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| 1 /* | |
| 2 ** 2007 September 9 | |
| 3 ** | |
| 4 ** The author disclaims copyright to this source code. In place of | |
| 5 ** a legal notice, here is a blessing: | |
| 6 ** | |
| 7 ** May you do good and not evil. | |
| 8 ** May you find forgiveness for yourself and forgive others. | |
| 9 ** May you share freely, never taking more than you give. | |
| 10 ** | |
| 11 ************************************************************************* | |
| 12 ** | |
| 13 ** This file contains the implementation of some Tcl commands used to | |
| 14 ** test that sqlite3 database handles may be concurrently accessed by | |
| 15 ** multiple threads. Right now this only works on unix. | |
| 16 */ | |
| 17 | |
| 18 #include "sqliteInt.h" | |
| 19 #include <tcl.h> | |
| 20 | |
| 21 #if SQLITE_THREADSAFE | |
| 22 | |
| 23 #include <errno.h> | |
| 24 | |
| 25 #if !defined(_MSC_VER) | |
| 26 #include <unistd.h> | |
| 27 #endif | |
| 28 | |
| 29 /* | |
| 30 ** One of these is allocated for each thread created by [sqlthread spawn]. | |
| 31 */ | |
| 32 typedef struct SqlThread SqlThread; | |
| 33 struct SqlThread { | |
| 34 Tcl_ThreadId parent; /* Thread id of parent thread */ | |
| 35 Tcl_Interp *interp; /* Parent interpreter */ | |
| 36 char *zScript; /* The script to execute. */ | |
| 37 char *zVarname; /* Varname in parent script */ | |
| 38 }; | |
| 39 | |
| 40 /* | |
| 41 ** A custom Tcl_Event type used by this module. When the event is | |
| 42 ** handled, script zScript is evaluated in interpreter interp. If | |
| 43 ** the evaluation throws an exception (returns TCL_ERROR), then the | |
| 44 ** error is handled by Tcl_BackgroundError(). If no error occurs, | |
| 45 ** the result is simply discarded. | |
| 46 */ | |
| 47 typedef struct EvalEvent EvalEvent; | |
| 48 struct EvalEvent { | |
| 49 Tcl_Event base; /* Base class of type Tcl_Event */ | |
| 50 char *zScript; /* The script to execute. */ | |
| 51 Tcl_Interp *interp; /* The interpreter to execute it in. */ | |
| 52 }; | |
| 53 | |
| 54 static Tcl_ObjCmdProc sqlthread_proc; | |
| 55 static Tcl_ObjCmdProc clock_seconds_proc; | |
| 56 #if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) | |
| 57 static Tcl_ObjCmdProc blocking_step_proc; | |
| 58 static Tcl_ObjCmdProc blocking_prepare_v2_proc; | |
| 59 #endif | |
| 60 int Sqlitetest1_Init(Tcl_Interp *); | |
| 61 int Sqlite3_Init(Tcl_Interp *); | |
| 62 | |
| 63 /* Functions from main.c */ | |
| 64 extern const char *sqlite3ErrName(int); | |
| 65 | |
| 66 /* Functions from test1.c */ | |
| 67 extern void *sqlite3TestTextToPtr(const char *); | |
| 68 extern int getDbPointer(Tcl_Interp *, const char *, sqlite3 **); | |
| 69 extern int sqlite3TestMakePointerStr(Tcl_Interp *, char *, void *); | |
| 70 extern int sqlite3TestErrCode(Tcl_Interp *, sqlite3 *, int); | |
| 71 | |
| 72 /* | |
| 73 ** Handler for events of type EvalEvent. | |
| 74 */ | |
| 75 static int tclScriptEvent(Tcl_Event *evPtr, int flags){ | |
| 76 int rc; | |
