tests/utils/utils.c

   1 /*
   2  * Copyright (C) 2015 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <assert.h>
   9 #include <common/compat/time.h>
  10 #include <common/time.h>
  11 #include <fcntl.h>
  12 #include <poll.h>
  13 #include <stdbool.h>
  14 #include <stdint.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <sys/stat.h>
  18 #include <sys/types.h>
  19 #include <unistd.h>
  20
  21 #include <common/compat/errno.h>
  22
  23 #include "utils.h"
  24
  25 static inline
  26 int64_t elapsed_time_ns(struct timespec *t1, struct timespec *t2)
  27 {
  28         struct timespec delta;
  29
  30         assert(t1 && t2);
  31         delta.tv_sec = t2->tv_sec - t1->tv_sec;
  32         delta.tv_nsec = t2->tv_nsec - t1->tv_nsec;
  33         return ((int64_t) NSEC_PER_SEC * (int64_t) delta.tv_sec) +
  34                         (int64_t) delta.tv_nsec;
  35 }
  36
  37 int usleep_safe(useconds_t usec)
  38 {
  39         int ret = 0;
  40         struct timespec t1, t2;
  41         int64_t time_remaining_ns = (int64_t) usec * (int64_t) NSEC_PER_USEC;
  42
  43         ret = lttng_clock_gettime(CLOCK_MONOTONIC, &t1);
  44         if (ret) {
  45                 ret = -1;
  46                 perror("clock_gettime");
  47                 goto end;
  48         }
  49
  50         while (time_remaining_ns > 0) {
  51                 ret = usleep(time_remaining_ns / (int64_t) NSEC_PER_USEC);
  52                 if (ret && errno != EINTR) {
  53                         perror("usleep");
  54                         goto end;
  55                 }
  56
  57                 ret = lttng_clock_gettime(CLOCK_MONOTONIC, &t2);
  58                 if (ret) {
  59                         perror("clock_gettime");
  60                         goto end;
  61                 }
  62
  63                 time_remaining_ns -= elapsed_time_ns(&t1, &t2);
  64         }
  65 end:
  66         return ret;
  67 }
  68
  69 int create_file(const char *path)
  70 {
  71         int ret;
  72
  73         if (!path) {
  74                 return -1;
  75         }
  76
  77         ret = creat(path, S_IRWXU);
  78         if (ret < 0) {
  79                 perror("creat");
  80                 return -1;
  81         }
  82
  83         ret = close(ret);
  84         if (ret < 0) {
  85                 perror("close");
  86                 return -1;
  87         }
  88
  89         return 0;
  90 }
  91
  92 int wait_on_file(const char *path)
  93 {
  94         int ret;
  95         struct stat buf;
  96
  97         if (!path) {
  98                 return -1;
  99         }
 100
 101         for (;;) {
 102                 ret = stat(path, &buf);
 103                 if (ret == -1 && errno == ENOENT) {
 104                         ret = poll(NULL, 0, 10);        /* 10 ms delay */
 105                         /* Should return 0 everytime */
 106                         if (ret) {
 107                                 if (ret < 0) {
 108                                         perror("perror");
 109                                 } else {
 110                                         fprintf(stderr,
 111                                                 "poll return value is larger than zero\n");
 112                                 }
 113                                 return -1;
 114                         }
 115                         continue;                       /* retry */
 116                 }
 117                 if (ret) {
 118                         perror("stat");
 119                         return -1;
 120                 }
 121                 break;  /* found */
 122         }
 123
 124         return 0;
 125 }