xref: /titanic_41/usr/src/uts/common/sys/thread.h (revision 0a44ef6d9afbfe052a7e975f55ea0d2954b62a82)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #ifndef	_SYS_THREAD_H
27 #define	_SYS_THREAD_H
28 
29 #pragma ident	"%Z%%M%	%I%	%E% SMI"
30 
31 #include <sys/types.h>
32 #include <sys/t_lock.h>
33 #include <sys/klwp.h>
34 #include <sys/time.h>
35 #include <sys/signal.h>
36 #include <sys/kcpc.h>
37 #if defined(__GNUC__) && defined(_ASM_INLINES) && defined(_KERNEL)
38 #include <asm/thread.h>
39 #endif
40 
41 #ifdef	__cplusplus
42 extern "C" {
43 #endif
44 
45 /*
46  * The thread object, its states, and the methods by which it
47  * is accessed.
48  */
49 
50 /*
51  * Values that t_state may assume. Note that t_state cannot have more
52  * than one of these flags set at a time.
53  */
54 #define	TS_FREE		0x00	/* Thread at loose ends */
55 #define	TS_SLEEP	0x01	/* Awaiting an event */
56 #define	TS_RUN		0x02	/* Runnable, but not yet on a processor */
57 #define	TS_ONPROC	0x04	/* Thread is being run on a processor */
58 #define	TS_ZOMB		0x08	/* Thread has died but hasn't been reaped */
59 #define	TS_STOPPED	0x10	/* Stopped, initial state */
60 
61 typedef struct ctxop {
62 	void	(*save_op)(void *);	/* function to invoke to save context */
63 	void	(*restore_op)(void *);	/* function to invoke to restore ctx */
64 	void	(*fork_op)(void *, void *);	/* invoke to fork context */
65 	void	(*lwp_create_op)(void *, void *);	/* lwp_create context */
66 	void	(*exit_op)(void *);	/* invoked during {thread,lwp}_exit() */
67 	void	(*free_op)(void *, int); /* function which frees the context */
68 	void	*arg;		/* argument to above functions, ctx pointer */
69 	struct ctxop *next;	/* next context ops */
70 } ctxop_t;
71 
72 /*
73  * The active file descriptor table.
74  * Each member of a_fd[] not equalling -1 represents an active fd.
75  * The structure is initialized on first use; all zeros means uninitialized.
76  */
77 typedef struct _afd {
78 	int	*a_fd;		/* pointer to list of fds */
79 	short	a_nfd;		/* number of entries in *a_fd */
80 	short	a_stale;	/* one of the active fds is being closed */
81 	int	a_buf[1];	/* buffer to which a_fd initially refers */
82 } afd_t;
83 
84 /*
85  * An lwpchan provides uniqueness when sleeping on user-level
86  * synchronization primitives.  The lc_wchan member is used
87  * for sleeping on kernel synchronization primitives.