| 77 EvalEvent *p = (EvalEvent *)evPtr; | |
| 78 rc = Tcl_Eval(p->interp, p->zScript); | |
| 79 if( rc!=TCL_OK ){ | |
| 80 Tcl_BackgroundError(p->interp); | |
| 81 } | |
| 82 UNUSED_PARAMETER(flags); | |
| 83 return 1; | |
| 84 } | |
| 85 | |
| 86 /* | |
| 87 ** Register an EvalEvent to evaluate the script pScript in the | |
| 88 ** parent interpreter/thread of SqlThread p. | |
| 89 */ | |
| 90 static void postToParent(SqlThread *p, Tcl_Obj *pScript){ | |
| 91 EvalEvent *pEvent; | |
| 92 char *zMsg; | |
| 93 int nMsg; | |
| 94 | |
| 95 zMsg = Tcl_GetStringFromObj(pScript, &nMsg); | |
| 96 pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1); | |
| 97 pEvent->base.nextPtr = 0; | |
| 98 pEvent->base.proc = tclScriptEvent; | |
| 99 pEvent->zScript = (char *)&pEvent[1]; | |
| 100 memcpy(pEvent->zScript, zMsg, nMsg+1); | |
| 101 pEvent->interp = p->interp; | |
| 102 | |
| 103 Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL); | |
| 104 Tcl_ThreadAlert(p->parent); | |
| 105 } | |
| 106 | |
| 107 /* | |
| 108 ** The main function for threads created with [sqlthread spawn]. | |
| 109 */ | |
| 110 static Tcl_ThreadCreateType tclScriptThread(ClientData pSqlThread){ | |
| 111 Tcl_Interp *interp; | |
| 112 Tcl_Obj *pRes; | |
| 113 Tcl_Obj *pList; | |
| 114 int rc; | |
| 115 SqlThread *p = (SqlThread *)pSqlThread; | |
| 116 extern int Sqlitetest_mutex_Init(Tcl_Interp*); | |
| 117 | |
| 118 interp = Tcl_CreateInterp(); | |
| 119 Tcl_CreateObjCommand(interp, "clock_seconds", clock_seconds_proc, 0, 0); | |
| 120 Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, pSqlThread, 0); | |
| 121 #if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) | |
| 122 Tcl_CreateObjCommand(interp, "sqlite3_blocking_step", blocking_step_proc,0,0); | |
| 123 Tcl_CreateObjCommand(interp, | |
| 124 "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0); | |
| 125 Tcl_CreateObjCommand(interp, | |
| 126 "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0); | |
| 127 #endif | |
| 128 Sqlitetest1_Init(interp); | |
| 129 Sqlitetest_mutex_Init(interp); | |
| 130 Sqlite3_Init(interp); | |
| 131 | |
| 132 rc = Tcl_Eval(interp, p->zScript); | |
| 133 pRes = Tcl_GetObjResult(interp); | |
| 134 pList = Tcl_NewObj(); | |
| 135 Tcl_IncrRefCount(pList); | |
| 136 Tcl_IncrRefCount(pRes); | |
| 137 | |
| 138 if( rc!=TCL_OK ){ | |
| 139 Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("error", -1)); | |
| 140 Tcl_ListObjAppendElement(interp, pList, pRes); | |
| 141 postToParent(p, pList); | |
| 142 Tcl_DecrRefCount(pList); | |
| 143 pList = Tcl_NewObj(); | |
| 144 } | |
| 145 | |
| 146 Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj("set", -1)); | |
| 147 Tcl_ListObjAppendElement(interp, pList, Tcl_NewStringObj(p->zVarname, -1)); | |
| 148 Tcl_ListObjAppendElement(interp, pList, pRes); | |
| 149 postToParent(p, pList); | |
| 150 | |
| 151 ckfree((void *)p); | |
| 152 Tcl_DecrRefCount(pList); | |
| 153 Tcl_DecrRefCount(pRes); | |
| 154 Tcl_DeleteInterp(interp); | |
| 155 while( Tcl_DoOneEvent(TCL_ALL_EVENTS|TCL_DONT_WAIT) ); | |
