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
use std::any::Any;
#[cfg(windows)]
#[allow(nonstandard_style)]
pub fn acquire_global_lock(name: &str) -> Box<dyn Any> {
use std::ffi::CString;
use std::io;
type LPSECURITY_ATTRIBUTES = *mut u8;
type BOOL = i32;
type LPCSTR = *const u8;
type HANDLE = *mut u8;
type DWORD = u32;
const INFINITE: DWORD = !0;
const WAIT_OBJECT_0: DWORD = 0;
const WAIT_ABANDONED: DWORD = 0x00000080;
extern "system" {
fn CreateMutexA(lpMutexAttributes: LPSECURITY_ATTRIBUTES,
bInitialOwner: BOOL,
lpName: LPCSTR)
-> HANDLE;
fn WaitForSingleObject(hHandle: HANDLE, dwMilliseconds: DWORD) -> DWORD;
fn ReleaseMutex(hMutex: HANDLE) -> BOOL;
fn CloseHandle(hObject: HANDLE) -> BOOL;
}
struct Handle(HANDLE);
impl Drop for Handle {
fn drop(&mut self) {
unsafe {
CloseHandle(self.0);
}
}
}
struct Guard(Handle);
impl Drop for Guard {
fn drop(&mut self) {
unsafe {
ReleaseMutex((self.0).0);
}
}
}
let cname = CString::new(name).unwrap();
unsafe {
let mutex = CreateMutexA(0 as *mut _, 0, cname.as_ptr() as *const u8);
if mutex.is_null() {
panic!("failed to create global mutex named `{}`: {}",
name,
io::Error::last_os_error());
}
let mutex = Handle(mutex);
match WaitForSingleObject(mutex.0, INFINITE) {
WAIT_OBJECT_0 | WAIT_ABANDONED => {}
code => {
panic!("WaitForSingleObject failed on global mutex named \
`{}`: {} (ret={:x})",
name,
io::Error::last_os_error(),
code);
}
}
Box::new(Guard(mutex))
}
}
#[cfg(not(windows))]
pub fn acquire_global_lock(_name: &str) -> Box<dyn Any> {
Box::new(())
}