src/common/utils.c

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-only
   3  *
   4  * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
   5  * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  */
   7
   8 #include <errno.h>
   9 #include <stdio.h>
  10 #include <unistd.h>
  11
  12 #include "common/utils.h"
  13
  14 ssize_t lttng_ust_read(int fd, void *buf, size_t len)
  15 {
  16         ssize_t ret;
  17         size_t copied = 0, to_copy = len;
  18
  19         do {
  20                 ret = read(fd, buf + copied, to_copy);
  21                 if (ret > 0) {
  22                         copied += ret;
  23                         to_copy -= ret;
  24                 }
  25         } while ((ret > 0 && to_copy > 0)
  26                 || (ret < 0 && errno == EINTR));
  27         if (ret > 0) {
  28                 ret = copied;
  29         }
  30         return ret;
  31 }