util.c

// Misc helper functions
#include "util.h"
#include "mt.h"
#include "worker.h"
#include "mt19937p.h"

// Let's us replace the  random function
int randomFunction(){
  //int rand_int =  genrand_int32();
//  printf("rand int %d\n", rand_int);
  int rand_int = rand();
  return rand_int;
}

// Let's us replace the  random function
int parRandomFunction(struct worker* worker){
  //return rand();
//  return genrand_int32();
//  printf("generating rand...");
  int rand_int = genrand(&(worker->myMT19937p));
  //printf("rand int %d\n", rand_int);
  //int rand_int = rand();
//  printf("Done\n");
  return rand_int;
}//End randomFunction()

double round(double d) {
  return floor(d + 0.5);
}

void timingTests() {

  timestampTest();
  lockTest();

}

void lockTest() {

  int nIterations = 100000;
  pthread_mutex_t lock;

  struct timeval timestamp1;
  int i;
  gettimeofday(&timestamp1, NULL);
  for(i = 0; i < nIterations; i++){
    pthread_mutex_lock(&lock);  
    pthread_mutex_lock(&lock);  
  }
  struct timeval timestamp2;
  gettimeofday(&timestamp2, NULL);
  double diff = (timestamp2.tv_sec - timestamp1.tv_sec) + 1e-6*(timestamp2.tv_usec - timestamp1.tv_usec);
  double time = diff/(float)nIterations;
 
  printf("Lock/unlock time %.9f \n", time);

}


void timestampTest() {


  printf("--- Timestamp test ---\n");

  int i;
  struct stat res;
  int nIterations = 100000;
  for( i = 0; i < nIterations; i++) {
    struct timeval timestamp1;
    gettimeofday(&timestamp1, NULL);
    struct timeval timestamp2;
    gettimeofday(&timestamp2, NULL);
    double diff = (timestamp2.tv_sec - timestamp1.tv_sec) + 1e-6*(timestamp2.tv_usec - timestamp1.tv_usec);
    addSample(&res, diff);
  }
  printf("Timestamp resolution %.9f s\n", getAvg(&res));


}

//Translate a hostname to an IP address
char* nslookup(char* hostname){

  struct hostent* host_info = 0 ;
  int attempt;
  for( attempt=0 ; (host_info==0) && (attempt<3) ; ++attempt ) {
    host_info = gethostbyname(hostname) ;
  }

  char* ip_address;
  if(host_info){

    struct in_addr * address = (struct in_addr * )host_info->h_addr;
    ip_address = inet_ntoa(* address);

    printf("host: %s\n", host_info->h_name);
    printf("address: %s\n",ip_address);

  } else {
    printf("DNS error\n");
    exit(-1);
  }

  //pretty sure i should free something here... 
  return ip_address;

}//End nslookup

void writeBlock(int fd, void* buffer, int writeSize) {

#if DEBUG_READ_WRITE
  printf("Going to write %d bytes\n", writeSize);
#endif

  int nWriteTotal = 0;
  int nWrite = 0;

#if DEBUG_READ_WRITE
  printf("Writing:\n");
  int i;
  for(i = 0; i < writeSize; i++){
    printf("%8x ", *((unsigned char*)buffer+i));
    if(i % 4 == 3 && i != 0){
     printf("\n");
    }
  }
  printf("\n");
#endif

  while(nWriteTotal != writeSize){
    nWrite = write(fd, buffer + nWriteTotal, writeSize - nWriteTotal);
    if(nWrite < 0) {
      printf("Write error: %d\n", nWrite);
      perror("Write error");
      exit(-1);
    }
    nWriteTotal += nWrite;
  }

  if(nWriteTotal != writeSize){
    printf("Write block failed\n");
    exit(-1);
  }

#if DEBUG_READ_WRITE
  printf("Done with write block\n");
#endif

}//End writeBlock()

void readBlock(int fd, void* buffer, int readSize) {

#if DEBUG_READ_WRITE
  printf("Going to read %d bytes\n", readSize);
#endif

  int nReadTotal = 0;
  int nRead = 0;
  while(nReadTotal != readSize){
    nRead = read(fd, buffer + nReadTotal, readSize - nReadTotal);
    if(nRead < 0) {
      perror("Read error");
      exit(-1);
    }
    nReadTotal += nRead;
  }

#if DEBUG_READ_WRITE
  printf("Reading:\n");
  int i;
  for(i = 0; i < readSize; i++){
    printf("%8x ", *((unsigned char*)buffer+i));
    if(i % 4 == 3 && i != 0){
     printf("\n");
    }
  }
  printf("----\n");
#endif

  if( nReadTotal != readSize){
    printf("Read block failed\n");
    exit(-1);
  }

#if DEBUG_READ_WRITE
  printf("Done with read block\n");
#endif

}//End readBlock()