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54
55 package ti.sysbios.knl;
56
57 import xdc.rov.ViewInfo;
58
59 import xdc.runtime.Assert;
60 import xdc.runtime.Diags;
61 import xdc.runtime.Log;
62
63 import ti.sysbios.knl.Queue;
64 import ti.sysbios.knl.Clock;
65 import ti.sysbios.knl.Task;
66
67 /*!
68 * ======== Event ========
69 * Event Manager.
70 *
71 * SYS/BIOS events are a means of communication between Tasks and other
72 * threads such as Hwis, Swis, and other Tasks, or between Tasks and
73 * other SYS/BIOS objects. Other SYS/BIOS objects include semaphores,
74 * mailboxes,
75 * message queues, etc. Only tasks can wait for events; whereas tasks,
76 * Hwis, Swis, or SYS/BIOS objects can post them.
77 *
78 * In order for a task to be notified of an event from a SYS/BIOS object an
79 * event object must first be registered with that object. Separate APIs
80 * are provided (in their respective modules) for each of the SYS/BIOS object
81 * types that support this feature.
82 *
83 * Events are synchronous in nature, meaning that a receiving task will
84 * block or pend while waiting for the events to occur. When the desired
85 * events are received, the pending task continues its execution, as it
86 * would after a call to Semaphore_pend(), for example.
87 *
88 * Tasks can also wait on events that are not linked to other SYS/BIOS objects.
89 * These events are explicitly posted from other threads such as tasks,
90 * Swis, or Hwis. A task does not register to receive these events; the
91 * sending thread simply posts its event(s) to the event object the task
92 * is pending on. This scenario is similar to having an ISR post a
93 * semaphore.
94 *
95 * A task can wait on events from multiple resources and/or threads; thus,
96 * it can be waiting for a semaphore to be posted and for a message to
97 * arrive in a message queue or an ISR thread to signal that an event has
98 * occurred.
99 *
100 * Events are binary. Events become available (posted) on each Event_post()
101 * of the eventId and become non-available (consumed) on each qualifying
102 * Event_pend() mask.
103 *
104 * Unlike Semaphores, only a single task can pend on an Event object.
105 *
106 * {@link #pend} is used to wait for events. The andMask & orMask
107 * determine which
108 * event(s) must occur before returning from {@link #pend}. The timeout
109 * parameter
110 * allows the task to wait until a timeout, wait indefinitely, or not wait
111 * at all. A return value of zero indicates that a timeout has occurred. A
112 * non-zero return value is the set of events that were active at the time
113 * the task was unblocked.
114 *
115 * The andMask defines a set of events that must ALL occur to allow
116 * {@link #pend} to return.
117 *
118 * The orMask defines a set of events that will cause {@link #pend} to
119 * return if ANY of them occur.
120 *
121 * All active events present in the orMask are consumed (ie removed from
122 * the event object) upon return from {@link #pend}. Only when all events
123 * present in the andMask are active are they consumed on return from
124 * {@link #pend}.
125 *
126 * {@link #pend} returns immediately if the andMask OR orMask conditions
127 * are true upon entry.
128 *
129 * {@link #post} is used to signal events. If a task is waiting for the event
130 * and all of the event conditions are met, {@link #post} unblocks the task.
131 * If no task is waiting, {@link #post} simply registers the event with the
132 * event object and returns.
133 *
134 * The maximum number of eventIds supported is target specific and depends
135 * on the number of bits in a UInt data type.
136 * For 6x and ARM devices the maximum number of eventIds is therefore 32.
137 * For 28x and MSP430 devices, the maximum number of eventIds is 16.
