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 /* Health component for the health check function. */
  43 enum lttng_health_component {
  44         LTTNG_HEALTH_CMD,
  45         LTTNG_HEALTH_APP_MANAGE,
  46         LTTNG_HEALTH_APP_REG,
  47         LTTNG_HEALTH_KERNEL,
  48         LTTNG_HEALTH_CONSUMER,
  49         LTTNG_HEALTH_HT_CLEANUP,
  50         LTTNG_HEALTH_APP_MANAGE_NOTIFY,
  51         LTTNG_HEALTH_APP_REG_DISPATCH,
  52         LTTNG_HEALTH_ALL,
  53 };
  54
  55 enum lttng_calibrate_type {
  56         LTTNG_CALIBRATE_FUNCTION              = 0,
  57 };
  58
  59 #define LTTNG_CALIBRATE_PADDING1           16
  60 struct lttng_calibrate {
  61         enum lttng_calibrate_type type;
  62
  63         char padding[LTTNG_CALIBRATE_PADDING1];
  64 };
  65
  66 /*
  67  * Check if a session daemon is alive.
  68  *
  69  * Return 1 if alive or 0 if not. On error, returns a negative negative LTTng
  70  * error code.
  71  */
  72 extern int lttng_session_daemon_alive(void);
  73
  74 /*
  75  * Set the tracing group for the *current* flow of execution.
  76  *
  77  * On success, returns 0 else a negative LTTng error code.
  78  */
  79 extern int lttng_set_tracing_group(const char *name);
  80
  81 /*
  82  * This call registers an "outside consumer" for a session and an lttng domain.
  83  * No consumer will be spawned and all fds/commands will go through the socket
  84  * path given (socket_path).
  85  *
  86  * NOTE that this is not recommended unless you absolutely know what you are
  87  * doing.
  88  *
  89  * Return 0 on success else a negative LTTng error code.
  90  */
  91 extern int lttng_register_consumer(struct lttng_handle *handle,
  92                 const char *socket_path);
  93
  94 /*
  95  * Start tracing for *all* domain(s) in the session.
  96  *
  97  * Return 0 on success else a negative LTTng error code.
  98  */
  99 extern int lttng_start_tracing(const char *session_name);
 100
 101 /*
 102  * Stop tracing for *all* domain(s) in the session.
 103  *
 104  * This call will wait for data availability for each domain of the session so
 105  * this can take an abritrary amount of time. However, when returning you have
 106  * the guarantee that the data is ready to be read and analyze. Use the
 107  * _no_wait call below to avoid this behavior.
 108  *
 109  * The session_name can't be NULL.
 110  *
 111  * Return 0 on success else a negative LTTng error code.
 112  */
 113 extern int lttng_stop_tracing(const char *session_name);
 114
 115 /*
 116  * Behave exactly like lttng_stop_tracing but does not wait for data
 117  * availability.
 118  */
 119 extern int lttng_stop_tracing_no_wait(const char *session_name);
 120
 121 /*
 122  * Calibrate LTTng overhead.
 123  *
 124  * The chan and handle params can not be NULL.
 125  *
 126  * Return 0 on success else a negative LTTng error code.
 127  */
 128 extern int lttng_calibrate(struct lttng_handle *handle,
 129                 struct lttng_calibrate *calibrate);
 130
 131 /*
 132  * Set URL for a consumer for a session and domain.
 133  *
 134  * Both data and control URL must be defined. If both URLs are the same, only
 135  * the control URL is used even for network streaming.
 136  *
 137  * Default port are 5342 and 5343 respectively for control and data which uses
 138  * the TCP protocol.
 139  *
 140  * URL format: proto://[HOST|IP][:PORT1[:PORT2]][/TRACE_PATH]
 141  *
 142  * Possible protocols are:
 143  * > file://...
 144  *   Local filesystem full path.
 145  *
 146  * > net[6]://...
 147  *   This will use the default network transport layer which is TCP for both
 148  *   control (PORT1) and data port (PORT2).
 149  *
 150  * > tcp[6]://...
 151  *   TCP only streaming. For this one, both data and control URL must be given.
 152  *
 153  * Return 0 on success else a negative LTTng error code.
 154  */
 155 extern int lttng_set_consumer_url(struct lttng_handle *handle,
 156                 const char *control_url, const char *data_url);
 157
 158 /*
 159  * Enable the consumer for a session and domain.
 160  */
 161 extern LTTNG_DEPRECATED("This call is now obsolete.")
 162 int lttng_enable_consumer(struct lttng_handle *handle);
 163
 164 /*
 165  * Disable consumer for a session and domain.
 166  */
 167 extern LTTNG_DEPRECATED("This call is now obsolete.")
 168 int lttng_disable_consumer(struct lttng_handle *handle);
 169
 170 /*
 171  * Check session daemon health for a specific component.
 172  *
 173  * Return 0 if health is OK or 1 if BAD. A returned value of -1 indicate that
 174  * the control library was not able to connect to the session daemon health
 175  * socket.
 176  *
 177  * Any other positive value is an lttcomm error which can be translate with
 178  * lttng_strerror().
 179  *
 180  * Please see lttng-health-check(3) man page for more information.
 181  */
 182 extern LTTNG_DEPRECATED("This call is now obsolete.")
 183 int lttng_health_check(enum lttng_health_component c);
 184
 185 /*
 186  * For a given session name, this call checks if the data is ready to be read
 187  * or is still being extracted by the consumer(s) (pending) hence not ready to
 188  * be used by any readers.
 189  *
 190  * Return 0 if there is _no_ data pending in the buffers thus having a
 191  * guarantee that the data can be read safely. Else, return 1 if there is still
 192  * traced data is pending. On error, a negative value is returned and readable
 193  * by lttng_strerror().
 194  */
 195 extern int lttng_data_pending(const char *session_name);
 196
 197 #ifdef __cplusplus
 198 }
 199 #endif
 200
 201 #endif /* LTTNG_H */