| 156 Tcl_ExitThread(0); | |
| 157 TCL_THREAD_CREATE_RETURN; | |
| 158 } | |
| 159 | |
| 160 /* | |
| 161 ** sqlthread spawn VARNAME SCRIPT | |
| 162 ** | |
| 163 ** Spawn a new thread with its own Tcl interpreter and run the | |
| 164 ** specified SCRIPT(s) in it. The thread terminates after running | |
| 165 ** the script. The result of the script is stored in the variable | |
| 166 ** VARNAME. | |
| 167 ** | |
| 168 ** The caller can wait for the script to terminate using [vwait VARNAME]. | |
| 169 */ | |
| 170 static int sqlthread_spawn( | |
| 171 ClientData clientData, | |
| 172 Tcl_Interp *interp, | |
| 173 int objc, | |
| 174 Tcl_Obj *CONST objv[] | |
| 175 ){ | |
| 176 Tcl_ThreadId x; | |
| 177 SqlThread *pNew; | |
| 178 int rc; | |
| 179 | |
| 180 int nVarname; char *zVarname; | |
| 181 int nScript; char *zScript; | |
| 182 | |
| 183 /* Parameters for thread creation */ | |
| 184 const int nStack = TCL_THREAD_STACK_DEFAULT; | |
| 185 const int flags = TCL_THREAD_NOFLAGS; | |
| 186 | |
| 187 assert(objc==4); | |
| 188 UNUSED_PARAMETER(clientData); | |
| 189 UNUSED_PARAMETER(objc); | |
| 190 | |
| 191 zVarname = Tcl_GetStringFromObj(objv[2], &nVarname); | |
| 192 zScript = Tcl_GetStringFromObj(objv[3], &nScript); | |
| 193 | |
| 194 pNew = (SqlThread *)ckalloc(sizeof(SqlThread)+nVarname+nScript+2); | |
| 195 pNew->zVarname = (char *)&pNew[1]; | |
| 196 pNew->zScript = (char *)&pNew->zVarname[nVarname+1]; | |
| 197 memcpy(pNew->zVarname, zVarname, nVarname+1); | |
| 198 memcpy(pNew->zScript, zScript, nScript+1); | |
| 199 pNew->parent = Tcl_GetCurrentThread(); | |
| 200 pNew->interp = interp; | |
| 201 | |
| 202 rc = Tcl_CreateThread(&x, tclScriptThread, (void *)pNew, nStack, flags); | |
| 203 if( rc!=TCL_OK ){ | |
| 204 Tcl_AppendResult(interp, "Error in Tcl_CreateThread()", 0); | |
| 205 ckfree((char *)pNew); | |
| 206 return TCL_ERROR; | |
| 207 } | |
| 208 | |
| 209 return TCL_OK; | |
| 210 } | |
| 211 | |
| 212 /* | |
| 213 ** sqlthread parent SCRIPT | |
| 214 ** | |
| 215 ** This can be called by spawned threads only. It sends the specified | |
| 216 ** script back to the parent thread for execution. The result of | |
| 217 ** evaluating the SCRIPT is returned. The parent thread must enter | |
| 218 ** the event loop for this to work - otherwise the caller will | |
| 219 ** block indefinitely. | |
| 220 ** | |
| 221 ** NOTE: At the moment, this doesn't work. FIXME. | |
| 222 */ | |
| 223 static int sqlthread_parent( | |
| 224 ClientData clientData, | |
| 225 Tcl_Interp *interp, | |
| 226 int objc, | |
| 227 Tcl_Obj *CONST objv[] | |
| 228 ){ | |
| 229 EvalEvent *pEvent; | |
| 230 char *zMsg; | |
| 231 int nMsg; | |
| 232 SqlThread *p = (SqlThread *)clientData; | |
| 233 | |
| 234 assert(objc==3); | |
| 235 UNUSED_PARAMETER(objc); | |
| 236 | |
| 237 if( p==0 ){ | |
| 238 Tcl_AppendResult(interp, "no parent thread", 0); | |
| 239 return TCL_ERROR; | |
| 240 } | |
| 241 | |
| 242 zMsg = Tcl_GetStringFromObj(objv[2], &nMsg); | |
| 243 pEvent = (EvalEvent *)ckalloc(sizeof(EvalEvent)+nMsg+1); | |