138 *
139 * @p(html)
140 * <h3> Calling Context </h3>
141 * <table border="1" cellpadding="3">
142 * <colgroup span="1"></colgroup> <colgroup span="5" align="center">
143 * </colgroup>
144 *
145 * <tr><th> Function </th><th> Hwi </th><th> Swi </th>
146 * <th> Task </th><th> Main </th><th> Startup </th></tr>
147 * <!-- -->
148 * <tr><td> {@link #create} </td><td> N </td><td> N </td>
149 * <td> Y </td><td> Y </td><td> N </td></tr>
150 * <tr><td> {@link #Params_init} </td><td> Y </td><td> Y </td>
151 * <td> Y </td><td> Y </td><td> Y </td></tr>
152 * <tr><td> {@link #construct} </td><td> N </td><td> N </td>
153 * <td> Y </td><td> Y </td><td> N </td></tr>
154 * <tr><td> {@link #delete} </td><td> N </td><td> N </td>
155 * <td> Y </td><td> Y </td><td> N </td></tr>
156 * <tr><td> {@link #destruct} </td><td> N </td><td> N </td>
157 * <td> Y </td><td> Y </td><td> N </td></tr>
158 * <tr><td> {@link #getPostedEvents} </td><td> Y </td><td> Y </td>
159 * <td> Y </td><td> Y </td><td> Y </td></tr>
160 * <tr><td> {@link #pend} </td><td> N </td><td> N </td>
161 * <td> Y </td><td> N </td><td> N </td></tr>
162 * <tr><td> {@link #post} </td><td> Y </td><td> Y </td>
163 * <td> Y </td><td> Y </td><td> N </td></tr>
164 * <tr><td colspan="6"> Definitions: <br />
165 * <ul>
166 * <li> <b>Hwi</b>: API is callable from a Hwi thread. </li>
167 * <li> <b>Swi</b>: API is callable from a Swi thread. </li>
168 * <li> <b>Task</b>: API is callable from a Task thread. </li>
169 * <li> <b>Main</b>: API is callable during any of these phases: </li>
170 * <ul>
171 * <li> In your module startup after this module is started
172 * (e.g. Event_Module_startupDone() returns TRUE). </li>
173 * <li> During xdc.runtime.Startup.lastFxns. </li>
174 * <li> During main().</li>
175 * <li> During BIOS.startupFxns.</li>
176 * </ul>
177 * <li> <b>Startup</b>: API is callable during any of these phases:</li>
178 * <ul>
179 * <li> During xdc.runtime.Startup.firstFxns.</li>
180 * <li> In your module startup before this module is started
181 * (e.g. Event_Module_startupDone() returns FALSE).</li>
182 * </ul>
183 * </ul>
184 * </td></tr>
185 *
186 * </table>
187 * @p
188 */
189
190 191 192
193 @CustomHeader
194
195 module Event
196 {
197 /*!
198 * Pre-defined Event Ids
199 *
200 * Event_Ids are provided to simplify the specification of
201 * andMasks and orMasks arguments to {@link #pend Event_pend()}.
202 *
203 * Since each Event_Id is a bitmask composed of only a single bit,
204 * a group of Event_Ids within an andMask or orMask can be indicated
205 * by simply adding them together. For instance, to indicate that a task
206 * is to be awakened only when both Event_Id_00 and Event_Id_01 have
207 * been posted, the andMask for Event_pend() would be constructed
208 * as below:
209 *
210 * @p(code)
211 * Event_pend(event, Event_Id_00+EventId_01, Event_Id_NONE,
212 * BIOS_WAIT_FOREVER);
213 * @p
214 *
215 * As shown above, Event_Id_NONE is to be used as an empty (NULL)
216 * andMask or orMask.
217 *
218 * @a(Note)
219 * For targets where a UInt is 32 bits in length,
220 * Event_Id_00 thru Event_Id_31 can be used.
221 *
222 * For targets where a UInt is 16 bits in length,
223 * Event_Id_00 thru Event_Id_15 can be used.
