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pthread_int.h revision 1.86.2.3
      1 /*	$NetBSD: pthread_int.h,v 1.86.2.3 2013/06/23 06:21:08 tls 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/rbtree.h>
     54 
     55 #include <limits.h>
     56 #include <lwp.h>
     57 #include <signal.h>
     58 #include <stdbool.h>
     59 
     60 #ifdef __GNUC__
     61 #define	PTHREAD_HIDE	__attribute__ ((visibility("hidden")))
     62 #else
     63 #define	PTHREAD_HIDE	/* nothing */
     64 #endif
     65 
     66 #define	PTHREAD__UNPARK_MAX	32
     67 
     68 /*
     69  * The size of this structure needs to be no larger than struct
     70  * __pthread_cleanup_store, defined in pthread.h.
     71  */
     72 struct pt_clean_t {
     73 	PTQ_ENTRY(pt_clean_t)	ptc_next;
     74 	void	(*ptc_cleanup)(void *);
     75 	void	*ptc_arg;
     76 };
     77 
     78 /* Private data for pthread_attr_t */
     79 struct pthread_attr_private {
     80 	char ptap_name[PTHREAD_MAX_NAMELEN_NP];
     81 	void *ptap_namearg;
     82 	void *ptap_stackaddr;
     83 	size_t ptap_stacksize;
     84 	size_t ptap_guardsize;
     85 	struct sched_param ptap_sp;
     86 	int ptap_policy;
     87 };
     88 
     89 struct pthread_lock_ops {
     90 	void	(*plo_init)(__cpu_simple_lock_t *);
     91 	int	(*plo_try)(__cpu_simple_lock_t *);
     92 	void	(*plo_unlock)(__cpu_simple_lock_t *);
     93 	void	(*plo_lock)(__cpu_simple_lock_t *);
     94 };
     95 
     96 struct	__pthread_st {
     97 	pthread_t	pt_self;	/* Must be first. */
     98 #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
     99 	struct tls_tcb	*pt_tls;	/* Thread Local Storage area */
    100 #endif
    101 	unsigned int	pt_magic;	/* Magic number */
    102 	int		pt_state;	/* running, blocked, etc. */
    103 	pthread_mutex_t	pt_lock;	/* lock on state */
    104 	int		pt_flags;	/* see PT_FLAG_* below */
    105 	int		pt_cancel;	/* Deferred cancellation */
    106 	int		pt_errno;	/* Thread-specific errno. */
    107 	stack_t		pt_stack;	/* Our stack */
    108 	bool		pt_stack_allocated;
    109 	size_t		pt_guardsize;
    110 	void		*pt_exitval;	/* Read by pthread_join() */
    111 	char		*pt_name;	/* Thread's name, set by the app. */
    112 	int		pt_willpark;	/* About to park */
    113 	lwpid_t		pt_unpark;	/* Unpark this when parking */
    114 	struct pthread_lock_ops pt_lockops;/* Cached to avoid PIC overhead */
    115 	pthread_mutex_t	*pt_droplock;	/* Drop this lock if cancelled */
    116 	pthread_cond_t	pt_joiners;	/* Threads waiting to join. */
    117 	void		*(*pt_func)(void *);/* Function to call at start. */
    118 	void		*pt_arg;	/* Argument to pass at start. */
    119 
    120 	/* Threads to defer waking, usually until pthread_mutex_unlock(). */
    121 	lwpid_t		pt_waiters[PTHREAD__UNPARK_MAX];
    122 	size_t		pt_nwaiters;
    123 
    124 	/* Stack of cancellation cleanup handlers and their arguments */
    125 	PTQ_HEAD(, pt_clean_t)	pt_cleanup_stack;
    126 
    127 	/* LWP ID and entry on the list of all threads. */
    128 	lwpid_t		pt_lid;
    129 	rb_node_t	pt_alltree;
    130 	PTQ_ENTRY(__pthread_st) pt_allq;
    131 	PTQ_ENTRY(__pthread_st)	pt_deadq;
    132 
    133 	/*
    134 	 * General synchronization data.  We try to align, as threads
    135 	 * on other CPUs will access this data frequently.
