src/helper/jim-eventloop.c

   1 /* Jim - A small embeddable Tcl interpreter
   2  *
   3  * Copyright 2005 Salvatore Sanfilippo <antirez@invece.org>
   4  * Copyright 2005 Clemens Hintze <c.hintze@gmx.net>
   5  * Copyright 2005 patthoyts - Pat Thoyts <patthoyts@users.sf.net>
   6  * Copyright 2008 oharboe - Øyvind Harboe - oyvind.harboe@zylin.com
   7  * Copyright 2008 Andrew Lunn <andrew@lunn.ch>
   8  * Copyright 2008 Duane Ellis <openocd@duaneellis.com>
   9  * Copyright 2008 Uwe Klein <uklein@klein-messgeraete.de>
  10  *
  11  * The FreeBSD license
  12  *
  13  * Redistribution and use in source and binary forms, with or without
  14  * modification, are permitted provided that the following conditions
  15  * are met:
  16  *
  17  * 1. Redistributions of source code must retain the above copyright
  18  *    notice, this list of conditions and the following disclaimer.
  19  * 2. Redistributions in binary form must reproduce the above
  20  *    copyright notice, this list of conditions and the following
  21  *    disclaimer in the documentation and/or other materials
  22  *    provided with the distribution.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE JIM TCL PROJECT ``AS IS'' AND ANY
  25  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  26  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
  27  * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  28  * JIM TCL PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  29  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  30  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  33  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  35  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * The views and conclusions contained in the software and documentation
  38  * are those of the authors and should not be interpreted as representing
  39  * official policies, either expressed or implied, of the Jim Tcl Project.
  40  **/
  41 /* TODO:
  42  *
  43  *  - to really use flags in Jim_ProcessEvents()
  44  *  - more complete [after] command with [after info] and other subcommands.
  45  *  - Win32 port
  46  */
  47 #ifdef HAVE_CONFIG_H
  48 #include "config.h"
  49 #endif
  50
  51 #define JIM_EXTENSION
  52 #define __JIM_EVENTLOOP_CORE__
  53 #ifdef __ECOS
  54 #include <pkgconf/jimtcl.h>
  55 #include <sys/time.h>
  56 #include <cyg/jimtcl/jim.h>
  57 #include <cyg/jimtcl/jim-eventloop.h>
  58 #else
  59 #include "jim.h"
  60 #include "jim-eventloop.h"
  61 #endif
  62
  63 /* File event structure */
  64 typedef struct Jim_FileEvent {
  65     void *handle;
  66     int mask; /* one of JIM_EVENT_(READABLE | WRITABLE | EXCEPTION) */
  67     Jim_FileProc *fileProc;
  68     Jim_EventFinalizerProc *finalizerProc;
  69     void *clientData;
  70     struct Jim_FileEvent *next;
  71 } Jim_FileEvent;
  72
  73 /* Time event structure */
  74 typedef struct Jim_TimeEvent {
  75     jim_wide id; /* time event identifier. */
  76     int mode;   /* restart, repetitive .. UK */
  77     long initialms; /* initial relativ timer value UK */
  78     long when_sec; /* seconds */
  79     long when_ms; /* milliseconds */
  80     Jim_TimeProc *timeProc;
  81     Jim_EventFinalizerProc *finalizerProc;
  82     void *clientData;
  83     struct Jim_TimeEvent *next;
  84 } Jim_TimeEvent;
  85
  86 /* Per-interp stucture containing the state of the event loop */
  87 typedef struct Jim_EventLoop {
  88     jim_wide timeEventNextId;
  89     Jim_FileEvent *fileEventHead;
  90     Jim_TimeEvent *timeEventHead;
  91 } Jim_EventLoop;
  92
  93 void Jim_CreateFileHandler(Jim_Interp *interp, void *handle, int mask,
  94         Jim_FileProc *proc, void *clientData,
  95         Jim_EventFinalizerProc *finalizerProc)
  96 {
  97     Jim_FileEvent *fe;
  98     Jim_EventLoop *eventLoop = Jim_GetAssocData(interp, "eventloop");
  99