88  */
89 typedef struct {
90 	caddr_t lc_wchan0;
91 	caddr_t lc_wchan;
92 } lwpchan_t;
93 
94 typedef struct _kthread	*kthread_id_t;
95 
96 struct turnstile;
97 struct trap_info;
98 struct upimutex;
99 struct kproject;
100 struct on_trap_data;
101 
102 /* Definition for kernel thread identifier type */
103 typedef uint64_t kt_did_t;
104 
105 typedef struct _kthread {
106 	struct _kthread	*t_link; /* dispq, sleepq, and free queue link */
107 
108 	caddr_t	t_stk;		/* base of stack (kernel sp value to use) */
109 	void	(*t_startpc)(void);	/* PC where thread started */
110 	struct cpu *t_bound_cpu; /* cpu bound to, or NULL if not bound */
111 	short	t_affinitycnt;	/* nesting level of kernel affinity-setting */
112 	short	t_bind_cpu;	/* user-specified CPU binding (-1 if none) */
113 	ushort_t t_flag;		/* modified only by current thread */
114 	ushort_t t_proc_flag;	/* modified holding ttproc(t)->p_lock */
115 	ushort_t t_schedflag;	/* modified holding thread_lock(t) */
116 	volatile char t_preempt;	/* don't preempt thread if set */
117 	volatile char t_preempt_lk;
118 	uint_t	t_state;	/* thread state	(protected by thread_lock) */
119 	pri_t	t_pri;		/* assigned thread priority */
120 	pri_t	t_epri;		/* inherited thread priority */
121 	char	t_writer;	/* sleeping in lwp_rwlock_lock(RW_WRITE_LOCK) */
122 	label_t	t_pcb;		/* pcb, save area when switching */
123 	lwpchan_t t_lwpchan;	/* reason for blocking */
124 #define	t_wchan0	t_lwpchan.lc_wchan0
125 #define	t_wchan		t_lwpchan.lc_wchan
126 	struct _sobj_ops *t_sobj_ops;
127 	id_t	t_cid;		/* scheduling class id */
128 	struct thread_ops *t_clfuncs;	/* scheduling class ops vector */
129 	void	*t_cldata;	/* per scheduling class specific data */
130 	ctxop_t	*t_ctx;		/* thread context */
131 	uintptr_t t_lofault;	/* ret pc for failed page faults */
132 	label_t	*t_onfault;	/* on_fault() setjmp buf */
133 	struct on_trap_data *t_ontrap;	/* on_trap() protection data */
134 	caddr_t t_swap;		/* swappable thread storage */
135 	lock_t	t_lock;		/* used to resume() a thread */
136 	uint8_t	t_lockstat;	/* set while thread is in lockstat code */
137 	uint8_t	t_pil;		/* interrupt thread PIL */
138 	disp_lock_t	t_pi_lock;	/* lock protecting t_prioinv list */
139 	char	t_nomigrate;	/* do not migrate if set */
140 	struct cpu	*t_cpu;	/* CPU that thread last ran on */
141 	struct cpu	*t_weakbound_cpu;	/* cpu weakly bound to */
142 	struct lgrp_ld	*t_lpl;	/* load average for home lgroup */
143 	void		*t_lgrp_reserv[2];	/* reserved for future */
144 	struct _kthread	*t_intr; /* interrupted (pinned) thread */
145 	uint64_t	t_intr_start;	/* timestamp when time slice began */
146 	kt_did_t	t_did;	/* thread id for kernel debuggers */
147 	caddr_t t_tnf_tpdp;	/* Trace facility data pointer */
148 	kcpc_ctx_t	*t_cpc_ctx;	/* performance counter context */
149 	kcpc_set_t	*t_cpc_set;	/* set this thread has bound */
150 
151 	/*
152 	 * non swappable part of the lwp state.
153 	 */
154 	id_t		t_tid;		/* lwp's id */
155 	id_t		t_waitfor;	/* target lwp id in lwp_wait() */
156 	struct sigqueue	*t_sigqueue;	/* queue of siginfo structs */
157 	k_sigset_t	t_sig;		/* signals pending to this process */
158 	k_sigset_t	t_extsig;	/* signals sent from another contract */
159 	k_sigset_t	t_hold;		/* hold signal bit mask */
160 	struct	_kthread *t_forw;	/* process's forward thread link */
161 	struct	_kthread *t_back;	/* process's backward thread link */
162 	struct	_kthread *t_thlink;	/* tid (lwpid) lookup hash link */
163 	klwp_t	*t_lwp;			/* thread's lwp pointer */
164 	struct	proc	*t_procp;	/* proc pointer */
165 	struct	t_audit_data *t_audit_data;	/* per thread audit data */
166 	struct	_kthread *t_next;	/* doubly linked list of all threads */
167 	struct	_kthread *t_prev;
168 	ushort_t t_whystop;		/* reason for stopping */
169 	ushort_t t_whatstop;		/* more detailed reason */
170 	int	t_dslot;		/* index in proc's thread directory */
171 	struct	pollstate *t_pollstate;	/* state used during poll(2) */
172 	struct	pollcache *t_pollcache;	/* to pass a pcache ptr by /dev/poll */
173 	struct	cred	*t_cred;	/* pointer to current cred */
174 	time_t	t_start;		/* start time, seconds since epoch */
175 	clock_t	t_lbolt;		/* lbolt at last clock_tick() */
176 	hrtime_t t_stoptime;		/* timestamp at stop() */
177 	uint_t	t_pctcpu;		/* %cpu at last clock_tick(), binary */
178 					/* point at right of high-order bit */
179 	short	t_sysnum;		/* system call number */
180 	kcondvar_t	t_delay_cv;
181 	kmutex_t	t_delay_lock;
182 
183 	/*
184 	 * Pointer to the dispatcher lock protecting t_state and state-related
185 	 * flags.  This pointer can change during waits on the lock, so
186 	 * it should be grabbed only by thread_lock().
