xref: /netbsd-src/lib/libpthread/pthread_int.h (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 /*	$NetBSD: pthread_int.h,v 1.107 2020/06/10 22:45:15 ad Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001, 2002, 2003, 2006, 2007, 2008, 2020
5  *     The NetBSD Foundation, Inc.
6  * All rights reserved.
7  *
8  * This code is derived from software contributed to The NetBSD Foundation
9  * by Nathan J. Williams and Andrew Doran.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 #ifndef _LIB_PTHREAD_INT_H
34 #define _LIB_PTHREAD_INT_H
35 
36 #include <sys/tls.h>
37 
38 /* #define PTHREAD__DEBUG */
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 #include <sys/param.h>
50 
51 #include <limits.h>
52 #include <lwp.h>
53 #include <signal.h>
54 #include <stdbool.h>
55 
56 #ifdef __GNUC__
57 #define	PTHREAD_HIDE	__attribute__ ((visibility("hidden")))
58 #else
59 #define	PTHREAD_HIDE	/* nothing */
60 #endif
61 
62 #define	PTHREAD__UNPARK_MAX	128
63 
64 /*
65  * The size of this structure needs to be no larger than struct
66  * __pthread_cleanup_store, defined in pthread.h.
67  */
68 struct pt_clean_t {
69 	PTQ_ENTRY(pt_clean_t)	ptc_next;
70 	void	(*ptc_cleanup)(void *);
71 	void	*ptc_arg;
72 };
73 
74 /* Private data for pthread_attr_t */
75 struct pthread_attr_private {
76 	char ptap_name[PTHREAD_MAX_NAMELEN_NP];
77 	void *ptap_namearg;
78 	void *ptap_stackaddr;
79 	size_t ptap_stacksize;
80 	size_t ptap_guardsize;
81 	struct sched_param ptap_sp;
82 	int ptap_policy;
83 };
84 
85 struct pthread_lock_ops {
86 	void	(*plo_init)(__cpu_simple_lock_t *);
87 	int	(*plo_try)(__cpu_simple_lock_t *);
88 	void	(*plo_unlock)(__cpu_simple_lock_t *);
89 	void	(*plo_lock)(__cpu_simple_lock_t *);
90 };
91 
92 struct	__pthread_st {
93 	pthread_t	pt_self;	/* Must be first. */
94 #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
95 	struct tls_tcb	*pt_tls;	/* Thread Local Storage area */
96 #endif
97 	unsigned int	pt_magic;	/* Magic number */
98 	int		pt_state;	/* running, blocked, etc. */
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 	struct pthread_lock_ops pt_lockops;/* Cached to avoid PIC overhead */
108 	void		*(*pt_func)(void *);/* Function to call at start. */
109 	void		*pt_arg;	/* Argument to pass at start. */
110 
111 	/* Stack of cancellation cleanup handlers and their arguments */
112 	PTQ_HEAD(, pt_clean_t)	pt_cleanup_stack;
113 
114 	/* LWP ID and entry on the list of all threads. */
115 	lwpid_t		pt_lid;
116 	PTQ_ENTRY(__pthread_st)	pt_deadq;
117 
118 	/*
119 	 * rbtree node and entry on the list of all threads.  pt_alltree in
120 	 * its own cacheline, so pthread__find() is not needlessly impacted
121 	 * by threads going about their normal business.  pt_allq is
122 	 * adjusted at the same time as pt_alltree.