| 244 pEvent->base.nextPtr = 0; | |
| 245 pEvent->base.proc = tclScriptEvent; | |
| 246 pEvent->zScript = (char *)&pEvent[1]; | |
| 247 memcpy(pEvent->zScript, zMsg, nMsg+1); | |
| 248 pEvent->interp = p->interp; | |
| 249 Tcl_ThreadQueueEvent(p->parent, (Tcl_Event *)pEvent, TCL_QUEUE_TAIL); | |
| 250 Tcl_ThreadAlert(p->parent); | |
| 251 | |
| 252 return TCL_OK; | |
| 253 } | |
| 254 | |
| 255 static int xBusy(void *pArg, int nBusy){ | |
| 256 UNUSED_PARAMETER(pArg); | |
| 257 UNUSED_PARAMETER(nBusy); | |
| 258 sqlite3_sleep(50); | |
| 259 return 1; /* Try again... */ | |
| 260 } | |
| 261 | |
| 262 /* | |
| 263 ** sqlthread open | |
| 264 ** | |
| 265 ** Open a database handle and return the string representation of | |
| 266 ** the pointer value. | |
| 267 */ | |
| 268 static int sqlthread_open( | |
| 269 ClientData clientData, | |
| 270 Tcl_Interp *interp, | |
| 271 int objc, | |
| 272 Tcl_Obj *CONST objv[] | |
| 273 ){ | |
| 274 int sqlite3TestMakePointerStr(Tcl_Interp *interp, char *zPtr, void *p); | |
| 275 | |
| 276 const char *zFilename; | |
| 277 sqlite3 *db; | |
| 278 char zBuf[100]; | |
| 279 extern void Md5_Register(sqlite3*); | |
| 280 | |
| 281 UNUSED_PARAMETER(clientData); | |
| 282 UNUSED_PARAMETER(objc); | |
| 283 | |
| 284 zFilename = Tcl_GetString(objv[2]); | |
| 285 sqlite3_open(zFilename, &db); | |
| 286 #ifdef SQLITE_HAS_CODEC | |
| 287 if( db && objc>=4 ){ | |
| 288 const char *zKey; | |
| 289 int nKey; | |
| 290 int rc; | |
| 291 zKey = Tcl_GetStringFromObj(objv[3], &nKey); | |
| 292 rc = sqlite3_key(db, zKey, nKey); | |
| 293 if( rc!=SQLITE_OK ){ | |
| 294 char *zErrMsg = sqlite3_mprintf("error %d: %s", rc, sqlite3_errmsg(db)); | |
| 295 sqlite3_close(db); | |
| 296 Tcl_AppendResult(interp, zErrMsg, (char*)0); | |
| 297 sqlite3_free(zErrMsg); | |
| 298 return TCL_ERROR; | |
| 299 } | |
| 300 } | |
| 301 #endif | |
| 302 Md5_Register(db); | |
| 303 sqlite3_busy_handler(db, xBusy, 0); | |
| 304 | |
| 305 if( sqlite3TestMakePointerStr(interp, zBuf, db) ) return TCL_ERROR; | |
| 306 Tcl_AppendResult(interp, zBuf, 0); | |
| 307 | |
| 308 return TCL_OK; | |
| 309 } | |
| 310 | |
| 311 | |
| 312 /* | |
| 313 ** sqlthread open | |
| 314 ** | |
| 315 ** Return the current thread-id (Tcl_GetCurrentThread()) cast to | |
| 316 ** an integer. | |
| 317 */ | |
| 318 static int sqlthread_id( | |
| 319 ClientData clientData, | |
| 320 Tcl_Interp *interp, | |
| 321 int objc, | |
| 322 Tcl_Obj *CONST objv[] | |
| 323 ){ | |
| 324 Tcl_ThreadId id = Tcl_GetCurrentThread(); | |
| 325 Tcl_SetObjResult(interp, Tcl_NewIntObj(SQLITE_PTR_TO_INT(id))); | |
| 326 UNUSED_PARAMETER(clientData); | |
| 327 UNUSED_PARAMETER(objc); | |
| 328 UNUSED_PARAMETER(objv); | |
| 329 return TCL_OK; | |
| 330 } | |
| 331 | |
| 332 | |
| 333 /* | |
| 334 ** Dispatch routine for the sub-commands of [sqlthread]. | |
| 335 */ | |
| 336 static int sqlthread_proc( | |
| 337 ClientData clientData, | |
| 338 Tcl_Interp *interp, | |
| 339 int objc, | |
| 340 Tcl_Obj *CONST objv[] | |
| 341 ){ | |