    136 	 */
    137 	int		pt_dummy1 __aligned(128);
    138 	struct lwpctl 	*pt_lwpctl;	/* Kernel/user comms area */
    139 	volatile int	pt_blocking;	/* Blocking in userspace */
    140 	volatile int	pt_rwlocked;	/* Handed rwlock successfully */
    141 	volatile int	pt_signalled;	/* Received pthread_cond_signal() */
    142 	volatile int	pt_mutexwait;	/* Waiting to acquire mutex */
    143 	void * volatile pt_mutexnext;	/* Next thread in chain */
    144 	void * volatile	pt_sleepobj;	/* Object slept on */
    145 	PTQ_ENTRY(__pthread_st) pt_sleep;
    146 	void		(*pt_early)(void *);
    147 	int		pt_dummy2 __aligned(128);
    148 
    149 	/* Thread-specific data.  Large so it sits close to the end. */
    150 	int		pt_havespecific;
    151 	struct pt_specific {
    152 		void *pts_value;
    153 		PTQ_ENTRY(pt_specific) pts_next;
    154 	} pt_specific[PTHREAD_KEYS_MAX];
    155 
    156 	/*
    157 	 * Context for thread creation.  At the end as it's cached
    158 	 * and then only ever passed to _lwp_create().
    159 	 */
    160 	ucontext_t	pt_uc;
    161 };
    162 
    163 /* Thread states */
    164 #define PT_STATE_RUNNING	1
    165 #define PT_STATE_ZOMBIE		5
    166 #define PT_STATE_DEAD		6
    167 
    168 /* Flag values */
    169 
    170 #define PT_FLAG_DETACHED	0x0001
    171 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
    172 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
    173 #define PT_FLAG_CS_PENDING	0x0010
    174 #define PT_FLAG_SCOPE_SYSTEM	0x0040
    175 #define PT_FLAG_EXPLICIT_SCHED	0x0080
    176 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
    177 
    178 #define PT_MAGIC	0x11110001
    179 #define PT_DEAD		0xDEAD0001
    180 
    181 #define PT_ATTR_MAGIC	0x22220002
    182 #define PT_ATTR_DEAD	0xDEAD0002
    183 
    184 extern size_t	pthread__stacksize;
    185 extern size_t	pthread__pagesize;
    186 extern int	pthread__nspins;
    187 extern int	pthread__concurrency;
    188 extern int 	pthread__osrev;
    189 extern int 	pthread__unpark_max;
    190 
    191 extern int	__uselibcstub;
    192 
    193 /* Flag to be used in a ucontext_t's uc_flags indicating that
    194  * the saved register state is "user" state only, not full
    195  * trap state.
