(PECL pthreads >= 2.0.0)
Worker Threads have a persistent context, as such should be used over Threads in most cases.
When a Worker is started, the run method will be executed, but the Thread will not leave until one of the following conditions are met:
the Worker goes out of scope (no more references remain)
the programmer calls shutdown
the script dies
This means the programmer can reuse the context throughout execution; placing objects on the stack of the Worker will cause the Worker to execute the stacked objects run method.