C++ UV__ERR函数代码示例

int uv__cloexec_fcntl(int fd, int set) {
  int flags;
  int r;

  do
    r = fcntl(fd, F_GETFD);
  while (r == -1 && errno == EINTR);

  if (r == -1)
    return UV__ERR(errno);

  /* Bail out now if already set/clear. */
  if (!!(r & FD_CLOEXEC) == !!set)
    return 0;

  if (set)
    flags = r | FD_CLOEXEC;
  else
    flags = r & ~FD_CLOEXEC;

  do
    r = fcntl(fd, F_SETFD, flags);
  while (r == -1 && errno == EINTR);

  if (r)
    return UV__ERR(errno);

  return 0;
}

int uv__nonblock_fcntl(int fd, int set) {
  int flags;
  int r;

  do
    r = fcntl(fd, F_GETFL);
  while (r == -1 && errno == EINTR);

  if (r == -1)
    return UV__ERR(errno);

  /* Bail out now if already set/clear. */
  if (!!(r & O_NONBLOCK) == !!set)
    return 0;

  if (set)
    flags = r | O_NONBLOCK;
  else
    flags = r & ~O_NONBLOCK;

  do
    r = fcntl(fd, F_SETFL, flags);
  while (r == -1 && errno == EINTR);

  if (r)
    return UV__ERR(errno);

  return 0;
}

int uv__open_cloexec(const char* path, int flags) {
  int err;
  int fd;

#if defined(UV__O_CLOEXEC)
  static int no_cloexec;

  if (!no_cloexec) {
    fd = open(path, flags | UV__O_CLOEXEC);
    if (fd != -1)
      return fd;

    if (errno != EINVAL)
      return UV__ERR(errno);

    /* O_CLOEXEC not supported. */
    no_cloexec = 1;
  }
#endif

  fd = open(path, flags);
  if (fd == -1)
    return UV__ERR(errno);

  err = uv__cloexec(fd, 1);
  if (err) {
    uv__close(fd);
    return err;
  }

  return fd;
}

int uv_cond_init(uv_cond_t* cond) {
  pthread_condattr_t attr;
  int err;

  err = pthread_condattr_init(&attr);
  if (err)
    return UV__ERR(err);

#if !(defined(__ANDROID_API__) && __ANDROID_API__ < 21)
  err = pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
  if (err)
    goto error2;
#endif

  err = pthread_cond_init(cond, &attr);
  if (err)
    goto error2;

  err = pthread_condattr_destroy(&attr);
  if (err)
    goto error;

  return 0;

error:
  pthread_cond_destroy(cond);
error2:
  pthread_condattr_destroy(&attr);
  return UV__ERR(err);
}

int uv__make_pipe(int fds[2], int flags) {
#if defined(__linux__)
  static int no_pipe2;

  if (no_pipe2)
    goto skip;

  if (uv__pipe2(fds, flags | UV__O_CLOEXEC) == 0)
    return 0;

  if (errno != ENOSYS)
    return UV__ERR(errno);

  no_pipe2 = 1;

skip:
#endif

  if (pipe(fds))
    return UV__ERR(errno);

  uv__cloexec(fds[0], 1);
  uv__cloexec(fds[1], 1);

  if (flags & UV__F_NONBLOCK) {
    uv__nonblock(fds[0], 1);
    uv__nonblock(fds[1], 1);
  }

  return 0;
}

int uv__make_socketpair(int fds[2], int flags) {
#if defined(__linux__)
  static int no_cloexec;

  if (no_cloexec)
    goto skip;

  if (socketpair(AF_UNIX, SOCK_STREAM | UV__SOCK_CLOEXEC | flags, 0, fds) == 0)
    return 0;

  /* Retry on EINVAL, it means SOCK_CLOEXEC is not supported.
   * Anything else is a genuine error.
   */
  if (errno != EINVAL)
    return UV__ERR(errno);

  no_cloexec = 1;

skip:
#endif

  if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds))
    return UV__ERR(errno);

  uv__cloexec(fds[0], 1);
  uv__cloexec(fds[1], 1);

  if (flags & UV__F_NONBLOCK) {
    uv__nonblock(fds[0], 1);
    uv__nonblock(fds[1], 1);
  }

  return 0;
}

int uv_sem_init(uv_sem_t* sem, unsigned int value) {
  uv_sem_t semid;
  int err;
  union {
    int val;
    struct semid_ds* buf;
    unsigned short* array;
  } arg;


  semid = semget(IPC_PRIVATE, 1, S_IRUSR | S_IWUSR);
  if (semid == -1)
    return UV__ERR(errno);

  arg.val = value;
  if (-1 == semctl(semid, 0, SETVAL, arg)) {
    err = errno;
    if (-1 == semctl(*sem, 0, IPC_RMID))
      abort();
    return UV__ERR(err);
  }

