cy-rwlock 1.3.post5

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

1. Reader

   1. from rwlock import RwLock

   2. rwlock = RwLock()

   3.  rwlock.acquire_r()
       //Do read
       rwlock.release_r()
       

   4. OR

   5.  with rwlock.lock_r():
           //Do read
       

2. Writer

   1. from rwlock import RwLock

   2. rwlock = RwLock()

   3.  rwlock.acquire_w()
       //Do write
       rwlock.release_w()
       

   4. OR

   5.  with rwlock.lock_w():
           //Do write
       

3. full example:

   1. https://github.com/cy-arduino/cy_rwlock/blob/master/rwlock/tests/test_rwlock.py

Unittest

• run scripts\run.bat

Deploy

• run scripts\deploy.bat