187 	 */
188 	disp_lock_t	*t_lockp;	/* pointer to the dispatcher lock */
189 	ushort_t 	t_oldspl;	/* spl level before dispatcher locked */
190 	volatile char	t_pre_sys;	/* pre-syscall work needed */
191 	lock_t		t_lock_flush;	/* for lock_mutex_flush() impl */
192 	struct _disp	*t_disp_queue;	/* run queue for chosen CPU */
193 	clock_t		t_disp_time;	/* last time this thread was running */
194 	uint_t		t_kpri_req;	/* kernel priority required */
195 
196 	/*
197 	 * Post-syscall / post-trap flags.
198 	 * 	No lock is required to set these.
199 	 *	These must be cleared only by the thread itself.
200 	 *
201 	 *	t_astflag indicates that some post-trap processing is required,
202 	 *		possibly a signal or a preemption.  The thread will not
203 	 *		return to user with this set.
204 	 *	t_post_sys indicates that some unusualy post-system call
205 	 *		handling is required, such as an error or tracing.
206 	 *	t_sig_check indicates that some condition in ISSIG() must be
207 	 * 		checked, but doesn't prevent returning to user.
208 	 *	t_post_sys_ast is a way of checking whether any of these three
209 	 *		flags are set.
210 	 */
211 	union __tu {
212 		struct __ts {
213 			volatile char	_t_astflag;	/* AST requested */
214 			volatile char	_t_sig_check;	/* ISSIG required */
215 			volatile char	_t_post_sys;	/* post_syscall req */
216 			volatile char	_t_trapret;	/* call CL_TRAPRET */
217 		} _ts;
218 		volatile int	_t_post_sys_ast;	/* OR of these flags */
219 	} _tu;
220 #define	t_astflag	_tu._ts._t_astflag
221 #define	t_sig_check	_tu._ts._t_sig_check
222 #define	t_post_sys	_tu._ts._t_post_sys
223 #define	t_trapret	_tu._ts._t_trapret
224 #define	t_post_sys_ast	_tu._t_post_sys_ast
225 
226 	/*
227 	 * Real time microstate profiling.
228 	 */
229 					/* possible 4-byte filler */
230 	hrtime_t t_waitrq;		/* timestamp for run queue wait time */
231 	int	t_mstate;		/* current microstate */
232 	struct rprof {
233 		int	rp_anystate;		/* set if any state non-zero */
234 		uint_t	rp_state[NMSTATES];	/* mstate profiling counts */
235 	} *t_rprof;
236 
237 	/*
238 	 * There is a turnstile inserted into the list below for
239 	 * every priority inverted synchronization object that
240 	 * this thread holds.
241 	 */
242 
243 	struct turnstile *t_prioinv;
244 
245 	/*
246 	 * Pointer to the turnstile attached to the synchronization
247 	 * object where this thread is blocked.
