| 1 | /* |
| 2 | * Copyright (C) 2014 - David Goulet <dgoulet@efficios.com> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU Lesser General Public License, version 2.1 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This library is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License |
| 11 | * for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU Lesser General Public License |
| 14 | * along with this library; if not, write to the Free Software Foundation, |
| 15 | * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 16 | */ |
| 17 | |
| 18 | #ifndef LTTNG_SESSION_H |
| 19 | #define LTTNG_SESSION_H |
| 20 | |
| 21 | #ifdef __cplusplus |
| 22 | extern "C" { |
| 23 | #endif |
| 24 | |
| 25 | /* |
| 26 | * Basic session information. |
| 27 | * |
| 28 | * The "enabled" field is only used when listing the sessions which indicate if |
| 29 | * it's started or not. |
| 30 | * |
| 31 | * The structures should be initialized to zero before use. |
| 32 | */ |
| 33 | #define LTTNG_SESSION_PADDING1 12 |
| 34 | struct lttng_session { |
| 35 | char name[LTTNG_NAME_MAX]; |
| 36 | /* |
| 37 | * Human-readable representation of the trace's destination. |
| 38 | * In the case of a local tracing session, a path is provided: |
| 39 | * /path/to/the/output |
| 40 | * |
| 41 | * In the case of a remote (network) tracing session, the string has |
| 42 | * the following format: |
| 43 | * net://hostname/path:ctrl_port [data: data_port] |
| 44 | */ |
| 45 | char path[PATH_MAX]; |
| 46 | uint32_t enabled; /* enabled/started: 1, disabled/stopped: 0 */ |
| 47 | uint32_t snapshot_mode; |
| 48 | unsigned int live_timer_interval; /* usec */ |
| 49 | |
| 50 | char padding[LTTNG_SESSION_PADDING1]; |
| 51 | }; |
| 52 | |
| 53 | /* |
| 54 | * Create a tracing session using a name and an optional URL. |
| 55 | * |
| 56 | * If _url_ is NULL, no consumer is created for the session. The name can't be |
| 57 | * NULL here. |
| 58 | * |
| 59 | * Return 0 on success else a negative LTTng error code. |
| 60 | */ |
| 61 | extern int lttng_create_session(const char *name, const char *url); |
| 62 | |
| 63 | /* |
| 64 | * Create a tracing session that will exclusively be used for snapshot meaning |
| 65 | * the session will be in no output mode and every channel enabled for that |
| 66 | * session will be set in overwrite mode and in mmap output since splice is not |
| 67 | * supported. |
| 68 | * |
| 69 | * Name can't be NULL. If an url is given, it will be used to create a default |
| 70 | * snapshot output using it as a destination. If NULL, no output will be |
| 71 | * defined and an add-output call will be needed. |
| 72 | * |
| 73 | * Return 0 on success else a negative LTTng error code. |
| 74 | */ |
| 75 | extern int lttng_create_session_snapshot(const char *name, |
| 76 | const char *snapshot_url); |
| 77 | |
| 78 | /* |
| 79 | * Create a session exclusively used for live reading. |
| 80 | * |
| 81 | * In this mode, the switch-timer parameter is forced for each UST channel, a |
| 82 | * live-switch-timer is enabled for kernel channels, manually setting |
| 83 | * switch-timer is forbidden. Synchronization beacons are sent to the relayd, |
| 84 | * indexes are sent and metadata is checked for each packet. |
| 85 | * |
| 86 | * Name can't be NULL. If no URL is given, the default is to send the data to |
| 87 | * net://127.0.0.1. The timer_interval is in usec. |
| 88 | * |
| 89 | * Return 0 on success else a negative LTTng error code. |
| 90 | */ |
| 91 | extern int lttng_create_session_live(const char *name, const char *url, |
| 92 | unsigned int timer_interval); |
| 93 | |
| 94 | /* |
| 95 | * Destroy a tracing session. |
| 96 | * |
| 97 | * The session will not be usable, tracing will be stopped thus buffers will be |
| 98 | * flushed. |
| 99 | * |
| 100 | * This call will wait for data availability for each domain of the session, |
| 101 | * which can take an arbitrary amount of time. However, when returning the |
| 102 | * tracing data is guaranteed to be ready to be read and analyzed. |
| 103 | * |
| 104 | * lttng_destroy_session_no_wait() may be used if such a guarantee is not |
| 105 | * needed. |
| 106 | * |
| 107 | * The name can't be NULL here. |
| 108 | * |
| 109 | * Return 0 on success else a negative LTTng error code. |
| 110 | */ |
| 111 | extern int lttng_destroy_session(const char *name); |
| 112 | |
| 113 | /* |
| 114 | * Behaves exactly like lttng_destroy_session but does not wait for data |
| 115 | * availability. |
| 116 | */ |
| 117 | extern int lttng_destroy_session_no_wait(const char *name); |
| 118 | |
| 119 | /* |
| 120 | * List all the tracing sessions. |
| 121 | * |
| 122 | * Return the size (number of entries) of the "lttng_session" array. Caller |
| 123 | * must free sessions. On error, a negative LTTng error code is returned. |
| 124 | */ |
| 125 | extern int lttng_list_sessions(struct lttng_session **sessions); |
| 126 | |
| 127 | /* |
| 128 | * Set the shared memory path for a session. |
| 129 | * |
| 130 | * Sets the (optional) file system path where shared memory buffers will |
| 131 | * be created for the session. This is useful for buffer extraction on |
| 132 | * crash, when used with filesystems like pramfs. |
| 133 | * |
| 134 | * Return 0 on success else a negative LTTng error code. |
| 135 | */ |
| 136 | extern int lttng_set_session_shm_path(const char *session_name, |
| 137 | const char *shm_path); |
| 138 | |
| 139 | /* |
| 140 | * Add PID to session tracker. |
| 141 | * |
| 142 | * A pid argument >= 0 adds the PID to the session tracker. |
| 143 | * A pid argument of -1 means "track all PIDs". |
| 144 | * |
| 145 | * Return 0 on success else a negative LTTng error code. |
| 146 | */ |
| 147 | extern int lttng_track_pid(struct lttng_handle *handle, int pid); |
| 148 | |
| 149 | /* |
| 150 | * Remove PID from session tracker. |
| 151 | * |
| 152 | * A pid argument >= 0 removes the PID from the session tracker. |
| 153 | * A pid argument of -1 means "untrack all PIDs". |
| 154 | * |
| 155 | * Return 0 on success else a negative LTTng error code. |
| 156 | */ |
| 157 | extern int lttng_untrack_pid(struct lttng_handle *handle, int pid); |
| 158 | |
| 159 | /* |
| 160 | * List PIDs in the tracker. |
| 161 | * |
| 162 | * enabled is set to whether the PID tracker is enabled. |
| 163 | * pids is set to an allocated array of PIDs currently tracked. On |
| 164 | * success, pids must be freed by the caller. |
| 165 | * nr_pids is set to the number of entries contained by the pids array. |
| 166 | * |
| 167 | * Returns 0 on success, else a negative LTTng error code. |
| 168 | */ |
| 169 | extern int lttng_list_tracker_pids(struct lttng_handle *handle, |
| 170 | int *enabled, int32_t **pids, size_t *nr_pids); |
| 171 | |
| 172 | #ifdef __cplusplus |
| 173 | } |
| 174 | #endif |
| 175 | |
| 176 | #endif /* LTTNG_SESSION_H */ |