| 342 struct SubCommand { | |
| 343 char *zName; | |
| 344 Tcl_ObjCmdProc *xProc; | |
| 345 int nArg; | |
| 346 char *zUsage; | |
| 347 } aSub[] = { | |
| 348 {"parent", sqlthread_parent, 1, "SCRIPT"}, | |
| 349 {"spawn", sqlthread_spawn, 2, "VARNAME SCRIPT"}, | |
| 350 {"open", sqlthread_open, 1, "DBNAME"}, | |
| 351 {"id", sqlthread_id, 0, ""}, | |
| 352 {0, 0, 0} | |
| 353 }; | |
| 354 struct SubCommand *pSub; | |
| 355 int rc; | |
| 356 int iIndex; | |
| 357 | |
| 358 if( objc<2 ){ | |
| 359 Tcl_WrongNumArgs(interp, 1, objv, "SUB-COMMAND"); | |
| 360 return TCL_ERROR; | |
| 361 } | |
| 362 | |
| 363 rc = Tcl_GetIndexFromObjStruct( | |
| 364 interp, objv[1], aSub, sizeof(aSub[0]), "sub-command", 0, &iIndex | |
| 365 ); | |
| 366 if( rc!=TCL_OK ) return rc; | |
| 367 pSub = &aSub[iIndex]; | |
| 368 | |
| 369 if( objc<(pSub->nArg+2) ){ | |
| 370 Tcl_WrongNumArgs(interp, 2, objv, pSub->zUsage); | |
| 371 return TCL_ERROR; | |
| 372 } | |
| 373 | |
| 374 return pSub->xProc(clientData, interp, objc, objv); | |
| 375 } | |
| 376 | |
| 377 /* | |
| 378 ** The [clock_seconds] command. This is more or less the same as the | |
| 379 ** regular tcl [clock seconds], except that it is available in testfixture | |
| 380 ** when linked against both Tcl 8.4 and 8.5. Because [clock seconds] is | |
| 381 ** implemented as a script in Tcl 8.5, it is not usually available to | |
| 382 ** testfixture. | |
| 383 */ | |
| 384 static int clock_seconds_proc( | |
| 385 ClientData clientData, | |
| 386 Tcl_Interp *interp, | |
| 387 int objc, | |
| 388 Tcl_Obj *CONST objv[] | |
| 389 ){ | |
| 390 Tcl_Time now; | |
| 391 Tcl_GetTime(&now); | |
| 392 Tcl_SetObjResult(interp, Tcl_NewIntObj(now.sec)); | |
| 393 UNUSED_PARAMETER(clientData); | |
| 394 UNUSED_PARAMETER(objc); | |
| 395 UNUSED_PARAMETER(objv); | |
| 396 return TCL_OK; | |
| 397 } | |
| 398 | |
| 399 /************************************************************************* | |
| 400 ** This block contains the implementation of the [sqlite3_blocking_step] | |
| 401 ** command available to threads created by [sqlthread spawn] commands. It | |
| 402 ** is only available on UNIX for now. This is because pthread condition | |
| 403 ** variables are used. | |
| 404 ** | |
| 405 ** The source code for the C functions sqlite3_blocking_step(), | |
| 406 ** blocking_step_notify() and the structure UnlockNotification is | |
| 407 ** automatically extracted from this file and used as part of the | |
| 408 ** documentation for the sqlite3_unlock_notify() API function. This | |
| 409 ** should be considered if these functions are to be extended (i.e. to | |
| 410 ** support windows) in the future. | |
| 411 */ | |
| 412 #if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) | |
| 413 | |
| 414 /* BEGIN_SQLITE_BLOCKING_STEP */ | |
| 415 /* This example uses the pthreads API */ | |
| 416 #include <pthread.h> | |
| 417 | |
| 418 /* | |
| 419 ** A pointer to an instance of this structure is passed as the user-context | |
| 420 ** pointer when registering for an unlock-notify callback. | |
