summaryrefslogtreecommitdiff
path: root/lib/libpthread/uthread/pthread_private.h
blob: 69a36e13477c2a0e661e68066b1a9265d554360c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
/*
 * Copyright (c) 1995-1998 John Birrell <jb@cimlogic.com.au>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by John Birrell.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY JOHN BIRRELL AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Private thread definitions for the uthread kernel.
 *
 * $OpenBSD: pthread_private.h,v 1.17 1999/09/08 08:21:47 espie Exp $
 *
 */

#ifndef _PTHREAD_PRIVATE_H
#define _PTHREAD_PRIVATE_H

#include <paths.h>

/*
 * Include files.
 */
#include <setjmp.h>
#include <signal.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sched.h>
#include <spinlock.h>
#include <pthread_np.h>
#ifndef _NO_UTHREAD_MACHDEP
#include "uthread_machdep.h"
#endif

/*
 * Kernel fatal error handler macro.
 */
#define PANIC(string)   _thread_exit(__FILE__,__LINE__,string)

/* Output debug messages like this: */
#define	stdout_debug(_x)	_thread_sys_write(1,_x,strlen(_x));
#define	stderr_debug(_x)	_thread_sys_write(2,_x,strlen(_x));


/*
 * Priority queue manipulation macros:
 */
#define PTHREAD_PRIOQ_INSERT_HEAD(thrd)	_pq_insert_head(&_readyq,thrd)
#define PTHREAD_PRIOQ_INSERT_TAIL(thrd)	_pq_insert_tail(&_readyq,thrd)
#define PTHREAD_PRIOQ_REMOVE(thrd)	_pq_remove(&_readyq,thrd)
#define PTHREAD_PRIOQ_FIRST		_pq_first(&_readyq)

/*
 * Waiting queue manipulation macros:
 */
#define PTHREAD_WAITQ_INSERT(thrd)	TAILQ_INSERT_TAIL(&_waitingq,thrd,pqe)
#define PTHREAD_WAITQ_REMOVE(thrd)	TAILQ_REMOVE(&_waitingq,thrd,pqe)

/*
 * State change macro without scheduling queue change:
 */
#define PTHREAD_SET_STATE(thrd, newstate) {				\
	(thrd)->state = newstate;					\
	(thrd)->fname = __FILE__;					\
	(thrd)->lineno = __LINE__;					\
}

/*
 * State change macro with scheduling queue change - This must be
 * called with preemption deferred (see thread_kern_sched_[un]defer).
 */
#define PTHREAD_NEW_STATE(thrd, newstate) {				\
	if ((thrd)->state != newstate) {				\
		if ((thrd)->state == PS_RUNNING) {			\
			PTHREAD_PRIOQ_REMOVE(thrd);			\
			PTHREAD_WAITQ_INSERT(thrd);			\
		} else if (newstate == PS_RUNNING) { 			\
			PTHREAD_WAITQ_REMOVE(thrd);			\
			PTHREAD_PRIOQ_INSERT_TAIL(thrd);		\
		}							\
	}								\
	PTHREAD_SET_STATE(thrd, newstate);				\
}

/*
 * Define the signals to be used for scheduling.
 */
#if defined(_PTHREADS_COMPAT_SCHED)
#define _ITIMER_SCHED_TIMER	ITIMER_VIRTUAL
#define _SCHED_SIGNAL		SIGVTALRM
#else
#define _ITIMER_SCHED_TIMER	ITIMER_PROF
#define _SCHED_SIGNAL		SIGPROF
#endif

/*
 * Queue definitions.
 */
struct pthread_queue {
	struct pthread	*q_next;
	struct pthread	*q_last;
	void		*q_data;
};

/*
 * Priority queues.
 *
 * XXX It'd be nice if these were contained in uthread_priority_queue.[ch].
 */
typedef struct pq_list {
	TAILQ_HEAD(, pthread)	pl_head; /* list of threads at this priority */
	TAILQ_ENTRY(pq_list)	pl_link; /* link for queue of priority lists */
	int			pl_prio; /* the priority of this list */
	int			pl_queued; /* is this in the priority queue */
} pq_list_t;

typedef struct pq_queue {
	TAILQ_HEAD(, pq_list)	 pq_queue; /* queue of priority lists */
	pq_list_t		*pq_lists; /* array of all priority lists */
	int			 pq_size;  /* number of priority lists */
} pq_queue_t;


/*
 * Static queue initialization values. 
 */
#define PTHREAD_QUEUE_INITIALIZER { NULL, NULL, NULL }

/*
 * TailQ initialization values.
 */
#define TAILQ_INITIALIZER { NULL, NULL }

/* 
 * Mutex definitions.
 */
union pthread_mutex_data {
	void	*m_ptr;
	int	m_count;
};

struct pthread_mutex {
	enum pthread_mutextype		m_type;
	int				m_protocol;
	TAILQ_HEAD(mutex_head, pthread)	m_queue;
	struct pthread			*m_owner;
	union pthread_mutex_data	m_data;
	long				m_flags;
	int				m_refcount;

	/*
	 * Used for priority inheritence and protection.
	 *
	 *   m_prio       - For priority inheritence, the highest active
	 *                  priority (threads locking the mutex inherit
	 *                  this priority).  For priority protection, the
	 *                  ceiling priority of this mutex.
	 *   m_saved_prio - mutex owners inherited priority before
	 *                  taking the mutex, restored when the owner
	 *                  unlocks the mutex.
	 */
	int				m_prio;
	int				m_saved_prio;

	/*
	 * Link for list of all mutexes a thread currently owns.
	 */
	TAILQ_ENTRY(pthread_mutex)	m_qe;

	/*
	 * Lock for accesses to this structure.
	 */
	spinlock_t			lock;
};

/*
 * Flags for mutexes. 
 */
#define MUTEX_FLAGS_PRIVATE	0x01
#define MUTEX_FLAGS_INITED	0x02
#define MUTEX_FLAGS_BUSY	0x04

/*
 * Static mutex initialization values. 
 */
#define PTHREAD_MUTEX_STATIC_INITIALIZER   \
	{ PTHREAD_MUTEX_DEFAULT, PTHREAD_PRIO_NONE, TAILQ_INITIALIZER, \
	NULL, { NULL }, 0, 0, 0, 0, TAILQ_INITIALIZER, \
	_SPINLOCK_INITIALIZER }

struct pthread_mutex_attr {
	enum pthread_mutextype	m_type;
	int			m_protocol;
	int			m_ceiling;
	long			m_flags;
};

/* 
 * Condition variable definitions.
 */
enum pthread_cond_type {
	COND_TYPE_FAST,
	COND_TYPE_MAX
};

struct pthread_cond {
	enum pthread_cond_type		c_type;
	TAILQ_HEAD(cond_head, pthread)	c_queue;
	pthread_mutex_t			c_mutex;
	void				*c_data;
	long				c_flags;

	/*
	 * Lock for accesses to this structure.
	 */
	spinlock_t			lock;
};

struct pthread_cond_attr {
	enum pthread_cond_type	c_type;
	long			c_flags;
};

/*
 * Flags for condition variables.
 */
#define COND_FLAGS_PRIVATE	0x01
#define COND_FLAGS_INITED	0x02
#define COND_FLAGS_BUSY		0x04

/*
 * Static cond initialization values. 
 */
#define PTHREAD_COND_STATIC_INITIALIZER    \
 	{ COND_TYPE_FAST, PTHREAD_QUEUE_INITIALIZER, NULL, NULL, \
 	0, _SPINLOCK_INITIALIZER }

/*
 * Cleanup definitions.
 */
struct pthread_cleanup {
	struct pthread_cleanup	*next;
	void			(*routine) ();
	void			*routine_arg;
};

struct pthread_attr {
	int	sched_policy;
	int	sched_inherit;
	int	sched_interval;
	int	prio;
	int	suspend;
	int	flags;
	void	*arg_attr;
	void	(*cleanup_attr) ();
	void	*stackaddr_attr;
	size_t	stacksize_attr;
};

/*
 * Thread creation state attributes.
 */
#define PTHREAD_CREATE_RUNNING			0
#define PTHREAD_CREATE_SUSPENDED		1

/*
 * Miscellaneous definitions.
 */
#define PTHREAD_STACK_DEFAULT			65536
#define PTHREAD_DEFAULT_PRIORITY		64
#define PTHREAD_MAX_PRIORITY			126
#define PTHREAD_MIN_PRIORITY			0
#define _POSIX_THREAD_ATTR_STACKSIZE

/*
 * Clock resolution in nanoseconds.
 */
#define CLOCK_RES_NSEC				10000000

/*
 * Number of microseconds between incremental priority updates for
 * threads that are ready to run, but denied being run.
 */
#define INC_PRIO_USEC				500000

/*
 * Time slice period in microseconds.
 */
#define TIMESLICE_USEC				100000

struct pthread_key {
	spinlock_t	lock;
	volatile int	allocated;
	volatile int	count;
	void            (*destructor) ();
};

struct pthread_rwlockattr {
	int		pshared;
};

struct pthread_rwlock {
	pthread_mutex_t	lock;	/* monitor lock */
	int		state;	/* 0 = idle  >0 = # of readers  -1 = writer */
	pthread_cond_t	read_signal;
	pthread_cond_t	write_signal;
	int		blocked_writers;
};

/*
 * Thread states.
 */
enum pthread_state {
	PS_RUNNING,
	PS_SIGTHREAD,
	PS_MUTEX_WAIT,
	PS_COND_WAIT,
	PS_FDLR_WAIT,
	PS_FDLW_WAIT,
	PS_FDR_WAIT,
	PS_FDW_WAIT,
	PS_FILE_WAIT,
	PS_SELECT_WAIT,
	PS_SLEEP_WAIT,
	PS_WAIT_WAIT,
	PS_SIGSUSPEND,
	PS_SIGWAIT,
	PS_SPINBLOCK,
	PS_JOIN,
	PS_SUSPENDED,
	PS_DEAD,
	PS_DEADLOCK,
	PS_STATE_MAX
};


/*
 * File descriptor locking definitions.
 */
#define FD_READ             0x1
#define FD_WRITE            0x2
#define FD_RDWR             (FD_READ | FD_WRITE)

/*
 * File descriptor table structure.
 */
struct fd_table_entry {
	/*
	 * Lock for accesses to this file descriptor table
	 * entry. This is passed to _spinlock() to provide atomic
	 * access to this structure. It does *not* represent the
	 * state of the lock on the file descriptor.
	 */
	spinlock_t		lock;
	struct pthread_queue	r_queue;	/* Read queue.                        */
	struct pthread_queue	w_queue;	/* Write queue.                       */
	struct pthread		*r_owner;	/* Ptr to thread owning read lock.    */
	struct pthread		*w_owner;	/* Ptr to thread owning write lock.   */
	const char		*r_fname;	/* Ptr to read lock source file name  */
	int			r_lineno;	/* Read lock source line number.      */
	const char		*w_fname;	/* Ptr to write lock source file name */
	int			w_lineno;	/* Write lock source line number.     */
	int			r_lockcount;	/* Count for FILE read locks.         */
	int			w_lockcount;	/* Count for FILE write locks.        */
	int			flags;		/* Flags used in open.                */
};

struct pthread_select_data {
	int	nfds;
	fd_set	readfds;
	fd_set	writefds;
	fd_set	exceptfds;
};

union pthread_wait_data {
	pthread_mutex_t	mutex;
	pthread_cond_t	cond;
	const sigset_t	*sigwait;	/* Waiting on a signal in sigwait */
	struct {
		short	fd;		/* Used when thread waiting on fd */
		short	branch;		/* Line number, for debugging.    */
		const char *fname;	/* Source file name for debugging.*/
	} fd;
	struct pthread_select_data * select_data;
	spinlock_t	*spinlock;
};

/*
 * Thread structure.
 */
struct pthread {
	/*
	 * Magic value to help recognize a valid thread structure
	 * from an invalid one:
	 */
#define	PTHREAD_MAGIC		((u_int32_t) 0xd09ba115)
	u_int32_t		magic;
	char			*name;

	/*
	 * Lock for accesses to this thread structure.
	 */
	spinlock_t		lock;

	/*
	 * Pointer to the next thread in the thread linked list.
	 */
	struct pthread	*nxt;

	/*
	 * Pointer to the next thread in the dead thread linked list.
	 */
	struct pthread	*nxt_dead;

	/*
	 * Thread start routine, argument, stack pointer and thread
	 * attributes.
	 */
	void			*(*start_routine)(void *);
	void			*arg;
	void			*stack;
	struct pthread_attr	attr;

	/*
	 * Saved signal context used in call to sigreturn by
	 * _thread_kern_sched if sig_saved is TRUE.
	 */
	struct  sigcontext saved_sigcontext;

	/*
	 * TRUE if the last state saved was a signal context. FALSE if the
	 * last state saved was a jump buffer.
	 */
	int	sig_saved;

	/*
	 * Cancelability state.
	 */
	int	cancelstate;
	int	canceltype;

	/*
	 * Current signal mask and pending signals.
	 */
	sigset_t	sigmask;
	sigset_t	sigpend;

	/* Thread state: */
	enum pthread_state	state;

	/* Time that this thread was last made active. */
	struct  timeval		last_active;

	/* Time that this thread was last made inactive. */
	struct  timeval		last_inactive;

	/*
	 * Number of microseconds accumulated by this thread when
	 * time slicing is active.
	 */
	long	slice_usec;

	/*
	 * Cumulative times spent in thread
	 */
	struct	timeval		ru_utime;
	struct	timeval		ru_stime;

	/*
	 * Incremental priority accumulated by thread while it is ready to
	 * run but is denied being run.
	 */
	int	inc_prio;

	/*
	 * Time to wake up thread. This is used for sleeping threads and
	 * for any operation which may time out (such as select).
	 */
	struct timespec	wakeup_time;

	/* TRUE if operation has timed out. */
	int	timeout;

	/*
	 * Error variable used instead of errno. The function __error()
	 * returns a pointer to this. 
	 */
	int	error;

	/* Join queue for waiting threads: */
	struct pthread_queue	join_queue;

	/*
	 * The current thread can belong to only one scheduling queue
	 * at a time (ready or waiting queue).  It can also belong to
	 * a queue of threads waiting on mutexes or condition variables.
	 * Use pqe for the scheduling queue link (both ready and waiting),
	 * and qe for other links (mutexes and condition variables).
	 *
	 * Pointer to queue (if any) on which the current thread is waiting.
	 *
	 * XXX The queuing should be changed to use the TAILQ entry below.
	 * XXX For the time being, it's hybrid.
	 */
	struct pthread_queue	*queue;

	/* Pointer to next element in queue. */
	struct pthread	*qnxt;

	/* Priority queue entry for this thread: */
	TAILQ_ENTRY(pthread)	pqe;

	/* Queue entry for this thread: */
	TAILQ_ENTRY(pthread)	qe;

	/* Wait data. */
	union pthread_wait_data data;

	/*
	 * Set to TRUE if a blocking operation was
	 * interrupted by a signal:
	 */
	int		interrupted;

	/* Signal number when in state PS_SIGWAIT: */
	int		signo;

	/*
	 * Set to non-zero when this thread has deferred thread
	 * scheduling.  We allow for recursive deferral.
	 */
	int		sched_defer_count;

	/*
	 * Set to TRUE if this thread should yield after undeferring
	 * thread scheduling.
	 */
	int		yield_on_sched_undefer;

	/* Miscellaneous data. */
	int		flags;
#define PTHREAD_FLAGS_PRIVATE	0x0001
#define PTHREAD_EXITING		0x0002
#define PTHREAD_FLAGS_QUEUED	0x0004	/* in queue (qe is used) */
#define PTHREAD_FLAGS_TRACE	0x0008
#define PTHREAD_CANCELLING	0x0010	/* thread has been cancelled */
#define PTHREAD_AT_CANCEL_POINT	0x0020	/* thread at cancel point */

	/*
	 * Base priority is the user setable and retrievable priority
	 * of the thread.  It is only affected by explicit calls to
	 * set thread priority and upon thread creation via a thread
	 * attribute or default priority.
	 */
	char		base_priority;

	/*
	 * Inherited priority is the priority a thread inherits by
	 * taking a priority inheritence or protection mutex.  It
	 * is not affected by base priority changes.  Inherited
	 * priority defaults to and remains 0 until a mutex is taken
	 * that is being waited on by any other thread whose priority
	 * is non-zero.
	 */
	char		inherited_priority;

	/*
	 * Active priority is always the maximum of the threads base
	 * priority and inherited priority.  When there is a change
	 * in either the real or inherited priority, the active
	 * priority must be recalculated.
	 */
	char		active_priority;

	/* Number of priority ceiling or protection mutexes owned. */
	int		priority_mutex_count;

	/*
	 * Queue of currently owned mutexes.
	 */
	TAILQ_HEAD(, pthread_mutex)	mutexq;

	void		*ret;
	const void	**specific_data;
	int		specific_data_count;

	/* Cleanup handlers Link List */
	struct pthread_cleanup *cleanup;
	const char		*fname;	/* Ptr to source file name  */
	int			lineno;	/* Source line number.      */

	/* 
	 * Saved jump buffer used in call to longjmp by _thread_kern_sched
	 * if sig_saved is FALSE.
	 */
	_machdep_jmp_buf	saved_jmp_buf;

#ifndef _UTHREAD_MACHDEP
	/* Machine dependent information */
	struct _machdep_struct	_machdep;
#endif
};

/*
 * Global variables for the uthread kernel.
 */

/* Kernel thread structure used when there are no running threads: */
extern struct pthread   volatile _thread_kern_thread;
extern struct pthread   * volatile _thread_kern_threadp;

/* Ptr to the thread structure for the running thread: */
extern struct pthread   * volatile _thread_run;

/* Ptr to the thread structure for the last user thread to run: */
extern struct pthread	* volatile _last_user_thread;

/*
 * Ptr to the thread running in single-threaded mode or NULL if
 * running multi-threaded (default POSIX behaviour).
 */
extern struct pthread   * volatile _thread_single;

/* Ptr to the first thread in the thread linked list: */
extern struct pthread   * volatile _thread_link_list;

/*
 * Array of kernel pipe file descriptors that are used to ensure that
 * no signals are missed in calls to _select.
 */
extern int              _thread_kern_pipe[2];
extern int              _thread_kern_in_select;
extern int              _thread_kern_in_sched;

/* Last time that an incremental priority update was performed: */
extern struct timeval   kern_inc_prio_time;

/* Dead threads: */
extern struct pthread * volatile _thread_dead;

/* Initial thread: */
extern struct pthread *_thread_initial;

/* Default thread attributes: */
extern struct pthread_attr pthread_attr_default;

/* Default mutex attributes: */
extern struct pthread_mutex_attr pthread_mutexattr_default;

/* Default condition variable attributes: */
extern struct pthread_cond_attr pthread_condattr_default;

/*
 * Standard I/O file descriptors need special flag treatment since
 * setting one to non-blocking does all on *BSD. Sigh. This array
 * is used to store the initial flag settings.
 */
extern int	_pthread_stdio_flags[3];

/* File table information: */
extern struct fd_table_entry **_thread_fd_table;
extern const int dtablecount;
extern int    _thread_dtablesize;

/* Garbage collector mutex and condition variable. */
extern pthread_mutex_t _gc_mutex;
extern pthread_cond_t _gc_cond;

/*
 * Array of signal actions for this process.
 */
extern struct  sigaction _thread_sigact[NSIG];

/*
 * Scheduling queues:
 */
extern pq_queue_t		_readyq;
typedef TAILQ_HEAD(, pthread)	_waitingq_t;
extern _waitingq_t		_waitingq;

/* Indicates that the waitingq now has threads ready to run. */
extern volatile int	_waitingq_check_reqd;

/* Thread switch hook. */
extern pthread_switch_routine_t _sched_switch_hook;

/*
 * Where SIGINFO writes thread states when /dev/tty cannot be opened
 */
#define INFO_DUMP_FILE  "/tmp/uthread.dump"

#ifdef	_LOCK_DEBUG
#define	_FD_LOCK(_fd,_type,_ts)		_thread_fd_lock_debug(_fd, _type, \
						_ts, __FILE__, __LINE__)
#define _FD_UNLOCK(_fd,_type)		_thread_fd_unlock_debug(_fd, _type, \
						__FILE__, __LINE__)
#else
#define	_FD_LOCK(_fd,_type,_ts)		_thread_fd_lock(_fd, _type, _ts)
#define _FD_UNLOCK(_fd,_type)		_thread_fd_unlock(_fd, _type)
#endif

/*
 * Function prototype definitions.
 */
__BEGIN_DECLS
int     _find_dead_thread(pthread_t);
int     _find_thread(pthread_t);
int     _thread_create(pthread_t *,const pthread_attr_t *,void *(*start_routine)(void *),void *,pthread_t);
int     _thread_fd_lock(int, int, struct timespec *);
int     _thread_fd_lock_debug(int, int, struct timespec *,const char *fname,int lineno);
void    _dispatch_signals(void);
void    _thread_signal(pthread_t, int);
void    _lock_thread(void);
void    _lock_thread_list(void);
void    _unlock_thread(void);
void    _unlock_thread_list(void);
int	_mutex_cv_lock(pthread_mutex_t *);
int	_mutex_cv_unlock(pthread_mutex_t *);
void	_mutex_notify_priochange(struct pthread *);
int	_pq_init(struct pq_queue *pq, int, int);
void	_pq_remove(struct pq_queue *pq, struct pthread *);
void	_pq_insert_head(struct pq_queue *pq, struct pthread *);
void	_pq_insert_tail(struct pq_queue *pq, struct pthread *);
struct pthread *_pq_first(struct pq_queue *pq);
void    _thread_exit(const char *, int, const char *)
		__attribute__((noreturn));
void    _thread_fd_unlock(int, int);
void    _thread_fd_unlock_debug(int, int, char *, int);
void    *_thread_cleanup(pthread_t);
void    _thread_cleanupspecific(void);
void    _thread_dump_info(void);
void    _thread_init(void);
void    _thread_kern_sched(struct sigcontext *);
void    _thread_kern_sched_state(enum pthread_state, const char *, int);
void	_thread_kern_sched_state_unlock(enum pthread_state state,
	    spinlock_t *lock, char *fname, int lineno);
void    _thread_kern_set_timeout(struct timespec *);
void    _thread_kern_sched_defer(void);
void    _thread_kern_sched_undefer(void);
void    _thread_sig_handler(int, int, struct sigcontext *);
void    _thread_start(void);
void    _thread_start_sig_handler(void);
void	_thread_seterrno(pthread_t,int);
void    _thread_queue_init(struct pthread_queue *);
void    _thread_queue_enq(struct pthread_queue *, struct pthread *);
int     _thread_queue_remove(struct pthread_queue *, struct pthread *);
int     _thread_fd_table_init(int fd);
struct pthread *_thread_queue_get(struct pthread_queue *);
struct pthread *_thread_queue_deq(struct pthread_queue *);
pthread_addr_t _thread_gc(pthread_addr_t);
void	_thread_enter_cancellation_point(void);
void	_thread_leave_cancellation_point(void);
void	_thread_cancellation_point(void);
int	_thread_slow_atomic_lock(volatile _spinlock_lock_t *);
int	_thread_slow_atomic_is_locked(volatile _spinlock_lock_t *);

/* #include <signal.h> */
#ifdef _USER_SIGNAL_H
int     _thread_sys_sigaction(int, const struct sigaction *, struct sigaction *);
int     _thread_sys_sigpending(sigset_t *);
int     _thread_sys_sigprocmask(int, const sigset_t *, sigset_t *);
int     _thread_sys_sigsuspend(const sigset_t *);
int     _thread_sys_siginterrupt(int, int);
int     _thread_sys_sigpause(int);
int     _thread_sys_sigreturn(struct sigcontext *);
int     _thread_sys_sigaltstack(const struct sigaltstack *, struct sigaltstack *);
int     _thread_sys_sigvec(int, struct sigvec *, struct sigvec *);
void    _thread_sys_psignal(unsigned int, const char *);
void    (*_thread_sys_signal(int, void (*)(int)))(int);
#endif

/* #include <sys/stat.h> */
#ifdef  _SYS_STAT_H_
int     _thread_sys_fchmod(int, mode_t);
int     _thread_sys_fstat(int, struct stat *);
int     _thread_sys_fchflags(int, unsigned int);
#endif

/* #include <sys/mount.h> */
#ifdef  _SYS_MOUNT_H_
int     _thread_sys_fstatfs(int, struct statfs *);
#endif
int     _thread_sys_pipe(int *);

/* #include <sys/socket.h> */
#ifdef  _SYS_SOCKET_H_
int     _thread_sys_accept(int, struct sockaddr *, socklen_t *);
int     _thread_sys_bind(int, const struct sockaddr *, socklen_t);
int     _thread_sys_connect(int, const struct sockaddr *, socklen_t);
int     _thread_sys_getpeername(int, struct sockaddr *, socklen_t *);
int     _thread_sys_getsockname(int, struct sockaddr *, socklen_t *);
int     _thread_sys_getsockopt(int, int, int, void *, socklen_t *);
int     _thread_sys_listen(int, int);
int     _thread_sys_setsockopt(int, int, int, const void *, socklen_t);
int     _thread_sys_shutdown(int, int);
int     _thread_sys_socket(int, int, int);
int     _thread_sys_socketpair(int, int, int, int *);
ssize_t _thread_sys_recv(int, void *, size_t, int);
ssize_t _thread_sys_recvfrom(int, void *, size_t, int, struct sockaddr *, socklen_t *);
ssize_t _thread_sys_recvmsg(int, struct msghdr *, int);
ssize_t _thread_sys_send(int, const void *, size_t, int);
ssize_t _thread_sys_sendmsg(int, const struct msghdr *, int);
ssize_t _thread_sys_sendto(int, const void *,size_t, int, const struct sockaddr *, socklen_t);
#endif

/* #include <stdio.h> */
#ifdef  _STDIO_H_
FILE    *_thread_sys_fdopen(int, const char *);
FILE    *_thread_sys_fopen(const char *, const char *);
FILE    *_thread_sys_freopen(const char *, const char *, FILE *);
FILE    *_thread_sys_popen(const char *, const char *);
FILE    *_thread_sys_tmpfile(void);
char    *_thread_sys_ctermid(char *);
char    *_thread_sys_cuserid(char *);
char    *_thread_sys_fgetln(FILE *, size_t *);
char    *_thread_sys_fgets(char *, int, FILE *);
char    *_thread_sys_gets(char *);
char    *_thread_sys_tempnam(const char *, const char *);
char    *_thread_sys_tmpnam(char *);
int     _thread_sys_fclose(FILE *);
int     _thread_sys_feof(FILE *);
int     _thread_sys_ferror(FILE *);
int     _thread_sys_fflush(FILE *);
int     _thread_sys_fgetc(FILE *);
int     _thread_sys_fgetpos(FILE *, fpos_t *);
int     _thread_sys_fileno(FILE *);
int     _thread_sys_fprintf(FILE *, const char *, ...);
int     _thread_sys_fpurge(FILE *);
int     _thread_sys_fputc(int, FILE *);
int     _thread_sys_fputs(const char *, FILE *);
int     _thread_sys_fscanf(FILE *, const char *, ...);
int     _thread_sys_fseek(FILE *, long, int);
int     _thread_sys_fsetpos(FILE *, const fpos_t *);
int     _thread_sys_getc(FILE *);
int     _thread_sys_getchar(void);
int     _thread_sys_getw(FILE *);
int     _thread_sys_pclose(FILE *);
int     _thread_sys_printf(const char *, ...);
int     _thread_sys_putc(int, FILE *);
int     _thread_sys_putchar(int);
int     _thread_sys_puts(const char *);
int     _thread_sys_putw(int, FILE *);
int     _thread_sys_remove(const char *);
int     _thread_sys_rename (const char *, const char *);
int     _thread_sys_scanf(const char *, ...);
int     _thread_sys_setlinebuf(FILE *);
int     _thread_sys_setvbuf(FILE *, char *, int, size_t);
int     _thread_sys_snprintf(char *, size_t, const char *, ...);
int     _thread_sys_sprintf(char *, const char *, ...);
int     _thread_sys_sscanf(const char *, const char *, ...);
int     _thread_sys_ungetc(int, FILE *);
int     _thread_sys_vfprintf(FILE *, const char *, _BSD_VA_LIST_);
int     _thread_sys_vprintf(const char *, _BSD_VA_LIST_);
int     _thread_sys_vscanf(const char *, _BSD_VA_LIST_);
int     _thread_sys_vsnprintf(char *, size_t, const char *, _BSD_VA_LIST_);
int     _thread_sys_vsprintf(char *, const char *, _BSD_VA_LIST_);
int     _thread_sys_vsscanf(const char *, const char *, _BSD_VA_LIST_);
long    _thread_sys_ftell(FILE *);
size_t  _thread_sys_fread(void *, size_t, size_t, FILE *);
size_t  _thread_sys_fwrite(const void *, size_t, size_t, FILE *);
void    _thread_sys_clearerr(FILE *);
void    _thread_sys_perror(const char *);
void    _thread_sys_rewind(FILE *);
void    _thread_sys_setbuf(FILE *, char *);
void    _thread_sys_setbuffer(FILE *, char *, int);
#endif

/* #include <unistd.h> */
#ifdef  _UNISTD_H_
char    *_thread_sys_ttyname(int);
int     _thread_sys_close(int);
int     _thread_sys_dup(int);
int     _thread_sys_dup2(int, int);
int     _thread_sys_exect(const char *, char * const *, char * const *);
int     _thread_sys_execve(const char *, char * const *, char * const *);
int     _thread_sys_fchdir(int);
int     _thread_sys_fchown(int, uid_t, gid_t);
int     _thread_sys_fsync(int);
int     _thread_sys_ftruncate(int, off_t);
long    _thread_sys_fpathconf(int, int);
int     _thread_sys_pause(void);
int     _thread_sys_pipe(int *);
int     _thread_sys_select(int, fd_set *, fd_set *, fd_set *, struct timeval *);
off_t   _thread_sys_lseek(int, off_t, int);
pid_t   _thread_sys_fork(void);
pid_t   _thread_sys_tcgetpgrp(int);
ssize_t _thread_sys_read(int, void *, size_t);
ssize_t _thread_sys_write(int, const void *, size_t);
void	_thread_sys__exit(int)
		__attribute__((noreturn));
#endif

/* #include <fcntl.h> */
#ifdef  _SYS_FCNTL_H_
int     _thread_sys_creat(const char *, mode_t);
int     _thread_sys_fcntl(int, int, ...);
int     _thread_sys_flock(int, int);
int     _thread_sys_open(const char *, int, ...);
#endif

/* #include <sys/ioctl.h> */
#ifdef  _SYS_IOCTL_H_
int     _thread_sys_ioctl(int, unsigned long, ...);
#endif

/* #include <dirent.h> */
#ifdef  _DIRENT_H_
DIR     *___thread_sys_opendir2(const char *, int);
DIR     *_thread_sys_opendir(const char *);
int     _thread_sys_alphasort(const void *, const void *);
int     _thread_sys_scandir(const char *, struct dirent ***,
	int (*)(struct dirent *), int (*)(const void *, const void *));
int     _thread_sys_closedir(DIR *);
int     _thread_sys_getdirentries(int, char *, int, long *);
long    _thread_sys_telldir(const DIR *);
struct  dirent *_thread_sys_readdir(DIR *);
void    _thread_sys_rewinddir(DIR *);
void    _thread_sys_seekdir(DIR *, long);
#endif

/* #include <sys/uio.h> */
#ifdef  _SYS_UIO_H_
ssize_t _thread_sys_readv(int, const struct iovec *, int);
ssize_t _thread_sys_writev(int, const struct iovec *, int);
#endif

/* #include <sys/wait.h> */
#ifdef _SYS_WAIT_H_
pid_t   _thread_sys_wait(int *);
pid_t   _thread_sys_waitpid(pid_t, int *, int);
pid_t   _thread_sys_wait3(int *, int, struct rusage *);
pid_t   _thread_sys_wait4(pid_t, int *, int, struct rusage *);
#endif

/* #include <sys/poll.h> */
#ifdef _SYS_POLL_H_
int	_thread_sys_poll(struct pollfd[], int, int);
#endif

/* #include <sys/mman.h> */
int	_thread_sys_msync(void *, size_t, int);

__END_DECLS

#endif  /* !_PTHREAD_PRIVATE_H */