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/* Internal definitions for pthreads library.
Copyright (C) 2016-2019 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C 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 2.1 of the License, or (at your option) any later version.
The GNU C 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 the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#ifndef _PT_MUTEX_H
#define _PT_MUTEX_H 1
/* Special ID used to signal an unrecoverable robust mutex. */
#define NOTRECOVERABLE_ID (1U << 31)
/* Common path for robust mutexes. Assumes the variable 'ret'
* is bound in the function this is called from. */
#define ROBUST_LOCK(self, mtxp, cb, ...) \
if (mtxp->__owner_id == NOTRECOVERABLE_ID) \
return ENOTRECOVERABLE; \
else if (mtxp->__owner_id == self->thread \
&& __getpid () == (int)(mtxp->__lock & LLL_OWNER_MASK)) \
{ \
if (mtxp->__type == PT_MTX_RECURSIVE) \
{ \
if (__glibc_unlikely (mtxp->__cnt + 1 == 0)) \
return EAGAIN; \
\
++mtxp->__cnt; \
return 0; \
} \
else if (mtxp->__type == PT_MTX_ERRORCHECK) \
return EDEADLK; \
} \
\
ret = cb (&mtxp->__lock, ##__VA_ARGS__); \
if (ret == 0 || ret == EOWNERDEAD) \
{ \
if (mtxp->__owner_id == ENOTRECOVERABLE) \
ret = ENOTRECOVERABLE; \
else \
{ \
mtxp->__owner_id = self->thread; \
mtxp->__cnt = 1; \
if (ret == EOWNERDEAD) \
{ \
mtxp->__lock = mtxp->__lock | LLL_DEAD_OWNER; \
atomic_write_barrier (); \
} \
} \
} \
(void)0
/* Check that a thread owns the mutex. For non-robust, task-shared
* objects, we have to check the thread *and* process-id. */
#define mtx_owned_p(mtx, pt, flags) \
((mtx)->__owner_id == (pt)->thread \
&& (((flags) & GSYNC_SHARED) == 0 \
|| (mtx)->__shpid == __getpid ()))
/* Record a thread as the owner of the mutex. */
#define mtx_set_owner(mtx, pt, flags) \
(void) \
({ \
(mtx)->__owner_id = (pt)->thread; \
if ((flags) & GSYNC_SHARED) \
(mtx)->__shpid = __getpid (); \
})
/* Redefined mutex types. The +1 is for binary compatibility. */
#define PT_MTX_NORMAL __PTHREAD_MUTEX_TIMED
#define PT_MTX_RECURSIVE (__PTHREAD_MUTEX_RECURSIVE + 1)
#define PT_MTX_ERRORCHECK (__PTHREAD_MUTEX_ERRORCHECK + 1)
/* Mutex type, including robustness. */
#define MTX_TYPE(mtxp) \
((mtxp)->__type | ((mtxp)->__flags & PTHREAD_MUTEX_ROBUST))
extern int __getpid (void) __attribute__ ((const));
#endif /* pt-mutex.h */
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