emacs/mps/code/lockutw3.c

/* impl.c.lockutw3: LOCK UTILIZATION TEST
 *
 * $Id$
 * Copyright (c) 2001 Ravenbrook Limited.
 */

#include "mpm.h"
#include "testlib.h"

#include "mpswin.h"


#ifndef MPS_OS_W3
#error "Relies on Win32 threads"
#endif


#define nTHREADS 4

static Lock lock;
unsigned long shared, tmp;


void incR(unsigned long i)
{
  LockClaimRecursive(lock);
  if (i < 100) {
    while(i--) {
      tmp = shared;
      shared = tmp + 1;
    }
  } else {
    incR(i >> 1);
    incR(i+1 >> 1);
  }
  LockReleaseRecursive(lock);
}


void inc(unsigned long i)
{
  incR(i+1>>1);
  i >>= 1;
  while (i) {
    LockClaim(lock);
    if (i > 10000) {
      incR(5000);
      i -= 5000;
    }
    tmp = shared;
    shared = tmp+1;
    i--;
    LockReleaseMPM(lock);
  }
}


#define COUNT 100000l
DWORD WINAPI thread0(void *p)
{
  (void)p;
  inc(COUNT);
  return 0;
}


int main(void)
{
  DWORD id;
  HANDLE t[10];
  unsigned i;

  lock = malloc(LockSize());
  Insist(lock != NULL);

  LockInit(lock);

  shared = 0;

  for(i = 0; i < nTHREADS; i++)
    t[i] = CreateThread(NULL, 0, thread0, NULL, 0, &id);

  for(i = 0; i < nTHREADS; i++)
    WaitForSingleObject(t[i], INFINITE);

  Insist(shared == nTHREADS*COUNT);

  LockFinish(lock);

  fflush(stdout); /* synchronize */
  fprintf(stderr, "\nConclusion:  Failed to find any defects.\n");
  return 0;
}