248 	 */
249 
250 	struct turnstile *t_ts;
251 
252 	/*
253 	 * kernel thread specific data
254 	 *	Borrowed from userland implementation of POSIX tsd
255 	 */
256 	struct tsd_thread {
257 		struct tsd_thread *ts_next;	/* threads with TSD */
258 		struct tsd_thread *ts_prev;	/* threads with TSD */
259 		uint_t		  ts_nkeys;	/* entries in value array */
260 		void		  **ts_value;	/* array of value/key */
261 	} *t_tsd;
262 
263 	clock_t		t_stime;	/* time stamp used by the swapper */
264 	struct door_data *t_door;	/* door invocation data */
265 	kmutex_t	*t_plockp;	/* pointer to process's p_lock */
266 
267 	struct sc_shared *t_schedctl;	/* scheduler activations shared data */
268 	uintptr_t	t_sc_uaddr;	/* user-level address of shared data */
269 
270 	struct cpupart	*t_cpupart;	/* partition containing thread */
271 	int		t_bind_pset;	/* processor set binding */
272 
273 	struct copyops	*t_copyops;	/* copy in/out ops vector */
274 
275 	caddr_t		t_stkbase;	/* base of the the stack */
276 	struct page	*t_red_pp;	/* if non-NULL, redzone is mapped */
277 
278 	struct _afd	t_activefd;	/* active file descriptor table */
279 
280 	struct _kthread	*t_priforw;	/* sleepq per-priority sublist */
281 	struct _kthread	*t_priback;
282 
283 	struct sleepq	*t_sleepq;	/* sleep queue thread is waiting on */
284 	struct trap_info *t_panic_trap;	/* saved data from fatal trap */
285 	int		*t_lgrp_affinity;	/* lgroup affinity */
286 	struct upimutex	*t_upimutex;	/* list of upimutexes owned by thread */
287 	uint32_t	t_nupinest;	/* number of nested held upi mutexes */
288 	struct kproject *t_proj;	/* project containing this thread */
289 	uint8_t		t_unpark;	/* modified holding t_delay_lock */
290 	uint8_t		t_release;	/* lwp_release() waked up the thread */
291 	uint8_t		t_hatdepth;	/* depth of recursive hat_memloads */
292 	kcondvar_t	t_joincv;	/* cv used to wait for thread exit */
293 	void		*t_taskq;	/* for threads belonging to taskq */
294 	hrtime_t	t_anttime;	/* most recent time anticipatory load */
295 					/*	was added to an lgroup's load */
296 					/*	on this thread's behalf */
297 	char		*t_pdmsg;	/* privilege debugging message */
298 
299 	uint_t		t_predcache;	/* DTrace predicate cache */
300 	hrtime_t	t_dtrace_vtime;	/* DTrace virtual time */
301 	hrtime_t	t_dtrace_start;	/* DTrace slice start time */
302 
303 	uint8_t		t_dtrace_stop;	/* indicates a DTrace-desired stop */
304 	uint8_t		t_dtrace_sig;	/* signal sent via DTrace's raise() */
305 
306 	union __tdu {
307 		struct __tds {
308 			uint8_t	_t_dtrace_on;	/* hit a fasttrap tracepoint */
309 			uint8_t	_t_dtrace_step;	/* about to return to kernel */
310 			uint8_t	_t_dtrace_ret;	/* handling a return probe */
311 			uint8_t	_t_dtrace_ast;	/* saved ast flag */
312 #ifdef __amd64
313 			uint8_t	_t_dtrace_reg;	/* modified register */
314 #endif
315 		} _tds;
316 		ulong_t	_t_dtrace_ft;		/* bitwise or of these flags */
317 	} _tdu;
318 #define	t_dtrace_ft	_tdu._t_dtrace_ft
319 #define	t_dtrace_on	_tdu._tds._t_dtrace_on
320 #define	t_dtrace_step	_tdu._tds._t_dtrace_step
321 #define	t_dtrace_ret	_tdu._tds._t_dtrace_ret
322 #define	t_dtrace_ast	_tdu._tds._t_dtrace_ast
323 #ifdef __amd64
324 #define	t_dtrace_reg	_tdu._tds._t_dtrace_reg
325 #endif
326 
327 	uintptr_t	t_dtrace_pc;	/* DTrace saved pc from fasttrap */
328 	uintptr_t	t_dtrace_npc;	/* DTrace next pc from fasttrap */
329 	uintptr_t	t_dtrace_scrpc;	/* DTrace per-thread scratch location */
330 	uintptr_t	t_dtrace_astpc;	/* DTrace return sequence location */
331 #ifdef __amd64
332 	uint64_t	t_dtrace_regv;	/* DTrace saved reg from fasttrap */
333 #endif
334 	hrtime_t	t_hrtime;	/* high-res last time on cpu */
335 	kmutex_t	t_ctx_lock;	/* protects t_ctx in removectx() */
336 } kthread_t;
337 
338 /*
339  * Thread flag (t_flag) definitions.
