OpenSolaris Launch

1 files changed, 632 insertions, 0 deletions

diff --git a/usr/src/uts/common/sys/thread.h b/usr/src/uts/common/sys/thread.h
new file mode 100644
index 0000000000..4966fb3516
--- /dev/null
+++ b/usr/src/uts/common/sys/thread.h
@@ -0,0 +1,632 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef	_SYS_THREAD_H
+#define	_SYS_THREAD_H
+
+#pragma ident	"%Z%%M%	%I%	%E% SMI"
+
+#include <sys/types.h>
+#include <sys/t_lock.h>
+#include <sys/klwp.h>
+#include <sys/time.h>
+#include <sys/signal.h>
+#include <sys/kcpc.h>
+#if defined(__GNUC__) && defined(_ASM_INLINES) && defined(_KERNEL)
+#include <asm/thread.h>
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/*
+ * The thread object, its states, and the methods by which it
+ * is accessed.
+ */
+
+/*
+ * Values that t_state may assume. Note that t_state cannot have more
+ * than one of these flags set at a time.
+ */
+#define	TS_FREE		0x00	/* Thread at loose ends */
+#define	TS_SLEEP	0x01	/* Awaiting an event */
+#define	TS_RUN		0x02	/* Runnable, but not yet on a processor */
+#define	TS_ONPROC	0x04	/* Thread is being run on a processor */
+#define	TS_ZOMB		0x08	/* Thread has died but hasn't been reaped */
+#define	TS_STOPPED	0x10	/* Stopped, initial state */
+
+typedef struct ctxop {
+	void	(*save_op)(void *);	/* function to invoke to save context */
+	void	(*restore_op)(void *);	/* function to invoke to restore ctx */
+	void	(*fork_op)(void *, void *);	/* invoke to fork context */
+	void	(*lwp_create_op)(void *, void *);	/* lwp_create context */
+	void	(*exit_op)(void *);	/* invoked during {thread,lwp}_exit() */
+	void	(*free_op)(void *, int); /* function which frees the context */
+	void	*arg;		/* argument to above functions, ctx pointer */
+	struct ctxop *next;	/* next context ops */
+} ctxop_t;
+
+/*
+ * The active file descriptor table.
+ * Each member of a_fd[] not equalling -1 represents an active fd.
+ * The structure is initialized on first use; all zeros means uninitialized.
+ */
+typedef struct _afd {
+	int	*a_fd;		/* pointer to list of fds */
+	short	a_nfd;		/* number of entries in *a_fd */
+	short	a_stale;	/* one of the active fds is being closed */
+	int	a_buf[1];	/* buffer to which a_fd initially refers */
+} afd_t;
+
+/*
+ * An lwpchan provides uniqueness when sleeping on user-level
+ * synchronization primitives.  The lc_wchan member is used
+ * for sleeping on kernel synchronization primitives.
+ */
+typedef struct {
+	caddr_t lc_wchan0;
+	caddr_t lc_wchan;
+} lwpchan_t;
+
+typedef struct _kthread	*kthread_id_t;
+
+struct turnstile;
+struct trap_info;
+struct upimutex;
+struct kproject;
+struct on_trap_data;
+
+/* Definition for kernel thread identifier type */
+typedef uint64_t kt_did_t;
+
+typedef struct _kthread {
+	struct _kthread	*t_link; /* dispq, sleepq, and free queue link */
+
+	caddr_t	t_stk;		/* base of stack (kernel sp value to use) */
+#if defined(__ia64)
+	caddr_t	t_regstk;	/* base of register stack (initial bsp value) */
+#endif
+	void	(*t_startpc)(void);	/* PC where thread started */
+	struct cpu *t_bound_cpu; /* cpu bound to, or NULL if not bound */
+	short	t_affinitycnt;	/* nesting level of kernel affinity-setting */
+	short	t_bind_cpu;	/* user-specified CPU binding (-1 if none) */
+	ushort_t t_flag;		/* modified only by current thread */
+	ushort_t t_proc_flag;	/* modified holding ttproc(t)->p_lock */
+	ushort_t t_schedflag;	/* modified holding thread_lock(t) */
+	volatile char t_preempt;	/* don't preempt thread if set */