224 */
225
226 const UInt Id_00 = 0x1;
227 const UInt Id_01 = 0x2; /*! @see #Id_00 Pre-defined Event IDs. */
228 const UInt Id_02 = 0x4; /*! @see #Id_00 Pre-defined Event IDs. */
229 const UInt Id_03 = 0x8; /*! @see #Id_00 Pre-defined Event IDs. */
230 const UInt Id_04 = 0x10; /*! @see #Id_00 Pre-defined Event IDs. */
231 const UInt Id_05 = 0x20; /*! @see #Id_00 Pre-defined Event IDs. */
232 const UInt Id_06 = 0x40; /*! @see #Id_00 Pre-defined Event IDs. */
233 const UInt Id_07 = 0x80; /*! @see #Id_00 Pre-defined Event IDs. */
234 const UInt Id_08 = 0x100; /*! @see #Id_00 Pre-defined Event IDs. */
235 const UInt Id_09 = 0x200; /*! @see #Id_00 Pre-defined Event IDs. */
236 const UInt Id_10 = 0x400; /*! @see #Id_00 Pre-defined Event IDs. */
237 const UInt Id_11 = 0x800; /*! @see #Id_00 Pre-defined Event IDs. */
238 const UInt Id_12 = 0x1000; /*! @see #Id_00 Pre-defined Event IDs. */
239 const UInt Id_13 = 0x2000; /*! @see #Id_00 Pre-defined Event IDs. */
240 const UInt Id_14 = 0x4000; /*! @see #Id_00 Pre-defined Event IDs. */
241 const UInt Id_15 = 0x8000; /*! @see #Id_00 Pre-defined Event IDs. */
242 const UInt Id_16 = 0x10000; /*! @see #Id_00 Pre-defined Event IDs. */
243 const UInt Id_17 = 0x20000; /*! @see #Id_00 Pre-defined Event IDs. */
244 const UInt Id_18 = 0x40000; /*! @see #Id_00 Pre-defined Event IDs. */
245 const UInt Id_19 = 0x80000; /*! @see #Id_00 Pre-defined Event IDs. */
246 const UInt Id_20 = 0x100000; /*! @see #Id_00 Pre-defined Event IDs. */
247 const UInt Id_21 = 0x200000; /*! @see #Id_00 Pre-defined Event IDs. */
248 const UInt Id_22 = 0x400000; /*! @see #Id_00 Pre-defined Event IDs. */
249 const UInt Id_23 = 0x800000; /*! @see #Id_00 Pre-defined Event IDs. */
250 const UInt Id_24 = 0x1000000; /*! @see #Id_00 Pre-defined Event IDs. */
251 const UInt Id_25 = 0x2000000; /*! @see #Id_00 Pre-defined Event IDs. */
252 const UInt Id_26 = 0x4000000; /*! @see #Id_00 Pre-defined Event IDs. */
253 const UInt Id_27 = 0x8000000; /*! @see #Id_00 Pre-defined Event IDs. */
254 const UInt Id_28 = 0x10000000; /*! @see #Id_00 Pre-defined Event IDs. */
255 const UInt Id_29 = 0x20000000; /*! @see #Id_00 Pre-defined Event IDs. */
256 const UInt Id_30 = 0x40000000; /*! @see #Id_00 Pre-defined Event IDs. */
257 const UInt Id_31 = 0x80000000; /*! @see #Id_00 Pre-defined Event IDs. */
258
259 const UInt Id_NONE = 0; /*! @see #Id_00 Pre-defined Event IDs. */
260
261 metaonly struct BasicView {
262 String label;
263 String postedEvents;
264 String pendedTask;
265 String andMask;
266 String orMask;
267 String timeout;
268 };
269
270 @Facet
271 metaonly config ViewInfo.Instance rovViewInfo =
272 ViewInfo.create({
273 viewMap: [
274 ['Basic', {type: ViewInfo.INSTANCE, viewInitFxn: 'viewInitBasic',
275 structName: 'BasicView'}]
276 ]
277 });
278
279
280
281
282
283 /*! Logged on calls to Event_post() */
284 config Log.Event LM_post = {
285 mask: Diags.USER1 | Diags.USER2,
286 msg: "LM_post: event: 0x%x, currEvents: 0x%x, eventId: 0x%x"
287 };
288
289 /*! Logged on calls to Event_pend() */
290 config Log.Event LM_pend = {
291 mask: Diags.USER1 | Diags.USER2,
292 msg: "LM_pend: event: 0x%x, currEvents: 0x%x, andMask: 0x%x, orMask: 0x%x, timeout: %d"
293 };
294
295
296
297 /*!
298 * Asserted when {@link #pend} is called with andMask and orMask == 0
299 */
300 config Assert.Id A_nullEventMasks = {
301 msg: "A_nullEventMasks: orMask and andMask are null."
302 };
303
304 /*!
305 * Asserted when {@link #post} is called with eventId == 0
306 */
307 config Assert.Id A_nullEventId = {
308 msg: "A_nullEventId: posted eventId is null."
309 };
310
311 /*!
312 * Asserted when {@link #pend} is called by multiple tasks on the same
313 * Event object.
314 */
315 config Assert.Id A_eventInUse = {
316 msg: "A_eventInUse: Event object already in use."
317 };
318
319 /*!