340  *	These flags must be changed only for the current thread,
341  * 	and not during preemption code, since the code being
342  *	preempted could be modifying the flags.
343  *
344  *	For the most part these flags do not need locking.
345  *	The following flags will only be changed while the thread_lock is held,
346  *	to give assurrance that they are consistent with t_state:
347  *		T_WAKEABLE
348  */
349 #define	T_INTR_THREAD	0x0001	/* thread is an interrupt thread */
350 #define	T_WAKEABLE	0x0002	/* thread is blocked, signals enabled */
351 #define	T_TOMASK	0x0004	/* use lwp_sigoldmask on return from signal */
352 #define	T_TALLOCSTK	0x0008  /* thread structure allocated from stk */
353 #define	T_FORKALL	0x0010	/* thread was cloned by forkall() */
354 #define	T_WOULDBLOCK	0x0020	/* for lockfs */
355 #define	T_DONTBLOCK	0x0040	/* for lockfs */
356 #define	T_DONTPEND	0x0080	/* for lockfs */
357 #define	T_SYS_PROF	0x0100	/* profiling on for duration of system call */
358 #define	T_WAITCVSEM	0x0200	/* waiting for a lwp_cv or lwp_sema on sleepq */
359 #define	T_WATCHPT	0x0400	/* thread undergoing a watchpoint emulation */
360 #define	T_PANIC		0x0800	/* thread initiated a system panic */
361 #define	T_DFLTSTK	0x1000	/* stack is default size */
362 
363 /*
364  * Flags in t_proc_flag.
365  *	These flags must be modified only when holding the p_lock
366  *	for the associated process.
367  */
368 #define	TP_DAEMON	0x0001	/* this is an LWP_DAEMON lwp */
369 #define	TP_HOLDLWP	0x0002	/* hold thread's lwp */
370 #define	TP_TWAIT	0x0004	/* wait to be freed by lwp_wait() */
371 #define	TP_LWPEXIT	0x0008	/* lwp has exited */
372 #define	TP_PRSTOP	0x0010	/* thread is being stopped via /proc */
373 #define	TP_CHKPT	0x0020	/* thread is being stopped via CPR checkpoint */
374 #define	TP_EXITLWP	0x0040	/* terminate this lwp */
375 #define	TP_PRVSTOP	0x0080	/* thread is virtually stopped via /proc */
376 #define	TP_MSACCT	0x0100	/* collect micro-state accounting information */
377 #define	TP_STOPPING	0x0200	/* thread is executing stop() */
378 #define	TP_WATCHPT	0x0400	/* process has watchpoints in effect */
379 #define	TP_PAUSE	0x0800	/* process is being stopped via pauselwps() */
380 #define	TP_CHANGEBIND	0x1000	/* thread has a new cpu/cpupart binding */
381 #define	TP_ZTHREAD	0x2000	/* this is a kernel thread for a zone */
382 #define	TP_WATCHSTOP	0x4000	/* thread is stopping via holdwatch() */
383 
384 /*
385  * Thread scheduler flag (t_schedflag) definitions.
