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pthread_int.h revision 1.82.2.1
      1 /*	$NetBSD: pthread_int.h,v 1.82.2.1 2012/11/28 23:58:35 riz Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Nathan J. Williams and Andrew Doran.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 /*
     33  * NOTE: when changing anything in this file, please ensure that
     34  * libpthread_dbg still compiles.
     35  */
     36 
     37 #ifndef _LIB_PTHREAD_INT_H
     38 #define _LIB_PTHREAD_INT_H
     39 
     40 #include <sys/tls.h>
     41 
     42 /* #define PTHREAD__DEBUG */
     43 #define ERRORCHECK
     44 
     45 #include "pthread_types.h"
     46 #include "pthread_queue.h"
     47 #include "pthread_md.h"
     48 
     49 /* Need to use libc-private names for atomic operations. */
     50 #include "../../common/lib/libc/atomic/atomic_op_namespace.h"
     51 
     52 #include <sys/atomic.h>
     53 #include <sys/tree.h>
     54 
     55 #include <lwp.h>
     56 #include <signal.h>
     57 #include <limits.h>
     58 
     59 #ifdef __GNUC__
     60 #define	PTHREAD_HIDE	__attribute__ ((visibility("hidden")))
     61 #else
     62 #define	PTHREAD_HIDE	/* nothing */
     63 #endif
     64 
     65 #define	PTHREAD__UNPARK_MAX	32
     66 
     67 /*
     68  * The size of this structure needs to be no larger than struct
     69  * __pthread_cleanup_store, defined in pthread.h.
     70  */
     71 struct pt_clean_t {
     72 	PTQ_ENTRY(pt_clean_t)	ptc_next;
     73 	void	(*ptc_cleanup)(void *);
     74 	void	*ptc_arg;
     75 };
     76 
     77 /* Private data for pthread_attr_t */
     78 struct pthread_attr_private {
     79 	char ptap_name[PTHREAD_MAX_NAMELEN_NP];
     80 	void *ptap_namearg;
     81 	void *ptap_stackaddr;
     82 	size_t ptap_stacksize;
     83 	size_t ptap_guardsize;
     84 	struct sched_param ptap_sp;
     85 	int ptap_policy;
     86 };
     87 
     88 struct pthread_lock_ops {
     89 	void	(*plo_init)(__cpu_simple_lock_t *);
     90 	int	(*plo_try)(__cpu_simple_lock_t *);
     91 	void	(*plo_unlock)(__cpu_simple_lock_t *);
     92 	void	(*plo_lock)(__cpu_simple_lock_t *);
     93 };
     94 
     95 struct	__pthread_st {
     96 	pthread_t	pt_self;	/* Must be first. */
     97 #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
     98 	struct tls_tcb	*pt_tls;	/* Thread Local Storage area */
     99 #endif
    100 	unsigned int	pt_magic;	/* Magic number */
    101 	int		pt_state;	/* running, blocked, etc. */
    102 	pthread_mutex_t	pt_lock;	/* lock on state */
    103 	int		pt_flags;	/* see PT_FLAG_* below */
    104 	int		pt_cancel;	/* Deferred cancellation */
    105 	int		pt_errno;	/* Thread-specific errno. */
    106 	stack_t		pt_stack;	/* Our stack */
    107 	void		*pt_exitval;	/* Read by pthread_join() */
    108 	char		*pt_name;	/* Thread's name, set by the app. */
    109 	int		pt_willpark;	/* About to park */
    110 	lwpid_t		pt_unpark;	/* Unpark this when parking */
    111 	struct pthread_lock_ops pt_lockops;/* Cached to avoid PIC overhead */
    112 	pthread_mutex_t	*pt_droplock;	/* Drop this lock if cancelled */
    113 	pthread_cond_t	pt_joiners;	/* Threads waiting to join. */
    114 	void		*(*pt_func)(void *);/* Function to call at start. */
    115 	void		*pt_arg;	/* Argument to pass at start. */
    116 
    117 	/* Threads to defer waking, usually until pthread_mutex_unlock(). */
    118 	lwpid_t		pt_waiters[PTHREAD__UNPARK_MAX];
    119 	size_t		pt_nwaiters;
    120 
    121 	/* Stack of cancellation cleanup handlers and their arguments */
    122 	PTQ_HEAD(, pt_clean_t)	pt_cleanup_stack;
    123 
    124 	/* LWP ID and entry on the list of all threads. */
    125 	lwpid_t		pt_lid;
    126 	RB_ENTRY(__pthread_st) pt_alltree;
    127 	PTQ_ENTRY(__pthread_st) pt_allq;
    128 	PTQ_ENTRY(__pthread_st)	pt_deadq;
    129 
    130 	/*
    131 	 * General synchronization data.  We try to align, as threads
    132 	 * on other CPUs will access this data frequently.
