The Mutex class

简介

The following paragraph was taken, in part, from the Posix Threads documentation:

Mutex is an abbreviation for "mutual exclusion". Mutex variables are one of the primary means of implementing thread synchronization and for protecting shared data when multiple writes occur. A mutex variable acts like a "lock" protecting access to a shared data resource. The basic concept of a mutex is that only one thread can lock (or own) a mutex variable at any given time. Thus, even if several threads try to lock a mutex only one thread will be successful. No other thread can own that mutex until the owning thread unlocks that mutex. Threads must "take turns" accessing protected data. Mutex can be used to prevent race conditions.

pthreads provides PHP with direct access to a carefully selected subset of Mutex functions.

The Mutex created by pthreads for PHP are of an error-checking type where available (PTHREAD_MUTEX_ERRORCHECK), in the alpha stages of development this is the only type of Mutex supported by pthreads.

Because of their nature, the programmer must take care to destroy Mutex handles they are finished with.

类摘要