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pthread_int.h revision 1.92.4.1
      1 /*	$NetBSD: pthread_int.h,v 1.92.4.1 2017/04/21 16:53:12 bouyer 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 #ifndef _LIB_PTHREAD_INT_H
     33 #define _LIB_PTHREAD_INT_H
     34 
     35 #include <sys/tls.h>
     36 
     37 /* #define PTHREAD__DEBUG */
     38 #define ERRORCHECK
     39 
     40 #include "pthread_types.h"
     41 #include "pthread_queue.h"
     42 #include "pthread_md.h"
     43 
     44 /* Need to use libc-private names for atomic operations. */
     45 #include "../../common/lib/libc/atomic/atomic_op_namespace.h"
     46 
     47 #include <sys/atomic.h>
     48 #include <sys/rbtree.h>
     49 
     50 #include <limits.h>
     51 #include <lwp.h>
     52 #include <signal.h>
     53 #include <stdbool.h>
     54 
     55 #ifdef __GNUC__
     56 #define	PTHREAD_HIDE	__attribute__ ((visibility("hidden")))
     57 #else
     58 #define	PTHREAD_HIDE	/* nothing */
     59 #endif
     60 
     61 #define	PTHREAD__UNPARK_MAX	32
     62 
     63 /*
     64  * The size of this structure needs to be no larger than struct
     65  * __pthread_cleanup_store, defined in pthread.h.
     66  */
     67 struct pt_clean_t {
     68 	PTQ_ENTRY(pt_clean_t)	ptc_next;
     69 	void	(*ptc_cleanup)(void *);
     70 	void	*ptc_arg;
     71 };
     72 
     73 /* Private data for pthread_attr_t */
     74 struct pthread_attr_private {
     75 	char ptap_name[PTHREAD_MAX_NAMELEN_NP];
     76 	void *ptap_namearg;
     77 	void *ptap_stackaddr;
     78 	size_t ptap_stacksize;
     79 	size_t ptap_guardsize;
     80 	struct sched_param ptap_sp;
     81 	int ptap_policy;
     82 };
     83 
     84 struct pthread_lock_ops {
     85 	void	(*plo_init)(__cpu_simple_lock_t *);
     86 	int	(*plo_try)(__cpu_simple_lock_t *);
     87 	void	(*plo_unlock)(__cpu_simple_lock_t *);
     88 	void	(*plo_lock)(__cpu_simple_lock_t *);
     89 };
     90 
     91 struct	__pthread_st {
     92 	pthread_t	pt_self;	/* Must be first. */
     93 #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
     94 	struct tls_tcb	*pt_tls;	/* Thread Local Storage area */
     95 #endif
     96 	unsigned int	pt_magic;	/* Magic number */
     97 	int		pt_state;	/* running, blocked, etc. */
     98 	pthread_mutex_t	pt_lock;	/* lock on state */
     99 	int		pt_flags;	/* see PT_FLAG_* below */
    100 	int		pt_cancel;	/* Deferred cancellation */
    101 	int		pt_errno;	/* Thread-specific errno. */
    102 	stack_t		pt_stack;	/* Our stack */
    103 	bool		pt_stack_allocated;
    104 	size_t		pt_guardsize;
    105 	void		*pt_exitval;	/* Read by pthread_join() */
    106 	char		*pt_name;	/* Thread's name, set by the app. */
    107 	int		pt_willpark;	/* About to park */
    108 	lwpid_t		pt_unpark;	/* Unpark this when parking */
    109 	struct pthread_lock_ops pt_lockops;/* Cached to avoid PIC overhead */
    110 	pthread_mutex_t	*pt_droplock;	/* Drop this lock if cancelled */
    111 	pthread_cond_t	pt_joiners;	/* Threads waiting to join. */
    112 	void		*(*pt_func)(void *);/* Function to call at start. */
    113 	void		*pt_arg;	/* Argument to pass at start. */
    114 
    115 	/* Threads to defer waking, usually until pthread_mutex_unlock(). */
    116 	lwpid_t		pt_waiters[PTHREAD__UNPARK_MAX];
    117 	size_t		pt_nwaiters;
    118 
    119 	/* Stack of cancellation cleanup handlers and their arguments */
    120 	PTQ_HEAD(, pt_clean_t)	pt_cleanup_stack;
    121 
    122 	/* LWP ID and entry on the list of all threads. */
    123 	lwpid_t		pt_lid;
    124 	rb_node_t	pt_alltree;
    125 	PTQ_ENTRY(__pthread_st) pt_allq;
    126 	PTQ_ENTRY(__pthread_st)	pt_deadq;
    127 
    128 	/*
    129 	 * General synchronization data.  We try to align, as threads
    130 	 * on other CPUs will access this data frequently.
