Common multithreaded programming errors

Several programming errors often occur when writing multithreaded applications.

• Calling functions that are not threadsafe
  The most common programming error when writing a threaded application is the use of APIs or system services that are not thread safe.
• Thread creation not allowed failure
  i5/OS™ does not allow every process on the system to create threads at every time while running.
• Activation group ending
  The i5/OS™ Integrated Language Environment^® (ILE) program model uses activation groups as a way to encapsulate resources for an application program within a job.
• Mixing thread models
  Do not mix Pthreads APIs with other thread management APIs that might be provided by the system.
• Commit operations in multithreaded programs
  Database transactions in i5/OS™ are scoped to the job or the activation group.
• Database record I/O and thread safety
  You can use the I/O feedback area of a database file to communicate results of I/O operations to the record I/O user. A typical application might have problems with thread safety because of the nature of the feedback area.