  *sem = semid;
  return 0;
}

/* Open a socket in non-blocking close-on-exec mode, atomically if possible. */
int uv__socket(int domain, int type, int protocol) {
  int sockfd;
  int err;

#if defined(SOCK_NONBLOCK) && defined(SOCK_CLOEXEC)
  sockfd = socket(domain, type | SOCK_NONBLOCK | SOCK_CLOEXEC, protocol);
  if (sockfd != -1)
    return sockfd;

  if (errno != EINVAL)
    return UV__ERR(errno);
#endif

  sockfd = socket(domain, type, protocol);
  if (sockfd == -1)
    return UV__ERR(errno);

  err = uv__nonblock(sockfd, 1);
  if (err == 0)
    err = uv__cloexec(sockfd, 1);

  if (err) {
    uv__close(sockfd);
    return err;
  }

#if defined(SO_NOSIGPIPE)
  {
    int on = 1;
    setsockopt(sockfd, SOL_SOCKET, SO_NOSIGPIPE, &on, sizeof(on));
  }
#endif

  return sockfd;
}

/*
 * Checks if /aha is mounted, then proceeds to set up the monitoring
 * objects for the specified file.
 * Returns 0 on success, or an error code < 0 on failure
 */
static int uv__setup_ahafs(const char* filename, int *fd) {
  int rc = 0;
  char mon_file_write_string[RDWR_BUF_SIZE];
  char mon_file[PATH_MAX];
  int file_is_directory = 0; /* -1 == NO, 0 == YES  */

  /* Create monitor file name for object */
  file_is_directory = uv__path_is_a_directory((char*)filename);

  if (file_is_directory == 0)
    sprintf(mon_file, "/aha/fs/modDir.monFactory");
  else
    sprintf(mon_file, "/aha/fs/modFile.monFactory");

  if ((strlen(mon_file) + strlen(filename) + 5) > PATH_MAX)
    return UV_ENAMETOOLONG;

  /* Make the necessary subdirectories for the monitor file */
  rc = uv__make_subdirs_p(filename);
  if (rc == -1 && errno != EEXIST)
    return rc;

  strcat(mon_file, filename);
  strcat(mon_file, ".mon");

  *fd = 0; errno = 0;

  /* Open the monitor file, creating it if necessary */
  *fd = open(mon_file, O_CREAT|O_RDWR);
  if (*fd < 0)
    return UV__ERR(errno);

  /* Write out the monitoring specifications.
   * In this case, we are monitoring for a state change event type
   *    CHANGED=YES
   * We will be waiting in select call, rather than a read:
   *    WAIT_TYPE=WAIT_IN_SELECT
   * We only want minimal information for files:
   *      INFO_LVL=1
   * For directories, we want more information to track what file
   * caused the change
   *      INFO_LVL=2
   */

  if (file_is_directory == 0)
    sprintf(mon_file_write_string, "CHANGED=YES;WAIT_TYPE=WAIT_IN_SELECT;INFO_LVL=2");
  else
    sprintf(mon_file_write_string, "CHANGED=YES;WAIT_TYPE=WAIT_IN_SELECT;INFO_LVL=1");

  rc = write(*fd, mon_file_write_string, strlen(mon_file_write_string)+1);
  if (rc < 0 && errno != EBUSY)
    return UV__ERR(errno);

  return 0;
}

int uv_resident_set_memory(size_t* rss) {
  char buf[1024];
  const char* s;
  ssize_t n;
  long val;
  int fd;
  int i;

  do
    fd = open("/proc/self/stat", O_RDONLY);
  while (fd == -1 && errno == EINTR);

  if (fd == -1)
    return UV__ERR(errno);

  do
    n = read(fd, buf, sizeof(buf) - 1);
  while (n == -1 && errno == EINTR);

  uv__close(fd);
  if (n == -1)
    return UV__ERR(errno);
  buf[n] = '\0';

  s = strchr(buf, ' ');
  if (s == NULL)
    goto err;

  s += 1;
  if (*s != '(')
    goto err;

  s = strchr(s, ')');
  if (s == NULL)
    goto err;

  for (i = 1; i <= 22; i++) {
    s = strchr(s + 1, ' ');
    if (s == NULL)
      goto err;
  }

  errno = 0;
  val = strtol(s, NULL, 10);
  if (errno != 0)
    goto err;
  if (val < 0)
    goto err;

