xref: /netbsd-src/lib/libpthread/pthread_int.h (revision ed75d7a867996c84cfa88e3b8906816277e957f7)
1 /*	$NetBSD: pthread_int.h,v 1.103 2020/02/16 17:45:11 kamil 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 	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 	void		*(*pt_func)(void *);/* Function to call at start. */
111 	void		*pt_arg;	/* Argument to pass at start. */
112 
113 	/* Threads to defer waking, usually until pthread_mutex_unlock(). */
114 	lwpid_t		pt_waiters[PTHREAD__UNPARK_MAX];
115 	size_t		pt_nwaiters;
116 
117 	/* Stack of cancellation cleanup handlers and their arguments */
118 	PTQ_HEAD(, pt_clean_t)	pt_cleanup_stack;
119 
120 	/* LWP ID and entry on the list of all threads. */
121 	lwpid_t		pt_lid;
122 	PTQ_ENTRY(__pthread_st)	pt_deadq;
123 
124 	/*
125 	 * rbtree node and entry on the list of all threads.  pt_alltree in
126 	 * its own cacheline, so pthread__find() is not needlessly impacted
127 	 * by threads going about their normal business.  pt_allq is
128 	 * adjusted at the same time as pt_alltree.
129 	 */
130 	rb_node_t	pt_alltree __aligned(COHERENCY_UNIT);
131 	PTQ_ENTRY(__pthread_st) pt_allq;
132 
133 	/* Lock on state also gets its own line. */
134 	pthread_mutex_t	pt_lock __aligned(COHERENCY_UNIT);
135 
136 	/*
137 	 * General synchronization data.  We try to align, as threads
138 	 * on other CPUs will access this data frequently.
139 	 */
140 	int		pt_dummy1 __aligned(COHERENCY_UNIT);
141 	struct lwpctl 	*pt_lwpctl;	/* Kernel/user comms area */
142 	volatile int	pt_rwlocked;	/* Handed rwlock successfully */
143 	volatile int	pt_signalled;	/* Received pthread_cond_signal() */
144 	volatile int	pt_mutexwait;	/* Waiting to acquire mutex */
145 	void * volatile pt_mutexnext;	/* Next thread in chain */
146 	void * volatile	pt_sleepobj;	/* Object slept on */
147 	PTQ_ENTRY(__pthread_st) pt_sleep;
148 	void		(*pt_early)(void *);
149 
150 	/* Thread-specific data.  Large so it sits close to the end. */
151 	int		pt_havespecific __aligned(COHERENCY_UNIT);
152 	struct pt_specific {
153 		void *pts_value;
154 		PTQ_ENTRY(pt_specific) pts_next;
155 	} pt_specific[];
156 };
157 
158 /* Thread states */
159 #define PT_STATE_RUNNING	1
160 #define PT_STATE_ZOMBIE		5
161 #define PT_STATE_DEAD		6
162 
163 /* Flag values */
164 
165 #define PT_FLAG_DETACHED	0x0001
166 #define PT_FLAG_CS_DISABLED	0x0004	/* Cancellation disabled */
167 #define PT_FLAG_CS_ASYNC	0x0008  /* Cancellation is async */
168 #define PT_FLAG_CS_PENDING	0x0010
169 #define PT_FLAG_SCOPE_SYSTEM	0x0040
170 #define PT_FLAG_EXPLICIT_SCHED	0x0080
171 #define PT_FLAG_SUSPENDED	0x0100	/* In the suspended queue */
172 
173 #define PT_MAGIC	0x11110001
174 #define PT_DEAD		0xDEAD0001
175 
176 #define PT_ATTR_MAGIC	0x22220002
177 #define PT_ATTR_DEAD	0xDEAD0002
178 
179 extern size_t	pthread__stacksize;
180 extern size_t	pthread__guardsize;
181 extern size_t	pthread__pagesize;
182 extern int	pthread__nspins;
183 extern int	pthread__concurrency;
184 extern int 	pthread__osrev;
185 extern int 	pthread__unpark_max;
186 extern int	pthread_keys_max;
187 
188 extern int	__uselibcstub;
189 
190 /* Flag to be used in a ucontext_t's uc_flags indicating that
191  * the saved register state is "user" state only, not full
192  * trap state.
193  */
194 #define _UC_USER_BIT		30
195 #define _UC_USER		(1LU << _UC_USER_BIT)
196 
197 /* Utility functions */
198 void	pthread__unpark_all(pthread_queue_t *, pthread_t, pthread_mutex_t *)
199     PTHREAD_HIDE;
200 void	pthread__unpark(pthread_queue_t *, pthread_t, pthread_mutex_t *)
201     PTHREAD_HIDE;
202 int	pthread__park(pthread_t, pthread_mutex_t *, pthread_queue_t *,
203 		      const struct timespec *, int, const void *)
204 		      PTHREAD_HIDE;
205 pthread_mutex_t *pthread__hashlock(volatile const void *) PTHREAD_HIDE;
206 
207 /* Internal locking primitives */
208 void	pthread__lockprim_init(void) PTHREAD_HIDE;
209 void	pthread_lockinit(pthread_spin_t *) PTHREAD_HIDE;
210 
211 static inline void pthread__spinlock(pthread_t, pthread_spin_t *)
212     __attribute__((__always_inline__));
213 static inline void
214 pthread__spinlock(pthread_t self, pthread_spin_t *lock)
215 {
216 	if (__predict_true((*self->pt_lockops.plo_try)(lock)))
217 		return;
218 	(*self->pt_lockops.plo_lock)(lock);
219 }
220 
221 static inline int pthread__spintrylock(pthread_t, pthread_spin_t *)
222     __attribute__((__always_inline__));
223 static inline int
224 pthread__spintrylock(pthread_t self, pthread_spin_t *lock)
225 {
226 	return (*self->pt_lockops.plo_try)(lock);
227 }
228 
229 static inline void pthread__spinunlock(pthread_t, pthread_spin_t *)
230     __attribute__((__always_inline__));
231 static inline void
232 pthread__spinunlock(pthread_t self, pthread_spin_t *lock)
233 {
234 	(*self->pt_lockops.plo_unlock)(lock);
235 }
236 
237 extern const struct pthread_lock_ops *pthread__lock_ops;
238 
239 int	pthread__simple_locked_p(__cpu_simple_lock_t *) PTHREAD_HIDE;
240 #define	pthread__simple_lock_init(alp)	(*pthread__lock_ops->plo_init)(alp)
241 #define	pthread__simple_lock_try(alp)	(*pthread__lock_ops->plo_try)(alp)
242 #define	pthread__simple_unlock(alp)	(*pthread__lock_ops->plo_unlock)(alp)
243 
244 void	pthread__testcancel(pthread_t) PTHREAD_HIDE;
245 int	pthread__find(pthread_t) PTHREAD_HIDE;
246 
247 #ifndef PTHREAD_MD_INIT
248 #define PTHREAD_MD_INIT
249 #endif
250 
251 #ifndef _INITCONTEXT_U_MD
252 #define _INITCONTEXT_U_MD(ucp)
253 #endif
254 
255 #define _INITCONTEXT_U(ucp) do {					\
256 	(ucp)->uc_flags = _UC_CPU | _UC_STACK;				\
257 	_INITCONTEXT_U_MD(ucp)						\
258 	} while (/*CONSTCOND*/0)
259 
260 
261 #if !defined(__HAVE_TLS_VARIANT_I) && !defined(__HAVE_TLS_VARIANT_II)
262 #error Either __HAVE_TLS_VARIANT_I or __HAVE_TLS_VARIANT_II must be defined
263 #endif
264 
265 #ifdef _PTHREAD_GETTCB_EXT
266 struct tls_tcb *_PTHREAD_GETTCB_EXT(void);
267 #endif
268 
269 static inline pthread_t __constfunc
270 pthread__self(void)
271 {
272 #if defined(_PTHREAD_GETTCB_EXT)
273 	struct tls_tcb * const tcb = _PTHREAD_GETTCB_EXT();
274 #elif defined(__HAVE___LWP_GETTCB_FAST)
275 	struct tls_tcb * const tcb = __lwp_gettcb_fast();
276 #else
277 	struct tls_tcb * const tcb = __lwp_getprivate_fast();
278 #endif
279 	return (pthread_t)tcb->tcb_pthread;
280 }
281 
282 #define pthread__abort()						\
283 	pthread__assertfunc(__FILE__, __LINE__, __func__, "unreachable")
284 
285 #define pthread__assert(e) do {						\
286 	if (__predict_false(!(e)))					\
287        	       pthread__assertfunc(__FILE__, __LINE__, __func__, #e);	\
288         } while (/*CONSTCOND*/0)
289 
290 #define pthread__error(err, msg, e) do {				\
291 	if (__predict_false(!(e))) {					\
292        	       pthread__errorfunc(__FILE__, __LINE__, __func__, msg);	\
293 	       return (err);						\
294 	} 								\
295         } while (/*CONSTCOND*/0)
296 
297 void 	*pthread_tsd_init(size_t *) PTHREAD_HIDE;
298 void	pthread__destroy_tsd(pthread_t) PTHREAD_HIDE;
299 void	pthread__copy_tsd(pthread_t) PTHREAD_HIDE;
300 
301 __dead void	pthread__assertfunc(const char *, int, const char *, const char *)
302 			    PTHREAD_HIDE;
303 void	pthread__errorfunc(const char *, int, const char *, const char *)
304 			   PTHREAD_HIDE;
305 char	*pthread__getenv(const char *) PTHREAD_HIDE;
306 __dead void	pthread__cancelled(void) PTHREAD_HIDE;
307 void	pthread__mutex_deferwake(pthread_t, pthread_mutex_t *) PTHREAD_HIDE;
308 int	pthread__checkpri(int) PTHREAD_HIDE;
309 int	pthread__add_specific(pthread_t, pthread_key_t, const void *) PTHREAD_HIDE;
310 
311 #ifndef pthread__smt_pause
312 #define	pthread__smt_pause()	/* nothing */
313 #endif
314 #ifndef pthread__smt_wake
315 #define	pthread__smt_wake()	/* nothing */
316 #endif
317 
318 /*
319  * Bits in the owner field of the lock that indicate lock state.  If the
320  * WRITE_LOCKED bit is clear, then the owner field is actually a count of
321  * the number of readers.
322  */
323 #define	RW_HAS_WAITERS		0x01	/* lock has waiters */
324 #define	RW_WRITE_WANTED		0x02	/* >= 1 waiter is a writer */
325 #define	RW_WRITE_LOCKED		0x04	/* lock is currently write locked */
326 #define	RW_UNUSED		0x08	/* currently unused */
327 
328 #define	RW_FLAGMASK		0x0f
329 
330 #define	RW_READ_COUNT_SHIFT	4
331 #define	RW_READ_INCR		(1 << RW_READ_COUNT_SHIFT)
332 #define	RW_THREAD		((uintptr_t)-RW_READ_INCR)
333 
334 #endif /* _LIB_PTHREAD_INT_H */
335