xref: /netbsd-src/lib/libpthread/pthread_int.h (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /*	$NetBSD: pthread_int.h,v 1.92 2015/05/29 16:05:13 christos 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[];
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 extern int	pthread_keys_max;
185 
186 extern int	__uselibcstub;
187 
188 /* Flag to be used in a ucontext_t's uc_flags indicating that
189  * the saved register state is "user" state only, not full
190  * trap state.
191  */
192 #define _UC_USER_BIT		30
193 #define _UC_USER		(1LU << _UC_USER_BIT)
194 
195 /* Utility functions */
196 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
197     PTHREAD_HIDE;
198 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
199     PTHREAD_HIDE;
200 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
201 		      const struct timespec *, int, const void *)
202 		      PTHREAD_HIDE;
203 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
204 
205 /* Internal locking primitives */
206 void	pthread__lockprim_init(void) PTHREAD_HIDE;
207 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
208 
209 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
210     __attribute__((__always_inline__));
211 static inline void
212 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
213 {
214 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
215 		return;
216 	(*self->pt_lockops.plo_lock)(lock);
217 }
218 
219 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
220     __attribute__((__always_inline__));
221 static inline int
222 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
223 {
224 	return (*self->pt_lockops.plo_try)(lock);
225 }
226 
227 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
228     __attribute__((__always_inline__));
229 static inline void
230 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
231 {
232 	(*self->pt_lockops.plo_unlock)(lock);
233 }
234 
235 extern const struct pthread_lock_ops *pthread__lock_ops;
236 
237 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
238 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
239 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
240 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
241 
242 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
243 int	pthread__find(pthread_t) PTHREAD_HIDE;
244 
245 #ifndef PTHREAD_MD_INIT
246 #define PTHREAD_MD_INIT
247 #endif
248 
249 #ifndef _INITCONTEXT_U_MD
250 #define _INITCONTEXT_U_MD(ucp)
251 #endif
252 
253 #define _INITCONTEXT_U(ucp) do {					\
254 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
255 	_INITCONTEXT_U_MD(ucp)						\
256 	} while (/*CONSTCOND*/0)
257 
258 
259 #if !defined(__HAVE_TLS_VARIANT_I) && !defined(__HAVE_TLS_VARIANT_II)
260 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
261 #endif
262 
263 #ifdef _PTHREAD_GETTCB_EXT
264 struct tls_tcb *_PTHREAD_GETTCB_EXT(void);
265 #endif
266 
267 static inline pthread_t __constfunc
268 pthread__self(void)
269 {
270 #if defined(_PTHREAD_GETTCB_EXT)
271 	struct tls_tcb * const tcb = _PTHREAD_GETTCB_EXT();
272 #elif defined(__HAVE___LWP_GETTCB_FAST)
273 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
274 #else
275 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
276 #endif
277 	return (pthread_t)tcb->tcb_pthread;
278 }
279 
280 #define pthread__abort()						\
281 	pthread__assertfunc(__FILE__, __LINE__, __func__, "unreachable")
282 
283 #define pthread__assert(e) do {						\
284 	if (__predict_false(!(e)))					\
285        	       pthread__assertfunc(__FILE__, __LINE__, __func__, #e);	\
286         } while (/*CONSTCOND*/0)
287 
288 #define pthread__error(err, msg, e) do {				\
289 	if (__predict_false(!(e))) {					\
290        	       pthread__errorfunc(__FILE__, __LINE__, __func__, msg);	\
291 	       return (err);						\
292 	} 								\
293         } while (/*CONSTCOND*/0)
294 
295 void 	*pthread_tsd_init(size_t *) PTHREAD_HIDE;
296 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
297 __dead void	pthread__assertfunc(const char *, int, const char *, const char *)
298 			    PTHREAD_HIDE;
299 void	pthread__errorfunc(const char *, int, const char *, const char *)
300 			   PTHREAD_HIDE;
301 char	*pthread__getenv(const char *) PTHREAD_HIDE;
302 __dead void	pthread__cancelled(void) PTHREAD_HIDE;
303 void	pthread__mutex_deferwake(pthread_t, pthread_mutex_t *) PTHREAD_HIDE;
304 int	pthread__checkpri(int) PTHREAD_HIDE;
305 int	pthread__add_specific(pthread_t, pthread_key_t, const void *) PTHREAD_HIDE;
306 
307 #ifndef pthread__smt_pause
308 #define	pthread__smt_pause()	/* nothing */
309 #endif
310 #ifndef pthread__smt_wake
311 #define	pthread__smt_wake()	/* nothing */
312 #endif
313 
314 /*
315  * Bits in the owner field of the lock that indicate lock state.  If the
316  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
317  * the number of readers.
318  */
319 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
320 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
321 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
322 #define	RW_UNUSED		0x08	/* currently unused */
323 
324 #define	RW_FLAGMASK		0x0f
325 
326 #define	RW_READ_COUNT_SHIFT	4
327 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
328 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
329 #define	RW_OWNER(rw)		((rw)->rw_owner & RW_THREAD)
330 #define	RW_COUNT(rw)		((rw)->rw_owner & RW_THREAD)
331 #define	RW_FLAGS(rw)		((rw)->rw_owner & ~RW_THREAD)
332 
333 #endif /* _LIB_PTHREAD_INT_H */
334