How to implement deletion of write barriers in golang

In concurrent programming, write barriers are a widely used technique to ensure the correctness of multiple threads writing concurrently to a shared data structure. However, write barriers require synchronization of all memory accesses and can lead to performance degradation and race conditions. To solve these problems, the Go language provides an optimization technique called write barrier removal.

Deleting write barriers is different from traditional write barrier technology in that it does not require forced synchronization of all memory operations. Instead, it leverages the concept of a Weak Consistency Memory Model, which allows partial synchronization between threads, thereby improving concurrency performance.

How to implement deletion of write barriers?

In the Go language, deleting write barriers is achieved by adopting a new type called "release memory order". Release memory order is used when a thread writes a shared data through the "StoreRelease" function in the "sync/atomic" package.

The definition of release memory order is: Any value X written by thread A can only be seen by other threads after thread A has completed all other memory accesses. This provides certain synchronization guarantees, but does not require that all memory operations be synchronized.

In addition, removing the write barrier also has an excellent feature: when the thread reads the value from the shared data through the "LoadAcquire" function, the data does not need to be synchronized. This is because the LoadAcquire function automatically ensures that all previous write operations have been completed.

These make deleting the write barrier very suitable for use in high concurrency situations, especially when there are many more read operations than write operations, because write operations require memory synchronization, and reads The operation only requires the use of memory barriers.

In addition, compared with traditional write barrier technology, removing write barriers also provides better fairness. Traditional write barrier techniques can result in performance degradation for some threads because they need to wait for other threads to complete memory synchronization. Removing the write barrier improves this problem through a weakly consistent memory model and improves thread fairness.

Summary

In high-concurrency programming, write barrier technology is very important. It ensures correctness when multiple threads write shared data concurrently. However, traditional write barrier technology may have a certain impact on concurrency performance and may lead to race conditions. The delete write barrier technology in the Go language can solve these problems well. It improves concurrency performance through the concept of weakly consistent memory model, while ensuring the correctness of shared data.

The above is the detailed content of How to implement deletion of write barriers in golang. For more information, please follow other related articles on the PHP Chinese website!