| 1 | /* This file is part of the Linux Trace Toolkit Graphic User Interface |
| 2 | * Copyright (C) 2003-2004 Mathieu Desnoyers |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License Version 2 as |
| 6 | * published by the Free Software Foundation; |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License |
| 14 | * along with this program; if not, write to the Free Software |
| 15 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 16 | * MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | /* This file is the API used to launch any background computation on a trace */ |
| 20 | |
| 21 | /* lttvwindowtraces |
| 22 | * |
| 23 | * This API consists in two main parts. The first one is for the background |
| 24 | * computation provider and the second is for the viewer which needs this |
| 25 | * information. |
| 26 | * |
| 27 | * A computation provider, i.e. a statistics computation module or a state |
| 28 | * computation module, have two things in common : they append data to a trace |
| 29 | * in an extensible container (LttvAttributes). This extended information, once |
| 30 | * computed, can be kept all along with the trace and does not need to be |
| 31 | * recomputed : a computation done on a trace must result in a identical result |
| 32 | * each time it is done. |
| 33 | * |
| 34 | * This API provides functions for computation provider to register their |
| 35 | * computation functions (or computation functions insertion and removal |
| 36 | * functions). Once the computation provider is registered with its module name, |
| 37 | * extended computation for a trace can be requested by any viewer by specifying |
| 38 | * the module name, as we will describe in a moment. |
| 39 | * |
| 40 | * A viewer which needs extended information about a trace must ask for it to be |
| 41 | * computed by doing a background computation request. It may also ask to be |
| 42 | * notified of the completion of its request by doing a notify request. |
| 43 | * |
| 44 | * Before asking for the computation, it must check for its readiness. If it is |
| 45 | * ready, the information has already been computed, so it is ready to use. If |
| 46 | * the information is not ready, in must check whether or not the processing of |
| 47 | * this task is in progress. If it is, it must not do any background computation |
| 48 | * request. It must only do a background notification request of the current |
| 49 | * processing to be informed of its completion. If the information is not ready |
| 50 | * and not being processed, then the viewer may do a background computation |
| 51 | * request and add a notify request to the notify queue. |
| 52 | * |
| 53 | * When a context takes control of a trace, it must lock the trace. This is a |
| 54 | * way of ensuring that not conflict will occur between two traceset contexts |
| 55 | * and shared traces. It will generate an error if a context try to get a lock |
| 56 | * on a trace what is not unlocked. Upon every trace locking, |
| 57 | * lttv_process_traceset_synchronize_tracefiles should be used to resynchronize |
| 58 | * the traces with the trace context information. |
| 59 | * |
| 60 | * The usefulness of the lock in this framework can be questionable in a |
| 61 | * single threaded environment, but can be great in the eventuality of |
| 62 | * multiple threads. |
| 63 | * |
| 64 | */ |
| 65 | |
| 66 | |
| 67 | |
| 68 | #ifndef LTTVWINDOWTRACES_H |
| 69 | #define LTTVWINDOWTRACES_H |
| 70 | |
| 71 | #include <ltt/time.h> |
| 72 | #include <glib.h> |
| 73 | |
| 74 | typedef GQuark LttvTraceInfo; |
| 75 | |
| 76 | extern LttvTraceInfo LTTV_TRACES, |
| 77 | LTTV_COMPUTATION, |
| 78 | LTTV_REQUESTS_QUEUE, |
| 79 | LTTV_REQUESTS_CURRENT, |
| 80 | LTTV_NOTIFY_QUEUE, |
| 81 | LTTV_NOTIFY_CURRENT, |
| 82 | LTTV_COMPUTATION_TRACESET, |
| 83 | LTTV_COMPUTATION_TRACESET_CONTEXT, |
| 84 | LTTV_COMPUTATION_SYNC_POSITION, |
| 85 | LTTV_BEFORE_CHUNK_TRACESET, |
| 86 | LTTV_BEFORE_CHUNK_TRACE, |
| 87 | LTTV_BEFORE_CHUNK_TRACEFILE, |
| 88 | LTTV_AFTER_CHUNK_TRACESET, |
| 89 | LTTV_AFTER_CHUNK_TRACE, |
| 90 | LTTV_AFTER_CHUNK_TRACEFILE, |
| 91 | LTTV_BEFORE_REQUEST, |
| 92 | LTTV_AFTER_REQUEST, |
| 93 | LTTV_EVENT_HOOK, |
| 94 | LTTV_EVENT_HOOK_BY_ID, |
