Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Present your own fully documented and tested programming example illustrating the problem of unbalanced loads. Describe the use of OpenMP's scheduler as a means of mitigating this problem.
The below example shows a number of tasks that all update a global counter. Since threads share the same memory space, they indeed see and update the same memory location. The code returns a false result because updating the variable is much quicker than creating the thread as on a multicore processor the chance of errors will greatly increase. If we artificially increase the time for the update, we will no longer get the right result. All threads read out the value of sum, wait a while (presumably calculating something) and then update.
#include
#include "pthread.h"
int sum=0;
void adder() {
int sum = 0;
int t = sum; sleep(1); sum = t+1;
return;
}
#define NTHREADS 50
int main() {
int i;
pthread_t threads[NTHREADS];
printf("forking\n");
for (i=0; i if (pthread_create(threads+i,NULL,&adder,NULL)!=0) return i+1; printf("joining\n"); for (i=0; i { if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1; printf("Sum computed: %d\n",sum); } return 0; } The use of OpenMP is the parallel loop. Here, all iterations can be executed independently and in any order. The pragma CPP directive then conveys this fact to the compiler. A sequential code can be easily parallelized this way. #include #include #include "pthread.h" int sum=0; void adder() { int sum = 0; int t = sum; sleep(1); sum = t+1; return; } #define NTHREADS 50 int main() { int i; pthread_t threads[NTHREADS]; printf("forking\n"); #pragma omp for for (i=0; i if (pthread_create(threads+i,NULL,&adder,NULL)!=0) return i+1; } printf("joining\n"); for (i=0; i { if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1; printf("Sum computed: %d\n",sum); } return 0; }
if (pthread_create(threads+i,NULL,&adder,NULL)!=0) return i+1;
printf("joining\n");
for (i=0; i { if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1; printf("Sum computed: %d\n",sum); } return 0; } The use of OpenMP is the parallel loop. Here, all iterations can be executed independently and in any order. The pragma CPP directive then conveys this fact to the compiler. A sequential code can be easily parallelized this way. #include #include #include "pthread.h" int sum=0; void adder() { int sum = 0; int t = sum; sleep(1); sum = t+1; return; } #define NTHREADS 50 int main() { int i; pthread_t threads[NTHREADS]; printf("forking\n"); #pragma omp for for (i=0; i if (pthread_create(threads+i,NULL,&adder,NULL)!=0) return i+1; } printf("joining\n"); for (i=0; i { if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1; printf("Sum computed: %d\n",sum); } return 0; }
{
if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1;
printf("Sum computed: %d\n",sum);
return 0;
The use of OpenMP is the parallel loop. Here, all iterations can be executed independently and in any order. The pragma CPP directive then conveys this fact to the compiler. A sequential code can be easily parallelized this way.
#pragma omp for
for (i=0; i if (pthread_create(threads+i,NULL,&adder,NULL)!=0) return i+1; } printf("joining\n"); for (i=0; i { if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1; printf("Sum computed: %d\n",sum); } return 0; }
for (i=0; i { if (pthread_join(threads[i],NULL)!=0) return NTHREADS+i+1; printf("Sum computed: %d\n",sum); } return 0; }
Explain thread in details
Fault tolerance Machine failures, Communication faults, storage device crashes, and decays of storage media should be tolerated by the system to some extent. A fault tolerant s
The term IPC (Inter-Process Communication) defines several paths by which different process executing on some operating system interact between each other.
What are the benefits of thread pools:- The benefits of thread pools are 1. It is usually faster to service a request with an existing thread than waiting to make a thread.
Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 Provide two programm
Operating Systems 1. Explain Micro-kernel? Specify the benefits of Micro-kernel? 2. Describe seven state process models used for OS with necessary diagram. Differentiate bet
Assume there are only 4 page frames in the physical memory, for the following reference string: 1, 2, 3, 4, 5, 3, 4, 1, 6, 7, 8, 7, 8, 9, 7, 8, 9, 5, 4, 5, 4, 2, 8. a) What i
There is a process bloacked by a semaphore and no other process in the ready queue, can the blocked process get back to the ready queue without the semsignal() function?
1. Problem Domain You will be considering the Wumpus world introduced in Russell and Norvig (2009) Chapter 7. For this programming assignment you'll use Prolog's ability to do in
PADM 530. case study part 1
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd