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#include "flock.h" 

#ifndef _unix_

    #include <util/generic/utility.h> 
 
    #include "winint.h" 
    #include <io.h> 
    #include <errno.h> 

    #ifdef __cplusplus 
extern "C" {
    #endif 

    int flock(int fd, int op) { 
        return Flock((HANDLE)_get_osfhandle(fd), op); 
    } 

    int Flock(void* hdl, int op) { 
        errno = 0; 

        if (hdl == INVALID_HANDLE_VALUE) { 
            errno = EBADF; 
            return -1; 
        } 

        DWORD low = 1, high = 0; 
        OVERLAPPED io; 

        Zero(io); 
 
        UnlockFileEx(hdl, 0, low, high, &io); 

        switch (op & ~LOCK_NB) { 
            case LOCK_EX: 
            case LOCK_SH: { 
                auto mode = ((op & ~LOCK_NB) == LOCK_EX) ? LOCKFILE_EXCLUSIVE_LOCK : 0; 
                if (op & LOCK_NB) { 
                    if (LockFileEx(hdl, mode | LOCKFILE_FAIL_IMMEDIATELY, 0, low, high, &io)) { 
                        return 0; 
                    } else if (GetLastError() == ERROR_LOCK_VIOLATION) { 
                        ClearLastSystemError(); 
                        errno = EWOULDBLOCK; 
                        return -1; 
                    } 
                } else { 
                    if (LockFileEx(hdl, mode, 0, low, high, &io)) { 
                        return 0; 
                    } 
                }
                break; 
            }
            case LOCK_UN: 
                return 0; 
                break; 
            default: 
                break; 
        }
        errno = EINVAL; 
        return -1; 
    }

    int fsync(int fd) { 
        return _commit(fd); 
    } 

    #ifdef __cplusplus 
}
    #endif 

#endif