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 "SkTaskGroup.h"
10 #include "Test.h"
11 
add_five(int * x)12 static void add_five(int* x) {
13     *x += 5;
14 }
15 
16 SK_DECLARE_STATIC_ONCE(st_once);
DEF_TEST(SkOnce_Singlethreaded,r)17 DEF_TEST(SkOnce_Singlethreaded, r) {
18     int x = 0;
19 
20     // No matter how many times we do this, x will be 5.
21     SkOnce(&st_once, add_five, &x);
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 
27     REPORTER_ASSERT(r, 5 == x);
28 }
29 
30 SK_DECLARE_STATIC_ONCE(mt_once);
DEF_TEST(SkOnce_Multithreaded,r)31 DEF_TEST(SkOnce_Multithreaded, r) {
32     int x = 0;
33     // Run a bunch of tasks to be the first to add six to x.
34     SkTaskGroup().batch(1021, [&](int) {
35         void(*add_six)(int*) = [](int* p) { *p += 6; };
36         SkOnce(&mt_once, add_six, &x);
37     });
38 
39     // Only one should have done the +=.
40     REPORTER_ASSERT(r, 6 == x);
41 }
42 
43 static int gX = 0;
inc_gX()44 static void inc_gX() { gX++; }
45 
46 SK_DECLARE_STATIC_ONCE(noarg_once);
DEF_TEST(SkOnce_NoArg,r)47 DEF_TEST(SkOnce_NoArg, r) {
48     SkOnce(&noarg_once, inc_gX);
49     SkOnce(&noarg_once, inc_gX);
50     SkOnce(&noarg_once, inc_gX);
51     REPORTER_ASSERT(r, 1 == gX);
52 }
53