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
use alloc::boxed::Box;
use core::mem;
use core::sync::atomic::{AtomicIsize, Ordering};
use crate::synch::semaphore::Semaphore;
struct CondQueue {
counter: AtomicIsize,
sem1: Semaphore,
sem2: Semaphore,
}
impl CondQueue {
pub fn new() -> Self {
CondQueue {
counter: AtomicIsize::new(0),
sem1: Semaphore::new(0),
sem2: Semaphore::new(0),
}
}
}
unsafe fn __sys_destroy_queue(ptr: usize) -> i32 {
let id = ptr as *mut usize;
if id.is_null() {
debug!("sys_wait: invalid address to condition variable");
return -1;
}
if *id != 0 {
let cond = Box::from_raw((*id) as *mut CondQueue);
mem::drop(cond);
}
0
}
#[no_mangle]
pub unsafe fn sys_destroy_queue(ptr: usize) -> i32 {
kernel_function!(__sys_destroy_queue(ptr))
}
unsafe fn __sys_notify(ptr: usize, count: i32) -> i32 {
let id = ptr as *const usize;
if id.is_null() {
debug!("sys_notify: invalid address to condition variable");
return -1;
}
if *id == 0 {
debug!("sys_notify: invalid reference to condition variable");
return -1;
}
let cond = &mut *((*id) as *mut CondQueue);
if count < 0 {
while cond.counter.load(Ordering::SeqCst) > 0 {
cond.counter.fetch_sub(1, Ordering::SeqCst);
cond.sem1.release();
cond.sem2.acquire(None);
}
} else {
for _ in 0..count {
cond.counter.fetch_sub(1, Ordering::SeqCst);
cond.sem1.release();
cond.sem2.acquire(None);
}
}
0
}
#[no_mangle]
pub unsafe fn sys_notify(ptr: usize, count: i32) -> i32 {
kernel_function!(__sys_notify(ptr, count))
}
unsafe fn __sys_init_queue(ptr: usize) -> i32 {
let id = ptr as *mut usize;
if id.is_null() {
debug!("sys_init_queue: invalid address to condition variable");
return -1;
}
if *id == 0 {
debug!("Create condition variable queue");
let queue = Box::new(CondQueue::new());
*id = Box::into_raw(queue) as usize;
}
0
}
#[no_mangle]
pub unsafe fn sys_init_queue(ptr: usize) -> i32 {
kernel_function!(__sys_init_queue(ptr))
}
unsafe fn __sys_add_queue(ptr: usize, timeout_ns: i64) -> i32 {
let id = ptr as *mut usize;
if id.is_null() {
debug!("sys_add_queue: invalid address to condition variable");
return -1;
}
if *id == 0 {
debug!("Create condition variable queue");
let queue = Box::new(CondQueue::new());
*id = Box::into_raw(queue) as usize;
}
if timeout_ns <= 0 {
let cond = &mut *((*id) as *mut CondQueue);
cond.counter.fetch_add(1, Ordering::SeqCst);
0
} else {
error!("Conditional variables with timeout is currently not supported");
-1
}
}
#[no_mangle]
pub unsafe fn sys_add_queue(ptr: usize, timeout_ns: i64) -> i32 {
kernel_function!(__sys_add_queue(ptr, timeout_ns))
}
unsafe fn __sys_wait(ptr: usize) -> i32 {
let id = ptr as *mut usize;
if id.is_null() {
debug!("sys_wait: invalid address to condition variable");
return -1;
}
if *id == 0 {
error!("sys_wait: Unable to determine condition variable");
return -1;
}
let cond = &mut *((*id) as *mut CondQueue);
cond.sem1.acquire(None);
cond.sem2.release();
0
}
#[no_mangle]
pub unsafe fn sys_wait(ptr: usize) -> i32 {
kernel_function!(__sys_wait(ptr))
}