| 421 */ | |
| 422 typedef struct UnlockNotification UnlockNotification; | |
| 423 struct UnlockNotification { | |
| 424 int fired; /* True after unlock event has occurred */ | |
| 425 pthread_cond_t cond; /* Condition variable to wait on */ | |
| 426 pthread_mutex_t mutex; /* Mutex to protect structure */ | |
| 427 }; | |
| 428 | |
| 429 /* | |
| 430 ** This function is an unlock-notify callback registered with SQLite. | |
| 431 */ | |
| 432 static void unlock_notify_cb(void **apArg, int nArg){ | |
| 433 int i; | |
| 434 for(i=0; i<nArg; i++){ | |
| 435 UnlockNotification *p = (UnlockNotification *)apArg[i]; | |
| 436 pthread_mutex_lock(&p->mutex); | |
| 437 p->fired = 1; | |
| 438 pthread_cond_signal(&p->cond); | |
| 439 pthread_mutex_unlock(&p->mutex); | |
| 440 } | |
| 441 } | |
| 442 | |
| 443 /* | |
| 444 ** This function assumes that an SQLite API call (either sqlite3_prepare_v2() | |
| 445 ** or sqlite3_step()) has just returned SQLITE_LOCKED. The argument is the | |
| 446 ** associated database connection. | |
| 447 ** | |
| 448 ** This function calls sqlite3_unlock_notify() to register for an | |
| 449 ** unlock-notify callback, then blocks until that callback is delivered | |
| 450 ** and returns SQLITE_OK. The caller should then retry the failed operation. | |
| 451 ** | |
| 452 ** Or, if sqlite3_unlock_notify() indicates that to block would deadlock | |
| 453 ** the system, then this function returns SQLITE_LOCKED immediately. In | |
| 454 ** this case the caller should not retry the operation and should roll | |
| 455 ** back the current transaction (if any). | |
| 456 */ | |
| 457 static int wait_for_unlock_notify(sqlite3 *db){ | |
| 458 int rc; | |
| 459 UnlockNotification un; | |
| 460 | |
| 461 /* Initialize the UnlockNotification structure. */ | |
| 462 un.fired = 0; | |
| 463 pthread_mutex_init(&un.mutex, 0); | |
| 464 pthread_cond_init(&un.cond, 0); | |
| 465 | |
| 466 /* Register for an unlock-notify callback. */ | |
| 467 rc = sqlite3_unlock_notify(db, unlock_notify_cb, (void *)&un); | |
| 468 assert( rc==SQLITE_LOCKED || rc==SQLITE_OK ); | |
| 469 | |
| 470 /* The call to sqlite3_unlock_notify() always returns either SQLITE_LOCKED | |
| 471 ** or SQLITE_OK. | |
| 472 ** | |
| 473 ** If SQLITE_LOCKED was returned, then the system is deadlocked. In this | |
| 474 ** case this function needs to return SQLITE_LOCKED to the caller so | |
| 475 ** that the current transaction can be rolled back. Otherwise, block | |
| 476 ** until the unlock-notify callback is invoked, then return SQLITE_OK. | |
| 477 */ | |
| 478 if( rc==SQLITE_OK ){ | |
| 479 pthread_mutex_lock(&un.mutex); | |
| 480 if( !un.fired ){ | |
| 481 pthread_cond_wait(&un.cond, &un.mutex); | |
| 482 } | |
| 483 pthread_mutex_unlock(&un.mutex); | |
| 484 } | |
| 485 | |
| 486 /* Destroy the mutex and condition variables. */ | |
| 487 pthread_cond_destroy(&un.cond); | |
| 488 pthread_mutex_destroy(&un.mutex); | |
| 489 | |
| 490 return rc; | |
| 491 } | |
| 492 | |
| 493 /* | |