    131 	 */
    132 	int		pt_dummy1 __aligned(128);
    133 	struct lwpctl 	*pt_lwpctl;	/* Kernel/user comms area */
    134 	volatile int	pt_blocking;	/* Blocking in userspace */
    135 	volatile int	pt_rwlocked;	/* Handed rwlock successfully */
    136 	volatile int	pt_signalled;	/* Received pthread_cond_signal() */
    137 	volatile int	pt_mutexwait;	/* Waiting to acquire mutex */
    138 	void * volatile pt_mutexnext;	/* Next thread in chain */
    139 	void * volatile	pt_sleepobj;	/* Object slept on */
    140 	PTQ_ENTRY(__pthread_st) pt_sleep;
    141 	void		(*pt_early)(void *);
    142 	int		pt_dummy2 __aligned(128);
    143 
    144 	/* Thread-specific data.  Large so it sits close to the end. */
    145 	int		pt_havespecific;
    146 	struct pt_specific {
    147 		void *pts_value;
    148 		PTQ_ENTRY(pt_specific) pts_next;
    149 	} pt_specific[];
    150 };
    151 
    152 /* Thread states */
    153 #define PT_STATE_RUNNING	1
    154 #define PT_STATE_ZOMBIE		5
    155 #define PT_STATE_DEAD		6
    156 
    157 /* Flag values */
    158 
    159 #define PT_FLAG_DETACHED	0x0001
    160 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
    161 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
    162 #define PT_FLAG_CS_PENDING	0x0010
    163 #define PT_FLAG_SCOPE_SYSTEM	0x0040
    164 #define PT_FLAG_EXPLICIT_SCHED	0x0080
    165 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
    166 
    167 #define PT_MAGIC	0x11110001
    168 #define PT_DEAD		0xDEAD0001
    169 
    170 #define PT_ATTR_MAGIC	0x22220002
    171 #define PT_ATTR_DEAD	0xDEAD0002
    172 
    173 extern size_t	pthread__stacksize;
    174 extern size_t	pthread__pagesize;
    175 extern int	pthread__nspins;
    176 extern int	pthread__concurrency;
    177 extern int 	pthread__osrev;
    178 extern int 	pthread__unpark_max;
    179 extern int	pthread_keys_max;
    180 
    181 extern int	__uselibcstub;
    182 
    183 /* Flag to be used in a ucontext_t's uc_flags indicating that
    184  * the saved register state is "user" state only, not full
    185  * trap state.