 100         // fprintf(stderr,"rein\n");
 101     fe = Jim_Alloc(sizeof(*fe));
 102     fe->handle = handle;
 103     fe->mask = mask;
 104     fe->fileProc = proc;
 105     fe->finalizerProc = finalizerProc;
 106     fe->clientData = clientData;
 107     fe->next = eventLoop->fileEventHead;
 108     eventLoop->fileEventHead = fe;
 109         // fprintf(stderr,"raus\n");
 110 }
 111
 112 void Jim_DeleteFileHandler(Jim_Interp *interp, void *handle)
 113 {
 114     Jim_FileEvent *fe, *prev = NULL;
 115     Jim_EventLoop *eventLoop = Jim_GetAssocData(interp, "eventloop");
 116
 117     fe = eventLoop->fileEventHead;
 118     while (fe) {
 119         if (fe->handle == handle) {
 120             if (prev == NULL)
 121                 eventLoop->fileEventHead = fe->next;
 122             else
 123                 prev->next = fe->next;
 124             if (fe->finalizerProc)
 125                 fe->finalizerProc(interp, fe->clientData);
 126             Jim_Free(fe);
 127             return;
 128         }
 129         prev = fe;
 130         fe = fe->next;
 131     }
 132 }
 133
 134 // The same for signals.
 135 void Jim_CreateSignalHandler(Jim_Interp *interp, int signum,
 136         Jim_FileProc *proc, void *clientData,
 137         Jim_EventFinalizerProc *finalizerProc)
 138 {
 139 }
 140 void Jim_DeleteSignalHandler(Jim_Interp *interp, int signum)
 141 {
 142 }
 143
 144 /* That's another part of this extension that needs to be ported
 145  * to WIN32. */
 146 static void JimGetTime(long *seconds, long *milliseconds)
 147 {
 148     struct timeval tv;
 149
 150     gettimeofday(&tv, NULL);
 151     *seconds = tv.tv_sec;
 152     *milliseconds = tv.tv_usec/1000;
 153 }
 154
 155 jim_wide Jim_CreateTimeHandler(Jim_Interp *interp, jim_wide milliseconds,
 156         Jim_TimeProc *proc, void *clientData,
 157         Jim_EventFinalizerProc *finalizerProc)
 158 {
 159     Jim_EventLoop *eventLoop = Jim_GetAssocData(interp, "eventloop");
 160     jim_wide id = eventLoop->timeEventNextId++;
 161     Jim_TimeEvent *te;
 162     long cur_sec, cur_ms;
 163
 164     JimGetTime(&cur_sec, &cur_ms);
 165
 166     te = Jim_Alloc(sizeof(*te));
 167     te->id = id;
 168     te->mode = 0;
 169     te->initialms = milliseconds;
 170     te->when_sec = cur_sec + milliseconds/1000;
 171     te->when_ms = cur_ms + milliseconds%1000;
 172     if (te->when_ms >= 1000) {
 173         te->when_sec ++;
 174         te->when_ms -= 1000;
 175     }
 176     te->timeProc = proc;
 177     te->finalizerProc = finalizerProc;
 178     te->clientData = clientData;
 179     te->next = eventLoop->timeEventHead;
 180     eventLoop->timeEventHead = te;
 181     return id;
 182 }
 183
 184 jim_wide Jim_DeleteTimeHandler(Jim_Interp *interp, jim_wide id)
 185 {
 186     Jim_TimeEvent *te, *prev = NULL;
 187     Jim_EventLoop *eventLoop = Jim_GetAssocData(interp, "eventloop");
 188     long cur_sec, cur_ms;
 189     jim_wide remain ;
 190
 191     JimGetTime(&cur_sec, &cur_ms);
 192
 193     te = eventLoop->timeEventHead;
 194     if (id >= eventLoop->timeEventNextId)
 195         return -2; /* wrong event ID */
 196     while (te) {
 197         if (te->id == id) {
 198             remain  = (te->when_sec - cur_sec) * 1000;
 199             remain += (te->when_ms  - cur_ms) ;
 200             remain = (remain < 0) ? 0 : remain ;
 201
 202             if (prev == NULL)
 203                 eventLoop->timeEventHead = te->next;
 204             else
 205                 prev->next = te->next;
 206             if (te->finalizerProc)
 207                 te->finalizerProc(interp, te->clientData);
 208             Jim_Free(te);
 209             return remain;
 210         }
 211         prev = te;
 212         te = te->next;
 213     }
 214     return -1; /* NO event with the specified ID found */
 215 }
 216
 217 /* Search the first timer to fire.