    196  */
    197 #define _UC_USER_BIT		30
    198 #define _UC_USER		(1LU << _UC_USER_BIT)
    199 
    200 /* Utility functions */
    201 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    202     PTHREAD_HIDE;
    203 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    204     PTHREAD_HIDE;
    205 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
    206 		      const struct timespec *, int, const void *)
    207 		      PTHREAD_HIDE;
    208 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
    209 
    210 /* Internal locking primitives */
    211 void	pthread__lockprim_init(void) PTHREAD_HIDE;
    212 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
    213 
    214 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
    215     __attribute__((__always_inline__));
    216 static inline void
    217 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
    218 {
    219 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
    220 		return;
    221 	(*self->pt_lockops.plo_lock)(lock);
    222 }
    223 
    224 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
    225     __attribute__((__always_inline__));
    226 static inline int
    227 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
    228 {
    229 	return (*self->pt_lockops.plo_try)(lock);
    230 }
    231 
    232 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
    233     __attribute__((__always_inline__));
    234 static inline void
    235 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
    236 {
    237 	(*self->pt_lockops.plo_unlock)(lock);
    238 }
    239 
    240 extern const struct pthread_lock_ops *pthread__lock_ops;
    241 
    242 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
    243 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
    244 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
    245 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
    246 
    247 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
    248 int	pthread__find(pthread_t) PTHREAD_HIDE;
    249 
    250 #ifndef PTHREAD_MD_INIT
    251 #define PTHREAD_MD_INIT
    252 #endif
    253 
    254 #ifndef _INITCONTEXT_U_MD
    255 #define _INITCONTEXT_U_MD(ucp)
    256 #endif
    257 
    258 #define _INITCONTEXT_U(ucp) do {					\
    259 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
    260 	_INITCONTEXT_U_MD(ucp)						\
    261 	} while (/*CONSTCOND*/0)
    262 
    263 
    264 #if !defined(__HAVE_TLS_VARIANT_I) && !defined(__HAVE_TLS_VARIANT_II)
    265 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
    266 #endif
    267 
    268 static inline pthread_t __constfunc
    269 pthread__self(void)
    270 {
    271 #ifdef __HAVE___LWP_GETTCB_FAST
    272 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
    273 #else
    274 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
    275 #endif
    276 	return (pthread_t)tcb->tcb_pthread;
    277 }
    278 
    279 #define pthread__abort()						\
    280 	pthread__assertfunc(__FILE__, __LINE__, __func__, "unreachable")
    281 
    282 #define pthread__assert(e) do {						\
    283 	if (__predict_false(!(e)))					\
    284        	       pthread__assertfunc(__FILE__, __LINE__, __func__, #e);	\
    285         } while (/*CONSTCOND*/0)
    286 
    287 #define pthread__error(err, msg, e) do {				\
    288 	if (__predict_false(!(e))) {					\
    289        	       pthread__errorfunc(__FILE__, __LINE__, __func__, msg);	\
    290 	       return (err);						\
    291 	} 								\
    292         } while (/*CONSTCOND*/0)
    293 
    294 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
    295 __dead void	pthread__assertfunc(const char *, int, const char *, const char *)
    296 			    PTHREAD_HIDE;
    297 void	pthread__errorfunc(const char *, int, const char *, const char *)
    298 			   PTHREAD_HIDE;
    299 char	*pthread__getenv(const char *) PTHREAD_HIDE;
    300 __dead void	pthread__cancelled(void) PTHREAD_HIDE;
    301 void	pthread__mutex_deferwake(pthread_t, pthread_mutex_t *) PTHREAD_HIDE;
    302 int	pthread__checkpri(int) PTHREAD_HIDE;
    303 int	pthread__add_specific(pthread_t, pthread_key_t, const void *) PTHREAD_HIDE;
    304 
    305 #ifndef pthread__smt_pause
    306 #define	pthread__smt_pause()	/* nothing */
    307 #endif
    308 #ifndef pthread__smt_wake
    309 #define	pthread__smt_wake()	/* nothing */
    310 #endif
    311 
    312 /*
    313  * Bits in the owner field of the lock that indicate lock state.  If the
    314  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
    315  * the number of readers.
    316  */
    317 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
    318 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
    319 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
    320 #define	RW_UNUSED		0x08	/* currently unused */
    321 
    322 #define	RW_FLAGMASK		0x0f
    323 
    324 #define	RW_READ_COUNT_SHIFT	4
    325 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
    326 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
    327 #define	RW_OWNER(rw)		((rw)->rw_owner & RW_THREAD)
    328 #define	RW_COUNT(rw)		((rw)->rw_owner & RW_THREAD)
    329 #define	RW_FLAGS(rw)		((rw)->rw_owner & ~RW_THREAD)
    330 
    331 #endif /* _LIB_PTHREAD_INT_H */
    332