+	volatile char t_preempt_lk;
+	uint_t	t_state;	/* thread state	(protected by thread_lock) */
+	pri_t	t_pri;		/* assigned thread priority */
+	pri_t	t_epri;		/* inherited thread priority */
+	char	t_writer;	/* sleeping in lwp_rwlock_lock(RW_WRITE_LOCK) */
+	label_t	t_pcb;		/* pcb, save area when switching */
+	lwpchan_t t_lwpchan;	/* reason for blocking */
+#define	t_wchan0	t_lwpchan.lc_wchan0
+#define	t_wchan		t_lwpchan.lc_wchan
+	struct _sobj_ops *t_sobj_ops;
+	id_t	t_cid;		/* scheduling class id */
+	struct thread_ops *t_clfuncs;	/* scheduling class ops vector */
+	void	*t_cldata;	/* per scheduling class specific data */
+	ctxop_t	*t_ctx;		/* thread context */
+	uintptr_t t_lofault;	/* ret pc for failed page faults */
+	label_t	*t_onfault;	/* on_fault() setjmp buf */
+	struct on_trap_data *t_ontrap;	/* on_trap() protection data */
+	caddr_t t_swap;		/* swappable thread storage */
+	lock_t	t_lock;		/* used to resume() a thread */
+	uint8_t	t_lockstat;	/* set while thread is in lockstat code */
+	uint8_t	t_pil;		/* interrupt thread PIL */
+	disp_lock_t	t_pi_lock;	/* lock protecting t_prioinv list */
+	char	t_nomigrate;	/* do not migrate if set */
+	struct cpu	*t_cpu;	/* CPU that thread last ran on */
+	struct cpu	*t_weakbound_cpu;	/* cpu weakly bound to */
+	struct lgrp_ld	*t_lpl;	/* load average for home lgroup */
+	void		*t_lgrp_reserv[2];	/* reserved for future */
+	struct _kthread	*t_intr; /* interrupted (pinned) thread */
+	uint64_t	t_intr_start;	/* timestamp when time slice began */
+	kt_did_t	t_did;	/* thread id for kernel debuggers */
+	caddr_t t_tnf_tpdp;	/* Trace facility data pointer */
+	kcpc_ctx_t	*t_cpc_ctx;	/* performance counter context */
+	kcpc_set_t	*t_cpc_set;	/* set this thread has bound */
+
+	/*
+	 * non swappable part of the lwp state.
+	 */
+	id_t		t_tid;		/* lwp's id */
+	id_t		t_waitfor;	/* target lwp id in lwp_wait() */
+	struct sigqueue	*t_sigqueue;	/* queue of siginfo structs */
+	k_sigset_t	t_sig;		/* signals pending to this process */
+	k_sigset_t	t_extsig;	/* signals sent from another contract */
+	k_sigset_t	t_hold;		/* hold signal bit mask */
+	struct	_kthread *t_forw;	/* process's forward thread link */
+	struct	_kthread *t_back;	/* process's backward thread link */
+	struct	_kthread *t_thlink;	/* tid (lwpid) lookup hash link */
+	klwp_t	*t_lwp;			/* thread's lwp pointer */
+	struct	proc	*t_procp;	/* proc pointer */
+	struct	t_audit_data *t_audit_data;	/* per thread audit data */
+	struct	_kthread *t_next;	/* doubly linked list of all threads */
+	struct	_kthread *t_prev;
+	ushort_t t_whystop;		/* reason for stopping */
+	ushort_t t_whatstop;		/* more detailed reason */
+	int	t_dslot;		/* index in proc's thread directory */
+	struct	pollstate *t_pollstate;	/* state used during poll(2) */
+	struct	pollcache *t_pollcache;	/* to pass a pcache ptr by /dev/poll */
+	struct	cred	*t_cred;	/* pointer to current cred */
+	time_t	t_start;		/* start time, seconds since epoch */
+	clock_t	t_lbolt;		/* lbolt at last clock_tick() */
+	hrtime_t t_stoptime;		/* timestamp at stop() */
+	uint_t	t_pctcpu;		/* %cpu at last clock_tick(), binary */
+					/* point at right of high-order bit */
+	short	t_sysnum;		/* system call number */
+	kcondvar_t	t_delay_cv;
+	kmutex_t	t_delay_lock;
+
+	/*
+	 * Pointer to the dispatcher lock protecting t_state and state-related
+	 * flags.  This pointer can change during waits on the lock, so
+	 * it should be grabbed only by thread_lock().
