zig/std/event/rwlocked.zig

59 lines
1.6 KiB
Zig

const std = @import("../std.zig");
const RwLock = std.event.RwLock;
const Loop = std.event.Loop;
/// Thread-safe async/await RW lock that protects one piece of data.
/// coroutines which are waiting for the lock are suspended, and
/// are resumed when the lock is released, in order.
pub fn RwLocked(comptime T: type) type {
return struct {
lock: RwLock,
locked_data: T,
const Self = @This();
pub const HeldReadLock = struct {
value: *const T,
held: RwLock.HeldRead,
pub fn release(self: HeldReadLock) void {
self.held.release();
}
};
pub const HeldWriteLock = struct {
value: *T,
held: RwLock.HeldWrite,
pub fn release(self: HeldWriteLock) void {
self.held.release();
}
};
pub fn init(loop: *Loop, data: T) Self {
return Self{
.lock = RwLock.init(loop),
.locked_data = data,
};
}
pub fn deinit(self: *Self) void {
self.lock.deinit();
}
pub async fn acquireRead(self: *Self) HeldReadLock {
return HeldReadLock{
.held = await (async self.lock.acquireRead() catch unreachable),
.value = &self.locked_data,
};
}
pub async fn acquireWrite(self: *Self) HeldWriteLock {
return HeldWriteLock{
.held = await (async self.lock.acquireWrite() catch unreachable),
.value = &self.locked_data,
};
}
};
}