    133 	 */
    134 	int		pt_dummy1 __aligned(128);
    135 	struct lwpctl 	*pt_lwpctl;	/* Kernel/user comms area */
    136 	volatile int	pt_blocking;	/* Blocking in userspace */
    137 	volatile int	pt_rwlocked;	/* Handed rwlock successfully */
    138 	volatile int	pt_signalled;	/* Received pthread_cond_signal() */
    139 	volatile int	pt_mutexwait;	/* Waiting to acquire mutex */
    140 	void * volatile pt_mutexnext;	/* Next thread in chain */
    141 	void * volatile	pt_sleepobj;	/* Object slept on */
    142 	PTQ_ENTRY(__pthread_st) pt_sleep;
    143 	void		(*pt_early)(void *);
    144 	int		pt_dummy2 __aligned(128);
    145 
    146 	/* Thread-specific data.  Large so it sits close to the end. */
    147 	int		pt_havespecific;
    148 	struct pt_specific {
    149 		void *pts_value;
    150 		PTQ_ENTRY(pt_specific) pts_next;
    151 	} pt_specific[PTHREAD_KEYS_MAX];
    152 
    153 	/*
    154 	 * Context for thread creation.  At the end as it's cached
    155 	 * and then only ever passed to _lwp_create().
    156 	 */
    157 	ucontext_t	pt_uc;
    158 };
    159 
    160 /* Thread states */
    161 #define PT_STATE_RUNNING	1
    162 #define PT_STATE_ZOMBIE		5
    163 #define PT_STATE_DEAD		6
    164 
    165 /* Flag values */
    166 
    167 #define PT_FLAG_DETACHED	0x0001
    168 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
    169 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
    170 #define PT_FLAG_CS_PENDING	0x0010
    171 #define PT_FLAG_SCOPE_SYSTEM	0x0040
    172 #define PT_FLAG_EXPLICIT_SCHED	0x0080
    173 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
    174 
    175 #define PT_MAGIC	0x11110001
    176 #define PT_DEAD		0xDEAD0001
    177 
    178 #define PT_ATTR_MAGIC	0x22220002
    179 #define PT_ATTR_DEAD	0xDEAD0002
    180 
    181 extern int	pthread__stacksize_lg;
    182 extern size_t	pthread__stacksize;
    183 extern vaddr_t	pthread__stackmask;
    184 extern vaddr_t	pthread__threadmask;
    185 extern int	pthread__nspins;
    186 extern int	pthread__concurrency;
    187 extern int 	pthread__osrev;
    188 extern int 	pthread__unpark_max;
    189 
    190 /* Flag to be used in a ucontext_t's uc_flags indicating that
    191  * the saved register state is "user" state only, not full
    192  * trap state.
