| 1 | /* |
| 2 | * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com> |
| 3 | * Copyright (C) 2019 - Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 4 | * |
| 5 | * This library is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU Lesser General Public License, version 2.1 only, |
| 7 | * as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This library is distributed in the hope that it will be useful, but WITHOUT |
| 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
| 12 | * for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public License |
| 15 | * along with this library; if not, write to the Free Software Foundation, |
| 16 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #ifndef LTTNG_SESSION_H |
| 20 | #define LTTNG_SESSION_H |
| 21 | |
| 22 | #ifdef __cplusplus |
| 23 | extern "C" { |
| 24 | #endif |
| 25 | |
| 26 | struct lttng_session_descriptor; |
| 27 | struct lttng_destruction_handle; |
| 28 | |
| 29 | /* |
| 30 | * Basic session information. |
| 31 | * |
| 32 | * The "enabled" field is only used when listing the sessions which indicate if |
| 33 | * it's started or not. |
| 34 | * |
| 35 | * The structures should be initialized to zero before use. |
| 36 | */ |
| 37 | #define LTTNG_SESSION_PADDING1 12 |
| 38 | struct lttng_session { |
| 39 | char name[LTTNG_NAME_MAX]; |
| 40 | /* |
| 41 | * Human-readable representation of the trace's destination. |
| 42 | * In the case of a local tracing session, a path is provided: |
| 43 | * /path/to/the/output |
| 44 | * |
| 45 | * In the case of a remote (network) tracing session, the string has |
| 46 | * the following format: |
| 47 | * net://hostname/path:ctrl_port [data: data_port] |
| 48 | */ |
| 49 | char path[PATH_MAX]; |
| 50 | uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */ |
| 51 | uint32_t snapshot_mode; |
| 52 | unsigned int live_timer_interval; /* usec */ |
| 53 | |
| 54 | union { |
| 55 | char padding[LTTNG_SESSION_PADDING1]; |
| 56 | void *ptr; |
| 57 | } extended; |
| 58 | }; |
| 59 | |
| 60 | /* |
| 61 | * Create a session on the session daemon from a session descriptor. |
| 62 | * |
| 63 | * See the session descriptor API description in session-descriptor.h |
| 64 | * |
| 65 | * Note that unspecified session descriptor parameters, such as a session's |
| 66 | * name, are updated in the session descriptor if the creation of the session |
| 67 | * succeeds. This allows users to query the session's auto-generated name |
| 68 | * after its creation. Note that other attributes can be queried using the |
| 69 | * session listing API. |
| 70 | * |
| 71 | * Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other |
| 72 | * return codes. |
| 73 | */ |
| 74 | extern enum lttng_error_code lttng_create_session_ext( |
| 75 | struct lttng_session_descriptor *session_descriptor); |
| 76 | |
| 77 | /* |
| 78 | * Create a tracing session using a name and an optional URL. |
| 79 | * |
| 80 | * If _url_ is NULL, no consumer is created for the session. The name can't be |
| 81 | * NULL here. |
| 82 | * |
| 83 | * Return 0 on success else a negative LTTng error code. |
| 84 | */ |
| 85 | extern int lttng_create_session(const char *name, const char *url); |
| 86 | |
| 87 | /* |
| 88 | * Create a tracing session that will exclusively be used for snapshot meaning |
| 89 | * the session will be in no output mode and every channel enabled for that |
| 90 | * session will be set in overwrite mode and in mmap output since splice is not |
| 91 | * supported. |
| 92 | * |
| 93 | * Name can't be NULL. If an url is given, it will be used to create a default |
| 94 | * snapshot output using it as a destination. If NULL, no output will be |
| 95 | * defined and an add-output call will be needed. |
| 96 | * |
| 97 | * Return 0 on success else a negative LTTng error code. |
| 98 | */ |
| 99 | extern int lttng_create_session_snapshot(const char *name, |
| 100 | const char *snapshot_url); |
| 101 | |
| 102 | /* |
| 103 | * Create a session exclusively used for live reading. |
| 104 | * |
| 105 | * In this mode, the switch-timer parameter is forced for each UST channel, a |
| 106 | * live-switch-timer is enabled for kernel channels, manually setting |
| 107 | * switch-timer is forbidden. Synchronization beacons are sent to the relayd, |
| 108 | * indexes are sent and metadata is checked for each packet. |
| 109 | * |
| 110 | * Name can't be NULL. If no URL is given, the default is to send the data to |
| 111 | * net://127.0.0.1. The timer_interval is in usec. |
| 112 | * |
| 113 | * Return 0 on success else a negative LTTng error code. |
| 114 | */ |
| 115 | extern int lttng_create_session_live(const char *name, const char *url, |
| 116 | unsigned int timer_interval); |
| 117 | |
| 118 | /* |
| 119 | * Destroy a tracing session. |