 218  * This operation is useful to know how many time the select can be
 219  * put in sleep without to delay any event.
 220  * If there are no timers NULL is returned. */
 221 static Jim_TimeEvent *JimSearchNearestTimer(Jim_EventLoop *eventLoop)
 222 {
 223     Jim_TimeEvent *te = eventLoop->timeEventHead;
 224     Jim_TimeEvent *nearest = NULL;
 225
 226     while (te) {
 227         if (!nearest || te->when_sec < nearest->when_sec ||
 228                 (te->when_sec == nearest->when_sec &&
 229                  te->when_ms < nearest->when_ms))
 230             nearest = te;
 231         te = te->next;
 232     }
 233     return nearest;
 234 }
 235
 236 /* --- POSIX version of Jim_ProcessEvents, for now the only available --- */
 237 #define JIM_FILE_EVENTS 1
 238 #define JIM_TIME_EVENTS 2
 239 #define JIM_ALL_EVENTS (JIM_FILE_EVENTS | JIM_TIME_EVENTS)
 240 #define JIM_DONT_WAIT 4
 241
 242 /* Process every pending time event, then every pending file event
 243  * (that may be registered by time event callbacks just processed).
 244  * Without special flags the function sleeps until some file event
 245  * fires, or when the next time event occurrs (if any).
 246  *
 247  * If flags is 0, the function does nothing and returns.
 248  * if flags has JIM_ALL_EVENTS set, all the kind of events are processed.
 249  * if flags has JIM_FILE_EVENTS set, file events are processed.
 250  * if flags has JIM_TIME_EVENTS set, time events are processed.
 251  * if flags has JIM_DONT_WAIT set the function returns ASAP until all
 252  * the events that's possible to process without to wait are processed.
 253  *
 254  * The function returns the number of events processed. */
 255 int Jim_ProcessEvents(Jim_Interp *interp, int flags)
 256 {
 257     int maxfd = 0, numfd = 0, processed = 0;
 258     fd_set rfds, wfds, efds;
 259     Jim_EventLoop *eventLoop = Jim_GetAssocData(interp, "eventloop");
 260     Jim_FileEvent *fe = eventLoop->fileEventHead;
 261     Jim_TimeEvent *te;
 262     jim_wide maxId;
 263     JIM_NOTUSED(flags);
 264
 265     FD_ZERO(&rfds);
 266     FD_ZERO(&wfds);
 267     FD_ZERO(&efds);
 268
 269     /* Check file events */
 270     while (fe != NULL) {
 271         int fd = fileno((FILE*)fe->handle);
 272
 273         if (fe->mask & JIM_EVENT_READABLE)
 274                 FD_SET(fd, &rfds);
 275         if (fe->mask & JIM_EVENT_WRITABLE) FD_SET(fd, &wfds);
 276         if (fe->mask & JIM_EVENT_EXCEPTION) FD_SET(fd, &efds);
 277         if (maxfd < fd) maxfd = fd;
 278         numfd++;
 279         fe = fe->next;
 280     }
 281     /* Note that we want call select() even if there are no
 282      * file events to process as long as we want to process time
 283      * events, in order to sleep until the next time event is ready
 284      * to fire. */
 285     if (numfd || ((flags & JIM_TIME_EVENTS) && !(flags & JIM_DONT_WAIT))) {
 286         int retval;
 287         Jim_TimeEvent *shortest;
 288         struct timeval tv, *tvp;
 289         jim_wide dt;
 290
 291         shortest = JimSearchNearestTimer(eventLoop);
 292         if (shortest) {
 293             long now_sec, now_ms;
 294
 295             /* Calculate the time missing for the nearest
 296              * timer to fire. */
 297             JimGetTime(&now_sec, &now_ms);
 298             tvp = &tv;
 299             dt   = 1000 * (shortest->when_sec - now_sec);
 300             dt  += (shortest->when_ms  - now_ms);
 301             if (dt < 0) {
 302                 dt = 1;
