1 /*
2 * Copyright 2013 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "SkOnce.h"
9 #include "SkRunnable.h"
10 #include "SkTaskGroup.h"
11 #include "Test.h"
12
add_five(int * x)13 static void add_five(int* x) {
14 *x += 5;
15 }
16
17 SK_DECLARE_STATIC_ONCE(st_once);
DEF_TEST(SkOnce_Singlethreaded,r)18 DEF_TEST(SkOnce_Singlethreaded, r) {
19 int x = 0;
20
21 // No matter how many times we do this, x will be 5.
22 SkOnce(&st_once, add_five, &x);
23 SkOnce(&st_once, add_five, &x);
24 SkOnce(&st_once, add_five, &x);
25 SkOnce(&st_once, add_five, &x);
26 SkOnce(&st_once, add_five, &x);
27
28 REPORTER_ASSERT(r, 5 == x);
29 }
30
add_six(int * x)31 static void add_six(int* x) {
32 *x += 6;
33 }
34
35 namespace {
36
37 class Racer : public SkRunnable {
38 public:
39 SkOnceFlag* once;
40 int* ptr;
41
run()42 void run() override {
43 SkOnce(once, add_six, ptr);
44 }
45 };
46
47 } // namespace
48
49 SK_DECLARE_STATIC_ONCE(mt_once);
DEF_TEST(SkOnce_Multithreaded,r)50 DEF_TEST(SkOnce_Multithreaded, r) {
51 const int kTasks = 16;
52
53 // Make a bunch of tasks that will race to be the first to add six to x.
54 Racer racers[kTasks];
55 int x = 0;
56 for (int i = 0; i < kTasks; i++) {
57 racers[i].once = &mt_once;
58 racers[i].ptr = &x;
59 }
60
61 // Let them race.
62 SkTaskGroup tg;
63 for (int i = 0; i < kTasks; i++) {
64 tg.add(&racers[i]);
65 }
66 tg.wait();
67
68 // Only one should have done the +=.
69 REPORTER_ASSERT(r, 6 == x);
70 }
71
72 static int gX = 0;
inc_gX()73 static void inc_gX() { gX++; }
74
75 SK_DECLARE_STATIC_ONCE(noarg_once);
DEF_TEST(SkOnce_NoArg,r)76 DEF_TEST(SkOnce_NoArg, r) {
77 SkOnce(&noarg_once, inc_gX);
78 SkOnce(&noarg_once, inc_gX);
79 SkOnce(&noarg_once, inc_gX);
80 REPORTER_ASSERT(r, 1 == gX);
81 }
82