Function flock [src]

Depending on the operating system flock may or may not interact with fcntl locks made by other processes.

Prototype

pub fn flock(fd: fd_t, operation: i32) FlockError!void

Parameters

fd: fd_toperation: i32

Possible Errors

FileLocksNotSupported

The underlying filesystem does not support file locks

SystemResources

The kernel ran out of memory for allocating file locks

Unexpected UnexpectedError

The Operating System returned an undocumented error code.

This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.

When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.

WouldBlock

Source

  pub fn flock(fd: fd_t, operation: i32) FlockError!void {
    while (true) {
        const rc = system.flock(fd, operation);
        switch (errno(rc)) {
            .SUCCESS => return,
            .BADF => unreachable,
            .INTR => continue,
            .INVAL => unreachable, // invalid parameters
            .NOLCK => return error.SystemResources,
            .AGAIN => return error.WouldBlock, // TODO: integrate with async instead of just returning an error
            .OPNOTSUPP => return error.FileLocksNotSupported,
            else => |err| return unexpectedErrno(err),
        }
    }
}  