320 * Asserted when {@link #pend} is called with non-zero timeout from other
321 * than a Task context.
322 */
323 config Assert.Id A_badContext = {
324 msg: "A_badContext: bad calling context. Must be called from a Task."
325 };
326
327 instance:
328
329 /*!
330 * ======== create ========
331 * Create an Event object.
332 *
333 * This function creates a new Event object.
334 */
335 @DirectCall
336 create();
337
338 /*!
339 * ======== pend ========
340 * Wait for events defined in 'and' OR 'or' masks.
341 *
342 * pend() is used to wait for events. The andMask and orMask determine
343 * which
344 * event(s) must occur before returning from pend(). The timeout parameter
345 * allows the task to wait until a timeout, wait indefinitely, or not wait
346 * at all. A return value of zero indicates that a timeout has occurred. A
347 * non-zero return value is the set of events that were active at the time
348 * the task was unblocked.
349 *
350 * The andMask defines a set of events that must
351 * ALL occur to allow pend() to return.
352 *
353 * The orMask defines a set of events
354 * that will cause pend() to return if ANY of them occur.
355 *
356 * All active events
357 * present in the orMask are consumed (i.e. removed from the event object)
358 * upon return from pend(). Only when all events present in the andMask
359 * are active are they consumed on return from pend().
360 *
361 * The pend conditions are satisfied when either ALL of the events
362 * in the andMask occur or ANY of the events in the orMask occur.
363 *
364 * A timeout value of
365 * {@link ti.sysbios.BIOS#WAIT_FOREVER, BIOS_WAIT_FOREVER} causes
366 * the task to wait indefinitely for matching events to be posted.
367 *
368 * A timeout value of {@link ti.sysbios.BIOS#NO_WAIT, BIOS_NO_WAIT}
369 * causes Event_pend to return immediately.
370 *
371 * @param(andMask) return from pend() when ALL of these
372 * events have occurred
373 * @param(orMask) return from pend() when ANY of these
374 * events have occurred
375 * @param(timeout) return from pend() after this many system
376 * time units
377 *
378 * @b(returns) All consumed events or zero if timeout.
379 */
380 @DirectCall
381 UInt pend(UInt andMask, UInt orMask, UInt timeout);
382
383 /*!
384 * ======== post ========
385 * Post event(s) to an event object.
386 *
387 * Event_post() is used to signal events. If a task is waiting for the
388 * event and the event conditions are met, post() unblocks the
389 * task. If no tasks are waiting, post() simply registers the event with
390 * the event object and returns.
391 *
392 * @param(eventMask) mask of eventIds to post (must be non-zero)
393 */
394 @DirectCall
395 Void post(UInt eventMask);
396
397 /*!
398 * ======== getPostedEvents ========
399 * Returns the set of events that have not been consumed by a task
400 * (ie those events that have not fully satisfied any pend() conditions).
401 * No events are consumed!
402 *
403 * @b(returns) All un-consumed events posted to the event.
404 */
405 @DirectCall
406 UInt getPostedEvents();
407
408 /*!
409 * @_nodoc
410 * ======== sync ========
411 * synchronize an eventId to the value given
412 * must call with interrupts disabled
413 *
414 * @param(eventId) eventId to sync
415 * @param(count) count
416 */
417 @DirectCall
418 Void sync(UInt eventId, UInt count);
419
420 /*!
421 * @_nodoc
422 * ======== syncMeta ========
423 * synchronize an eventId to the value given (static version)
424 *
425 * @param(eventId) eventId to sync
426 * @param(count) count
427 */
428 metaonly Void syncMeta(UInt eventId, UInt count);
429
430 internal:
431
432 /*!
433 * ======== pendTimeout ========
434 * This function is the clock event handler for pend
435 */
436 Void pendTimeout(UArg arg);
437
438
439 enum PendState {
440 PendState_TIMEOUT = 0,
441 PendState_POSTED = 1,
442 PendState_CLOCK_WAIT = 2,
443 PendState_WAIT_FOREVER = 3
444 };
445
446
447 struct PendElem {
448 Task.PendElem tpElem;
449 PendState pendState;
450 UInt matchingEvents;
451 UInt andMask;
452 UInt orMask;
453 };
454
455 struct Instance_State {
456 volatile UInt postedEvents;
457 Queue.Object pendQ;
458
459
460 };
461 }
462 463 464 465
466