Multithreaded programming techniques

If you are going to write multithreaded applications or server applications for i5/OS™, you should be familiar with several techniques.

The concepts that are described in this section pertain to all programming languages. To determine how each language enables these concepts, refer to the Language topic in the information center for the specific language.

• Existing application evaluation
  When writing a multithreaded application, you should evaluate all the parts of the application and all the services that it uses for thread safety.
• Synchronization techniques among threads
  When you create code that is threadsafe but still benefits from sharing data or resources between threads, the most important aspect of programming becomes the ability to synchronize threads.
• One-time initialization and thread safety
  At times, you might want to defer the initialization of resources until a thread requires them. However, your application might require that multiple threads use a certain resource, which requires you to initialize the resource only once in a threadsafe way.
• Thread-specific data
  Typical applications that are not threaded use global storage.
• Function calls that are not thread safe
  Your multithreaded application at times requires access to functions or system services that are not thread safe. There are few completely safe alternatives for calling these functions.
• Common multithreaded programming errors
  Several programming errors often occur when writing multithreaded applications.