ASSERT(sta->type() == kExternalInt32Array);
86 
87   Handle<JSArrayBuffer> array_buffer = sta->GetBuffer();
88   size_t addr = (index << 2) + NumberToSize(isolate, sta->byte_offset());
89 
90   return FutexEmulation::NumWaitersForTesting(isolate, array_buffer, addr);
91 }
92 }  // namespace internal
93 }  // namespace v8
94