firefox/nsprpub/pr/tests/rwlocktest.c

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 *
 * RWLock tests
 *
 *  Several threads are created to access and modify data arrays using
 *  PRRWLocks for synchronization. Two data arrays, array_A and array_B, are
 *  initialized with random data and a third array, array_C, is initialized
 *  with the sum of the first 2 arrays.
 *
 *  Each one of the threads acquires a read lock to verify that the sum of
 *  the arrays A and B is equal to array C, and acquires a write lock to
 *  consistently update arrays A and B so that their is equal to array C.
 *
 */

#include "nspr.h"
#include "plgetopt.h"
#include "prrwlock.h"

static int _debug_on;
static void rwtest(void* args);
static PRInt32 *array_A, *array_B, *array_C;
static void update_array(void);
static void check_array(void);

typedef struct thread_args {
  PRRWLock* rwlock;
  PRInt32 loop_cnt;
} thread_args;

PRFileDesc* output;
PRFileDesc* errhandle;

#define DEFAULT_THREAD_CNT 4
#define DEFAULT_LOOP_CNT 100
#define TEST_ARRAY_SIZE 100

int main(int argc, char** argv) {
  PRInt32 cnt;
  PRStatus rc;
  PRInt32 i;

  PRInt32 thread_cnt = DEFAULT_THREAD_CNT;
  PRInt32 loop_cnt = DEFAULT_LOOP_CNT;
  PRThread** threads;
  thread_args* params;
  PRRWLock* rwlock1;

  PLOptStatus os;
  PLOptState* opt = PL_CreateOptState(argc, argv, "dt:c:");

  while (PL_OPT_EOL != (os = PL_GetNextOpt(opt))) {
    if (PL_OPT_BAD == os) {
      continue;
    }
    switch (opt->option) {
      case 'd': /* debug mode */
        _debug_on = 1;
        break;
      case 't': /* thread count */
        thread_cnt = atoi(opt->value);
        break;
      case 'c': /* loop count */
        loop_cnt = atoi(opt->value);
        break;
      default:
        break;
    }
  }
  PL_DestroyOptState(opt);

  PR_SetConcurrency(4);

  output = PR_GetSpecialFD(PR_StandardOutput);
  errhandle = PR_GetSpecialFD(PR_StandardError);

  rwlock1 = PR_NewRWLock(0, "Lock 1");
  if (rwlock1 == NULL) {
    PR_fprintf(errhandle, "PR_NewRWLock failed - error %d\n", PR_GetError());
    return 1;
  }

  threads = (PRThread**)PR_CALLOC(sizeof(PRThread*) * thread_cnt);
  params = (thread_args*)PR_CALLOC(sizeof(thread_args) * thread_cnt);

  /*
   * allocate and initialize data arrays
   */
  array_A = (PRInt32*)PR_MALLOC(sizeof(PRInt32) * TEST_ARRAY_SIZE);
  array_B = (PRInt32*)PR_MALLOC(sizeof(PRInt32) * TEST_ARRAY_SIZE);
  array_C = (PRInt32*)PR_MALLOC(sizeof(PRInt32) * TEST_ARRAY_SIZE);
  cnt = 0;
  for (i = 0; i < TEST_ARRAY_SIZE; i++) {
    array_A[i] = cnt++;
    array_B[i] = cnt++;
    array_C[i] = array_A[i] + array_B[i];
  }

  if (_debug_on)
    PR_fprintf(output, "%s: thread_cnt = %d loop_cnt = %d\n", argv[0],
               thread_cnt, loop_cnt);
  for (cnt = 0; cnt < thread_cnt; cnt++) {
    PRThreadScope scope;

    params[cnt].rwlock = rwlock1;
    params[cnt].loop_cnt = loop_cnt;

    /*
     * create LOCAL and GLOBAL threads alternately
     */
    if (cnt & 1) {
      scope = PR_LOCAL_THREAD;
    } else {
      scope = PR_GLOBAL_THREAD;
    }

    threads[cnt] =
        PR_CreateThread(PR_USER_THREAD, rwtest, &params[cnt],
                        PR_PRIORITY_NORMAL, scope, PR_JOINABLE_THREAD, 0);
    if (threads[cnt] == NULL) {
      PR_fprintf(errhandle, "PR_CreateThread failed - error %d\n",
                 PR_GetError());
      PR_ProcessExit(2);
    }
    if (_debug_on)
      PR_fprintf(output, "%s: created thread = %p\n", argv[0], threads[cnt]);
  }

  for (cnt = 0; cnt < thread_cnt; cnt++) {
    rc = PR_JoinThread(threads[cnt]);
    PR_ASSERT(rc == PR_SUCCESS);
  }

  PR_DELETE(threads);
  PR_DELETE(params);

  PR_DELETE(array_A);
  PR_DELETE(array_B);
  PR_DELETE(array_C);

  PR_DestroyRWLock(rwlock1);

  printf("PASS\n");
  return 0;
}

static void rwtest(void* args) {
  PRInt32 index;
  thread_args* arg = (thread_args*)args;

  for (index = 0; index < arg->loop_cnt; index++) {
    /*
     * verify sum, update arrays and verify sum again
     */

    PR_RWLock_Rlock(arg->rwlock);
    check_array();
    PR_RWLock_Unlock(arg->rwlock);

    PR_RWLock_Wlock(arg->rwlock);
    update_array();
    PR_RWLock_Unlock(arg->rwlock);

    PR_RWLock_Rlock(arg->rwlock);
    check_array();
    PR_RWLock_Unlock(arg->rwlock);
  }
  if (_debug_on)
    PR_fprintf(output, "Thread[0x%x] lock = 0x%x exiting\n",
               PR_GetCurrentThread(), arg->rwlock);
}

static void check_array(void) {
  PRInt32 i;

  for (i = 0; i < TEST_ARRAY_SIZE; i++)
    if (array_C[i] != (array_A[i] + array_B[i])) {
      PR_fprintf(output, "Error - data check failed\n");
      PR_ProcessExit(1);
    }
}

static void update_array(void) {
  PRInt32 i;

  for (i = 0; i < TEST_ARRAY_SIZE; i++) {
    array_A[i] += i;
    array_B[i] -= i;
  }
}