| 494 ** This function is a wrapper around the SQLite function sqlite3_step(). | |
| 495 ** It functions in the same way as step(), except that if a required | |
| 496 ** shared-cache lock cannot be obtained, this function may block waiting for | |
| 497 ** the lock to become available. In this scenario the normal API step() | |
| 498 ** function always returns SQLITE_LOCKED. | |
| 499 ** | |
| 500 ** If this function returns SQLITE_LOCKED, the caller should rollback | |
| 501 ** the current transaction (if any) and try again later. Otherwise, the | |
| 502 ** system may become deadlocked. | |
| 503 */ | |
| 504 int sqlite3_blocking_step(sqlite3_stmt *pStmt){ | |
| 505 int rc; | |
| 506 while( SQLITE_LOCKED==(rc = sqlite3_step(pStmt)) ){ | |
| 507 rc = wait_for_unlock_notify(sqlite3_db_handle(pStmt)); | |
| 508 if( rc!=SQLITE_OK ) break; | |
| 509 sqlite3_reset(pStmt); | |
| 510 } | |
| 511 return rc; | |
| 512 } | |
| 513 | |
| 514 /* | |
| 515 ** This function is a wrapper around the SQLite function sqlite3_prepare_v2(). | |
| 516 ** It functions in the same way as prepare_v2(), except that if a required | |
| 517 ** shared-cache lock cannot be obtained, this function may block waiting for | |
| 518 ** the lock to become available. In this scenario the normal API prepare_v2() | |
| 519 ** function always returns SQLITE_LOCKED. | |
| 520 ** | |
| 521 ** If this function returns SQLITE_LOCKED, the caller should rollback | |
| 522 ** the current transaction (if any) and try again later. Otherwise, the | |
| 523 ** system may become deadlocked. | |
| 524 */ | |
| 525 int sqlite3_blocking_prepare_v2( | |
| 526 sqlite3 *db, /* Database handle. */ | |
| 527 const char *zSql, /* UTF-8 encoded SQL statement. */ | |
| 528 int nSql, /* Length of zSql in bytes. */ | |
| 529 sqlite3_stmt **ppStmt, /* OUT: A pointer to the prepared statement */ | |
| 530 const char **pz /* OUT: End of parsed string */ | |
| 531 ){ | |
| 532 int rc; | |
| 533 while( SQLITE_LOCKED==(rc = sqlite3_prepare_v2(db, zSql, nSql, ppStmt, pz)) ){ | |
| 534 rc = wait_for_unlock_notify(db); | |
| 535 if( rc!=SQLITE_OK ) break; | |
| 536 } | |
| 537 return rc; | |
| 538 } | |
| 539 /* END_SQLITE_BLOCKING_STEP */ | |
| 540 | |
| 541 /* | |
| 542 ** Usage: sqlite3_blocking_step STMT | |
| 543 ** | |
| 544 ** Advance the statement to the next row. | |
| 545 */ | |
| 546 static int blocking_step_proc( | |
| 547 void * clientData, | |
| 548 Tcl_Interp *interp, | |
| 549 int objc, | |
| 550 Tcl_Obj *CONST objv[] | |
| 551 ){ | |
| 552 | |
| 553 sqlite3_stmt *pStmt; | |
| 554 int rc; | |
| 555 | |
| 556 if( objc!=2 ){ | |
| 557 Tcl_WrongNumArgs(interp, 1, objv, "STMT"); | |
| 558 return TCL_ERROR; | |
| 559 } | |
| 560 | |
| 561 pStmt = (sqlite3_stmt*)sqlite3TestTextToPtr(Tcl_GetString(objv[1])); | |
| 562 rc = sqlite3_blocking_step(pStmt); | |
| 563 | |
| 564 Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), 0); | |
| 565 return TCL_OK; | |
| 566 } | |
| 567 | |
| 568 /* | |
| 569 ** Usage: sqlite3_blocking_prepare_v2 DB sql bytes ?tailvar? | |