 303             }
 304             tvp->tv_sec  = dt / 1000;
 305             tvp->tv_usec = dt % 1000;
 306             // fprintf(stderr,"Next %d.% 8d\n",(int)tvp->tv_sec,(int)tvp->tv_usec);
 307         } else {
 308             tvp = NULL; /* wait forever */
 309                 // fprintf(stderr,"No Event\n");
 310         }
 311
 312         retval = select(maxfd + 1, &rfds, &wfds, &efds, tvp);
 313         if (retval < 0) {
 314            switch (errno) {
 315                case EINTR:   fprintf(stderr,"select EINTR\n"); break;
 316                case EINVAL:  fprintf(stderr,"select EINVAL\n"); break;
 317                case ENOMEM:  fprintf(stderr,"select ENOMEM\n"); break;
 318            }
 319         } else if (retval > 0) {
 320             fe = eventLoop->fileEventHead;
 321             while (fe != NULL) {
 322                 int fd = fileno((FILE*)fe->handle);
 323
 324                 // fprintf(stderr,"fd: %d mask: %02x \n",fd,fe->mask);
 325
 326                 if ((fe->mask & JIM_EVENT_READABLE && FD_ISSET(fd, &rfds)) ||
 327                     (fe->mask & JIM_EVENT_WRITABLE && FD_ISSET(fd, &wfds)) ||
 328                     (fe->mask & JIM_EVENT_EXCEPTION && FD_ISSET(fd, &efds)))
 329                 {
 330                     int mask = 0;
 331
 332                     if (fe->mask & JIM_EVENT_READABLE && FD_ISSET(fd, &rfds)) {
 333                         mask |= JIM_EVENT_READABLE;
 334                         if ((fe->mask & JIM_EVENT_FEOF) && feof((FILE *)fe->handle))
 335                                 mask |= JIM_EVENT_FEOF;
 336                     }
 337                     if (fe->mask & JIM_EVENT_WRITABLE && FD_ISSET(fd, &wfds))
 338                         mask |= JIM_EVENT_WRITABLE;
 339                     if (fe->mask & JIM_EVENT_EXCEPTION && FD_ISSET(fd, &efds))
 340                         mask |= JIM_EVENT_EXCEPTION;
 341                     if (fe->fileProc(interp, fe->clientData, mask) == JIM_ERR) {
 342                         /* Remove the element on handler error */
 343                         Jim_DeleteFileHandler(interp, fe->handle);
 344                     }
 345                     processed++;
 346                     /* After an event is processed our file event list
 347                      * may no longer be the same, so what we do
 348                      * is to clear the bit for this file descriptor and
 349                      * restart again from the head. */
 350                     fe = eventLoop->fileEventHead;
 351                     FD_CLR(fd, &rfds);
 352                     FD_CLR(fd, &wfds);
 353                     FD_CLR(fd, &efds);
 354                 } else {
 355                     fe = fe->next;
 356                 }
 357             }
 358         }
 359     }
 360     /* Check time events */
 361     te = eventLoop->timeEventHead;
 362     maxId = eventLoop->timeEventNextId-1;
 363     while (te) {
 364         long now_sec, now_ms;
 365         jim_wide id;
 366
 367         if (te->id > maxId) {
 368             te = te->next;
 369             continue;
 370         }
 371         JimGetTime(&now_sec, &now_ms);
 372         if (now_sec > te->when_sec ||
 373             (now_sec == te->when_sec && now_ms >= te->when_ms))
 374         {
 375             id = te->id;
 376             te->timeProc(interp, te->clientData);
 377             /* After an event is processed our time event list may
 378              * no longer be the same, so we restart from head.
