include/lttng/lttng.h

   1 /*
   2  * lttng.h
   3  *
   4  * Linux Trace Toolkit Control Library Header File
   5  *
   6  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   7  *
   8  * This library is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU Lesser General Public License, version 2.1 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This library is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
  15  * for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this library; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #ifndef LTTNG_H
  23 #define LTTNG_H
  24
  25 /* Error codes that can be returned by API calls */
  26 #include <lttng/lttng-error.h>
  27
  28 /* Include every LTTng ABI/API available. */
  29 #include <lttng/channel.h>
  30 #include <lttng/domain.h>
  31 #include <lttng/event.h>
  32 #include <lttng/handle.h>
  33 #include <lttng/health.h>
  34 #include <lttng/save.h>
  35 #include <lttng/session.h>
  36 #include <lttng/snapshot.h>
  37
  38 #ifdef __cplusplus
  39 extern "C" {
  40 #endif
  41
  42 enum lttng_calibrate_type {
  43         LTTNG_CALIBRATE_FUNCTION              = 0,
  44 };
  45
  46 /* Machine interface output type */
  47 enum lttng_mi_output_type {
  48         LTTNG_MI_XML                          = 1 /* XML output */
  49 };
  50
  51 #define LTTNG_CALIBRATE_PADDING1           16
  52 struct lttng_calibrate {
  53         enum lttng_calibrate_type type;
  54
  55         char padding[LTTNG_CALIBRATE_PADDING1];
  56 };
  57
  58 /*
  59  * Check if a session daemon is alive.
  60  *
  61  * Return 1 if alive or 0 if not. On error, returns a negative negative LTTng
  62  * error code.
  63  */
  64 extern int lttng_session_daemon_alive(void);
  65
  66 /*
  67  * Set the tracing group for the *current* flow of execution.
  68  *
  69  * On success, returns 0 else a negative LTTng error code.
  70  */
  71 extern int lttng_set_tracing_group(const char *name);
  72
  73 /*
  74  * This call registers an "outside consumer" for a session and an lttng domain.
  75  * No consumer will be spawned and all fds/commands will go through the socket
  76  * path given (socket_path).
  77  *
  78  * NOTE that this is not recommended unless you absolutely know what you are
  79  * doing.
  80  *
  81  * Return 0 on success else a negative LTTng error code.
  82  */
  83 extern int lttng_register_consumer(struct lttng_handle *handle,
  84                 const char *socket_path);
  85
  86 /*
  87  * Start tracing for *all* domain(s) in the session.
  88  *
  89  * Return 0 on success else a negative LTTng error code.
  90  */
  91 extern int lttng_start_tracing(const char *session_name);
  92
  93 /*
  94  * Stop tracing for *all* domain(s) in the session.
  95  *
  96  * This call will wait for data availability for each domain of the session so
  97  * this can take an abritrary amount of time. However, when returning you have
  98  * the guarantee that the data is ready to be read and analyze. Use the
  99  * _no_wait call below to avoid this behavior.
 100  *
 101  * The session_name can't be NULL.
 102  *
 103  * Return 0 on success else a negative LTTng error code.
 104  */
 105 extern int lttng_stop_tracing(const char *session_name);
 106
 107 /*
 108  * Behave exactly like lttng_stop_tracing but does not wait for data
 109  * availability.
 110  */
 111 extern int lttng_stop_tracing_no_wait(const char *session_name);
 112
 113 /*
 114  * Calibrate LTTng overhead.
 115  *
 116  * The chan and handle params can not be NULL.
 117  *
 118  * Return 0 on success else a negative LTTng error code.
 119  */
 120 extern int lttng_calibrate(struct lttng_handle *handle,
 121                 struct lttng_calibrate *calibrate);
 122
 123 /*
 124  * Set URL for a consumer for a session and domain.
 125  *
 126  * Both data and control URL must be defined. If both URLs are the same, only
 127  * the control URL is used even for network streaming.
 128  *
 129  * Default port are 5342 and 5343 respectively for control and data which uses
 130  * the TCP protocol.
 131  *
 132  * URL format: proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
 133  *
 134  * Possible protocols are:
 135  * > file://...
 136  *   Local filesystem full path.
 137  *
 138  * > net[6]://...
 139  *   This will use the default network transport layer which is TCP for both
 140  *   control (PORT1) and data port (PORT2).
 141  *
 142  * > tcp[6]://...
 143  *   TCP only streaming. For this one, both data and control URL must be given.
 144  *
 145  * Return 0 on success else a negative LTTng error code.
 146  */
 147 extern int lttng_set_consumer_url(struct lttng_handle *handle,
 148                 const char *control_url, const char *data_url);
 149
 150 /*
 151  * For a given session name, this call checks if the data is ready to be read
 152  * or is still being extracted by the consumer(s) (pending) hence not ready to
 153  * be used by any readers.
 154  *
 155  * Return 0 if there is _no_ data pending in the buffers thus having a
 156  * guarantee that the data can be read safely. Else, return 1 if there is still
 157  * traced data is pending. On error, a negative value is returned and readable
 158  * by lttng_strerror().
 159  */
 160 extern int lttng_data_pending(const char *session_name);
 161
 162 /*
 163  * Trigger the regeneration of the metadata for a session.
 164  * The new metadata overwrite the previous one locally or remotely (through
 165  * the lttng-relayd). Only kernel, per-uid and non-live sessions are supported.
 166  * Return 0 on success, a negative LTTng error code on error.
 167  */
 168 extern int lttng_metadata_regenerate(const char *session_name);
 169
 170 #ifdef __cplusplus
 171 }
 172 #endif
 173
 174 #endif /* LTTNG_H */