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

What are the necessary conditions for deadlocks?, What are the necessary co...

What are the necessary conditions for deadlocks? 1. Mutual exclusion :  Only one process at a time is able to use the resource. 2. Hold and wait :  A process should be holdi

Fork join, fork and join syntax in java

fork and join syntax in java

What is the lower bound on the numeral of page faults, Q. Presume that you...

Q. Presume that you have a page-reference string for a process with m frames (initially all empty). The page-reference string has length p along with n distinct page numbers

What is scheduler, What is scheduler? A process migrates among the vari...

What is scheduler? A process migrates among the various scheduling queues throughout its life time. The OS must choose processes from these queues in some fashion. This selecti

Mutual exclusion, With software algorithms for mutual exclusion, such as De...

With software algorithms for mutual exclusion, such as Dekker's algorithm, Peterson's algorithm, or Lamport's bakery algorithm, note that optimizing compilers and out-of-order exec

Operating systems concepts, The code should be nicely formatted with plenty...

The code should be nicely formatted with plenty of comments. It should be easy to read, properly The summary section should include three parts: (1) Record the running t

Define unixware, Define UnixWare UnixWare manages resources at the proc...

Define UnixWare UnixWare manages resources at the process level. Each resource allocated to the application is actually allocated to the process representing the application. C

Define the sleep (sec) function, Define the Sleep (sec) Function Sleep ...

Define the Sleep (sec) Function Sleep function suspends execution of this process for sec number of seconds. While this function is used in our example for consistency, other f

Explain file allocation using i nodes, File allocation using I nodes. T...

File allocation using I nodes. This method is used to decrease the size of the table in the above method. Every file will have an I-node list. Allow a file have 15 pointers a

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