Pthreads, Operating System

Assignment Help:

A thread is defined as an independent stream of instructions that can be scheduled to run as such by the operating system. Each program contains a number of threads which can be running in parallel.

The program  intro.c is a demonstration of using  pthread_create(thread,attr,start_routine,arg) function to create a new thread. The parameter thread is used as a way to pass variable between the main programs to the thread. The  attr parameter is used to set the thread attributes, which is usually set to NULL. The start_routine parameter is the C routine being executed when the thread starts. The arg parameter is the argument passed to the routine.

A thread is terminated using the function pthread_exit(NULL).
 
In the beginning of the main program a  thread_id of 1 is assigned to the first thread via the thread_data structure that is declared at the beginning of the program. This is used to identify which process is being run by the processor. Then the thread is created using the pthread_create() function with the rc variable which is used to identified the problem if the thread fail to be created. The first thread will execute the PrintProcess1 routine when the thread is created. After the first thread is created we create the second thread with a thread_id of 2 using the same procedure, but this time the PrintProcess2 routine will be used for the second thread.

In each of the PrintProcess routine the thread_id will be passed onto a process_id variable via the threadid data structure. Then the process will print a message saying the process is running, then delay by the number of seconds that is decided by the process_id, and display a message saying the process is finished. The pthread_exit(NULL) function will be used to terminate the current thread.


Related Discussions:- Pthreads

Differences between symmetric and asymmetric multiprocessing, Describe the ...

Describe the differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantage of multiprocessor systems? Symmetric multiprocessing t

Perl script, Write a Perl script assignGrades.pl to assign letter grades to...

Write a Perl script assignGrades.pl to assign letter grades to the students.

State in a deadlock-avoidance system, Question: In a deadlock, processe...

Question: In a deadlock, processes never finish executing and system resources are tied up, preventing other jobs from starting. Deadlocks can be characterised by a set of cond

Conversion of binary to hex, Take the binary number and divide it into grou...

Take the binary number and divide it into groups of 4 bits starting from the right hand side , if no group of 4 exists fill out leading 0's, then convert each group of 4 to a hex n

What is a real-time system?, What is a Real-time system? A Real-time sy...

What is a Real-time system? A Real-time system is used when inflexible time requirements have placed on the operation of processor or the flow of data so it is often used as a

Semispace, Semispace works by maintaining two disjoint areas from which mem...

Semispace works by maintaining two disjoint areas from which memory can be allocated. These areas are called the from-space and the to-space. At ?rst, the algorithm allocates memor

What is the exclusive feature of unix, What is the exclusive feature of UNI...

What is the exclusive feature of UNIX Shell is the exclusive feature of UNIX.

Differences between foreground and background, Describe the differences bet...

Describe the differences between foreground and background processing. What advantage does background processing provide? 1. Background processes typically run with little or no

What is an effector process, What is an effector process? The effector ...

What is an effector process? The effector process is a method that verifies itself.The effector process exists in particular criteria.

For what reason would such a scheme be useful, Q. A Burroughs B7000/B6000 ...

Q. A Burroughs B7000/B6000 MCP file is able to be tagged as sensitive data. When such a file is removed its storage area is overwritten by some random bits. For what reason would

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd