1 /* 2 * Copyright (c) 2004-2006 Voltaire, Inc. All rights reserved. 3 * Copyright (c) 2002-2005 Mellanox Technologies LTD. All rights reserved. 4 * Copyright (c) 1996-2003 Intel Corporation. All rights reserved. 5 * 6 * This software is available to you under a choice of one of two 7 * licenses. You may choose to be licensed under the terms of the GNU 8 * General Public License (GPL) Version 2, available from the file 9 * COPYING in the main directory of this source tree, or the 10 * OpenIB.org BSD license below: 11 * 12 * Redistribution and use in source and binary forms, with or 13 * without modification, are permitted provided that the following 14 * conditions are met: 15 * 16 * - Redistributions of source code must retain the above 17 * copyright notice, this list of conditions and the following 18 * disclaimer. 19 * 20 * - Redistributions in binary form must reproduce the above 21 * copyright notice, this list of conditions and the following 22 * disclaimer in the documentation and/or other materials 23 * provided with the distribution. 24 * 25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 26 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 27 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 28 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 29 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 30 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 31 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 32 * SOFTWARE. 33 * 34 */ 35 36 /* 37 * Abstract: 38 * Abstraction of Timer create, destroy functions. 39 * 40 */ 41 42 #if HAVE_CONFIG_H 43 # include <config.h> 44 #endif /* HAVE_CONFIG_H */ 45 46 #include <stdlib.h> 47 #include <string.h> 48 #include <complib/cl_timer.h> 49 #include <sys/time.h> 50 #include <sys/errno.h> 51 #include <stdio.h> 52 53 /* Timer provider (emulates timers in user mode). */ 54 typedef struct _cl_timer_prov { 55 pthread_t thread; 56 pthread_mutex_t mutex; 57 pthread_cond_t cond; 58 cl_qlist_t queue; 59 60 boolean_t exit; 61 62 } cl_timer_prov_t; 63 64 /* Global timer provider. */ 65 static cl_timer_prov_t *gp_timer_prov = NULL; 66 67 static void *__cl_timer_prov_cb(IN void *const context); 68 69 /* 70 * Creates the process global timer provider. Must be called by the shared 71 * object framework to solve all serialization issues. 72 */ 73 cl_status_t __cl_timer_prov_create(void) 74 { 75 CL_ASSERT(gp_timer_prov == NULL); 76 77 gp_timer_prov = malloc(sizeof(cl_timer_prov_t)); 78 if (!gp_timer_prov) 79 return (CL_INSUFFICIENT_MEMORY); 80 else 81 memset(gp_timer_prov, 0, sizeof(cl_timer_prov_t)); 82 83 cl_qlist_init(&gp_timer_prov->queue); 84 85 pthread_mutex_init(&gp_timer_prov->mutex, NULL); 86 pthread_cond_init(&gp_timer_prov->cond, NULL); 87 88 if (pthread_create(&gp_timer_prov->thread, NULL, 89 __cl_timer_prov_cb, NULL)) { 90 __cl_timer_prov_destroy(); 91 return (CL_ERROR); 92 } 93 94 return (CL_SUCCESS); 95 } 96 97 void __cl_timer_prov_destroy(void) 98 { 99 pthread_t tid; 100 101 if (!gp_timer_prov) 102 return; 103 104 tid = gp_timer_prov->thread; 105 pthread_mutex_lock(&gp_timer_prov->mutex); 106 gp_timer_prov->exit = TRUE; 107 pthread_cond_broadcast(&gp_timer_prov->cond); 108 pthread_mutex_unlock(&gp_timer_prov->mutex); 109 pthread_join(tid, NULL); 110 111 /* Destroy the mutex and condition variable. */ 112 pthread_mutex_destroy(&gp_timer_prov->mutex); 113 pthread_cond_destroy(&gp_timer_prov->cond); 114 115 /* Free the memory and reset the global pointer. */ 116 free(gp_timer_prov); 117 gp_timer_prov = NULL; 118 } 119 120 /* 121 * This is the internal work function executed by the timer's thread. 122 */ 123 static void *__cl_timer_prov_cb(IN void *const context) 124 { 125 int ret; 126 cl_timer_t *p_timer; 127 128 pthread_mutex_lock(&gp_timer_prov->mutex); 129 while (!gp_timer_prov->exit) { 130 if (cl_is_qlist_empty(&gp_timer_prov->queue)) { 131 /* Wait until we exit or a timer is queued. */ 132 /* cond wait does: 133 * pthread_cond_wait atomically unlocks the mutex (as per 134 * pthread_unlock_mutex) and waits for the condition variable 135 * cond to be signaled. The thread execution is suspended and 136 * does not consume any CPU time until the condition variable is 137 * signaled. The mutex must be locked by the calling thread on 138 * entrance to pthread_cond_wait. Before RETURNING TO THE 139 * CALLING THREAD, PTHREAD_COND_WAIT RE-ACQUIRES MUTEX (as per 140 * pthread_lock_mutex). 141 */ 142 ret = pthread_cond_wait(&gp_timer_prov->cond, 143 &gp_timer_prov->mutex); 144 } else { 145 /* 146 * The timer elements are on the queue in expiration order. 147 * Get the first in the list to determine how long to wait. 148 */ 149 150 p_timer = 151 (cl_timer_t *) cl_qlist_head(&gp_timer_prov->queue); 152 ret = 153 pthread_cond_timedwait(&gp_timer_prov->cond, 154 &gp_timer_prov->mutex, 155 &p_timer->timeout); 156 157 /* 158 Sleep again on every event other than timeout and invalid 159 Note: EINVAL means that we got behind. This can occur when 160 we are very busy... 161 */ 162 if (ret != ETIMEDOUT && ret != EINVAL) 163 continue; 164 165 /* 166 * The timer expired. Check the state in case it was cancelled 167 * after it expired but before we got a chance to invoke the 168 * callback. 169 */ 170 if (p_timer->timer_state != CL_TIMER_QUEUED) 171 continue; 172 173 /* 174 * Mark the timer as running to synchronize with its 175 * cancelation since we can't hold the mutex during the 176 * callback. 177 */ 178 p_timer->timer_state = CL_TIMER_RUNNING; 179 180 /* Remove the item from the timer queue. */ 181 cl_qlist_remove_item(&gp_timer_prov->queue, 182 &p_timer->list_item); 183 pthread_mutex_unlock(&gp_timer_prov->mutex); 184 /* Invoke the callback. */ 185 p_timer->pfn_callback((void *)p_timer->context); 186 187 /* Acquire the mutex again. */ 188 pthread_mutex_lock(&gp_timer_prov->mutex); 189 /* 190 * Only set the state to idle if the timer has not been accessed 191 * from the callback 192 */ 193 if (p_timer->timer_state == CL_TIMER_RUNNING) 194 p_timer->timer_state = CL_TIMER_IDLE; 195 196 /* 197 * Signal any thread trying to manipulate the timer 198 * that expired. 