Ищу thread-safe реализацию FIFO для C или Python

import sys

from cStringIO import StringIO
from threading import Lock, Thread


class FIFOBuffer(object):
    def __init__(self, compact_threshold=2**20):
        self.buf = StringIO()
        self.lock = Lock()
        self.cthreshold = compact_threshold
        self.read_fp = 0

    def write(self, data):
        with self.lock:
            self.buf.seek(0, 2)
            self.buf.write(data)

    def read(self, size=-1):
        with self.lock:
            self.buf.seek(self.read_fp)
            data = self.buf.read(size)
            self.read_fp = self.buf.tell()
            if self.read_fp > self.cthreshold:
                buf = StringIO()
                buf.write(self.buf.read())
                self.buf.close()
                self.buf = buf
                self.read_fp = 0

            return data


do_read = True
buf = FIFOBuffer()
bufsize = int(sys.argv[1])


def reader():
    while do_read:
        sys.stdout.write(buf.read())


def writer():
    while True:
        data = sys.stdin.read(bufsize)
        if not data:
            break

        buf.write(data)



wt = Thread(target=writer)
rt = Thread(target=reader)
rt.daemon = True

wt.start()
rt.start()

wt.join()
do_read = False

/tmp$ pv data | python2 boo.py 1024 > data.out
 847MiB 0:00:06 [ 136MiB/s] [============>] 100%            
/tmp$ pv data | python2 boo.py 4096 > data.out
 847MiB 0:00:03 [ 263MiB/s] [============>] 100%            
/tmp$ pv data | python2 boo.py 16384 > data.out
 847MiB 0:00:00 [1.01GiB/s] [============>] 100%