 379              * Still we make sure to don't process events registered
 380              * by event handlers itself in order to don't loop forever
 381              * even in case an [after 0] that continuously register
 382              * itself. To do so we saved the max ID we want to handle. */
 383             Jim_DeleteTimeHandler(interp, id);
 384             te = eventLoop->timeEventHead;
 385         } else {
 386             te = te->next;
 387         }
 388     }
 389
 390     return processed;
 391 }
 392 /* ---------------------------------------------------------------------- */
 393
 394 void JimELAssocDataDeleProc(Jim_Interp *interp, void *data)
 395 {
 396     void *next;
 397     Jim_FileEvent *fe;
 398     Jim_TimeEvent *te;
 399     Jim_EventLoop *eventLoop = data;
 400
 401     fe = eventLoop->fileEventHead;
 402     while (fe) {
 403         next = fe->next;
 404         if (fe->finalizerProc)
 405             fe->finalizerProc(interp, fe->clientData);
 406         Jim_Free(fe);
 407         fe = next;
 408     }
 409
 410     te = eventLoop->timeEventHead;
 411     while (te) {
 412         next = te->next;
 413         if (te->finalizerProc)
 414             te->finalizerProc(interp, te->clientData);
 415         Jim_Free(te);
 416         te = next;
 417     }
 418     Jim_Free(data);
 419 }
 420
 421 static int JimELVwaitCommand(Jim_Interp *interp, int argc,
 422         Jim_Obj *const *argv)
 423 {
 424     Jim_Obj *oldValue;
 425
 426     if (argc != 2) {
 427         Jim_WrongNumArgs(interp, 1, argv, "name");
 428         return JIM_ERR;
 429     }
 430     oldValue = Jim_GetGlobalVariable(interp, argv[1], JIM_NONE);
 431     if (oldValue) Jim_IncrRefCount(oldValue);
 432     while (1) {
 433         Jim_Obj *currValue;
 434
 435         Jim_ProcessEvents(interp, JIM_ALL_EVENTS);
 436         currValue = Jim_GetGlobalVariable(interp, argv[1], JIM_NONE);
 437         /* Stop the loop if the vwait-ed variable changed value,
 438          * or if was unset and now is set (or the contrary). */
 439         if ((oldValue && !currValue) ||
 440             (!oldValue && currValue) ||
 441             (oldValue && currValue &&
 442              !Jim_StringEqObj(oldValue, currValue, JIM_CASESENS)))
 443             break;
 444     }
 445     if (oldValue) Jim_DecrRefCount(interp, oldValue);
 446     return JIM_OK;
 447 }
 448
 449 void JimAfterTimeHandler(Jim_Interp *interp, void *clientData)
 450 {
 451     Jim_Obj *objPtr = clientData;
 452
 453     Jim_EvalObjBackground(interp, objPtr);
 454 }
 455
 456 void JimAfterTimeEventFinalizer(Jim_Interp *interp, void *clientData)
 457 {
 458     Jim_Obj *objPtr = clientData;
 459
 460     Jim_DecrRefCount(interp, objPtr);
 461 }
 462
 463 static int JimELAfterCommand(Jim_Interp *interp, int argc,
 464         Jim_Obj *const *argv)
 465 {
 466     jim_wide ms, id;
 467     Jim_Obj *objPtr, *idObjPtr;
 468     const char *options[] = {
 469         "info", "cancel", "restart", "expire", NULL
 470     };
 471     enum {INFO, CANCEL, RESTART, EXPIRE, CREATE };
