Maximum number of threads that can be created within a process in C

Given the task is to find the maximum number of threads that can be created within a process in C.

A thread is lightweight process and can be independently managed by the scheduler. Because a thread is a component of a process, therefore multiple number of threads can be associated in a process and also it takes less time for context switching as it is lighter than the process.

Threads require less resources than the processes and they also share memory with its peer threads. All user level peer threads are treated as a single task by the operating system. Less time is required for their creation as well as termination.

The output will always be different every time the program is executed.

Approach used in the below program as follows

• Create function void* create(void *) and leave it empty as it only demonstrates the work of the thread.

• In main() function initialize two variables max = 0 and ret = 0 both of type int to store the maximum number of threads and the return value respectively.

• Declare a variable “th” of type pthread_t.

• Run a while loop with condition ret == 0 and put ret = pthread_create (&th, NULL, create, NULL);

• Iterate max++ inside the loop.

• Print max outside the loop.

Example

#include<pthread.h>
#include<stdio.h>
/*Leave the function empty as it
only demonstrates work of thread*/
void *create ( void *){
}
//main function
int main(){
   int max = 0, ret = 0;
   pthread_t th;
   //Iterate until 0 is returned
   while (ret == 0){
      ret = pthread_create (&th, NULL, create, NULL);
      max++;
   }
   printf(" %d ", max);
}

Output

5741