+	 */
+	disp_lock_t	*t_lockp;	/* pointer to the dispatcher lock */
+	ushort_t 	t_oldspl;	/* spl level before dispatcher locked */
+	volatile char	t_pre_sys;	/* pre-syscall work needed */
+	lock_t		t_lock_flush;	/* for lock_mutex_flush() impl */
+	struct _disp	*t_disp_queue;	/* run queue for chosen CPU */
+	clock_t		t_disp_time;	/* last time this thread was running */
+	uint_t		t_kpri_req;	/* kernel priority required */
+
+	/*
+	 * Post-syscall / post-trap flags.
+	 * 	No lock is required to set these.
+	 *	These must be cleared only by the thread itself.
+	 *
+	 *	t_astflag indicates that some post-trap processing is required,
+	 *		possibly a signal or a preemption.  The thread will not
+	 *		return to user with this set.
+	 *	t_post_sys indicates that some unusualy post-system call
+	 *		handling is required, such as an error or tracing.
+	 *	t_sig_check indicates that some condition in ISSIG() must be
+	 * 		checked, but doesn't prevent returning to user.
+	 *	t_post_sys_ast is a way of checking whether any of these three
+	 *		flags are set.
+	 */
+	union __tu {
+		struct __ts {
+			volatile char	_t_astflag;	/* AST requested */
+			volatile char	_t_sig_check;	/* ISSIG required */
+			volatile char	_t_post_sys;	/* post_syscall req */
+			volatile char	_t_trapret;	/* call CL_TRAPRET */
+		} _ts;
+		volatile int	_t_post_sys_ast;	/* OR of these flags */
+	} _tu;
+#define	t_astflag	_tu._ts._t_astflag
+#define	t_sig_check	_tu._ts._t_sig_check
+#define	t_post_sys	_tu._ts._t_post_sys
+#define	t_trapret	_tu._ts._t_trapret
+#define	t_post_sys_ast	_tu._t_post_sys_ast
+
+	/*
+	 * Real time microstate profiling.
+	 */
+					/* possible 4-byte filler */
+	hrtime_t t_waitrq;		/* timestamp for run queue wait time */
+	int	t_mstate;		/* current microstate */
+	struct rprof {
+		int	rp_anystate;		/* set if any state non-zero */
+		uint_t	rp_state[NMSTATES];	/* mstate profiling counts */
+	} *t_rprof;
+
+	/*
+	 * There is a turnstile inserted into the list below for
+	 * every priority inverted synchronization object that
+	 * this thread holds.
+	 */
+
+	struct turnstile *t_prioinv;
+
+	/*
+	 * Pointer to the turnstile attached to the synchronization
+	 * object where this thread is blocked.
+	 */
+
+	struct turnstile *t_ts;
+
+	/*
+	 * kernel thread specific data
+	 *	Borrowed from userland implementation of POSIX tsd
+	 */
+	struct tsd_thread {
+		struct tsd_thread *ts_next;	/* threads with TSD */
+		struct tsd_thread *ts_prev;	/* threads with TSD */
+		uint_t		  ts_nkeys;	/* entries in value array */
+		void		  **ts_value;	/* array of value/key */
+	} *t_tsd;
+
+	clock_t		t_stime;	/* time stamp used by the swapper */
+	struct door_data *t_door;	/* door invocation data */
+	kmutex_t	*t_plockp;	/* pointer to process's p_lock */
+
+	struct sc_shared *t_schedctl;	/* scheduler activations shared data */
+	uintptr_t	t_sc_uaddr;	/* user-level address of shared data */
+
+	struct cpupart	*t_cpupart;	/* partition containing thread */
+	int		t_bind_pset;	/* processor set binding */
+
+	struct copyops	*t_copyops;	/* copy in/out ops vector */
+
+	caddr_t		t_stkbase;	/* base of the the stack */
+#if defined(__ia64)
+	size_t		t_stksize;	/* size of the the stack */
+#endif
+	struct page	*t_red_pp;	/* if non-NULL, redzone is mapped */
+
+	struct _afd	t_activefd;	/* active file descriptor table */
+
+	struct _kthread	*t_priforw;	/* sleepq per-priority sublist */
+	struct _kthread	*t_priback;
+