386  *	The thread must be locked via thread_lock() or equiv. to change these.
387  */
388 #define	TS_LOAD		0x0001	/* thread is in memory */
389 #define	TS_DONT_SWAP	0x0002	/* thread/lwp should not be swapped */
390 #define	TS_SWAPENQ	0x0004	/* swap thread when it reaches a safe point */
391 #define	TS_ON_SWAPQ	0x0008	/* thread is on the swap queue */
392 #define	TS_SIGNALLED	0x0010	/* thread was awakened by cv_signal() */
393 #define	TS_CSTART	0x0100	/* setrun() by continuelwps() */
394 #define	TS_UNPAUSE	0x0200	/* setrun() by unpauselwps() */
395 #define	TS_XSTART	0x0400	/* setrun() by SIGCONT */
396 #define	TS_PSTART	0x0800	/* setrun() by /proc */
397 #define	TS_RESUME	0x1000	/* setrun() by CPR resume process */
398 #define	TS_CREATE	0x2000	/* setrun() by syslwp_create() */
399 #define	TS_RUNQMATCH	0x4000	/* exact run queue balancing by setbackdq() */
400 #define	TS_ALLSTART	\
401 	(TS_CSTART|TS_UNPAUSE|TS_XSTART|TS_PSTART|TS_RESUME|TS_CREATE)
402 
403 /*
404  * No locking needed for AST field.
405  */
406 #define	aston(t)		((t)->t_astflag = 1)
407 #define	astoff(t)		((t)->t_astflag = 0)
408 
409 /* True if thread is stopped on an event of interest */
410 #define	ISTOPPED(t) ((t)->t_state == TS_STOPPED && \
411 			!((t)->t_schedflag & TS_PSTART))
412 
413 /* similar to ISTOPPED except the event of interest is CPR */
414 #define	CPR_ISTOPPED(t) ((t)->t_state == TS_STOPPED && \
415 			!((t)->t_schedflag & TS_RESUME))
416 
417 /*
418  * True if thread is virtually stopped (is or was asleep in
419  * one of the lwp_*() system calls and marked to stop by /proc.)
420  */
421 #define	VSTOPPED(t)	((t)->t_proc_flag & TP_PRVSTOP)
422 
423 /* similar to VSTOPPED except the point of interest is CPR */
424 #define	CPR_VSTOPPED(t)				\
425 	((t)->t_state == TS_SLEEP &&		\
426 	(t)->t_wchan0 != NULL &&		\
427 	((t)->t_flag & T_WAKEABLE) &&		\
428 	((t)->t_proc_flag & TP_CHKPT))
429 
430 /* True if thread has been stopped by hold*() or was created stopped */
431 #define	SUSPENDED(t) ((t)->t_state == TS_STOPPED && \
432 	((t)->t_schedflag & (TS_CSTART|TS_UNPAUSE)) != (TS_CSTART|TS_UNPAUSE))
433 
434 /* True if thread possesses an inherited priority */
435 #define	INHERITED(t)	((t)->t_epri != 0)
436 
437 /* The dispatch priority of a thread */
438 #define	DISP_PRIO(t) ((t)->t_epri > (t)->t_pri ? (t)->t_epri : (t)->t_pri)
439 
440 /* The assigned priority of a thread */
441 #define	ASSIGNED_PRIO(t)	((t)->t_pri)
442 
443 /*
444  * Macros to determine whether a thread can be swapped.
445  * If t_lock is held, the thread is either on a processor or being swapped.
446  */
447 #define	SWAP_OK(t)	(!LOCK_HELD(&(t)->t_lock))
448 
449 /*
450  * proctot(x)
451  *	convert a proc pointer to a thread pointer. this only works with
452  *	procs that have only one lwp.
