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
|
// Copyright (c) 2019-2021 Alexander Medvednikov. All rights reserved.
// Use of this source code is governed by an MIT license
// that can be found in the LICENSE file.
module sync
import time
#include <synchapi.h>
#include <time.h>
fn C.GetSystemTimeAsFileTime(lpSystemTimeAsFileTime &C._FILETIME)
fn C.InitializeConditionVariable(voidptr)
fn C.WakeConditionVariable(voidptr)
fn C.SleepConditionVariableSRW(voidptr, voidptr, u32, u32) int
// TODO: The suggestion of using CriticalSection instead of mutex
// was discussed. Needs consideration.
// Mutex HANDLE
type MHANDLE = voidptr
// Semaphore HANDLE
type SHANDLE = voidptr
//[init_with=new_mutex] // TODO: implement support for this struct attribute, and disallow Mutex{} from outside the sync.new_mutex() function.
// `SRWLOCK` is much more performant that `Mutex` on Windows, so use that in both cases since we don't want to share with other processes
[heap]
pub struct Mutex {
mut:
mx C.SRWLOCK // mutex handle
}
[heap]
pub struct RwMutex {
mut:
mx C.SRWLOCK // mutex handle
}
[heap]
struct Semaphore {
mtx C.SRWLOCK
cond C.CONDITION_VARIABLE
mut:
count u32
}
pub fn new_mutex() &Mutex {
mut m := &Mutex{}
m.init()
return m
}
pub fn new_rwmutex() &RwMutex {
mut m := &RwMutex{}
m.init()
return m
}
pub fn (mut m Mutex) init() {
C.InitializeSRWLock(&m.mx)
}
pub fn (mut m RwMutex) init() {
C.InitializeSRWLock(&m.mx)
}
pub fn (mut m Mutex) @lock() {
C.AcquireSRWLockExclusive(&m.mx)
}
pub fn (mut m Mutex) unlock() {
C.ReleaseSRWLockExclusive(&m.mx)
}
// RwMutex has separate read- and write locks
pub fn (mut m RwMutex) @rlock() {
C.AcquireSRWLockShared(&m.mx)
}
pub fn (mut m RwMutex) @lock() {
C.AcquireSRWLockExclusive(&m.mx)
}
// Windows SRWLocks have different function to unlock
// So provide two functions here, too, to have a common interface
pub fn (mut m RwMutex) runlock() {
C.ReleaseSRWLockShared(&m.mx)
}
pub fn (mut m RwMutex) unlock() {
C.ReleaseSRWLockExclusive(&m.mx)
}
pub fn (mut m Mutex) destroy() {
// nothing to do
}
[inline]
pub fn new_semaphore() &Semaphore {
return new_semaphore_init(0)
}
pub fn new_semaphore_init(n u32) &Semaphore {
mut sem := &Semaphore{}
sem.init(n)
return sem
}
pub fn (mut sem Semaphore) init(n u32) {
C.atomic_store_u32(&sem.count, n)
C.InitializeSRWLock(&sem.mtx)
C.InitializeConditionVariable(&sem.cond)
}
pub fn (mut sem Semaphore) post() {
mut c := C.atomic_load_u32(&sem.count)
for c > 1 {
if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c + 1) {
return
}
}
C.AcquireSRWLockExclusive(&sem.mtx)
c = C.atomic_fetch_add_u32(&sem.count, 1)
if c == 0 {
C.WakeConditionVariable(&sem.cond)
}
C.ReleaseSRWLockExclusive(&sem.mtx)
}
pub fn (mut sem Semaphore) wait() {
mut c := C.atomic_load_u32(&sem.count)
for c > 0 {
if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) {
return
}
}
C.AcquireSRWLockExclusive(&sem.mtx)
c = C.atomic_load_u32(&sem.count)
outer: for {
if c == 0 {
C.SleepConditionVariableSRW(&sem.cond, &sem.mtx, C.INFINITE, 0)
c = C.atomic_load_u32(&sem.count)
}
for c > 0 {
if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) {
if c > 1 {
C.WakeConditionVariable(&sem.cond)
}
break outer
}
}
}
C.ReleaseSRWLockExclusive(&sem.mtx)
}
pub fn (mut sem Semaphore) try_wait() bool {
mut c := C.atomic_load_u32(&sem.count)
for c > 0 {
if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) {
return true
}
}
return false
}
pub fn (mut sem Semaphore) timed_wait(timeout time.Duration) bool {
mut c := C.atomic_load_u32(&sem.count)
for c > 0 {
if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) {
return true
}
}
mut ft_start := C._FILETIME{}
C.GetSystemTimeAsFileTime(&ft_start)
time_end := ((u64(ft_start.dwHighDateTime) << 32) | ft_start.dwLowDateTime) +
u64(timeout / (100 * time.nanosecond))
mut t_ms := timeout.sys_milliseconds()
C.AcquireSRWLockExclusive(&sem.mtx)
mut res := 0
c = C.atomic_load_u32(&sem.count)
outer: for {
if c == 0 {
res = C.SleepConditionVariableSRW(&sem.cond, &sem.mtx, t_ms, 0)
if res == 0 {
break outer
}
c = C.atomic_load_u32(&sem.count)
}
for c > 0 {
if C.atomic_compare_exchange_weak_u32(&sem.count, &c, c - 1) {
if c > 1 {
C.WakeConditionVariable(&sem.cond)
}
break outer
}
}
C.GetSystemTimeAsFileTime(&ft_start)
time_now := ((u64(ft_start.dwHighDateTime) << 32) | ft_start.dwLowDateTime) // in 100ns
if time_now > time_end {
break outer // timeout exceeded
}
t_ms = u32((time_end - time_now) / 10000)
}
C.ReleaseSRWLockExclusive(&sem.mtx)
return res != 0
}
pub fn (s Semaphore) destroy() {
}
|