| 120 | * |
| 121 | * The session will not be usable, tracing will be stopped thus buffers will be |
| 122 | * flushed. |
| 123 | * |
| 124 | * This call will wait for data availability for each domain of the session, |
| 125 | * which can take an arbitrary amount of time. However, when returning the |
| 126 | * tracing data is guaranteed to be ready to be read and analyzed. |
| 127 | * |
| 128 | * lttng_destroy_session_no_wait() may be used if such a guarantee is not |
| 129 | * needed. |
| 130 | * |
| 131 | * The name can't be NULL here. |
| 132 | * |
| 133 | * Returns LTTNG_OK on success, else a negative LTTng error code. |
| 134 | */ |
| 135 | extern int lttng_destroy_session(const char *name); |
| 136 | |
| 137 | /* |
| 138 | * Destroy a tracing session. |
| 139 | * |
| 140 | * Performs the same function as lttng_destroy_session(), but provides |
| 141 | * an lttng_destruction_handle which can be used to wait for the completion |
| 142 | * of the session's destruction. The lttng_destroy_handle can also be used |
| 143 | * obtain the status and archive location of any implicit session |
| 144 | * rotation that may have occured during the session's destruction. |
| 145 | * |
| 146 | * Returns LTTNG_OK on success. The returned handle is owned by the caller |
| 147 | * and must be free'd using lttng_destruction_handle_destroy(). |
| 148 | */ |
| 149 | extern enum lttng_error_code lttng_destroy_session_ext(const char *session_name, |
| 150 | struct lttng_destruction_handle **handle); |
| 151 | |
| 152 | /* |
| 153 | * Behaves exactly like lttng_destroy_session but does not wait for data |
| 154 | * availability. |
| 155 | */ |
| 156 | extern int lttng_destroy_session_no_wait(const char *name); |
| 157 | |
| 158 | /* |
| 159 | * List all the tracing sessions. |
| 160 | * |
| 161 | * Return the number of entries of the "lttng_session" array. The caller |
| 162 | * must free the returned sessions array directly using free(). |
| 163 | * |
| 164 | * On error, a negative LTTng error code is returned. |
| 165 | */ |
| 166 | extern int lttng_list_sessions(struct lttng_session **sessions); |
| 167 | |
| 168 | /* |
| 169 | * Get the creation time of an lttng_session object on the session daemon. |
| 170 | * |
| 171 | * This function must only be used with lttng_session objects returned |
| 172 | * by lttng_list_sessions() or lttng_session_create(). |
| 173 | * |
| 174 | * The creation time returned is a UNIX timestamp; the number of seconds since |
| 175 | * Epoch (1970-01-01 00:00:00 +0000 (UTC)). |
| 176 | * |
| 177 | * Returns LTTNG_OK on success. See lttng-error.h for the meaning of the other |
| 178 | * return codes. |
| 179 | */ |
| 180 | extern enum lttng_error_code lttng_session_get_creation_time( |
| 181 | const struct lttng_session *session, uint64_t *creation_time); |
| 182 | |
| 183 | /* |
| 184 | * Set the shared memory path for a session. |
| 185 | * |
| 186 | * Sets the (optional) file system path where shared memory buffers will |
| 187 | * be created for the session. This is useful for buffer extraction on |
| 188 | * crash, when used with filesystems like pramfs. |
| 189 | * |
| 190 | * Return 0 on success else a negative LTTng error code. |
| 191 | */ |
| 192 | extern int lttng_set_session_shm_path(const char *session_name, |
| 193 | const char *shm_path); |
| 194 | |
| 195 | /* |
| 196 | * Add PID to session tracker. |
| 197 | * |
| 198 | * A pid argument >= 0 adds the PID to the session tracker. |
| 199 | * A pid argument of -1 means "track all PIDs". |
| 200 | * |
| 201 | * Return 0 on success else a negative LTTng error code. |
| 202 | */ |
| 203 | extern int lttng_track_pid(struct lttng_handle *handle, int pid); |
| 204 | |
| 205 | /* |
| 206 | * Remove PID from session tracker. |
| 207 | * |
| 208 | * A pid argument >= 0 removes the PID from the session tracker. |
| 209 | * A pid argument of -1 means "untrack all PIDs". |
| 210 | * |
| 211 | * Return 0 on success else a negative LTTng error code. |
| 212 | */ |
| 213 | extern int lttng_untrack_pid(struct lttng_handle *handle, int pid); |
| 214 | |
| 215 | /* |
| 216 | * List PIDs in the tracker. |
| 217 | * |
| 218 | * enabled is set to whether the PID tracker is enabled. |
| 219 | * pids is set to an allocated array of PIDs currently tracked. On |
| 220 | * success, pids must be freed by the caller. |
| 221 | * nr_pids is set to the number of entries contained by the pids array. |
| 222 | * |
| 223 | * Returns 0 on success, else a negative LTTng error code. |
| 224 | */ |
| 225 | extern int lttng_list_tracker_pids(struct lttng_handle *handle, |
| 226 | int *enabled, int32_t **pids, size_t *nr_pids); |
| 227 | |
| 228 | #ifdef __cplusplus |
| 229 | } |
| 230 | #endif |
| 231 | |
| 232 | #endif /* LTTNG_SESSION_H */ |