+	struct sleepq	*t_sleepq;	/* sleep queue thread is waiting on */
+	struct trap_info *t_panic_trap;	/* saved data from fatal trap */
+	int		*t_lgrp_affinity;	/* lgroup affinity */
+	struct upimutex	*t_upimutex;	/* list of upimutexes owned by thread */
+	uint32_t	t_nupinest;	/* number of nested held upi mutexes */
+	struct kproject *t_proj;	/* project containing this thread */
+	uint8_t		t_unpark;	/* modified holding t_delay_lock */
+	uint8_t		t_release;	/* lwp_release() waked up the thread */
+	uint8_t		t_hatdepth;	/* depth of recursive hat_memloads */
+	kcondvar_t	t_joincv;	/* cv used to wait for thread exit */
+	void		*t_taskq;	/* for threads belonging to taskq */
+	hrtime_t	t_anttime;	/* most recent time anticipatory load */
+					/*	was added to an lgroup's load */
+					/*	on this thread's behalf */
+	char		*t_pdmsg;	/* privilege debugging message */
+
+	uint_t		t_predcache;	/* DTrace predicate cache */
+	hrtime_t	t_dtrace_vtime;	/* DTrace virtual time */
+	hrtime_t	t_dtrace_start;	/* DTrace slice start time */
+
+	uint8_t		t_dtrace_stop;	/* indicates a DTrace-desired stop */
+	uint8_t		t_dtrace_sig;	/* signal sent via DTrace's raise() */
+
+	union __tdu {
+		struct __tds {
+			uint8_t	_t_dtrace_on;	/* hit a fasttrap tracepoint */
+			uint8_t	_t_dtrace_step;	/* about to return to kernel */
+			uint8_t	_t_dtrace_ret;	/* handling a return probe */
+			uint8_t	_t_dtrace_ast;	/* saved ast flag */
+#ifdef __amd64
+			uint8_t	_t_dtrace_reg;	/* modified register */
+#endif
+		} _tds;
+		ulong_t	_t_dtrace_ft;		/* bitwise or of these flags */
+	} _tdu;
+#define	t_dtrace_ft	_tdu._t_dtrace_ft
+#define	t_dtrace_on	_tdu._tds._t_dtrace_on
+#define	t_dtrace_step	_tdu._tds._t_dtrace_step
+#define	t_dtrace_ret	_tdu._tds._t_dtrace_ret
+#define	t_dtrace_ast	_tdu._tds._t_dtrace_ast
+#ifdef __amd64
+#define	t_dtrace_reg	_tdu._tds._t_dtrace_reg
+#endif
+
+	uintptr_t	t_dtrace_pc;	/* DTrace saved pc from fasttrap */
+	uintptr_t	t_dtrace_npc;	/* DTrace next pc from fasttrap */
+	uintptr_t	t_dtrace_scrpc;	/* DTrace per-thread scratch location */
+	uintptr_t	t_dtrace_astpc;	/* DTrace return sequence location */
+#ifdef __amd64
+	uint64_t	t_dtrace_regv;	/* DTrace saved reg from fasttrap */
+#endif
+	hrtime_t	t_hrtime;	/* high-res last time on cpu */
+} kthread_t;
+
+/*
+ * Thread flag (t_flag) definitions.
+ *	These flags must be changed only for the current thread,
+ * 	and not during preemption code, since the code being
+ *	preempted could be modifying the flags.
+ *
+ *	For the most part these flags do not need locking.
+ *	The following flags will only be changed while the thread_lock is held,
+ *	to give assurrance that they are consistent with t_state:
+ *		T_WAKEABLE
+ */
+#define	T_INTR_THREAD	0x0001	/* thread is an interrupt thread */
+#define	T_WAKEABLE	0x0002	/* thread is blocked, signals enabled */
+#define	T_TOMASK	0x0004	/* use lwp_sigoldmask on return from signal */
+#define	T_TALLOCSTK	0x0008  /* thread structure allocated from stk */
+#define	T_WOULDBLOCK	0x0020	/* for lockfs */
+#define	T_DONTBLOCK	0x0040	/* for lockfs */
+#define	T_DONTPEND	0x0080	/* for lockfs */
+#define	T_SYS_PROF	0x0100	/* profiling on for duration of system call */
+#define	T_WAITCVSEM	0x0200	/* waiting for a lwp_cv or lwp_sema on sleepq */
+#define	T_WATCHPT	0x0400	/* thread undergoing a watchpoint emulation */
+#define	T_PANIC		0x0800	/* thread initiated a system panic */
+#define	T_DFLTSTK	0x1000	/* stack is default size */
+
+/*
+ * Flags in t_proc_flag.