453  *
454  * proctolwp(x)
455  *	convert a proc pointer to a lwp pointer. this only works with
456  *	procs that have only one lwp.
457  *
458  * ttolwp(x)
459  *	convert a thread pointer to its lwp pointer.
460  *
461  * ttoproc(x)
462  *	convert a thread pointer to its proc pointer.
463  *
464  * ttoproj(x)
465  * 	convert a thread pointer to its project pointer.
466  *
467  * lwptot(x)
468  *	convert a lwp pointer to its thread pointer.
469  *
470  * lwptoproc(x)
471  *	convert a lwp to its proc pointer.
472  */
473 #define	proctot(x)	((x)->p_tlist)
474 #define	proctolwp(x)	((x)->p_tlist->t_lwp)
475 #define	ttolwp(x)	((x)->t_lwp)
476 #define	ttoproc(x)	((x)->t_procp)
477 #define	ttoproj(x)	((x)->t_proj)
478 #define	lwptot(x)	((x)->lwp_thread)
479 #define	lwptoproc(x)	((x)->lwp_procp)
480 
481 #define	t_pc		t_pcb.val[0]
482 #define	t_sp		t_pcb.val[1]
483 
484 #ifdef	_KERNEL
485 
486 extern	kthread_t	*threadp(void);	/* inline, returns thread pointer */
487 #define	curthread	(threadp())		/* current thread pointer */
488 #define	curproc		(ttoproc(curthread))	/* current process pointer */
489 #define	curproj		(ttoproj(curthread))	/* current project pointer */
490 
491 extern	struct _kthread	t0;		/* the scheduler thread */
492 extern	kmutex_t	pidlock;	/* global process lock */
493 
494 /*
495  * thread_free_lock is used by the clock thread to keep a thread
496  * from being freed while it is being examined.
497  */
498 extern	kmutex_t	thread_free_lock;
499 
500 /*
501  * Routines to change the priority and effective priority
502  * of a thread-locked thread, whatever its state.
503  */
504 extern int	thread_change_pri(kthread_t *t, pri_t disp_pri, int front);
505 extern void	thread_change_epri(kthread_t *t, pri_t disp_pri);
506 
507 /*
508  * Routines that manipulate the dispatcher lock for the thread.
509  * The locking heirarchy is as follows:
510  *	cpu_lock > sleepq locks > run queue locks
511  */
512 void	thread_transition(kthread_t *); /* move to transition lock */
513 void	thread_stop(kthread_t *);	/* move to stop lock */
514 void	thread_lock(kthread_t *);	/* lock thread and its queue */
515 void	thread_lock_high(kthread_t *);	/* lock thread and its queue */
516 void	thread_onproc(kthread_t *, struct cpu *); /* set onproc state lock */
517 
518 #define	thread_unlock(t)		disp_lock_exit((t)->t_lockp)
519 #define	thread_unlock_high(t)		disp_lock_exit_high((t)->t_lockp)
520 #define	thread_unlock_nopreempt(t)	disp_lock_exit_nopreempt((t)->t_lockp)
521 
522 #define	THREAD_LOCK_HELD(t)	(DISP_LOCK_HELD((t)->t_lockp))
523 
524 extern disp_lock_t transition_lock;	/* lock protecting transiting threads */
525 extern disp_lock_t stop_lock;		/* lock protecting stopped threads */
526 
527 caddr_t	thread_stk_init(caddr_t);	/* init thread stack */
528 
529 #endif	/* _KERNEL */
530 
531 /*
532  * Macros to indicate that the thread holds resources that could be critical
533  * to other kernel threads, so this thread needs to have kernel priority
534  * if it blocks or is preempted.  Note that this is not necessary if the
535  * resource is a mutex or a writer lock because of priority inheritance.
536  *
537  * The only way one thread may legally manipulate another thread's t_kpri_req
538  * is to hold the target thread's thread lock while that thread is asleep.
