Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | Re-integrate the recent changes from the 'winMutex' branch back into the Win32 mutex subsystem. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
5360ecb0b8891d0c27f3f02d81b6c7b5 |
User & Date: | mistachkin 2014-07-30 23:11:16.516 |
Context
2014-07-31
| ||
15:44 | Deactivate the DISTINCT in a SELECT on the right-hand side of an IN operator, since it should not make any difference in the output but dues consume extra memory and CPU time. (check-in: f4cb53651b user: drh tags: trunk) | |
2014-07-30
| ||
23:11 | Re-integrate the recent changes from the 'winMutex' branch back into the Win32 mutex subsystem. (check-in: 5360ecb0b8 user: mistachkin tags: trunk) | |
21:10 | Add three new static mutexes for use by the application. This is a partial import of changes from the threads branch. (check-in: 3aad01960f user: drh tags: trunk) | |
Changes
Changes to src/mutex_w32.c.
1 2 3 4 5 6 7 8 9 10 11 | /* ** 2007 August 14 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* | | > > > > > | | < < < < < < < < < < < < < < > > | < < < < < < > | | | > < < < < < < < < < < | > > | < > > | | | < > | > | | | | | | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 | /* ** 2007 August 14 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** This file contains the C functions that implement mutexes for Win32. */ #include "sqliteInt.h" #if SQLITE_OS_WIN /* ** Include code that is common to all os_*.c files */ #include "os_common.h" /* ** Include the header file for the Windows VFS. */ #include "os_win.h" #endif /* ** The code in this file is only used if we are compiling multithreaded ** on a Win32 system. */ #ifdef SQLITE_MUTEX_W32 /* ** Each recursive mutex is an instance of the following structure. */ struct sqlite3_mutex { CRITICAL_SECTION mutex; /* Mutex controlling the lock */ int id; /* Mutex type */ #ifdef SQLITE_DEBUG volatile int nRef; /* Number of enterances */ volatile DWORD owner; /* Thread holding this mutex */ volatile int trace; /* True to trace changes */ #endif }; /* ** These are the initializer values used when declaring a "static" mutex ** on Win32. It should be noted that all mutexes require initialization ** on the Win32 platform. */ #define SQLITE_W32_MUTEX_INITIALIZER { 0 } #ifdef SQLITE_DEBUG #define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0, \ 0L, (DWORD)0, 0 } #else #define SQLITE3_MUTEX_INITIALIZER { SQLITE_W32_MUTEX_INITIALIZER, 0 } #endif #ifdef SQLITE_DEBUG /* ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routine are ** intended for use only inside assert() statements. */ static int winMutexHeld(sqlite3_mutex *p){ return p->nRef!=0 && p->owner==GetCurrentThreadId(); } static int winMutexNotheld2(sqlite3_mutex *p, DWORD tid){ return p->nRef==0 || p->owner!=tid; } static int winMutexNotheld(sqlite3_mutex *p){ DWORD tid = GetCurrentThreadId(); return winMutexNotheld2(p, tid); } #endif /* ** Initialize and deinitialize the mutex subsystem. */ static sqlite3_mutex winMutex_staticMutexes[] = { SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER, SQLITE3_MUTEX_INITIALIZER }; static int winMutex_isInit = 0; /* As the winMutexInit() and winMutexEnd() functions are called as part ** of the sqlite3_initialize() and sqlite3_shutdown() processing, the ** "interlocked" magic used here is probably not strictly necessary. */ static LONG winMutex_lock = 0; int sqlite3_win32_is_nt(void); /* os_win.c */ void sqlite3_win32_sleep(DWORD milliseconds); /* os_win.c */ static int winMutexInit(void){ /* The first to increment to 1 does actual initialization */ if( InterlockedCompareExchange(&winMutex_lock, 1, 0)==0 ){ int i; for(i=0; i<ArraySize(winMutex_staticMutexes); i++){ #if SQLITE_OS_WINRT InitializeCriticalSectionEx(&winMutex_staticMutexes[i].mutex, 0, 0); #else InitializeCriticalSection(&winMutex_staticMutexes[i].mutex); #endif } winMutex_isInit = 1; }else{ /* Another thread is (in the process of) initializing the static ** mutexes */ while( !winMutex_isInit ){ sqlite3_win32_sleep(1); } } return SQLITE_OK; } static int winMutexEnd(void){ /* The first to decrement to 0 does actual shutdown ** (which should be the last to shutdown.) */ if( InterlockedCompareExchange(&winMutex_lock, 0, 1)==1 ){ if( winMutex_isInit==1 ){ int i; for(i=0; i<ArraySize(winMutex_staticMutexes); i++){ DeleteCriticalSection(&winMutex_staticMutexes[i].mutex); } winMutex_isInit = 0; } } return SQLITE_OK; } /* ** The sqlite3_mutex_alloc() routine allocates a new ** mutex and returns a pointer to it. If it returns NULL ** that means that a mutex could not be allocated. SQLite ** will unwind its stack and return an error. The argument |
︙ | ︙ | |||