| 570 ** Usage: sqlite3_nonblocking_prepare_v2 DB sql bytes ?tailvar? | |
| 571 */ | |
| 572 static int blocking_prepare_v2_proc( | |
| 573 void * clientData, | |
| 574 Tcl_Interp *interp, | |
| 575 int objc, | |
| 576 Tcl_Obj *CONST objv[] | |
| 577 ){ | |
| 578 sqlite3 *db; | |
| 579 const char *zSql; | |
| 580 int bytes; | |
| 581 const char *zTail = 0; | |
| 582 sqlite3_stmt *pStmt = 0; | |
| 583 char zBuf[50]; | |
| 584 int rc; | |
| 585 int isBlocking = !(clientData==0); | |
| 586 | |
| 587 if( objc!=5 && objc!=4 ){ | |
| 588 Tcl_AppendResult(interp, "wrong # args: should be \"", | |
| 589 Tcl_GetString(objv[0]), " DB sql bytes tailvar", 0); | |
| 590 return TCL_ERROR; | |
| 591 } | |
| 592 if( getDbPointer(interp, Tcl_GetString(objv[1]), &db) ) return TCL_ERROR; | |
| 593 zSql = Tcl_GetString(objv[2]); | |
| 594 if( Tcl_GetIntFromObj(interp, objv[3], &bytes) ) return TCL_ERROR; | |
| 595 | |
| 596 if( isBlocking ){ | |
| 597 rc = sqlite3_blocking_prepare_v2(db, zSql, bytes, &pStmt, &zTail); | |
| 598 }else{ | |
| 599 rc = sqlite3_prepare_v2(db, zSql, bytes, &pStmt, &zTail); | |
| 600 } | |
| 601 | |
| 602 assert(rc==SQLITE_OK || pStmt==0); | |
| 603 if( zTail && objc>=5 ){ | |
| 604 if( bytes>=0 ){ | |
| 605 bytes = bytes - (zTail-zSql); | |
| 606 } | |
| 607 Tcl_ObjSetVar2(interp, objv[4], 0, Tcl_NewStringObj(zTail, bytes), 0); | |
| 608 } | |
| 609 if( rc!=SQLITE_OK ){ | |
| 610 assert( pStmt==0 ); | |
| 611 sqlite3_snprintf(sizeof(zBuf), zBuf, "%s ", (char *)sqlite3ErrName(rc)); | |
| 612 Tcl_AppendResult(interp, zBuf, sqlite3_errmsg(db), 0); | |
| 613 return TCL_ERROR; | |
| 614 } | |
| 615 | |
| 616 if( pStmt ){ | |
| 617 if( sqlite3TestMakePointerStr(interp, zBuf, pStmt) ) return TCL_ERROR; | |
| 618 Tcl_AppendResult(interp, zBuf, 0); | |
| 619 } | |
| 620 return TCL_OK; | |
| 621 } | |
| 622 | |
| 623 #endif /* SQLITE_OS_UNIX && SQLITE_ENABLE_UNLOCK_NOTIFY */ | |
| 624 /* | |
| 625 ** End of implementation of [sqlite3_blocking_step]. | |
| 626 ************************************************************************/ | |
| 627 | |
| 628 /* | |
| 629 ** Register commands with the TCL interpreter. | |
| 630 */ | |
| 631 int SqlitetestThread_Init(Tcl_Interp *interp){ | |
| 632 Tcl_CreateObjCommand(interp, "sqlthread", sqlthread_proc, 0, 0); | |
| 633 Tcl_CreateObjCommand(interp, "clock_seconds", clock_seconds_proc, 0, 0); | |
| 634 #if SQLITE_OS_UNIX && defined(SQLITE_ENABLE_UNLOCK_NOTIFY) | |
| 635 Tcl_CreateObjCommand(interp, "sqlite3_blocking_step", blocking_step_proc,0,0); | |
| 636 Tcl_CreateObjCommand(interp, | |
| 637 "sqlite3_blocking_prepare_v2", blocking_prepare_v2_proc, (void *)1, 0); | |
| 638 Tcl_CreateObjCommand(interp, | |
| 639 "sqlite3_nonblocking_prepare_v2", blocking_prepare_v2_proc, 0, 0); | |
| 640 #endif | |
| 641 return TCL_OK; | |
| 642 } | |
| 643 #else | |
| 644 int SqlitetestThread_Init(Tcl_Interp *interp){ | |
| 645 return TCL_OK; | |
| 646 } | |
| 647 #endif | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 2846743003:
[sql] Remove SQLite 3.10.2 reference directory. (Closed)