    186  */
    187 #define _UC_USER_BIT		30
    188 #define _UC_USER		(1LU << _UC_USER_BIT)
    189 
    190 /* Utility functions */
    191 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    192     PTHREAD_HIDE;
    193 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
    194     PTHREAD_HIDE;
    195 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
    196 		      const struct timespec *, int, const void *)
    197 		      PTHREAD_HIDE;
    198 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
    199 
    200 /* Internal locking primitives */
    201 void	pthread__lockprim_init(void) PTHREAD_HIDE;
    202 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
    203 
    204 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
    205     __attribute__((__always_inline__));
    206 static inline void
    207 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
    208 {
    209 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
    210 		return;
    211 	(*self->pt_lockops.plo_lock)(lock);
    212 }
    213 
    214 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
    215     __attribute__((__always_inline__));
    216 static inline int
    217 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
    218 {
    219 	return (*self->pt_lockops.plo_try)(lock);
    220 }
    221 
    222 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
    223     __attribute__((__always_inline__));
    224 static inline void
    225 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
    226 {
    227 	(*self->pt_lockops.plo_unlock)(lock);
    228 }
    229 
    230 extern const struct pthread_lock_ops *pthread__lock_ops;
    231 
    232 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
    233 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
    234 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
    235 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
    236 
    237 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
    238 int	pthread__find(pthread_t) PTHREAD_HIDE;
    239 
    240 #ifndef PTHREAD_MD_INIT
    241 #define PTHREAD_MD_INIT
    242 #endif
    243 
    244 #ifndef _INITCONTEXT_U_MD
    245 #define _INITCONTEXT_U_MD(ucp)
    246 #endif
    247 
    248 #define _INITCONTEXT_U(ucp) do {					\
    249 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
    250 	_INITCONTEXT_U_MD(ucp)						\
    251 	} while (/*CONSTCOND*/0)
    252 
    253 
    254 #if !defined(__HAVE_TLS_VARIANT_I) && !defined(__HAVE_TLS_VARIANT_II)
    255 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
    256 #endif
    257 
    258 #ifdef _PTHREAD_GETTCB_EXT
    259 struct tls_tcb *_PTHREAD_GETTCB_EXT(void);
    260 #endif
    261 
    262 static inline pthread_t __constfunc
    263 pthread__self(void)
    264 {
    265 #if defined(_PTHREAD_GETTCB_EXT)
    266 	struct tls_tcb * const tcb = _PTHREAD_GETTCB_EXT();
    267 #elif defined(__HAVE___LWP_GETTCB_FAST)
    268 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
    269 #else
    270 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
    271 #endif
    272 	return (pthread_t)tcb->tcb_pthread;
    273 }
    274 
    275 #define pthread__abort()						\
    276 	pthread__assertfunc(__FILE__, __LINE__, __func__, "unreachable")
    277 
    278 #define pthread__assert(e) do {						\
    279 	if (__predict_false(!(e)))					\
    280        	       pthread__assertfunc(__FILE__, __LINE__, __func__, #e);	\
    281         } while (/*CONSTCOND*/0)
    282 
    283 #define pthread__error(err, msg, e) do {				\
    284 	if (__predict_false(!(e))) {					\
    285        	       pthread__errorfunc(__FILE__, __LINE__, __func__, msg);	\
    286 	       return (err);						\
    287 	} 								\
    288         } while (/*CONSTCOND*/0)
    289 
    290 void 	*pthread_tsd_init(size_t *) PTHREAD_HIDE;
    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 #ifndef pthread__smt_wake
    306 #define	pthread__smt_wake()	/* nothing */
    307 #endif
    308 
    309 /*
    310  * Bits in the owner field of the lock that indicate lock state.  If the
    311  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
    312  * the number of readers.
    313  */
    314 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
    315 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
    316 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
    317 #define	RW_UNUSED		0x08	/* currently unused */
    318 
    319 #define	RW_FLAGMASK		0x0f
    320 
    321 #define	RW_READ_COUNT_SHIFT	4
    322 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
    323 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
    324 #define	RW_OWNER(rw)		((rw)->rw_owner & RW_THREAD)
    325 #define	RW_COUNT(rw)		((rw)->rw_owner & RW_THREAD)
    326 #define	RW_FLAGS(rw)		((rw)->rw_owner & ~RW_THREAD)
    327 
    328 #endif /* _LIB_PTHREAD_INT_H */
    329