tests/regression/tools/notification/sessiond_testpoints.cpp

   1 /*
   2  * Copyright (C) 2017 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
   4  *
   5  * SPDX-License-Identifier: GPL-2.0-only
   6  *
   7  */
   8
   9 #include <common/compat/getenv.hpp>
  10 #include <common/consumer/consumer.hpp>
  11 #include <common/error.hpp>
  12 #include <common/pipe.hpp>
  13
  14 #include <lttng/constant.h>
  15 #include <lttng/lttng-export.h>
  16
  17 #include <dlfcn.h>
  18 #include <fcntl.h>
  19 #include <stdbool.h>
  20 #include <stdio.h>
  21 #include <unistd.h>
  22
  23 static char *pause_pipe_path;
  24 static struct lttng_pipe *pause_pipe;
  25 static int *notifier_notif_consumption_state;
  26 ;
  27
  28 int lttng_opt_verbose;
  29 int lttng_opt_mi;
  30 int lttng_opt_quiet;
  31
  32 static void __attribute__((destructor)) pause_pipe_fini()
  33 {
  34         int ret;
  35
  36         if (pause_pipe_path) {
  37                 ret = unlink(pause_pipe_path);
  38                 if (ret) {
  39                         PERROR("Failed to unlink pause pipe: path = %s", pause_pipe_path);
  40                 }
  41         }
  42
  43         free(pause_pipe_path);
  44         lttng_pipe_destroy(pause_pipe);
  45 }
  46
  47 extern "C" LTTNG_EXPORT int __testpoint_sessiond_thread_notification(void);
  48 int __testpoint_sessiond_thread_notification(void)
  49 {
  50         int ret = 0;
  51         const char *pause_pipe_path_prefix;
  52
  53         pause_pipe_path_prefix = lttng_secure_getenv("NOTIFIER_PAUSE_PIPE_PATH");
  54         if (!pause_pipe_path_prefix) {
  55                 ret = -1;
  56                 goto end;
  57         }
  58
  59         notifier_notif_consumption_state = (int *) dlsym(nullptr, "notifier_consumption_paused");
  60         LTTNG_ASSERT(notifier_notif_consumption_state);
  61
  62         ret = asprintf(&pause_pipe_path, "%s", pause_pipe_path_prefix);
  63         if (ret < 1) {
  64                 ERR("Failed to allocate pause pipe path");
  65                 goto end;
  66         }
  67
  68         DBG("Creating pause pipe at %s", pause_pipe_path);
  69         pause_pipe = lttng_pipe_named_open(
  70                 pause_pipe_path, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP, O_NONBLOCK);
  71         if (!pause_pipe) {
  72                 ERR("Failed to create pause pipe at %s", pause_pipe_path);
  73                 ret = -1;
  74                 goto end;
  75         }
  76
  77         /* Only the read end of the pipe is useful to us. */
  78         ret = lttng_pipe_write_close(pause_pipe);
  79 end:
  80         return ret;
  81 }
  82
  83 extern "C" LTTNG_EXPORT int __testpoint_sessiond_handle_notifier_event_pipe(void);
  84 int __testpoint_sessiond_handle_notifier_event_pipe(void)
  85 {
  86         int ret = 0;
  87         uint8_t value;
  88         bool value_read = false;
  89
  90         if (!pause_pipe) {
  91                 ret = -1;
  92                 goto end;
  93         }
  94
  95         /* Purge pipe and only consider the freshest value. */
  96         do {
  97                 ret = lttng_pipe_read(pause_pipe, &value, sizeof(value));
  98                 if (ret == sizeof(value)) {
  99                         value_read = true;
 100                 }
 101         } while (ret == sizeof(value));
 102
 103         ret = (errno == EAGAIN) ? 0 : -errno;
 104
 105         if (value_read) {
 106                 *notifier_notif_consumption_state = !!value;
 107                 DBG("Message received on pause pipe: %s data consumption",
 108                     *notifier_notif_consumption_state ? "paused" : "resumed");
 109         }
 110 end:
 111         return ret;
 112 }