test_poll.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2010, Digium, Inc.
 *
 * Tilghman Lesher <tlesher AT digium DOT com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief Poll Tests
 *
 * \author\verbatim Tilghman Lesher <tlesher AT digium DOT com> \endverbatim
 *
 * Verify that the various poll implementations work as desired (ast_poll, ast_poll2)
 * \ingroup tests
 */

/*** MODULEINFO
   <depend>TEST_FRAMEWORK</depend>
   <support_level>core</support_level>
 ***/

#include "asterisk.h"
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <unistd.h>

#include "asterisk/utils.h"
#include "asterisk/module.h"
#include "asterisk/test.h"
#include "asterisk/poll-compat.h"

static void *failsafe_cancel(void *vparent)
{
   pthread_t parent = (pthread_t) (long) vparent;

   sleep(1);
   pthread_testcancel();
   pthread_kill(parent, SIGURG);
   sleep(1);
   pthread_testcancel();
   pthread_kill(parent, SIGURG);
   sleep(1);
   pthread_testcancel();
   pthread_kill(parent, SIGURG);
   pthread_exit(NULL);
}

#define RESET for (i = 0; i < 4; i++) { pfd[i].revents = 0; }
AST_TEST_DEFINE(poll_test)
{
#define FDNO 3
   int fd[2], res = AST_TEST_PASS, i, res2;
   int rdblocker[2];
#if FDNO > 3
   int wrblocker[2], consec_interrupt = 0;
#endif
   struct pollfd pfd[4] = { { .events = POLLOUT, }, { .events = POLLIN, }, { .events = POLLIN }, { .events = POLLOUT } };
   pthread_t failsafe_tid;
   struct timeval tv = { 0, 0 };
#if FDNO > 3
   char garbage[256] =
      "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ@/"
      "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ@/"
      "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ@/"
      "abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ@/";
#endif

   switch (cmd) {
   case TEST_INIT:
      info->name = "poll_test";
      info->category = "/main/poll/";
      info->summary = "unit test for the ast_poll() API";
      info->description =
         "Verifies behavior for the ast_poll() API call";
      return AST_TEST_NOT_RUN;
   case TEST_EXECUTE:
      break;
   }

   ast_test_status_update(test, "Creating handle that should NEVER block on write\n");
   if ((fd[0] = open("/dev/null", O_WRONLY)) < 0) {
      ast_test_status_update(test, "Unable to open a writable handle to /dev/null: %s\n", strerror(errno));
      return AST_TEST_FAIL;
   }

   ast_test_status_update(test, "Creating handle that should NEVER block on read\n");
   if ((fd[1] = open("/dev/zero", O_RDONLY)) < 0) {
      ast_test_status_update(test, "Unable to open a readable handle to /dev/zero: %s\n", strerror(errno));
      close(fd[0]);
      return AST_TEST_FAIL;
   }

   ast_test_status_update(test, "Creating handle that should block on read\n");
   if (pipe(rdblocker) < 0) {
      ast_test_status_update(test, "Unable to open a pipe: %s\n", strerror(errno));
      close(fd[0]);
      close(fd[1]);
      return AST_TEST_FAIL;
   }

#if FDNO > 3
   ast_test_status_update(test, "Creating handle that should block on write\n");
   if (pipe(wrblocker) < 0) {
      ast_test_status_update(test, "Unable to open a pipe: %s\n", strerror(errno));
      close(fd[0]);
      close(fd[1]);
      close(rdblocker[0]);
      close(rdblocker[1]);
      return AST_TEST_FAIL;
   }

   ast_test_status_update(test, "Starting thread to ensure we don't block forever\n");
   if (ast_pthread_create_background(&failsafe_tid, NULL, failsafe_cancel, (void *) (long) pthread_self())) {
      ast_test_status_update(test, "Unable to start failsafe thread\n");
      close(fd[0]);
      close(fd[1]);
      close(fd[2]);
      close(rdblocker[0]);
      close(rdblocker[1]);
      close(wrblocker[0]);
      close(wrblocker[1]);
      return AST_TEST_FAIL;
   }