194 195 196 197 198 199 200 | ** may add additional static mutexes. Static mutexes are for internal ** use by SQLite only. Applications that use SQLite mutexes should ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or ** SQLITE_MUTEX_RECURSIVE. ** ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() | | | > > > < > > > > > > | | > > > > > | > | > | | > | | | > > | > | | > > > > | | 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 | ** may add additional static mutexes. Static mutexes are for internal ** use by SQLite only. Applications that use SQLite mutexes should ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or ** SQLITE_MUTEX_RECURSIVE. ** ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() ** returns a different mutex on every call. But for the static ** mutex types, the same mutex is returned on every call that has ** the same type number. */ static sqlite3_mutex *winMutexAlloc(int iType){ sqlite3_mutex *p; switch( iType ){ case SQLITE_MUTEX_FAST: case SQLITE_MUTEX_RECURSIVE: { p = sqlite3MallocZero( sizeof(*p) ); if( p ){ #ifdef SQLITE_DEBUG p->id = iType; #ifdef SQLITE_WIN32_MUTEX_TRACE_DYNAMIC p->trace = 1; #endif #endif #if SQLITE_OS_WINRT InitializeCriticalSectionEx(&p->mutex, 0, 0); #else InitializeCriticalSection(&p->mutex); #endif } break; } default: { assert( iType-2 >= 0 ); assert( iType-2 < ArraySize(winMutex_staticMutexes) ); assert( winMutex_isInit==1 ); p = &winMutex_staticMutexes[iType-2]; #ifdef SQLITE_DEBUG p->id = iType; #ifdef SQLITE_WIN32_MUTEX_TRACE_STATIC p->trace = 1; #endif #endif break; } } return p; } /* ** This routine deallocates a previously ** allocated mutex. SQLite is careful to deallocate every ** mutex that it allocates. */ static void winMutexFree(sqlite3_mutex *p){ assert( p ); #ifdef SQLITE_DEBUG assert( p->nRef==0 && p->owner==0 ); assert( p->id==SQLITE_MUTEX_FAST || p->id==SQLITE_MUTEX_RECURSIVE ); #endif assert( winMutex_isInit==1 ); DeleteCriticalSection(&p->mutex); sqlite3_free(p); } /* ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt ** to enter a mutex. If another thread is already within the mutex, ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return ** SQLITE_BUSY. The sqlite3_mutex_try() interface returns SQLITE_OK ** upon successful entry. Mutexes created using SQLITE_MUTEX_RECURSIVE can ** be entered multiple times by the same thread. In such cases the, ** mutex must be exited an equal number of times before another thread ** can enter. If the same thread tries to enter any other kind of mutex ** more than once, the behavior is undefined. */ static void winMutexEnter(sqlite3_mutex *p){ #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) DWORD tid = GetCurrentThreadId(); #endif #ifdef SQLITE_DEBUG assert( p ); assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) ); #else assert( p ); #endif assert( winMutex_isInit==1 ); EnterCriticalSection(&p->mutex); #ifdef SQLITE_DEBUG assert( p->nRef>0 || p->owner==0 ); p->owner = tid; p->nRef++; if( p->trace ){ OSTRACE(("ENTER-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n", tid, p, p->trace, p->nRef)); } #endif } static int winMutexTry(sqlite3_mutex *p){ #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) DWORD tid = GetCurrentThreadId(); #endif int rc = SQLITE_BUSY; assert( p ); assert( p->id==SQLITE_MUTEX_RECURSIVE || winMutexNotheld2(p, tid) ); /* ** The sqlite3_mutex_try() routine is very rarely used, and when it ** is used it is merely an optimization. So it is OK for it to always ** fail. ** ** The TryEnterCriticalSection() interface is only available on WinNT. ** And some windows compilers complain if you try to use it without ** first doing some #defines that prevent SQLite from building on Win98. ** For that reason, we will omit this optimization for now. See ** ticket #2685. */ #if defined(_WIN32_WINNT) && _WIN32_WINNT >= 0x0400 assert( winMutex_isInit==1 ); if( sqlite3_win32_is_nt() && TryEnterCriticalSection(&p->mutex) ){ #ifdef SQLITE_DEBUG p->owner = tid; p->nRef++; #endif rc = SQLITE_OK; } #else UNUSED_PARAMETER(p); #endif #ifdef SQLITE_DEBUG if( p->trace ){ OSTRACE(("TRY-MUTEX tid=%lu, mutex=%p (%d), owner=%lu, nRef=%d, rc=%s\n", tid, p, p->trace, p->owner, p->nRef, sqlite3ErrName(rc))); } #endif return rc; } /* ** The sqlite3_mutex_leave() routine exits a mutex that was ** previously entered by the same thread. The behavior ** is undefined if the mutex is not currently entered or ** is not currently allocated. SQLite will never do either. */ static void winMutexLeave(sqlite3_mutex *p){ #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST) DWORD tid = GetCurrentThreadId(); #endif assert( p ); #ifdef SQLITE_DEBUG assert( p->nRef>0 ); assert( p->owner==tid ); p->nRef--; if( p->nRef==0 ) p->owner = 0; assert( p->nRef==0 || p->id==SQLITE_MUTEX_RECURSIVE ); #endif assert( winMutex_isInit==1 ); LeaveCriticalSection(&p->mutex); #ifdef SQLITE_DEBUG if( p->trace ){ OSTRACE(("LEAVE-MUTEX tid=%lu, mutex=%p (%d), nRef=%d\n", tid, p, p->trace, p->nRef)); } #endif } sqlite3_mutex_methods const *sqlite3DefaultMutex(void){ static const sqlite3_mutex_methods sMutex = { winMutexInit, |
︙ | ︙ | |||
349 350 351 352 353 354 355 | winMutexHeld, winMutexNotheld #else 0, 0 #endif }; | < > | 355 356 357 358 359 360 361 362 363 364 365 | winMutexHeld, winMutexNotheld #else 0, 0 #endif }; return &sMutex; } #endif /* SQLITE_MUTEX_W32 */ |