+ *	These flags must be modified only when holding the p_lock
+ *	for the associated process.
+ */
+#define	TP_DAEMON	0x0001	/* this is an LWP_DAEMON lwp */
+#define	TP_HOLDLWP	0x0002	/* hold thread's lwp */
+#define	TP_TWAIT	0x0004	/* wait to be freed by lwp_wait() */
+#define	TP_LWPEXIT	0x0008	/* lwp has exited */
+#define	TP_PRSTOP	0x0010	/* thread is being stopped via /proc */
+#define	TP_CHKPT	0x0020	/* thread is being stopped via CPR checkpoint */
+#define	TP_EXITLWP	0x0040	/* terminate this lwp */
+#define	TP_PRVSTOP	0x0080	/* thread is virtually stopped via /proc */
+#define	TP_MSACCT	0x0100	/* collect micro-state accounting information */
+#define	TP_STOPPING	0x0200	/* thread is executing stop() */
+#define	TP_WATCHPT	0x0400	/* process has watchpoints in effect */
+#define	TP_PAUSE	0x0800	/* process is being stopped via pauselwps() */
+#define	TP_CHANGEBIND	0x1000	/* thread has a new cpu/cpupart binding */
+#define	TP_ZTHREAD	0x2000	/* this is a kernel thread for a zone */
+#define	TP_WATCHSTOP	0x4000	/* thread is stopping via holdwatch() */
+
+/*
+ * Thread scheduler flag (t_schedflag) definitions.
+ *	The thread must be locked via thread_lock() or equiv. to change these.
+ */
+#define	TS_LOAD		0x0001	/* thread is in memory */
+#define	TS_DONT_SWAP	0x0002	/* thread/lwp should not be swapped */
+#define	TS_SWAPENQ	0x0004	/* swap thread when it reaches a safe point */
+#define	TS_ON_SWAPQ	0x0008	/* thread is on the swap queue */
+#define	TS_SIGNALLED	0x0010	/* thread was awakened by cv_signal() */
+#define	TS_CSTART	0x0100	/* setrun() by continuelwps() */
+#define	TS_UNPAUSE	0x0200	/* setrun() by unpauselwps() */
+#define	TS_XSTART	0x0400	/* setrun() by SIGCONT */
+#define	TS_PSTART	0x0800	/* setrun() by /proc */
+#define	TS_RESUME	0x1000	/* setrun() by CPR resume process */
+#define	TS_CREATE	0x2000	/* setrun() by syslwp_create() */
+#define	TS_RUNQMATCH	0x4000	/* exact run queue balancing by setbackdq() */
+#define	TS_ALLSTART	\
+	(TS_CSTART|TS_UNPAUSE|TS_XSTART|TS_PSTART|TS_RESUME|TS_CREATE)
+
+/*
+ * No locking needed for AST field.
+ */
+#define	aston(t)		((t)->t_astflag = 1)
+#define	astoff(t)		((t)->t_astflag = 0)
+
+/* True if thread is stopped on an event of interest */
+#define	ISTOPPED(t) ((t)->t_state == TS_STOPPED && \
+			!((t)->t_schedflag & TS_PSTART))
+
+/* similar to ISTOPPED except the event of interest is CPR */
+#define	CPR_ISTOPPED(t) ((t)->t_state == TS_STOPPED && \
+			!((t)->t_schedflag & TS_RESUME))
+
+/*
+ * True if thread is virtually stopped (is or was asleep in
+ * one of the lwp_*() system calls and marked to stop by /proc.)