   /* Fill the pipe full of data */
   ast_test_status_update(test, "Making pipe block on write\n");
   for (i = 0; i < 4096; i++) { /* 1MB of data should be more than enough for any pipe */
      errno = 0;
      if (write(wrblocker[1], garbage, sizeof(garbage)) < sizeof(garbage)) {
         ast_test_status_update(test, "Got %d\n", errno);
         if (errno == EINTR && ++consec_interrupt > 1) {
            break;
         }
      } else {
         consec_interrupt = 0;
      }
   }

   ast_test_status_update(test, "Cancelling failsafe thread.\n");
   pthread_cancel(failsafe_tid);
   pthread_kill(failsafe_tid, SIGURG);
   pthread_join(failsafe_tid, NULL);
#endif

   pfd[0].fd = fd[0];
   pfd[1].fd = fd[1];
   pfd[2].fd = rdblocker[0];
#if FDNO > 3
   pfd[3].fd = wrblocker[1];
#endif

   /* Need to ensure the infinite timeout doesn't stall the process */
   ast_test_status_update(test, "Starting thread to ensure we don't block forever\n");
   if (ast_pthread_create_background(&failsafe_tid, NULL, failsafe_cancel, (void *) (long) pthread_self())) {
      ast_test_status_update(test, "Unable to start failsafe thread\n");
      close(fd[0]);
      close(fd[1]);
      close(rdblocker[0]);
      close(rdblocker[1]);
#if FDNO > 3
      close(wrblocker[0]);
      close(wrblocker[1]);
#endif
      return AST_TEST_FAIL;
   }

   RESET;
   if ((res2 = ast_poll(pfd, FDNO, -1)) != 2) {
      ast_test_status_update(test, "ast_poll does not return that only two handles are available (inf timeout): %d, %s\n", res2, res2 == -1 ? strerror(errno) : "");
      res = AST_TEST_FAIL;
   }

   RESET;
   if ((res2 = ast_poll2(pfd, FDNO, NULL)) != 2) {
      ast_test_status_update(test, "ast_poll2 does not return that only two handles are available (inf timeout): %d %s\n", res2, res2 == -1 ? strerror(errno) : "");
      res = AST_TEST_FAIL;
   }

   ast_test_status_update(test, "Cancelling failsafe thread.\n");
   pthread_cancel(failsafe_tid);
   pthread_kill(failsafe_tid, SIGURG);
   pthread_join(failsafe_tid, NULL);

   RESET;
   if (ast_poll(pfd, FDNO, 0) != 2) {
      ast_test_status_update(test, "ast_poll does not return that only two handles are available (0 timeout): %d, %s\n", res2, res2 == -1 ? strerror(errno) : "");
      res = AST_TEST_FAIL;
   }

   RESET;
   if (ast_poll2(pfd, FDNO, &tv) != 2) {
      ast_test_status_update(test, "ast_poll2 does not return that only two handles are available (0 timeout): %d, %s\n", res2, res2 == -1 ? strerror(errno) : "");
      res = AST_TEST_FAIL;
   }

   RESET;
   if (ast_poll(pfd, FDNO, 1) != 2) {
      ast_test_status_update(test, "ast_poll does not return that only two handles are available (1ms timeout): %d, %s\n", res2, res2 == -1 ? strerror(errno) : "");
      res = AST_TEST_FAIL;
   }

   tv.tv_usec = 1000;
   if (ast_poll2(pfd, FDNO, &tv) != 2) {
      ast_test_status_update(test, "ast_poll2 does not return that only two handles are available (1ms timeout): %d, %s\n", res2, res2 == -1 ? strerror(errno) : "");
      res = AST_TEST_FAIL;
   }

   close(fd[0]);
   close(fd[1]);
   close(rdblocker[0]);
   close(rdblocker[1]);
#if FDNO > 3
   close(wrblocker[0]);
   close(wrblocker[1]);
#endif
   return res;
}

static int unload_module(void)
{
   AST_TEST_UNREGISTER(poll_test);
   return 0;
}

static int load_module(void)
{
   AST_TEST_REGISTER(poll_test);
   return AST_MODULE_LOAD_SUCCESS;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Poll test");