199 */ 200 pthread_cond_signal(&p_timer->cond); 201 } 202 } 203 gp_timer_prov->thread = 0; 204 pthread_mutex_unlock(&gp_timer_prov->mutex); 205 pthread_exit(NULL); 206 } 207 208 /* Timer implementation. */ 209 void cl_timer_construct(IN cl_timer_t * const p_timer) 210 { 211 memset(p_timer, 0, sizeof(cl_timer_t)); 212 p_timer->state = CL_UNINITIALIZED; 213 } 214 215 cl_status_t cl_timer_init(IN cl_timer_t * const p_timer, 216 IN cl_pfn_timer_callback_t pfn_callback, 217 IN const void *const context) 218 { 219 CL_ASSERT(p_timer); 220 CL_ASSERT(pfn_callback); 221 222 cl_timer_construct(p_timer); 223 224 if (!gp_timer_prov) 225 return (CL_ERROR); 226 227 /* Store timer parameters. */ 228 p_timer->pfn_callback = pfn_callback; 229 p_timer->context = context; 230 231 /* Mark the timer as idle. */ 232 p_timer->timer_state = CL_TIMER_IDLE; 233 234 /* Create the condition variable that is used when cancelling a timer. */ 235 pthread_cond_init(&p_timer->cond, NULL); 236 237 p_timer->state = CL_INITIALIZED; 238 239 return (CL_SUCCESS); 240 } 241 242 void cl_timer_destroy(IN cl_timer_t * const p_timer) 243 { 244 CL_ASSERT(p_timer); 245 CL_ASSERT(cl_is_state_valid(p_timer->state)); 246 247 if (p_timer->state == CL_INITIALIZED) 248 cl_timer_stop(p_timer); 249 250 p_timer->state = CL_UNINITIALIZED; 251 252 /* is it possible we have some threads waiting on the cond now? */ 253 pthread_cond_broadcast(&p_timer->cond); 254 pthread_cond_destroy(&p_timer->cond); 255 256 } 257 258 /* 259 * Return TRUE if timeout value 1 is earlier than timeout value 2. 260 */ 261 static __inline boolean_t __cl_timer_is_earlier(IN struct timespec *p_timeout1, 262 IN struct timespec *p_timeout2) 263 { 264 return ((p_timeout1->tv_sec < p_timeout2->tv_sec) || 265 ((p_timeout1->tv_sec == p_timeout2->tv_sec) && 266 (p_timeout1->tv_nsec < p_timeout2->tv_nsec))); 267 } 268 269 /* 270 * Search for a timer with an earlier timeout than the one provided by 271 * the context. Both the list item and the context are pointers to 272 * a cl_timer_t structure with valid timeouts. 273 */ 274 static cl_status_t __cl_timer_find(IN const cl_list_item_t * const p_list_item, 275 IN void *const context) 276 { 277 cl_timer_t *p_in_list; 278 cl_timer_t *p_new; 279 280 CL_ASSERT(p_list_item); 281 CL_ASSERT(context); 282 283 p_in_list = (cl_timer_t *) p_list_item; 284 p_new = (cl_timer_t *) context; 285 286 CL_ASSERT(p_in_list->state == CL_INITIALIZED); 287 CL_ASSERT(p_new->state == CL_INITIALIZED); 288 289 CL_ASSERT(p_in_list->timer_state == CL_TIMER_QUEUED); 290 291 if (__cl_timer_is_earlier(&p_in_list->timeout, &p_new->timeout)) 292 return (CL_SUCCESS); 293 294 return (CL_NOT_FOUND); 295 } 296 297 /* 298 * Calculate 'struct timespec' value that is the 299 * current time plus the 'time_ms' milliseconds. 300 */ 301 static __inline void __cl_timer_calculate(IN const uint32_t time_ms, 302 OUT struct timespec * const p_timer) 303 { 304 struct timeval curtime, deltatime, endtime; 305 306 gettimeofday(&curtime, NULL); 307 308 deltatime.tv_sec = time_ms / 1000; 309 deltatime.tv_usec = (time_ms % 1000) * 1000; 310 timeradd(&curtime, &deltatime, &endtime); 311 p_timer->tv_sec = endtime.tv_sec; 312 p_timer->tv_nsec = endtime.tv_usec * 1000; 313 } 314 315 cl_status_t cl_timer_start(IN cl_timer_t * const p_timer, 316 IN const uint32_t time_ms) 317 { 318 cl_list_item_t *p_list_item; 319 320 CL_ASSERT(p_timer); 321 CL_ASSERT(p_timer->state == CL_INITIALIZED); 322 323 pthread_mutex_lock(&gp_timer_prov->mutex); 324 /* Signal