123 	 */
124 	rb_node_t	pt_alltree __aligned(COHERENCY_UNIT);
125 	PTQ_ENTRY(__pthread_st) pt_allq;
126 
127 	/* Lock on state also gets its own line. */
128 	pthread_mutex_t	pt_lock __aligned(COHERENCY_UNIT);
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(COHERENCY_UNIT);
135 	struct lwpctl 	*pt_lwpctl;	/* Kernel/user comms area */
136 	volatile int	pt_rwlocked;	/* Handed rwlock successfully */
137 	void * volatile	pt_sleepobj;	/* Object slept on */
138 	PTQ_ENTRY(__pthread_st) pt_sleep;
139 
140 	/* Thread-specific data.  Large so it sits close to the end. */
141 	int		pt_havespecific __aligned(COHERENCY_UNIT);
142 	struct pt_specific {
143 		void *pts_value;
144 		PTQ_ENTRY(pt_specific) pts_next;
145 	} pt_specific[];
146 };
147 
148 /* Thread states */
149 #define PT_STATE_RUNNING	1
150 #define PT_STATE_ZOMBIE		5
151 #define PT_STATE_DEAD		6
152 
153 /* Flag values */
154 
155 #define PT_FLAG_DETACHED	0x0001
156 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
157 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
158 #define PT_FLAG_CS_PENDING	0x0010
159 #define PT_FLAG_SCOPE_SYSTEM	0x0040
160 #define PT_FLAG_EXPLICIT_SCHED	0x0080
161 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
162 
163 #define PT_MAGIC	0x11110001
164 #define PT_DEAD		0xDEAD0001
165 
166 #define PT_ATTR_MAGIC	0x22220002
167 #define PT_ATTR_DEAD	0xDEAD0002
168 
169 extern size_t	pthread__stacksize;
170 extern size_t	pthread__guardsize;
171 extern size_t	pthread__pagesize;
172 extern int	pthread__nspins;
173 extern int	pthread__concurrency;
174 extern int 	pthread__osrev;
175 extern size_t 	pthread__unpark_max;
176 extern int	pthread_keys_max;
177 
178 extern int	__uselibcstub;
179 
180 struct pthread__waiter {
181 	struct pthread__waiter	*volatile next;
182 	lwpid_t			volatile lid;
183 };
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) PTHREAD_HIDE;
199 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
200 
201 /* Internal locking primitives */
202 void	pthread__lockprim_init(void) PTHREAD_HIDE;
203 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
204 
205 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
206     __attribute__((__always_inline__));
207 static inline void
208 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
209 {
210 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
211 		return;
212 	(*self->pt_lockops.plo_lock)(lock);
213 }
214 
215 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
216     __attribute__((__always_inline__));
217 static inline int
218 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
219 {
220 	return (*self->pt_lockops.plo_try)(lock);
221 }
222 
223 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
224     __attribute__((__always_inline__));
225 static inline void
226 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
227 {
228 	(*self->pt_lockops.plo_unlock)(lock);
229 }
230 
231 extern const struct pthread_lock_ops *pthread__lock_ops;
232 
233 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
234 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
235 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
236 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
237 
238 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
239 int	pthread__find(pthread_t) PTHREAD_HIDE;
240 
241 #ifndef PTHREAD_MD_INIT
242 #define PTHREAD_MD_INIT
243 #endif
244 
245 #ifndef _INITCONTEXT_U_MD
246 #define _INITCONTEXT_U_MD(ucp)
247 #endif
248 
249 #define _INITCONTEXT_U(ucp) do {					\
250 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
251 	_INITCONTEXT_U_MD(ucp)						\
252 	} while (/*CONSTCOND*/0)
253 
254 
255 #if !defined(__HAVE_TLS_VARIANT_I) && !defined(__HAVE_TLS_VARIANT_II)
256 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
257 #endif
258 
259 #ifdef _PTHREAD_GETTCB_EXT
260 struct tls_tcb *_PTHREAD_GETTCB_EXT(void);
261 #endif
262 
263 static inline pthread_t __constfunc
264 pthread__self(void)
265 {
266 #if defined(_PTHREAD_GETTCB_EXT)
267 	struct tls_tcb * const tcb = _PTHREAD_GETTCB_EXT();
268 #elif defined(__HAVE___LWP_GETTCB_FAST)
269 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
270 #else
271 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
272 #endif
273 	return (pthread_t)tcb->tcb_pthread;
274 }
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_tsd_init(size_t *) PTHREAD_HIDE;
292 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
293 void	pthread__copy_tsd(pthread_t) PTHREAD_HIDE;
294 
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 			    __printflike(4, 5) 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 *,
302     struct pthread__waiter *) PTHREAD_HIDE;
303 int	pthread__checkpri(int) PTHREAD_HIDE;
304 int	pthread__add_specific(pthread_t, pthread_key_t, const void *) PTHREAD_HIDE;
305 
306 #ifndef pthread__smt_pause
307 #define	pthread__smt_pause()	/* nothing */
308 #endif
309 #ifndef pthread__smt_wake
310 #define	pthread__smt_wake()	/* nothing */
311 #endif
312 
313 /*
314  * Bits in the owner field of the lock that indicate lock state.  If the
315  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
316  * the number of readers.
317  */
318 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
319 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
320 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
321 #define	RW_UNUSED		0x08	/* currently unused */
322 
323 #define	RW_FLAGMASK		0x0f
324 
325 #define	RW_READ_COUNT_SHIFT	4
326 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
327 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
328 
329 #endif /* _LIB_PTHREAD_INT_H */
330