PThreads Programming

Appendix B. Pthreads Draft 4 vs. the Final Standard

In this appendix:

• Detaching a Thread

• Mutex Variables

• Condition Variables

• Thread Attributes

• The pthread_once Function

• Keys

• Cancellation

• Scheduling

• Signals

• Threadsafe System Interfaces

• Error Reporting

• System Interfaces and Cancellation-Safety

• Process-Blocking Calls

• Process Management

So you’ve read the book that describes the final Pthreads standard and now discover that you must support or port a multithreaded program that’s based on the interfaces defined by Draft 4. Help!

The Pthreads interfaces and library implementations adopted by many vendors at Draft 4 can be significantly different from those the same vendors supply now in compliance with the final standard. We’ll help you sort out the differences in this appendix.

To help you track down the changes that particularly affect your program, we’ve organized this appendix into sections corresponding to the major activities of a multithreaded program. In each section, we’ve classified differences as relating to either features or syntax. (Of course, if a Draft 4 feature was removed in the final standard, you may need to make a syntax change in your program to remove an undefined call or constant.)

Detaching a Thread

Feature: Draft 4 doesn’t allow you to create a thread in a detached state; the final standard allows you to do so by using an attribute object. (See the section on thread attributes later in this appendix.)

Syntax: In an implementation that conforms to the final standard, you specify ...