15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ptw32_threadReuse.c 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Description: 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This translation unit implements miscellaneous thread functions. 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * -------------------------------------------------------------------------- 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Pthreads-win32 - POSIX Threads Library for Win32 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright(C) 1998 John E. Bossom 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Copyright(C) 1999,2005 Pthreads-win32 contributors 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Contact Email: rpj@callisto.canberra.edu.au 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The current list of contributors is contained 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * in the file CONTRIBUTORS included with the source 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * code distribution. The list can also be seen at the 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * following World Wide Web location: 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * http://sources.redhat.com/pthreads-win32/contributors.html 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This library is free software; you can redistribute it and/or 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * modify it under the terms of the GNU Lesser General Public 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * License as published by the Free Software Foundation; either 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * version 2 of the License, or (at your option) any later version. 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This library is distributed in the hope that it will be useful, 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * but WITHOUT ANY WARRANTY; without even the implied warranty of 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Lesser General Public License for more details. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * You should have received a copy of the GNU Lesser General Public 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * License along with this library in the file COPYING.LIB; 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * if not, write to the Free Software Foundation, Inc., 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "pthread.h" 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "implement.h" 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * How it works: 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * A pthread_t is a struct (2x32 bit scalar types on IA-32, 2x64 bit on IA-64) 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * which is normally passed/returned by value to/from pthreads routines. 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Applications are therefore storing a copy of the struct as it is at that 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * time. 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The original pthread_t struct plus all copies of it contain the address of 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * the thread state struct ptw32_thread_t_ (p), plus a reuse counter (x). Each 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * ptw32_thread_t contains the original copy of it's pthread_t. 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Once malloced, a ptw32_thread_t_ struct is not freed until the process exits. 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The thread reuse stack is a simple LILO stack managed through a singly 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * linked list element in the ptw32_thread_t. 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Each time a thread is destroyed, the ptw32_thread_t address is pushed onto the 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * reuse stack after it's ptHandle's reuse counter has been incremented. 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The following can now be said from this: 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - two pthread_t's are identical if their ptw32_thread_t reference pointers 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * are equal and their reuse counters are equal. That is, 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * equal = (a.p == b.p && a.x == b.x) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * - a pthread_t copy refers to a destroyed thread if the reuse counter in 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * the copy is not equal to the reuse counter in the original. 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * threadDestroyed = (copy.x != ((ptw32_thread_t *)copy.p)->ptHandle.x) 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Pop a clean pthread_t struct off the reuse stack. 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)pthread_t 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ptw32_threadReusePop (void) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles){ 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_t t = {NULL, 0}; 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_local_node_t node; 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_acquire(&ptw32_thread_reuse_lock, &node); 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (PTW32_THREAD_REUSE_EMPTY != ptw32_threadReuseTop) 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_thread_t * tp; 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp = ptw32_threadReuseTop; 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_threadReuseTop = tp->prevReuse; 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (PTW32_THREAD_REUSE_EMPTY == ptw32_threadReuseTop) 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_threadReuseBottom = PTW32_THREAD_REUSE_EMPTY; 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp->prevReuse = NULL; 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) t = tp->ptHandle; 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_release(&node); 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return t; 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/* 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Push a clean pthread_t struct onto the reuse stack. 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * Must be re-initialised when reused. 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * All object elements (mutexes, events etc) must have been either 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * detroyed before this, or never initialised. 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)ptw32_threadReusePush (pthread_t thread) 1155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles){ 1165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_thread_t * tp = (ptw32_thread_t *) thread.p; 1175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) pthread_t t; 1185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_local_node_t node; 1195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_acquire(&ptw32_thread_reuse_lock, &node); 1215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) t = tp->ptHandle; 1235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) memset(tp, 0, sizeof(ptw32_thread_t)); 1245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* Must restore the original POSIX handle that we just wiped. */ 1265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp->ptHandle = t; 1275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) /* Bump the reuse counter now */ 1295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#if defined(PTW32_THREAD_ID_REUSE_INCREMENT) 1305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp->ptHandle.x += PTW32_THREAD_ID_REUSE_INCREMENT; 1315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#else 1325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp->ptHandle.x++; 1335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif 1345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp->state = PThreadStateReuse; 1365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) tp->prevReuse = PTW32_THREAD_REUSE_EMPTY; 1385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (PTW32_THREAD_REUSE_EMPTY != ptw32_threadReuseBottom) 1405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_threadReuseBottom->prevReuse = tp; 1425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) else 1445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) { 1455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_threadReuseTop = tp; 1465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 1475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_threadReuseBottom = tp; 1495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ptw32_mcs_lock_release(&node); 1515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 152