+ */
+#define	VSTOPPED(t)	((t)->t_proc_flag & TP_PRVSTOP)
+
+/* similar to VSTOPPED except the point of interest is CPR */
+#define	CPR_VSTOPPED(t)				\
+	((t)->t_state == TS_SLEEP &&		\
+	(t)->t_wchan0 != NULL &&		\
+	((t)->t_flag & T_WAKEABLE) &&		\
+	((t)->t_proc_flag & TP_CHKPT))
+
+/* True if thread has been stopped by hold*() or was created stopped */
+#define	SUSPENDED(t) ((t)->t_state == TS_STOPPED && \
+	((t)->t_schedflag & (TS_CSTART|TS_UNPAUSE)) != (TS_CSTART|TS_UNPAUSE))
+
+/* True if thread possesses an inherited priority */
+#define	INHERITED(t)	((t)->t_epri != 0)
+
+/* The dispatch priority of a thread */
+#define	DISP_PRIO(t) ((t)->t_epri > (t)->t_pri ? (t)->t_epri : (t)->t_pri)
+
+/* The assigned priority of a thread */
+#define	ASSIGNED_PRIO(t)	((t)->t_pri)
+
+/*
+ * Macros to determine whether a thread can be swapped.
+ * If t_lock is held, the thread is either on a processor or being swapped.
+ */
+#define	SWAP_OK(t)	(!LOCK_HELD(&(t)->t_lock))
+
+/*
+ * proctot(x)
+ *	convert a proc pointer to a thread pointer. this only works with
+ *	procs that have only one lwp.
+ *
+ * proctolwp(x)
+ *	convert a proc pointer to a lwp pointer. this only works with
+ *	procs that have only one lwp.
+ *
+ * ttolwp(x)
+ *	convert a thread pointer to its lwp pointer.
+ *
+ * ttoproc(x)
+ *	convert a thread pointer to its proc pointer.
+ *
+ * ttoproj(x)
+ * 	convert a thread pointer to its project pointer.
+ *
+ * lwptot(x)
+ *	convert a lwp pointer to its thread pointer.
+ *
+ * lwptoproc(x)
+ *	convert a lwp to its proc pointer.
+ */
+#define	proctot(x)	((x)->p_tlist)
+#define	proctolwp(x)	((x)->p_tlist->t_lwp)
+#define	ttolwp(x)	((x)->t_lwp)
+#define	ttoproc(x)	((x)->t_procp)
+#define	ttoproj(x)	((x)->t_proj)
+#define	lwptot(x)	((x)->lwp_thread)
+#define	lwptoproc(x)	((x)->lwp_procp)
+
+#define	t_pc		t_pcb.val[0]
+#define	t_sp		t_pcb.val[1]
+
+#ifdef	_KERNEL
+
+extern	kthread_t	*threadp(void);	/* inline, returns thread pointer */
+#define	curthread	(threadp())		/* current thread pointer */
+#define	curproc		(ttoproc(curthread))	/* current process pointer */
+#define	curproj		(ttoproj(curthread))	/* current project pointer */
+
+extern	struct _kthread	t0;		/* the scheduler thread */
+extern	kmutex_t	pidlock;	/* global process lock */
+
+/*
+ * thread_free_lock is used by the clock thread to keep a thread
+ * from being freed while it is being examined.
+ */
+extern	kmutex_t	thread_free_lock;
+
+/*
+ * Routines to change the priority and effective priority
+ * of a thread-locked thread, whatever its state.
+ */
+extern int	thread_change_pri(kthread_t *t, pri_t disp_pri, int front);
+extern void	thread_change_epri(kthread_t *t, pri_t disp_pri);
+
+/*
+ * Routines that manipulate the dispatcher lock for the thread.
+ * The locking heirarchy is as follows:
+ *	cpu_lock > sleepq locks > run queue locks
+ */
+void	thread_transition(kthread_t *); /* move to transition lock */
+void	thread_stop(kthread_t *);	/* move to stop lock */
+void	thread_lock(kthread_t *);	/* lock thread and its queue */
+void	thread_lock_high(kthread_t *);	/* lock thread and its queue */
+void	thread_onproc(kthread_t *, struct cpu *); /* set onproc state lock */
+
+#define	thread_unlock(t)		disp_lock_exit((t)->t_lockp)
+#define	thread_unlock_high(t)		disp_lock_exit_high((t)->t_lockp)
+#define	thread_unlock_nopreempt(t)	disp_lock_exit_nopreempt((t)->t_lockp)
+
+#define	THREAD_LOCK_HELD(t)	(DISP_LOCK_HELD((t)->t_lockp))
+
+extern disp_lock_t transition_lock;	/* lock protecting transiting threads */
+extern disp_lock_t stop_lock;		/* lock protecting stopped threads */
+
+caddr_t	thread_stk_init(caddr_t);	/* init thread stack */
+
+#endif	/* _KERNEL */
+
+/*
+ * Macros to indicate that the thread holds resources that could be critical
+ * to other kernel threads, so this thread needs to have kernel priority
+ * if it blocks or is preempted.  Note that this is not necessary if the
+ * resource is a mutex or a writer lock because of priority inheritance.
