cy-rwlock 1.5

RwLock: Reader-Writer lock

RwLock: Reader-Writer lock

Release Note

1. V1.2:
   1. fix version convert issue in setup.py
2. V1.1:
   1. Reduce test time
   2. Refactoring
3. V1.0: first release

Introduction

We can simply protect a shared resource by a lock. But the performance is not good because each reader should run one-by-one.

A Reader-Writer lock can improve the performance by let readers running simultaneously.

By the way, a writer should wait until all readers done. In a frequently read situation, a new reader after the writer can also increase the read count, let read count never decrease to 0. This will starve writer.

RwLock:

1. Let readers running simultaneously.
2. Exclude "multiple readers" and each writer.
3. provide a flag "write_first" to prevent starve writer.

Usage

Install

1. pip install cy_rwlock
2. download latest version from https://pypi.org/project/cy_rwlock/#files

Example

from rwlock import RwLock

rwlock = RwLock()

### READER
rwlock.acquire_r()
# read...
rwlock.release_r()

# OR
with rwlock.lock_r():
    # read...

### WRITER
rwlock.acquire_w()
# write...
rwlock.release_w()

# OR
with rwlock.lock_w():
    # write...

Unittest

• local(windows)
  • run scripts\run.bat
• github
  • auto run when push

Deploy

• PyPI version
  • convertd from git tag
    • see setup.py: convert_version()
• local(windows)
  • run scripts\deploy.bat
• github -> PyPI
  • When release in github