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
|
// Copyright 2015 The Chromium 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 "content/common/discardable_shared_memory_heap.h"
#include <stddef.h>
#include <algorithm>
#include <cmath>
#include <cstdlib>
#include <utility>
#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/memory/discardable_shared_memory.h"
#include "base/memory/scoped_vector.h"
#include "base/process/process_metrics.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "testing/perf/perf_test.h"
namespace content {
namespace {
const int kTimeLimitMs = 2000;
const int kTimeCheckInterval = 8192;
void NullTask() {
}
TEST(DiscardableSharedMemoryHeapTest, SearchFreeLists) {
size_t block_size = base::GetPageSize();
DiscardableSharedMemoryHeap heap(block_size);
const size_t kBlocks = 4096;
const size_t kSegments = 16;
size_t segment_size = block_size * kBlocks;
int next_discardable_shared_memory_id = 0;
for (size_t i = 0; i < kSegments; ++i) {
scoped_ptr<base::DiscardableSharedMemory> memory(
new base::DiscardableSharedMemory);
ASSERT_TRUE(memory->CreateAndMap(segment_size));
heap.MergeIntoFreeLists(heap.Grow(std::move(memory), segment_size,
next_discardable_shared_memory_id++,
base::Bind(NullTask)));
}
unsigned kSeed = 1;
// Use kSeed as seed for random number generator.
srand(kSeed);
// Pre-compute random values.
int random_span[kTimeCheckInterval];
size_t random_blocks[kTimeCheckInterval];
for (int i = 0; i < kTimeCheckInterval; ++i) {
random_span[i] = std::rand();
// Exponentially distributed block size.
const double kLambda = 2.0;
double v = static_cast<double>(std::rand()) / RAND_MAX;
random_blocks[i] = 1 + log(1.0 - v) / -kLambda * kBlocks;
}
ScopedVector<base::ScopedClosureRunner> spans;
base::TimeTicks start = base::TimeTicks::Now();
base::TimeTicks end = start + base::TimeDelta::FromMilliseconds(kTimeLimitMs);
base::TimeDelta accumulator;
int count = 0;
while (start < end) {
for (int i = 0; i < kTimeCheckInterval; ++i) {
// Search for a perfect fit if greater than kBlocks.
size_t slack =
random_blocks[i] < kBlocks ? kBlocks - random_blocks[i] : 0;
scoped_ptr<DiscardableSharedMemoryHeap::Span> span =
heap.SearchFreeLists(random_blocks[i], slack);
if (span) {
spans.push_back(new base::ScopedClosureRunner(
base::Bind(&DiscardableSharedMemoryHeap::MergeIntoFreeLists,
base::Unretained(&heap), base::Passed(&span))));
} else if (!spans.empty()) {
// Merge a random span back into the free list.
std::swap(spans[random_span[i] % spans.size()], spans.back());
spans.pop_back();
}
++count;
}
base::TimeTicks now = base::TimeTicks::Now();
accumulator += now - start;
start = now;
}
spans.clear();
perf_test::PrintResult("search_free_list", "", "",
count / accumulator.InSecondsF(), "runs/s", true);
}
} // namespace
} // namespace content
|
