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
|
/*
* Lock and unlock a mutex with a globally visible name. Used to
* synchronise between unrelated processes, such as two
* connection-sharing PuTTYs deciding which will be the upstream.
*/
#include "putty.h"
#include "security-api.h"
HANDLE lock_interprocess_mutex(const char *mutexname, char **error)
{
PSECURITY_DESCRIPTOR psd = NULL;
PACL acl = NULL;
HANDLE mutex = NULL;
if (should_have_security() && !make_private_security_descriptor(
MUTEX_ALL_ACCESS, &psd, &acl, error))
goto out;
SECURITY_ATTRIBUTES sa;
memset(&sa, 0, sizeof(sa));
sa.nLength = sizeof(sa);
sa.lpSecurityDescriptor = psd;
sa.bInheritHandle = false;
mutex = CreateMutex(&sa, false, mutexname);
if (!mutex) {
*error = dupprintf("CreateMutex(\"%s\") failed: %s",
mutexname, win_strerror(GetLastError()));
goto out;
}
WaitForSingleObject(mutex, INFINITE);
out:
if (psd)
LocalFree(psd);
if (acl)
LocalFree(acl);
return mutex;
}
void unlock_interprocess_mutex(HANDLE mutex)
{
ReleaseMutex(mutex);
CloseHandle(mutex);
}
|