    193  */
    194 #define _UC_USER_BIT		30
    195 #define _UC_USER		(1LU << _UC_USER_BIT)
    196 
    197 /* Utility functions */
    198 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    199     PTHREAD_HIDE;
    200 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    201     PTHREAD_HIDE;
    202 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
    203 		      const struct timespec *, int, const void *)
    204 		      PTHREAD_HIDE;
    205 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
    206 
    207 /* Internal locking primitives */
    208 void	pthread__lockprim_init(void) PTHREAD_HIDE;
    209 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
    210 
    211 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
    212     __attribute__((__always_inline__));
    213 static inline void
    214 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
    215 {
    216 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
    217 		return;
    218 	(*self->pt_lockops.plo_lock)(lock);
    219 }
    220 
    221 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
    222     __attribute__((__always_inline__));
    223 static inline int
    224 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
    225 {
    226 	return (*self->pt_lockops.plo_try)(lock);
    227 }
    228 
    229 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
    230     __attribute__((__always_inline__));
    231 static inline void
    232 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
    233 {
    234 	(*self->pt_lockops.plo_unlock)(lock);
    235 }
    236 
    237 extern const struct pthread_lock_ops *pthread__lock_ops;
    238 
    239 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
    240 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
    241 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
    242 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
    243 
    244 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
    245 int	pthread__find(pthread_t) PTHREAD_HIDE;
    246 
    247 #ifndef PTHREAD_MD_INIT
    248 #define PTHREAD_MD_INIT
    249 #endif
    250 
    251 #ifndef _INITCONTEXT_U_MD
    252 #define _INITCONTEXT_U_MD(ucp)
    253 #endif
    254 
    255 #define _INITCONTEXT_U(ucp) do {					\
    256 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
    257 	_INITCONTEXT_U_MD(ucp)						\
    258 	} while (/*CONSTCOND*/0)
    259 
    260 
    261 #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
    262 static inline pthread_t __constfunc
    263 pthread__self(void)
    264 {
    265 #ifdef __HAVE___LWP_GETTCB_FAST
    266 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
    267 #else
    268 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
    269 #endif
    270 	return (pthread_t)tcb->tcb_pthread;
    271 }
    272 #else
    273 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
    274 #endif
    275 
    276 #define pthread__abort()						\
    277 	pthread__assertfunc(__FILE__, __LINE__, __func__, "unreachable")
    278 
    279 #define pthread__assert(e) do {						\
    280 	if (__predict_false(!(e)))					\
    281        	       pthread__assertfunc(__FILE__, __LINE__, __func__, #e);	\
    282         } while (/*CONSTCOND*/0)
    283 
    284 #define pthread__error(err, msg, e) do {				\
    285 	if (__predict_false(!(e))) {					\
    286        	       pthread__errorfunc(__FILE__, __LINE__, __func__, msg);	\
    287 	       return (err);						\
    288 	} 								\
    289         } while (/*CONSTCOND*/0)
    290 
    291 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
    292 __dead void	pthread__assertfunc(const char *, int, const char *, const char *)
    293 			    PTHREAD_HIDE;
    294 void	pthread__errorfunc(const char *, int, const char *, const char *)
    295 			   PTHREAD_HIDE;
    296 char	*pthread__getenv(const char *) PTHREAD_HIDE;
    297 __dead void	pthread__cancelled(void) PTHREAD_HIDE;
    298 void	pthread__mutex_deferwake(pthread_t, pthread_mutex_t *) PTHREAD_HIDE;
    299 int	pthread__checkpri(int) PTHREAD_HIDE;
    300 int	pthread__add_specific(pthread_t, pthread_key_t, const void *) PTHREAD_HIDE;
    301 
    302 #ifndef pthread__smt_pause
    303 #define	pthread__smt_pause()	/* nothing */
    304 #endif
    305 
    306 /*
    307  * Bits in the owner field of the lock that indicate lock state.  If the
    308  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
    309  * the number of readers.
    310  */
    311 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
    312 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
    313 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
    314 #define	RW_UNUSED		0x08	/* currently unused */
    315 
    316 #define	RW_FLAGMASK		0x0f
    317 
    318 #define	RW_READ_COUNT_SHIFT	4
    319 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
    320 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
    321 #define	RW_OWNER(rw)		((rw)->rw_owner & RW_THREAD)
    322 #define	RW_COUNT(rw)		((rw)->rw_owner & RW_THREAD)
    323 #define	RW_FLAGS(rw)		((rw)->rw_owner & ~RW_THREAD)
    324 
    325 #endif /* _LIB_PTHREAD_INT_H */
    326