1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
|
// Copyright 2018 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.
// Flags: --experimental-wasm-threads
load("test/mjsunit/wasm/wasm-constants.js");
load("test/mjsunit/wasm/wasm-module-builder.js");
const kSequenceLength = 8192;
const kNumberOfWorkers = 4;
const kBitMask = kNumberOfWorkers - 1;
const kSequenceStartAddress = 32;
function makeWorkerCodeForOpcode(compareExchangeOpcode, size, functionName,
builder) {
let loadMemOpcode = kTrapUnreachable;
switch (size) {
case 64:
loadMemOpcode = kExprI64LoadMem;
break;
case 32:
loadMemOpcode = kExprI64LoadMem32U;
break;
case 16:
loadMemOpcode = kExprI64LoadMem16U;
break;
case 8:
loadMemOpcode = kExprI64LoadMem8U;
break;
default:
throw "!";
}
const kArgMemoryCell = 0; // target for atomic ops
const kArgSequencePtr = 1; // address of sequence
const kArgSeqenceLength = 2; // lenght of sequence
const kArgWorkerId = 3; // id of this worker
const kArgBitMask = 4; // mask to extract worker id from value
const kLocalCurrentOffset = 5; // current position in sequence in bytes
const kLocalExpectedValue = 6; // the value we are waiting for
const kLocalNextValue = 7; // the value to write in the update
let body = [
// Turn sequence length to equivalent in bytes.
kExprGetLocal, kArgSeqenceLength,
kExprI32Const, size / 8,
kExprI32Mul,
kExprSetLocal, kArgSeqenceLength,
// Outer block so we have something to jump for return.
...[kExprBlock, kWasmStmt,
// Set counter to 0.
kExprI32Const, 0,
kExprSetLocal, kLocalCurrentOffset,
// Outer loop until maxcount.
...[kExprLoop, kWasmStmt,
// Find the next value to wait for.
...[kExprLoop, kWasmStmt,
// Check end of sequence.
kExprGetLocal, kLocalCurrentOffset,
kExprGetLocal, kArgSeqenceLength,
kExprI32Eq,
kExprBrIf, 2, // return
...[kExprBlock, kWasmStmt,
// Load next value.
kExprGetLocal, kArgSequencePtr,
kExprGetLocal, kLocalCurrentOffset,
kExprI32Add,
loadMemOpcode, 0, 0,
// Mask off bits.
kExprGetLocal, kArgBitMask,
kExprI64UConvertI32,
kExprI64And,
// Compare with worker id.
kExprGetLocal, kArgWorkerId,
kExprI64UConvertI32,
kExprI64Eq,
kExprBrIf, 0,
// Not found, increment position.
kExprGetLocal, kLocalCurrentOffset,
kExprI32Const, size / 8,
kExprI32Add,
kExprSetLocal, kLocalCurrentOffset,
kExprBr, 1,
kExprEnd
],
// Found, end loop.
kExprEnd
],
// Load expected value to local.
kExprGetLocal, kArgSequencePtr,
kExprGetLocal, kLocalCurrentOffset,
kExprI32Add,
loadMemOpcode, 0, 0,
kExprSetLocal, kLocalExpectedValue,
// Load value after expected one.
kExprGetLocal, kArgSequencePtr,
kExprGetLocal, kLocalCurrentOffset,
kExprI32Add,
kExprI32Const, size / 8,
kExprI32Add,
loadMemOpcode, 0, 0,
kExprSetLocal, kLocalNextValue,
// Hammer on memory until value found.
...[kExprLoop, kWasmStmt,
// Load address.
kExprGetLocal, kArgMemoryCell,
// Load expected value.
kExprGetLocal, kLocalExpectedValue,
// Load updated value.
kExprGetLocal, kLocalNextValue,
// Try update.
kAtomicPrefix, compareExchangeOpcode, 0, 0,
// Load expected value.
kExprGetLocal, kLocalExpectedValue,
// Spin if not what expected.
kExprI64Ne,
kExprBrIf, 0,
kExprEnd
],
// Next iteration of loop.
kExprGetLocal, kLocalCurrentOffset,
kExprI32Const, size / 8,
kExprI32Add,
kExprSetLocal, kLocalCurrentOffset,
kExprBr, 0,
kExprEnd
], // outer loop
kExprEnd
], // the block
kExprReturn
];
builder.addFunction(functionName, makeSig([kWasmI32, kWasmI32, kWasmI32,
kWasmI32, kWasmI32
], []))
.addLocals({
i32_count: 1, i64_count: 2
})
.addBody(body)
.exportAs(functionName);
}
function generateSequence(typedarray, start, count) {
let end = count + start;
for (let i = start; i < end; i++) {
typedarray[i] = Math.floor(Math.random() * 256);
}
}
function spawnWorker(module, memory, address, sequence) {
let workers = [];
for (let i = 0; i < kNumberOfWorkers; i++) {
let worker = new Worker(
`onmessage = function(msg) {
this.instance = new WebAssembly.Instance(msg.module,
{m: {imported_mem: msg.memory}});
instance.exports.worker(msg.address, msg.sequence, msg.sequenceLength, msg.workerId,
msg.bitMask);
postMessage({workerId: msg.workerId});
}`,
{type: 'string'}
);
workers.push(worker);
worker.postMessage({
module: module,
memory: memory,
address: address,
sequence: sequence,
sequenceLength: kSequenceLength,
workerId: i,
bitMask: kBitMask
});
}
return workers;
}
function waitForWorkers(workers) {
for (let worker of workers) {
worker.getMessage();
worker.terminate();
}
}
function testOpcode(opcode, opcodeSize) {
print("Testing I64AtomicCompareExchange" + opcodeSize);
let builder = new WasmModuleBuilder();
builder.addImportedMemory("m", "imported_mem", 0, 2, "shared");
makeWorkerCodeForOpcode(opcode, opcodeSize, "worker", builder);
let memory = new WebAssembly.Memory({
initial: 2,
maximum: 2,
shared: true
});
let memoryView = new Uint8Array(memory.buffer);
generateSequence(memoryView, kSequenceStartAddress, kSequenceLength * (opcodeSize / 8));
let module = new WebAssembly.Module(builder.toBuffer());
let workers = spawnWorker(module, memory, 0, kSequenceStartAddress);
// Fire the workers off
for (let i = opcodeSize / 8 - 1; i >= 0; i--) {
memoryView[i] = memoryView[kSequenceStartAddress + i];
}
waitForWorkers(workers);
print("DONE");
}
testOpcode(kExprI64AtomicCompareExchange, 64);
testOpcode(kExprI64AtomicCompareExchange32U, 32);
testOpcode(kExprI64AtomicCompareExchange16U, 16);
testOpcode(kExprI64AtomicCompareExchange8U, 8);
|
