Pthread Error Codes
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Pthread_create Example C++
each other. Join them; it only takes a minute: Sign up Return code from pthread_create() is 11 up vote 2 down vote favorite 2 I am trying to run a simple multi threaded programming and i am getting this pthread error handling error from gcc return code from pthread_create() is 11 how do i solve this issue ? #include API Compiling Threaded Programs Thread Management Creating and Terminating Threads Passing Arguments to Threads Joining and Detaching Threads Stack Management Miscellaneous Routines Exercise 1 Mutex Variables Mutex Variables Overview Creating and Destroying Mutexes Locking and Unlocking Mutexes Condition Variables Condition Variables Overview Creating and pthread_create arguments Destroying Condition Variables Waiting and Signaling on Condition Variables Monitoring, Debugging and Performance Analysis Tools for Pthreads LLNL Specific Information and Recommendations Topics Not Covered Exercise 2 References and More Information Appendix A: Pthread Library Routines Reference Abstract In shared memory multiprocessor architectures, threads can be used to http://stackoverflow.com/questions/7038586/return-code-from-pthread-create-is-11 implement parallelism. Historically, hardware vendors have implemented their own proprietary versions of threads, making portability a concern for software developers. For UNIX systems, a standardized C language threads programming interface has been specified by the IEEE POSIX 1003.1c standard. Implementations that adhere to this standard are referred to as POSIX threads, or Pthreads. The tutorial begins with an introduction to concepts, https://computing.llnl.gov/tutorials/pthreads/ motivations, and design considerations for using Pthreads. Each of the three major classes of routines in the Pthreads API are then covered: Thread Management, Mutex Variables, and Condition Variables. Example codes are used throughout to demonstrate how to use most of the Pthreads routines needed by a new Pthreads programmer. The tutorial concludes with a discussion of LLNL specifics and how to mix MPI with pthreads. A lab exercise, with numerous example codes (C Language) is also included. Level/Prerequisites: This tutorial is ideal for those who are new to parallel programming with pthreads. A basic understanding of parallel programming in C is required. For those who are unfamiliar with Parallel Programming in general, the material covered in EC3500: Introduction to Parallel Computing would be helpful. Pthreads Overview What is a Thread? Technically, a thread is defined as an independent stream of instructions that can be scheduled to run as such by the operating system. But what does this mean? To the software developer, the concept of a "procedure" that runs independently from its main program may best describe a thread. To go to the Single Unix Specification standard consisted to submit an example of use for pthread_sigmask()[1]. Since my proposal was going to be viewed by many Austin Group's contributors (some being "recognized UNIX authority"), I tried to http://www.domaigne.com/blog/computing/pthreads-errors-and-errno/ make my example as perfect as possible. In an academic fashion, I checked every function's return code for possible errors. That's where I got it wrong for the Pthreads APIs. Oh well, they do not use errno… The Problem: Before the advent of Pthreads, POSIX functions used to return -1 on error, and set the corresponding error code in the global variable errno[2]. This mechanism has pthread error a few drawbacks even for single-threaded process: it is not simple to return -1 as valid value. a signal handler may change the errno value between the point a function set errno, and the point where you check the errno variable. Of course, a global errno doesn't work for multi-threaded processes. Indeed, a thread could execute a function that modifies errno just before you check the pthread error codes value in another thread. The (Pthreads) Solution: Since Pthreads, the errno variable is thread-local. That is, every thread has its own "errno copy". If you (or a system function) set the errno variable in one thread, it won't affect the errno value in any other thread. This is shown in the example below. Download errno_01.c1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 /*------------------------------ errno_01.c -------------------------------* compile with: cc -pthread errno_01.c -o errno_01 Copyright Loic Domaigne. Licensed under the Apache License, Version 2.0. *--------------------------------------------------------------------------*/ #include Pthread_create Function
Pthread_create Arguments Explanation