| 95 | LTTV_HOOK_ADDER, |
| 96 | LTTV_HOOK_REMOVER, |
| 97 | LTTV_IN_PROGRESS, |
| 98 | LTTV_READY, |
| 99 | LTTV_LOCK; |
| 100 | |
| 101 | |
| 102 | |
| 103 | /* Get a trace by its path name. |
| 104 | * |
| 105 | * @param path path of the trace on the virtual file system. |
| 106 | * @return Pointer to trace if found |
| 107 | * NULL is returned if the trace is not present |
| 108 | */ |
| 109 | |
| 110 | LttvTrace *lttvwindowtraces_get_trace_by_name(gchar *path); |
| 111 | |
| 112 | /* Get a trace by its number identifier */ |
| 113 | |
| 114 | LttvTrace *lttvwindowtraces_get_trace(guint num); |
| 115 | |
| 116 | /* Total number of traces */ |
| 117 | |
| 118 | guint lttvwindowtraces_get_number(); |
| 119 | |
| 120 | /* Add a trace to the global attributes */ |
| 121 | |
| 122 | void lttvwindowtraces_add_trace(LttvTrace *trace); |
| 123 | |
| 124 | /* Remove a trace from the global attributes */ |
| 125 | |
| 126 | void lttvwindowtraces_remove_trace(LttvTrace *trace); |
| 127 | |
| 128 | |
| 129 | /** |
| 130 | * Function to request data from a specific trace |
| 131 | * |
| 132 | * The memory allocated for the request will be managed by the API. |
| 133 | * |
| 134 | * @param trace the trace to compute |
| 135 | * @param module_name the name of the module which registered global computation |
| 136 | * hooks. |
| 137 | */ |
| 138 | |
| 139 | void lttvwindowtraces_background_request_queue |
| 140 | (LttvTrace *trace, gchar *module_name); |
| 141 | |
| 142 | /** |
| 143 | * Remove a background request from a trace. |
| 144 | * |
| 145 | * This should ONLY be used by the modules which registered the global hooks |
| 146 | * (module_name). If this is called by the viewers, it may lead to incomplete |
| 147 | * and incoherent background processing information. |
| 148 | * |
| 149 | * Even if the module which deals with the hooks removes the background |
| 150 | * requests, it may cause a problem if the module gets loaded again in the |
| 151 | * session : the data will be partially calculated. The calculation function |
| 152 | * must deal with this case correctly. |
| 153 | * |
| 154 | * @param trace the trace to compute |
| 155 | * @param module_name the name of the module which registered global computation |
| 156 | * hooks. |
| 157 | */ |
| 158 | |
| 159 | void lttvwindowtraces_background_request_remove |
| 160 | (LttvTrace *trace, gchar *module_name); |
| 161 | |
| 162 | |
| 163 | |
| 164 | /** |
| 165 | * Find a background request in a trace |
| 166 | * |
| 167 | */ |
| 168 | |
| 169 | gboolean lttvwindowtraces_background_request_find |
| 170 | (LttvTrace *trace, gchar *module_name); |
| 171 | |
| 172 | /** |
| 173 | * Register a callback to be called when requested data is passed in the next |
| 174 | * queued background processing. |
| 175 | * |
| 176 | * @param owner owner of the background notification |
| 177 | * @param trace the trace computed |
| 178 | * @param notify_time time when notification hooks must be called |
| 179 | * @param notify_position position when notification hooks must be called |
| 180 | * @param notify Hook to call when the notify position is passed |
| 181 | */ |
| 182 | |
| 183 | void lttvwindowtraces_background_notify_queue |
| 184 | (gpointer owner, |
| 185 | LttvTrace *trace, |
| 186 | LttTime notify_time, |
| 187 | const LttvTracesetContextPosition *notify_position, |
| 188 | const LttvHooks *notify); |
| 189 | |
| 190 | /** |
| 191 | * Register a callback to be called when requested data is passed in the current |
| 192 | * background processing. |
| 193 | * |
| 194 | * @param owner owner of the background notification |
| 195 | * @param trace the trace computed |
| 196 | * @param notify_time time when notification hooks must be called |
| 197 | * @param notify_position position when notification hooks must be called |
| 198 | * @param notify Hook to call when the notify position is passed |
| 199 | */ |
| 200 | |
| 201 | void lttvwindowtraces_background_notify_current |
| 202 | (gpointer owner, |
| 203 | LttvTrace *trace, |
| 204 | LttTime notify_time, |
| 205 | const LttvTracesetContextPosition *notify_position, |
| 206 | const LttvHooks *notify); |
| 207 | |
| 208 | /** |
| 209 | * Removes all the notifications requests from a specific viewer. |
