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; }
In this project, you will implement the Chandy and Misra's (CM) algorithm using POSIX Threads (Pthreads). The algorithm is a distributed algorithm to solve a generalized dining
What are threads? A thread - sometimes called as an implementation context or a lightweight process - is a single sequential flow of control within a program. We use threads
Why interrupt can be used? The majority of the different parts of the PC need to send information to and from the processor and they expect to be able to get the processor's at
How a virtual memory can be implemented? What are the benefits of using virtual memory?
Can you give me assistance on my operating system assignment?
Problem: (a) Discuss Distributed File System Caching. (Your discussion should include the goal and architecture of distributed file system caching and the various possible c
Case laws related to accounting for investment
Central to implementation of a modern memory management system is the page replacement algorithm. Modern virtual memory systems break memory up into pages and map (via a page table
Ask question #Minimum 100 words accepted application of bounded and unbounded buffers
what is secondary storage management
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd