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68 lines
2.2 KiB
C
68 lines
2.2 KiB
C
/* Out-of-line notification function for the GSCOPE locking mechanism.
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Copyright (C) 2007-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <ldsodefs.h>
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#include <pthread.h>
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#include <htl/pt-internal.h>
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static inline int *
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thread_gscope_flag (struct __pthread *t)
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{
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#if TLS_TCB_AT_TP
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return &t->tcb->gscope_flag;
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#elif TLS_DTV_AT_TP
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return &((tcbprehead_t *) t->tcb - 1)->gscope_flag;
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#else
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# error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
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#endif
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}
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void
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__thread_gscope_wait (void)
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{
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size_t i;
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struct __pthread *t;
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int *gscope_flagp;
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__libc_rwlock_rdlock (GL (dl_pthread_threads_lock));
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/* Iterate over the list of threads. */
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for (i = 0; i < GL (dl_pthread_num_threads); ++i)
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{
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t = GL (dl_pthread_threads[i]);
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if (t == NULL || *thread_gscope_flag (t) == THREAD_GSCOPE_FLAG_UNUSED)
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continue;
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gscope_flagp = thread_gscope_flag (t);
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/* We have to wait until this thread is done with the global
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scope. First tell the thread that we are waiting and
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possibly have to be woken. */
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if (atomic_compare_and_exchange_bool_acq (gscope_flagp,
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THREAD_GSCOPE_FLAG_WAIT,
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THREAD_GSCOPE_FLAG_USED))
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continue;
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do
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lll_wait (gscope_flagp, THREAD_GSCOPE_FLAG_WAIT, LLL_PRIVATE);
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while (*gscope_flagp == THREAD_GSCOPE_FLAG_WAIT);
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}
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__libc_rwlock_unlock (GL (dl_pthread_threads_lock));
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}
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