xref: /netbsd-src/lib/libpthread/pthread_int.h (revision 16543c49052c820334cffc5c69b2afde18f02458)
1 /*	$NetBSD: pthread_int.h,v 1.112 2024/11/30 01:04:04 christos 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 #include <sys/atomic.h>
45 #include <sys/rbtree.h>
46 #include <sys/param.h>
47 
48 #include <limits.h>
49 #include <lwp.h>
50 #include <signal.h>
51 #include <stdbool.h>
52 
53 #include <machine/lwp_private.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	128
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 	int		pt_flags;	/* see PT_FLAG_* below */
99 	int		pt_cancel;	/* Deferred cancellation */
100 	int		pt_errno;	/* Thread-specific errno. */
101 	stack_t		pt_stack;	/* Our stack */
102 	bool		pt_stack_allocated;
103 	size_t		pt_guardsize;
104 	void		*pt_exitval;	/* Read by pthread_join() */
105 	char		*pt_name;	/* Thread's name, set by the app. */
106 	struct pthread_lock_ops pt_lockops;/* Cached to avoid PIC overhead */
107 	void		*(*pt_func)(void *);/* Function to call at start. */
108 	void		*pt_arg;	/* Argument to pass at start. */
109 
110 	/* Stack of cancellation cleanup handlers and their arguments */
111 	PTQ_HEAD(, pt_clean_t)	pt_cleanup_stack;
112 
113 	/* LWP ID and entry on the list of all threads. */
114 	lwpid_t		pt_lid;
115 	PTQ_ENTRY(__pthread_st)	pt_deadq;
116 
117 	/*
118 	 * rbtree node and entry on the list of all threads.  pt_alltree in
119 	 * its own cacheline, so pthread__find() is not needlessly impacted
120 	 * by threads going about their normal business.  pt_allq is
121 	 * adjusted at the same time as pt_alltree.
122 	 */
123 	rb_node_t	pt_alltree __aligned(COHERENCY_UNIT);
124 	PTQ_ENTRY(__pthread_st) pt_allq;
125 
126 	/* Lock on state also gets its own line. */
127 	pthread_mutex_t	pt_lock __aligned(COHERENCY_UNIT);
128 
129 	/*
130 	 * General synchronization data.  We try to align, as threads
131 	 * on other CPUs will access this data frequently.
132 	 */
133 	int		pt_dummy1 __aligned(COHERENCY_UNIT);
134 	struct lwpctl 	*pt_lwpctl;	/* Kernel/user comms area */
135 	volatile int	pt_rwlocked;	/* Handed rwlock successfully */
136 	void * volatile	pt_sleepobj;	/* Object slept on */
137 	PTQ_ENTRY(__pthread_st) pt_sleep;
138 
139 	/* Thread-specific data.  Large so it sits close to the end. */
140 	int		pt_havespecific __aligned(COHERENCY_UNIT);
141 	struct pt_specific {
142 		void *pts_value;
143 		PTQ_ENTRY(pt_specific) pts_next;
144 	} pt_specific[];
145 };
146 
147 /* Thread states */
148 #define PT_STATE_RUNNING	1
149 #define PT_STATE_ZOMBIE		5
150 #define PT_STATE_DEAD		6
151 
152 /* Flag values */
153 
154 #define PT_FLAG_DETACHED	0x0001
155 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
156 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
157 #define PT_FLAG_CS_PENDING	0x0010
158 #define PT_FLAG_SCOPE_SYSTEM	0x0040
159 #define PT_FLAG_EXPLICIT_SCHED	0x0080
160 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
161 
162 #define PT_MAGIC	0x11110001
163 #define PT_DEAD		0xDEAD0001
164 
165 #define PT_ATTR_MAGIC	0x22220002
166 #define PT_ATTR_DEAD	0xDEAD0002
167 
168 extern size_t	pthread__stacksize;
169 extern size_t	pthread__guardsize;
170 extern size_t	pthread__pagesize;
171 extern int	pthread__nspins;
172 extern int	pthread__concurrency;
173 extern int 	pthread__osrev;
174 extern size_t 	pthread__unpark_max;
175 extern int	pthread_keys_max;
176 
177 extern int	__uselibcstub;
178 
179 struct pthread__waiter {
180 	struct pthread__waiter	*volatile next;
181 	lwpid_t			volatile lid;
182 };
183 
184 /* Flag to be used in a ucontext_t's uc_flags indicating that
185  * the saved register state is "user" state only, not full
186  * trap state.
187  */
188 #define _UC_USER_BIT		30
189 #define _UC_USER		(1LU << _UC_USER_BIT)
190 
191 /* Utility functions */
192 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
193     PTHREAD_HIDE;
194 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
195     PTHREAD_HIDE;
196 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
197 		      const struct timespec *, int) 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 (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 (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 (0)
289 
290 void 	*pthread_tsd_init(size_t *) PTHREAD_HIDE;
291 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
292 void	pthread__copy_tsd(pthread_t) PTHREAD_HIDE;
293 
294 __dead void	pthread__assertfunc(const char *, int, const char *, const char *)
295 			    PTHREAD_HIDE;
296 void	pthread__errorfunc(const char *, int, const char *, const char *, ...)
297 			    __printflike(4, 5) PTHREAD_HIDE;
298 char	*pthread__getenv(const char *) PTHREAD_HIDE;
299 __dead void	pthread__cancelled(void) PTHREAD_HIDE;
300 void	pthread__mutex_deferwake(pthread_t, pthread_mutex_t *,
301     struct pthread__waiter *) 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_wait
309 #define	pthread__smt_wait()	__nothing
310 #endif
311 #ifndef pthread__smt_wake
312 #define	pthread__smt_wake()	__nothing
313 #endif
314 
315 /*
316  * Bits in the owner field of the lock that indicate lock state.  If the
317  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
318  * the number of readers.
319  */
320 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
321 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
322 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
323 #define	RW_UNUSED		0x08	/* currently unused */
324 
325 #define	RW_FLAGMASK		0x0f
326 
327 #define	RW_READ_COUNT_SHIFT	4
328 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
329 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
330 
331 #endif /* _LIB_PTHREAD_INT_H */
332