| 210 | * |
| 211 | * @param owner owner of the background notification |
| 212 | */ |
| 213 | |
| 214 | void lttvwindowtraces_background_notify_remove(gpointer owner); |
| 215 | |
| 216 | |
| 217 | /** |
| 218 | * Tells if the information computed by a module for a trace is ready. |
| 219 | * |
| 220 | * Must be checked before a background processing request. |
| 221 | * |
| 222 | * @param module_name A GQuark : the name of the module which computes the |
| 223 | * information. |
| 224 | * @param trace The trace for which the information is verified. |
| 225 | */ |
| 226 | |
| 227 | gboolean lttvwindowtraces_get_ready(LttvAttributeName module_name, |
| 228 | LttvTrace *trace); |
| 229 | |
| 230 | /** |
| 231 | * Tells if the information computed by a module for a trace is being processed. |
| 232 | * |
| 233 | * Must be checked before a background processing request. |
| 234 | * |
| 235 | * If it is effectively processed, the typical thing to do is to call |
| 236 | * lttvwindowtraces_background_notify_current to be notified when the current |
| 237 | * processing will be over. |
| 238 | * |
| 239 | * @param module_name A GQuark : the name of the module which computes the |
| 240 | * information. |
| 241 | * @param trace The trace for which the information is verified. |
| 242 | */ |
| 243 | |
| 244 | gboolean lttvwindowtraces_get_in_progress(LttvAttributeName module_name, |
| 245 | LttvTrace *trace); |
| 246 | |
| 247 | /** |
| 248 | * Register the background computation hooks for a specific module. It adds the |
| 249 | * computation hooks to the global attrubutes, under "computation/module name" |
| 250 | * |
| 251 | * @param module_name A GQuark : the name of the module which computes the |
| 252 | * information. |
| 253 | */ |
| 254 | void lttvwindowtraces_register_computation_hooks(LttvAttributeName module_name, |
| 255 | LttvHooks *before_chunk_traceset, |
| 256 | LttvHooks *before_chunk_trace, |
| 257 | LttvHooks *before_chunk_tracefile, |
| 258 | LttvHooks *after_chunk_traceset, |
| 259 | LttvHooks *after_chunk_trace, |
| 260 | LttvHooks *after_chunk_tracefile, |
| 261 | LttvHooks *before_request, |
| 262 | LttvHooks *after_request, |
| 263 | LttvHooks *event_hook, |
| 264 | LttvHooksById *event_hook_by_id, |
| 265 | LttvHooks *hook_adder, |
| 266 | LttvHooks *hook_remover); |
| 267 | /** |
| 268 | * Unregister the background computation hooks for a specific module. |
| 269 | * |
| 270 | * It also removes all the requests than can be currently processed by the |
| 271 | * background computation algorithm for all the traces (list_in and list_out). |
| 272 | * |
| 273 | * @param module_name A GQuark : the name of the module which computes the |
| 274 | * information. |
| 275 | */ |
| 276 | |
| 277 | void lttvwindowtraces_unregister_computation_hooks |
| 278 | (LttvAttributeName module_name); |
| 279 | |
| 280 | |
| 281 | /** |
| 282 | * It removes all the requests than can be currently processed by the |
| 283 | * background computation algorithm for all the traces (list_in and list_out). |
| 284 | * |
| 285 | * Leaves the flag to in_progress or none.. depending if current or queue |
| 286 | * |
| 287 | * @param module_name A GQuark : the name of the module which computes the |
| 288 | * information. |
| 289 | */ |
| 290 | void lttvwindowtraces_unregister_requests(LttvAttributeName module_name); |
| 291 | |
| 292 | |
| 293 | /** |
| 294 | * Lock a trace so no other instance can use it. |
| 295 | * |
| 296 | * @param trace The trace to lock. |
| 297 | * @return 0 on success, -1 if cannot get lock. |
| 298 | */ |
| 299 | gint lttvwindowtraces_lock(LttvTrace *trace); |
| 300 | |
| 301 | |
| 302 | /** |
| 303 | * Unlock a trace. |
| 304 | * |
| 305 | * @param trace The trace to unlock. |
| 306 | * @return 0 on success, -1 if cannot unlock (not locked ?). |
| 307 | */ |
| 308 | gint lttvwindowtraces_unlock(LttvTrace *trace); |
| 309 | |
| 310 | /** |
| 311 | * Verify if a trace is locked. |
| 312 | * |
| 313 | * @param trace The trace to verify. |
| 314 | * @return TRUE if locked, FALSE is unlocked. |
| 315 | */ |
| 316 | gint lttvwindowtraces_get_lock_state(LttvTrace *trace); |
| 317 | |
| 318 | |
| 319 | #endif //LTTVWINDOWTRACES_H |