tests/utils/utils.c

   1 /*
   2  * Copyright (C) - 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * This library is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU Lesser General Public License as published by the
   6  * Free Software Foundation; version 2.1 of the License.
   7  *
   8  * This library is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
  11  * for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this library; if not, write to the Free Software Foundation,
  15  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
  16  */
  17
  18 #include <assert.h>
  19 #include <common/compat/time.h>
  20 #include <common/time.h>
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <poll.h>
  24 #include <stdbool.h>
  25 #include <stdint.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <sys/stat.h>
  29 #include <sys/types.h>
  30 #include <unistd.h>
  31
  32 #include "utils.h"
  33
  34 static inline
  35 int64_t elapsed_time_ns(struct timespec *t1, struct timespec *t2)
  36 {
  37         struct timespec delta;
  38
  39         assert(t1 && t2);
  40         delta.tv_sec = t2->tv_sec - t1->tv_sec;
  41         delta.tv_nsec = t2->tv_nsec - t1->tv_nsec;
  42         return ((int64_t) NSEC_PER_SEC * (int64_t) delta.tv_sec) +
  43                         (int64_t) delta.tv_nsec;
  44 }
  45
  46 int usleep_safe(useconds_t usec)
  47 {
  48         int ret = 0;
  49         struct timespec t1, t2;
  50         int64_t time_remaining_ns = (int64_t) usec * (int64_t) NSEC_PER_USEC;
  51
  52         ret = lttng_clock_gettime(CLOCK_MONOTONIC, &t1);
  53         if (ret) {
  54                 ret = -1;
  55                 perror("clock_gettime");
  56                 goto end;
  57         }
  58
  59         while (time_remaining_ns > 0) {
  60                 ret = usleep(time_remaining_ns / (int64_t) NSEC_PER_USEC);
  61                 if (ret && errno != EINTR) {
  62                         perror("usleep");
  63                         goto end;
  64                 }
  65
  66                 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &t2);
  67                 if (ret) {
  68                         perror("clock_gettime");
  69                         goto end;
  70                 }
  71
  72                 time_remaining_ns -= elapsed_time_ns(&t1, &t2);
  73         }
  74 end:
  75         return ret;
  76 }
  77
  78 int create_file(const char *path)
  79 {
  80         int ret;
  81
  82         if (!path) {
  83                 return -1;
  84         }
  85
  86         ret = creat(path, S_IRWXU);
  87         if (ret < 0) {
  88                 perror("creat");
  89                 return -1;
  90         }
  91
  92         ret = close(ret);
  93         if (ret < 0) {
  94                 perror("close");
  95                 return -1;
  96         }
  97
  98         return 0;
  99 }
 100
 101 int wait_on_file(const char *path)
 102 {
 103         int ret;
 104         struct stat buf;
 105
 106         if (!path) {
 107                 return -1;
 108         }
 109
 110         for (;;) {
 111                 ret = stat(path, &buf);
 112                 if (ret == -1 && errno == ENOENT) {
 113                         ret = poll(NULL, 0, 10);        /* 10 ms delay */
 114                         /* Should return 0 everytime */
 115                         if (ret) {
 116                                 if (ret < 0) {
 117                                         perror("perror");
 118                                 } else {
 119                                         fprintf(stderr,
 120                                                 "poll return value is larger than zero\n");
 121                                 }
 122                                 return -1;
 123                         }
 124                         continue;                       /* retry */
 125                 }
 126                 if (ret) {
 127                         perror("stat");
 128                         return -1;
 129                 }
 130                 break;  /* found */
 131         }
 132
 133         return 0;
 134 }