the timer provider thread to wake up. */ 325 pthread_cond_signal(&gp_timer_prov->cond); 326 327 /* Remove the timer from the queue if currently queued. */ 328 if (p_timer->timer_state == CL_TIMER_QUEUED) 329 cl_qlist_remove_item(&gp_timer_prov->queue, 330 &p_timer->list_item); 331 332 __cl_timer_calculate(time_ms, &p_timer->timeout); 333 334 /* Add the timer to the queue. */ 335 if (cl_is_qlist_empty(&gp_timer_prov->queue)) { 336 /* The timer list is empty. Add to the head. */ 337 cl_qlist_insert_head(&gp_timer_prov->queue, 338 &p_timer->list_item); 339 } else { 340 /* Find the correct insertion place in the list for the timer. */ 341 p_list_item = cl_qlist_find_from_tail(&gp_timer_prov->queue, 342 __cl_timer_find, p_timer); 343 344 /* Insert the timer. */ 345 cl_qlist_insert_next(&gp_timer_prov->queue, p_list_item, 346 &p_timer->list_item); 347 } 348 /* Set the state. */ 349 p_timer->timer_state = CL_TIMER_QUEUED; 350 pthread_mutex_unlock(&gp_timer_prov->mutex); 351 352 return (CL_SUCCESS); 353 } 354 355 void cl_timer_stop(IN cl_timer_t * const p_timer) 356 { 357 CL_ASSERT(p_timer); 358 CL_ASSERT(p_timer->state == CL_INITIALIZED); 359 360 pthread_mutex_lock(&gp_timer_prov->mutex); 361 switch (p_timer->timer_state) { 362 case CL_TIMER_RUNNING: 363 /* Wait for the callback to complete. */ 364 pthread_cond_wait(&p_timer->cond, &gp_timer_prov->mutex); 365 /* Timer could have been queued while we were waiting. */ 366 if (p_timer->timer_state != CL_TIMER_QUEUED) 367 break; 368 369 case CL_TIMER_QUEUED: 370 /* Change the state of the timer. */ 371 p_timer->timer_state = CL_TIMER_IDLE; 372 /* Remove the timer from the queue. */ 373 cl_qlist_remove_item(&gp_timer_prov->queue, 374 &p_timer->list_item); 375 /* 376 * Signal the timer provider thread to move onto the 377 * next timer in the queue. 378 */ 379 pthread_cond_signal(&gp_timer_prov->cond); 380 break; 381 382 case CL_TIMER_IDLE: 383 break; 384 } 385 pthread_mutex_unlock(&gp_timer_prov->mutex); 386 } 387 388 cl_status_t cl_timer_trim(IN cl_timer_t * const p_timer, 389 IN const uint32_t time_ms) 390 { 391 struct timespec newtime; 392 cl_status_t status; 393 394 CL_ASSERT(p_timer); 395 CL_ASSERT(p_timer->state == CL_INITIALIZED); 396 397 pthread_mutex_lock(&gp_timer_prov->mutex); 398 399 __cl_timer_calculate(time_ms, &newtime); 400 401 if (p_timer->timer_state == CL_TIMER_QUEUED) { 402 /* If the old time is earlier, do not trim it. Just return. */ 403 if (__cl_timer_is_earlier(&p_timer->timeout, &newtime)) { 404 pthread_mutex_unlock(&gp_timer_prov->mutex); 405 return (CL_SUCCESS); 406 } 407 } 408 409 /* Reset the timer to the new timeout value. */ 410 411 pthread_mutex_unlock(&gp_timer_prov->mutex); 412 status = cl_timer_start(p_timer, time_ms); 413 414 return (status); 415 } 416 417 uint64_t cl_get_time_stamp(void) 418 { 419 uint64_t tstamp; 420 struct timeval tv; 421 422 gettimeofday(&tv, NULL); 423 424 /* Convert the time of day into a microsecond timestamp. */ 425 tstamp = ((uint64_t) tv.tv_sec * 1000000) + (uint64_t) tv.tv_usec; 426 427 return (tstamp); 428 } 429 430 uint32_t cl_get_time_stamp_sec(void) 431 { 432 struct timeval tv; 433 434 gettimeofday(&tv, NULL); 435 436 return (tv.tv_sec); 437 } 438