use std::any::Any;
#[cfg(windows)]
#[allow(nonstandard_style)]
pub fn acquire_global_lock(name: &str) -> Box<dyn Any> {
use std::{ffi::CString, io};
type LPSECURITY_ATTRIBUTES = *mut u8;
#[allow(clippy::upper_case_acronyms)]
type BOOL = i32;
#[allow(clippy::upper_case_acronyms)]
type LPCSTR = *const u8;
#[allow(clippy::upper_case_acronyms)]
type HANDLE = *mut u8;
#[allow(clippy::upper_case_acronyms)]
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(std::ptr::null_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(())
}