From 5b085e54a51322522ce8d38d3139228f035a9bf4 Mon Sep 17 00:00:00 2001 From: rpj Date: Mon, 11 Apr 2005 07:27:56 +0000 Subject: pthread_once post-cancel starvation solution --- tests/once4.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 tests/once4.c (limited to 'tests/once4.c') diff --git a/tests/once4.c b/tests/once4.c new file mode 100644 index 0000000..980c9fe --- /dev/null +++ b/tests/once4.c @@ -0,0 +1,186 @@ +/* + * once4.c + * + * + * -------------------------------------------------------------------------- + * + * Pthreads-win32 - POSIX Threads Library for Win32 + * Copyright(C) 1998 John E. Bossom + * Copyright(C) 1999,2005 Pthreads-win32 contributors + * + * Contact Email: rpj@callisto.canberra.edu.au + * + * The current list of contributors is contained + * in the file CONTRIBUTORS included with the source + * code distribution. The list can also be seen at the + * following World Wide Web location: + * http://sources.redhat.com/pthreads-win32/contributors.html + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library in the file COPYING.LIB; + * if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + * + * -------------------------------------------------------------------------- + * + * Create several pthread_once objects and channel several threads + * through each. Make the init_routine cancelable and cancel them + * waiters waiting. Vary the priorities. + * + * Depends on API functions: + * pthread_once() + * pthread_create() + * pthread_testcancel() + * pthread_cancel() + * pthread_once() + */ + +#include "test.h" + +#define NUM_THREADS 100 /* Targeting each once control */ +#define NUM_ONCE 10 + +pthread_once_t o = PTHREAD_ONCE_INIT; +pthread_once_t once[NUM_ONCE]; + +typedef struct { + int i; + CRITICAL_SECTION cs; +} sharedInt_t; + +static sharedInt_t numOnce = {0, {0}}; +static sharedInt_t numThreads = {0, {0}}; + +typedef struct { + int threadnum; + int oncenum; + int myPrio; + HANDLE w32Thread; +} bag_t; + +static bag_t threadbag[NUM_THREADS][NUM_ONCE]; + +CRITICAL_SECTION print_lock; + +void +mycleanupfunc(void * arg) +{ + bag_t * bag = (bag_t *) arg; + EnterCriticalSection(&print_lock); + /* once thrd prio error */ + printf("%4d %4d %4d %4d\n", + bag->oncenum, + bag->threadnum, + bag->myPrio, + bag->myPrio - GetThreadPriority(bag->w32Thread)); + LeaveCriticalSection(&print_lock); +} + +void +myinitfunc(void) +{ + EnterCriticalSection(&numOnce.cs); + numOnce.i++; + LeaveCriticalSection(&numOnce.cs); + /* Simulate slow once routine so that following threads pile up behind it */ + Sleep(10); + /* test for cancelation late so we're sure to have waiters. */ + pthread_testcancel(); +} + +void * +mythread(void * arg) +{ + bag_t * bag = (bag_t *) arg; + struct sched_param param; + + /* + * Cancel every thread. These threads are deferred cancelable only, so + * only the thread performing the init_routine will see it (there are + * no other cancelation points here). The result will be that every thread + * eventually cancels only when it becomes the new initter. + */ + pthread_t self = pthread_self(); + bag->w32Thread = pthread_getw32threadhandle_np(self); + /* + * Set priority between -2 and 2 inclusive. + */ + bag->myPrio = (bag->threadnum % 5) - 2; + param.sched_priority = bag->myPrio; + pthread_setschedparam(self, SCHED_OTHER, ¶m); + + /* Trigger a cancellation at the next cancellation point in this thread */ + pthread_cancel(self); +#if 0 + pthread_cleanup_push(mycleanupfunc, arg); + assert(pthread_once(&once[bag->oncenum], myinitfunc) == 0); + pthread_cleanup_pop(1); +#else + assert(pthread_once(&once[bag->oncenum], myinitfunc) == 0); +#endif + EnterCriticalSection(&numThreads.cs); + numThreads.i++; + LeaveCriticalSection(&numThreads.cs); + return 0; +} + +int +main() +{ + pthread_t t[NUM_THREADS][NUM_ONCE]; + int i, j; + + InitializeCriticalSection(&print_lock); + InitializeCriticalSection(&numThreads.cs); + InitializeCriticalSection(&numOnce.cs); + +#if 0 + /* once thrd prio change */ + printf("once thrd prio error\n"); +#endif + + /* Set main thread to lower prio than threads */ + SetThreadPriority(GetCurrentThread(), -2); + + for (j = 0; j < NUM_ONCE; j++) + { + once[j] = o; + + for (i = 0; i < NUM_THREADS; i++) + { + bag_t * bag = &threadbag[i][j]; + bag->threadnum = i; + bag->oncenum = j; + assert(pthread_create(&t[i][j], NULL, mythread, (void *) bag) == 0); + } + } + + for (j = 0; j < NUM_ONCE; j++) + for (i = 0; i < NUM_THREADS; i++) + if (pthread_join(t[i][j], NULL) != 0) + printf("Join failed for [thread,once] = [%d,%d]\n", i, j); + + /* + * All threads will cancel, none will return normally from + * pthread_once and so numThreads should never be incremented. However, + * numOnce should be incremented by every thread (NUM_THREADS*NUM_ONCE). + */ + assert(numOnce.i == NUM_ONCE * NUM_THREADS); + assert(numThreads.i == 0); + + DeleteCriticalSection(&numOnce.cs); + DeleteCriticalSection(&numThreads.cs); + DeleteCriticalSection(&print_lock); + + return 0; +} -- cgit v1.2.3