  *rss = val * getpagesize();
  return 0;

err:
  return UV_EINVAL;
}

int uv__accept(int sockfd) {
  int peerfd;
  int err;

  assert(sockfd >= 0);

  while (1) {
#if defined(__linux__)                          || \
    (defined(__FreeBSD__) && __FreeBSD__ >= 10) || \
    defined(__NetBSD__)
    static int no_accept4;

    if (no_accept4)
      goto skip;

    peerfd = uv__accept4(sockfd,
                         NULL,
                         NULL,
                         UV__SOCK_NONBLOCK|UV__SOCK_CLOEXEC);
    if (peerfd != -1)
      return peerfd;

    if (errno == EINTR)
      continue;

    if (errno != ENOSYS)
      return UV__ERR(errno);

    no_accept4 = 1;
skip:
#endif

    peerfd = accept(sockfd, NULL, NULL);
    if (peerfd == -1) {
      if (errno == EINTR)
        continue;
      return UV__ERR(errno);
    }

    err = uv__cloexec(peerfd, 1);
    if (err == 0)
      err = uv__nonblock(peerfd, 1);

    if (err) {
      uv__close(peerfd);
      return err;
    }

    return peerfd;
  }
}

int uv__dup2_cloexec(int oldfd, int newfd) {
  int r;
#if (defined(__FreeBSD__) && __FreeBSD__ >= 10) || defined(__NetBSD__)
  r = dup3(oldfd, newfd, O_CLOEXEC);
  if (r == -1)
    return UV__ERR(errno);
  return r;
#elif defined(__FreeBSD__) && defined(F_DUP2FD_CLOEXEC)
  r = fcntl(oldfd, F_DUP2FD_CLOEXEC, newfd);
  if (r != -1)
    return r;
  if (errno != EINVAL)
    return UV__ERR(errno);
  /* Fall through. */
#elif defined(__linux__)
  static int no_dup3;
  if (!no_dup3) {
    do
      r = uv__dup3(oldfd, newfd, UV__O_CLOEXEC);
    while (r == -1 && errno == EBUSY);
    if (r != -1)
      return r;
    if (errno != ENOSYS)
      return UV__ERR(errno);
    /* Fall through. */
    no_dup3 = 1;
  }
#endif
  {
    int err;
    do
      r = dup2(oldfd, newfd);
#if defined(__linux__)
    while (r == -1 && errno == EBUSY);
#else
    while (0);  /* Never retry. */
#endif

    if (r == -1)
      return UV__ERR(errno);

    err = uv__cloexec(newfd, 1);
    if (err) {
      uv__close(newfd);
      return err;
    }

    return r;
  }
}

int uv_thread_create(uv_thread_t *tid, void (*entry)(void *arg), void *arg) {
  int err;
  size_t stack_size;
  pthread_attr_t* attr;
  pthread_attr_t attr_storage;

  attr = NULL;
  stack_size = thread_stack_size();

  if (stack_size > 0) {
    attr = &attr_storage;

    if (pthread_attr_init(attr))
      abort();

    if (pthread_attr_setstacksize(attr, stack_size))
      abort();
  }

  err = pthread_create(tid, attr, (void*(*)(void*)) (void(*)(void)) entry, arg);

  if (attr != NULL)
    pthread_attr_destroy(attr);

  return UV__ERR(err);
}

/*
 * Creates necessary subdirectories in the AIX Event Infrastructure
 * file system for monitoring the object specified.
 * Returns code from mkdir call
 */
static int uv__make_subdirs_p(const char *filename) {
  char cmd[2048];
  char *p;
  int rc = 0;

  /* Strip off the monitor file name */
  p = strrchr(filename, '/');

  if (p == NULL)
    return 0;

  if (uv__path_is_a_directory((char*)filename) == 0) {
    sprintf(cmd, "/aha/fs/modDir.monFactory");
  } else {
    sprintf(cmd, "/aha/fs/modFile.monFactory");
  }

  strncat(cmd, filename, (p - filename));
  rc = uv__makedir_p(cmd);

  if (rc == -1 && errno != EEXIST){
    return UV__ERR(errno);
  }

  return rc;
}

int uv_os_gethostname(char* buffer, size_t* size) {
  /*
    On some platforms, if the input buffer is not large enough, gethostname()
    succeeds, but truncates the result. libuv can detect this and return ENOBUFS
    instead by creating a large enough buffer and comparing the hostname length
    to the size input.
  */
  char buf[MAXHOSTNAMELEN + 1];
  size_t len;

  if (buffer == NULL || size == NULL || *size == 0)
    return UV_EINVAL;

  if (gethostname(buf, sizeof(buf)) != 0)
    return UV__ERR(errno);

  buf[sizeof(buf) - 1] = '\0'; /* Null terminate, just to be safe. */
  len = strlen(buf);

  if (len >= *size) {
    *size = len + 1;
    return UV_ENOBUFS;
  }

  memcpy(buffer, buf, len + 1);
  *size = len;
  return 0;
}