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pthread_int.h revision 1.83
      1 /*	$NetBSD: pthread_int.h,v 1.83 2012/03/02 18:06:05 joerg 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 	void		*pt_specific[PTHREAD_KEYS_MAX];
    149 
    150 	/*
    151 	 * Context for thread creation.  At the end as it's cached
    152 	 * and then only ever passed to _lwp_create().
    153 	 */
    154 	ucontext_t	pt_uc;
    155 };
    156 
    157 /* Thread states */
    158 #define PT_STATE_RUNNING	1
    159 #define PT_STATE_ZOMBIE		5
    160 #define PT_STATE_DEAD		6
    161 
    162 /* Flag values */
    163 
    164 #define PT_FLAG_DETACHED	0x0001
    165 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
    166 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
    167 #define PT_FLAG_CS_PENDING	0x0010
    168 #define PT_FLAG_SCOPE_SYSTEM	0x0040
    169 #define PT_FLAG_EXPLICIT_SCHED	0x0080
    170 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
    171 
    172 #define PT_MAGIC	0x11110001
    173 #define PT_DEAD		0xDEAD0001
    174 
    175 #define PT_ATTR_MAGIC	0x22220002
    176 #define PT_ATTR_DEAD	0xDEAD0002
    177 
    178 extern size_t	pthread__stacksize;
    179 extern size_t	pthread__pagesize;
    180 extern int	pthread__nspins;
    181 extern int	pthread__concurrency;
    182 extern int 	pthread__osrev;
    183 extern int 	pthread__unpark_max;
    184 
    185 /* Flag to be used in a ucontext_t's uc_flags indicating that
    186  * the saved register state is "user" state only, not full
    187  * trap state.
    188  */
    189 #define _UC_USER_BIT		30
    190 #define _UC_USER		(1LU << _UC_USER_BIT)
    191 
    192 /* Utility functions */
    193 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    194     PTHREAD_HIDE;
    195 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    196     PTHREAD_HIDE;
    197 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
    198 		      const struct timespec *, int, const void *)
    199 		      PTHREAD_HIDE;
    200 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
    201 
    202 /* Internal locking primitives */
    203 void	pthread__lockprim_init(void) PTHREAD_HIDE;
    204 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
    205 
    206 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
    207     __attribute__((__always_inline__));
    208 static inline void
    209 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
    210 {
    211 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
    212 		return;
    213 	(*self->pt_lockops.plo_lock)(lock);
    214 }
    215 
    216 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
    217     __attribute__((__always_inline__));
    218 static inline int
    219 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
    220 {
    221 	return (*self->pt_lockops.plo_try)(lock);
    222 }
    223 
    224 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
    225     __attribute__((__always_inline__));
    226 static inline void
    227 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
    228 {
    229 	(*self->pt_lockops.plo_unlock)(lock);
    230 }
    231 
    232 extern const struct pthread_lock_ops *pthread__lock_ops;
    233 
    234 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
    235 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
    236 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
    237 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
    238 
    239 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
    240 int	pthread__find(pthread_t) PTHREAD_HIDE;
    241 
    242 #ifndef PTHREAD_MD_INIT
    243 #define PTHREAD_MD_INIT
    244 #endif
    245 
    246 #ifndef _INITCONTEXT_U_MD
    247 #define _INITCONTEXT_U_MD(ucp)
    248 #endif
    249 
    250 #define _INITCONTEXT_U(ucp) do {					\
    251 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
    252 	_INITCONTEXT_U_MD(ucp)						\
    253 	} while (/*CONSTCOND*/0)
    254 
    255 
    256 #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
    257 static inline pthread_t __constfunc
    258 pthread__self(void)
    259 {
    260 #ifdef __HAVE___LWP_GETTCB_FAST
    261 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
    262 #else
    263 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
    264 #endif
    265 	return (pthread_t)tcb->tcb_pthread;
    266 }
    267 #else
    268 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
    269 #endif
    270 
    271 #define pthread__abort()						\
    272 	pthread__assertfunc(__FILE__, __LINE__, __func__, "unreachable")
    273 
    274 #define pthread__assert(e) do {						\
    275 	if (__predict_false(!(e)))					\
    276        	       pthread__assertfunc(__FILE__, __LINE__, __func__, #e);	\
    277         } while (/*CONSTCOND*/0)
    278 
    279 #define pthread__error(err, msg, e) do {				\
    280 	if (__predict_false(!(e))) {					\
    281        	       pthread__errorfunc(__FILE__, __LINE__, __func__, msg);	\
    282 	       return (err);						\
    283 	} 								\
    284         } while (/*CONSTCOND*/0)
    285 
    286 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
    287 __dead void	pthread__assertfunc(const char *, int, const char *, const char *)
    288 			    PTHREAD_HIDE;
    289 void	pthread__errorfunc(const char *, int, const char *, const char *)
    290 			   PTHREAD_HIDE;
    291 char	*pthread__getenv(const char *) PTHREAD_HIDE;
    292 __dead void	pthread__cancelled(void) PTHREAD_HIDE;
    293 void	pthread__mutex_deferwake(pthread_t, pthread_mutex_t *) PTHREAD_HIDE;
    294 int	pthread__checkpri(int) PTHREAD_HIDE;
    295 
    296 #ifndef pthread__smt_pause
    297 #define	pthread__smt_pause()	/* nothing */
    298 #endif
    299 
    300 /*
    301  * Bits in the owner field of the lock that indicate lock state.  If the
    302  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
    303  * the number of readers.
    304  */
    305 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
    306 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
    307 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
    308 #define	RW_UNUSED		0x08	/* currently unused */
    309 
    310 #define	RW_FLAGMASK		0x0f
    311 
    312 #define	RW_READ_COUNT_SHIFT	4
    313 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
    314 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
    315 #define	RW_OWNER(rw)		((rw)->rw_owner & RW_THREAD)
    316 #define	RW_COUNT(rw)		((rw)->rw_owner & RW_THREAD)
    317 #define	RW_FLAGS(rw)		((rw)->rw_owner & ~RW_THREAD)
    318 
    319 #endif /* _LIB_PTHREAD_INT_H */
    320