+ *
+ * The only way one thread may legally manipulate another thread's t_kpri_req
+ * is to hold the target thread's thread lock while that thread is asleep.
+ * (The rwlock code does this to implement direct handoff to waiting readers.)
+ */
+#define	THREAD_KPRI_REQUEST()	(curthread->t_kpri_req++)
+#define	THREAD_KPRI_RELEASE()	(curthread->t_kpri_req--)
+#define	THREAD_KPRI_RELEASE_N(n) (curthread->t_kpri_req -= (n))
+
+/*
+ * Macro to change a thread's priority.
+ */
+#define	THREAD_CHANGE_PRI(t, pri) {					\
+	pri_t __new_pri = (pri);					\
+	DTRACE_SCHED2(change__pri, kthread_t *, (t), pri_t, __new_pri);	\
+	(t)->t_pri = __new_pri;						\
+}
+
+/*
+ * Macro to indicate that a thread's priority is about to be changed.
+ */
+#define	THREAD_WILLCHANGE_PRI(t, pri) {					\
+	DTRACE_SCHED2(change__pri, kthread_t *, (t), pri_t, (pri));	\
+}
+
+/*
+ * Macros to change thread state and the associated lock.
+ */
+#define	THREAD_SET_STATE(tp, state, lp) \
+		((tp)->t_state = state, (tp)->t_lockp = lp)
+
+/*
+ * Point it at the transition lock, which is always held.
+ * The previosly held lock is dropped.
+ */
+#define	THREAD_TRANSITION(tp) 	thread_transition(tp);
+/*
+ * Set the thread's lock to be the transition lock, without dropping
+ * previosly held lock.
+ */
+#define	THREAD_TRANSITION_NOLOCK(tp) 	((tp)->t_lockp = &transition_lock)
+
+/*
+ * Put thread in run state, and set the lock pointer to the dispatcher queue
+ * lock pointer provided.  This lock should be held.
+ */
+#define	THREAD_RUN(tp, lp)	THREAD_SET_STATE(tp, TS_RUN, lp)
+
+/*
+ * Put thread in run state, and set the lock pointer to the dispatcher queue
+ * lock pointer provided (i.e., the "swapped_lock").  This lock should be held.
+ */
+#define	THREAD_SWAP(tp, lp)	THREAD_SET_STATE(tp, TS_RUN, lp)
+
+/*
+ * Put the thread in zombie state and set the lock pointer to NULL.
+ * The NULL will catch anything that tries to lock a zombie.
+ */
+#define	THREAD_ZOMB(tp)		THREAD_SET_STATE(tp, TS_ZOMB, NULL)
+
+/*
+ * Set the thread into ONPROC state, and point the lock at the CPUs
+ * lock for the onproc thread(s).  This lock should be held, so the
+ * thread deoes not become unlocked, since these stores can be reordered.
+ */
+#define	THREAD_ONPROC(tp, cpu)	\
+		THREAD_SET_STATE(tp, TS_ONPROC, &(cpu)->cpu_thread_lock)
+
+/*
+ * Set the thread into the TS_SLEEP state, and set the lock pointer to
+ * to some sleep queue's lock.  The new lock should already be held.
+ */
+#define	THREAD_SLEEP(tp, lp)	{				\
+			disp_lock_t	*tlp;			\
+			tlp = (tp)->t_lockp;			\
+			THREAD_SET_STATE(tp, TS_SLEEP, lp);	\
+			disp_lock_exit_high(tlp);		\
+			}
+
+/*
+ * Interrupt threads are created in TS_FREE state, and their lock
+ * points at the associated CPU's lock.
+ */
+#define	THREAD_FREEINTR(tp, cpu)	\
+		THREAD_SET_STATE(tp, TS_FREE, &(cpu)->cpu_thread_lock)
+
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif /* _SYS_THREAD_H */