Simple stress program

cpumem.cpp

/*
 * A small cpu and memory stress program
 * compile: CC cpumem.cpp -o cpumem -lpthread
 *      or: make LDFLAGS=-lpthread cpumem
 */
#include <pthread.h>
#include <iostream>
#include <vector>
#include <sys/types.h>
#include <assert.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>

using namespace std;

#if !defined(ulong)
typedef unsigned long ulong;
#endif

vector<ulong>* SieveOfEratosthenes(int lim)
{
  assert(lim < 1073741824);
  ulong* p;
  vector<ulong>* vp = new vector<ulong>();
  p = new ulong[lim];
  p[0]=p[1]=0;
  for (int i=2;i<lim;i++) p[i]=i;
  for (int i=0;i<lim;i++)
    if (p[i])
      for (int j=2;(j*i)<lim;j++)
        p[j*i]=0;
  for (int i=0;i<lim;i++) 
    if (p[i]) 
      vp->push_back(p[i]);
  return vp;
}

long fibonacci(long n)
{
  if (n == 0) return 0;
  if (n > 1) return fibonacci(n-1) + fibonacci(n-2);
  else return 1;
}

static int ZERO = 0;
static int MONE = -1;

void* cpuFunc(void *vp)
{
  vector<ulong>* ans = SieveOfEratosthenes(10000000);
  vector<ulong>::iterator p;

  fibonacci(40);
  return (void*)&ZERO;
}

void doCpuWork(int nthreads) 
{
  void *rp;
  pthread_t* tids = new pthread_t[nthreads];
  memset(tids, 0, sizeof(pthread_t)*nthreads);

  for (int i = 0; i < nthreads; i++) {
    if (pthread_create(&tids[i], NULL, cpuFunc, NULL)) {
      cerr << "E: pthread_create " << strerror(errno) << endl; 
    } 
  }
  for (int i = 0; i < nthreads; i++) {
    if (tids[i]) {
      if (pthread_join(tids[i], &rp)) {
        cerr << "E: pthread_join " << strerror(errno) << endl;
      }
    }
  }
}

void memOp1()
{
  const int npages = (16*1024*1024)/4096;
  void *vp = mmap(NULL, npages*0x1000, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
  if (vp == MAP_FAILED) {
    cerr << "E: mmap " << strerror(errno) << endl;
  }   
  int *ip = (int*)vp;
  int nints = (npages*4096)/sizeof(int);
  for (int i = 0; i < nints; i++) ip[i] = rand();
  for (int i = 0; i < nints; i++) {
    int nv = rand();
    if (nv > ip[i]) ip[i] = nv;
  }
  int *fip = ip;
  int *lip = ip + nints - 1;
  for (; fip < lip; fip++, lip--) {
    int x = *fip;
    *fip = *lip;
    *lip = x;
  }
}

void*
memFunc(void* va) 
{
  memOp1();
  return (void*)&ZERO;
}

void doMemWork(int nthreads) 
{
  void *rp;
  pthread_t* tids = new pthread_t[nthreads];
  memset(tids, 0, sizeof(pthread_t)*nthreads);

  for (int i = 0; i < nthreads; i++) {
    if (pthread_create(&tids[i], NULL, memFunc, NULL)) {
      cerr << "E: pthread_create " << strerror(errno) << endl; 
    } 
  }
  for (int i = 0; i < nthreads; i++) {
    if (tids[i]) {
      if (pthread_join(tids[i], &rp)) {
        cerr << "E: pthread_join " << strerror(errno) << endl;
      }
    }
  }
}

int cpuCount() 
{
  return sysconf(_SC_NPROCESSORS_CONF);
}

int main(int argc, char *argv[])
{
  int nthreads = cpuCount();

  if (argc > 1) {
    int tnt = atoi(argv[1]);
    if (tnt > 0) {
      nthreads = tnt;
      cout << "nthreads was set to " << nthreads << endl;
    }
  }
  srand(getpid());

  doCpuWork(nthreads);
  doMemWork(nthreads);

  return 0;
}