Function spawn [src]

Prototype

pub fn spawn(pool: *Pool, comptime func: anytype, args: anytype) !void

Parameters

pool: *Pool

Example

 test spawn {
    const TestFn = struct {
        fn checkRun(completed: *bool) void {
            completed.* = true;
        }
    };

    var completed: bool = false;

    {
        var pool: Pool = undefined;
        try pool.init(.{
            .allocator = std.testing.allocator,
        });
        defer pool.deinit();
        try pool.spawn(TestFn.checkRun, .{&completed});
    }

    try std.testing.expectEqual(true, completed);
}

Source

  pub fn spawn(pool: *Pool, comptime func: anytype, args: anytype) !void {
    if (builtin.single_threaded) {
        @call(.auto, func, args);
        return;
    }

    const Args = @TypeOf(args);
    const Closure = struct {
        arguments: Args,
        pool: *Pool,
        run_node: RunQueue.Node = .{ .data = .{ .runFn = runFn } },

        fn runFn(runnable: *Runnable, _: ?usize) void {
            const run_node: *RunQueue.Node = @fieldParentPtr("data", runnable);
            const closure: *@This() = @alignCast(@fieldParentPtr("run_node", run_node));
            @call(.auto, func, closure.arguments);

            // The thread pool's allocator is protected by the mutex.
            const mutex = &closure.pool.mutex;
            mutex.lock();
            defer mutex.unlock();

            closure.pool.allocator.destroy(closure);
        }
    };

    {
        pool.mutex.lock();
        defer pool.mutex.unlock();

        const closure = try pool.allocator.create(Closure);
        closure.* = .{
            .arguments = args,
            .pool = pool,
        };

        pool.run_queue.prepend(&closure.run_node);
    }

    // Notify waiting threads outside the lock to try and keep the critical section small.
    pool.cond.signal();
}  