 472     int option = CREATE ;
 473
 474     if (argc < 3) {
 475         Jim_WrongNumArgs(interp, 1, argv, "<after milliseconds> script");
 476         return JIM_ERR;
 477     }
 478     if (Jim_GetWide(interp, argv[1], &ms) != JIM_OK)
 479         if (Jim_GetEnum(interp, argv[1], options, &option, "after options",
 480                     JIM_ERRMSG) != JIM_OK)
 481             return JIM_ERR;
 482     switch (option) {
 483     case CREATE:
 484         Jim_IncrRefCount(argv[2]);
 485         id = Jim_CreateTimeHandler(interp, ms, JimAfterTimeHandler, argv[2],
 486                 JimAfterTimeEventFinalizer);
 487         objPtr = Jim_NewStringObj(interp, NULL, 0);
 488         Jim_AppendString(interp, objPtr, "after#", -1);
 489         idObjPtr = Jim_NewIntObj(interp, id);
 490         Jim_IncrRefCount(idObjPtr);
 491         Jim_AppendObj(interp, objPtr, idObjPtr);
 492         Jim_DecrRefCount(interp, idObjPtr);
 493         Jim_SetResult(interp, objPtr);
 494         return JIM_OK;
 495     case CANCEL:
 496         {
 497         int tlen ;
 498         jim_wide remain = 0;
 499         const char *tok = Jim_GetString(argv[2], &tlen);
 500         if (sscanf(tok,"after#%" JIM_WIDE_MODIFIER, &id) == 1) {
 501                 remain =  Jim_DeleteTimeHandler(interp, id);
 502                 if (remain > -2)  {
 503                         Jim_SetResult(interp, Jim_NewIntObj(interp, remain));
 504                         return JIM_OK;
 505                 }
 506         }
 507         Jim_SetResultString(interp, "invalid event" , -1);
 508         return JIM_ERR;
 509         }
 510     default:
 511         fprintf(stderr,"unserviced option to after %d\n",option);
 512     }
 513     return JIM_OK;
 514 }
 515
 516 /* This extension is not dynamically loaded, instead it's linked statically,
 517    which is why we shouldn't use the unspecific 'Jim_OnLoad' name */
 518 int Jim_EventLoopOnLoad(Jim_Interp *interp)
 519 {
 520     Jim_EventLoop *eventLoop;
 521
 522     Jim_InitExtension(interp);
 523     if (Jim_PackageProvide(interp, "eventloop", "1.0", JIM_ERRMSG) != JIM_OK)
 524         return JIM_ERR;
 525
 526     eventLoop = Jim_Alloc(sizeof(*eventLoop));
 527     eventLoop->fileEventHead = NULL;
 528     eventLoop->timeEventHead = NULL;
 529     eventLoop->timeEventNextId = 1;
 530     Jim_SetAssocData(interp, "eventloop", JimELAssocDataDeleProc, eventLoop);
 531
 532     Jim_CreateCommand(interp, "vwait", JimELVwaitCommand, NULL, NULL);
 533     Jim_CreateCommand(interp, "after", JimELAfterCommand, NULL, NULL);
 534
 535     /* Export events API */
 536     Jim_RegisterApi(interp, "Jim_CreateFileHandler", Jim_CreateFileHandler);
 537     Jim_RegisterApi(interp, "Jim_DeleteFileHandler", Jim_DeleteFileHandler);
 538     Jim_RegisterApi(interp, "Jim_CreateTimeHandler", Jim_CreateTimeHandler);
 539     Jim_RegisterApi(interp, "Jim_DeleteTimeHandler", Jim_DeleteTimeHandler);
 540     Jim_RegisterApi(interp, "Jim_ProcessEvents", Jim_ProcessEvents);
 541     return JIM_OK;
 542 }