pyshm 0.0.1

# pyshm - Python share memory library
[](https://opensource.org/licenses/BSD-2-Clause)
[](https://travis-ci.org/yuyang0/pyshm)

pyshm is a python library that used to pass memory block between multiple processes.
it exports three modules:

1. shm: mainly used to create share memory between multiple process(using `mmap`)
2. mempool: A memory pool is an allocator of fixed-size memory blocks. In python
memory block is represented as a buffer-like object.
3. ring: lockless FIFO queue in share memory. user can use `Ring` to manage the
memory blocks allocated from Mempool

## installation and usage

you can install pyshm using setuptools or pip:

pip install pyshm

or:

python setup.py install

## usage

1. create share memory

from pyshm import ShareMem

test_shm = ShareMem(64*1024*1024) # 64M

pls note: these code should execute before `fork`

2. using mempool

from pyshm import mempool
count = 4
mp = mempool.Mempool(count, 4, shm=test_shm)

pid = os.fork()
if pid == 0:
for i in range(count):
buf = mp.get()
struct.pack_into("=i", buf, 0, i)
mp.put(buf)
else:
cid, status = os.wait()
assert pid == cid
for i in range(count):
buf = mp.get()
v, = struct.unpack_from("=i", buf)
assert v == i
mp.cleanup()

`get` used to get memory block(a buffer-like object), `put` returns the memory block to the mempool

3. using ring

ring can used to pass the memory block(get from mempool) to the other process.
it proviod `enqueue` and `dequeue`, one process enequeue and the other process `dequeue`