539  * (The rwlock code does this to implement direct handoff to waiting readers.)
540  */
541 #define	THREAD_KPRI_REQUEST()	(curthread->t_kpri_req++)
542 #define	THREAD_KPRI_RELEASE()	(curthread->t_kpri_req--)
543 #define	THREAD_KPRI_RELEASE_N(n) (curthread->t_kpri_req -= (n))
544 
545 /*
546  * Macro to change a thread's priority.
547  */
548 #define	THREAD_CHANGE_PRI(t, pri) {					\
549 	pri_t __new_pri = (pri);					\
550 	DTRACE_SCHED2(change__pri, kthread_t *, (t), pri_t, __new_pri);	\
551 	(t)->t_pri = __new_pri;						\
552 }
553 
554 /*
555  * Macro to indicate that a thread's priority is about to be changed.
556  */
557 #define	THREAD_WILLCHANGE_PRI(t, pri) {					\
558 	DTRACE_SCHED2(change__pri, kthread_t *, (t), pri_t, (pri));	\
559 }
560 
561 /*
562  * Macros to change thread state and the associated lock.
563  */
564 #define	THREAD_SET_STATE(tp, state, lp) \
565 		((tp)->t_state = state, (tp)->t_lockp = lp)
566 
567 /*
568  * Point it at the transition lock, which is always held.
569  * The previosly held lock is dropped.
570  */
571 #define	THREAD_TRANSITION(tp) 	thread_transition(tp);
572 /*
573  * Set the thread's lock to be the transition lock, without dropping
574  * previosly held lock.
575  */
576 #define	THREAD_TRANSITION_NOLOCK(tp) 	((tp)->t_lockp = &transition_lock)
577 
578 /*
579  * Put thread in run state, and set the lock pointer to the dispatcher queue
580  * lock pointer provided.  This lock should be held.
581  */
582 #define	THREAD_RUN(tp, lp)	THREAD_SET_STATE(tp, TS_RUN, lp)
583 
584 /*
585  * Put thread in run state, and set the lock pointer to the dispatcher queue
586  * lock pointer provided (i.e., the "swapped_lock").  This lock should be held.
587  */
588 #define	THREAD_SWAP(tp, lp)	THREAD_SET_STATE(tp, TS_RUN, lp)
589 
590 /*
591  * Put the thread in zombie state and set the lock pointer to NULL.
592  * The NULL will catch anything that tries to lock a zombie.
593  */
594 #define	THREAD_ZOMB(tp)		THREAD_SET_STATE(tp, TS_ZOMB, NULL)
595 
596 /*
597  * Set the thread into ONPROC state, and point the lock at the CPUs
598  * lock for the onproc thread(s).  This lock should be held, so the
599  * thread deoes not become unlocked, since these stores can be reordered.
600  */
601 #define	THREAD_ONPROC(tp, cpu)	\
602 		THREAD_SET_STATE(tp, TS_ONPROC, &(cpu)->cpu_thread_lock)
603 
604 /*
605  * Set the thread into the TS_SLEEP state, and set the lock pointer to
606  * to some sleep queue's lock.  The new lock should already be held.
607  */
608 #define	THREAD_SLEEP(tp, lp)	{				\
609 			disp_lock_t	*tlp;			\
610 			tlp = (tp)->t_lockp;			\
611 			THREAD_SET_STATE(tp, TS_SLEEP, lp);	\
612 			disp_lock_exit_high(tlp);		\
613 			}
614 
615 /*
616  * Interrupt threads are created in TS_FREE state, and their lock
617  * points at the associated CPU's lock.
618  */
619 #define	THREAD_FREEINTR(tp, cpu)	\
620 		THREAD_SET_STATE(tp, TS_FREE, &(cpu)->cpu_thread_lock)
621 
622 
623 #ifdef	__cplusplus
624 }
625 #endif
626 
627 #endif /* _SYS_THREAD_H */
628