locker Namespace Reference

Classes
class	LockFile
	Lock a file. More...

Functions
def	lock
def	unlock

Function Documentation

def locker.lock

(

file

)

Lock first 10 bytes of a file.

Definition at line 16 of file locker.py.

    def lock(file):
        """
        Lock first 10 bytes of a file.
        """
        pos = file.tell() # remember current position
        file.seek(0)
        # By default, python tries about 10 times, then throws an exception.
        # We want to wait forever.
        acquired = False
        while not acquired:
            try:
                msvcrt.locking(file.fileno(),msvcrt.LK_LOCK,10)
                acquired = True
            except IOError, x:
                if x.errno != 36: # 36, AKA 'Resource deadlock avoided', is normal
                    raise
        file.seek(pos) # reset position