4 * Implements the architecture independant portion of the LWKT
7 * Types which must already be defined when this header is included by
8 * userland: struct md_thread
10 * $DragonFly: src/sys/sys/thread.h,v 1.97 2008/09/20 04:31:02 sephe Exp $
13 #ifndef _SYS_THREAD_H_
14 #define _SYS_THREAD_H_
16 #ifndef _SYS_STDINT_H_
17 #include <sys/stdint.h> /* __int types */
20 #include <sys/param.h> /* MAXCOMLEN */
23 #include <sys/queue.h> /* TAILQ_* macros */
25 #ifndef _SYS_MSGPORT_H_
26 #include <sys/msgport.h> /* lwkt_port */
29 #include <sys/time.h> /* struct timeval */
31 #ifndef _SYS_SPINLOCK_H_
32 #include <sys/spinlock.h>
34 #ifndef _SYS_IOSCHED_H_
35 #include <sys/iosched.h>
37 #ifndef _MACHINE_THREAD_H_
38 #include <machine/thread.h>
56 typedef struct lwkt_queue
*lwkt_queue_t
;
57 typedef struct lwkt_token
*lwkt_token_t
;
58 typedef struct lwkt_tokref
*lwkt_tokref_t
;
59 typedef struct lwkt_cpu_msg
*lwkt_cpu_msg_t
;
60 typedef struct lwkt_cpu_port
*lwkt_cpu_port_t
;
61 typedef struct lwkt_ipiq
*lwkt_ipiq_t
;
62 typedef struct lwkt_cpusync
*lwkt_cpusync_t
;
63 typedef struct thread
*thread_t
;
65 typedef TAILQ_HEAD(lwkt_queue
, thread
) lwkt_queue
;
68 * Differentiation between kernel threads and user threads. Userland
69 * programs which want to access to kernel structures have to define
70 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly
71 * written user programs from getting an LWKT thread that is neither the
72 * kernel nor the user version.
74 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
75 #ifndef _MACHINE_THREAD_H_
76 #include <machine/thread.h> /* md_thread */
78 #ifndef _MACHINE_FRAME_H_
79 #include <machine/frame.h>
86 * Tokens are used to serialize access to information. They are 'soft'
87 * serialization entities that only stay in effect while a thread is
88 * running. If the thread blocks, other threads can run holding the same
89 * token(s). The tokens are reacquired when the original thread resumes.
91 * A thread can depend on its serialization remaining intact through a
92 * preemption. An interrupt which attempts to use the same token as the
93 * thread being preempted will reschedule itself for non-preemptive
94 * operation, so the new token code is capable of interlocking against
95 * interrupts as well as other cpus. This means that your token can only
96 * be (temporarily) lost if you *explicitly* block.
98 * Tokens are managed through a helper reference structure, lwkt_tokref,
99 * which is typically declared on the caller's stack. Multiple tokref's
100 * may reference the same token.
103 typedef struct lwkt_token
{
104 struct lwkt_tokref
*t_ref
; /* Owning ref or NULL */
107 #define LWKT_TOKEN_INITIALIZER(head) \
112 #define ASSERT_LWKT_TOKEN_HELD(tok) \
113 KKASSERT((tok)->t_ref->tr_owner == curthread)
115 typedef struct lwkt_tokref
{
116 lwkt_token_t tr_tok
; /* token in question */
117 struct thread
*tr_owner
; /* me */
118 lwkt_tokref_t tr_next
; /* linked list */
121 #define MAXCPUFIFO 16 /* power of 2 */
122 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1)
123 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */
126 * Always cast to ipifunc_t when registering an ipi. The actual ipi function
127 * is called with both the data and an interrupt frame, but the ipi function
128 * that is registered might only declare a data argument.
130 typedef void (*ipifunc1_t
)(void *arg
);
131 typedef void (*ipifunc2_t
)(void *arg
, int arg2
);
132 typedef void (*ipifunc3_t
)(void *arg
, int arg2
, struct intrframe
*frame
);
134 typedef struct lwkt_ipiq
{
135 int ip_rindex
; /* only written by target cpu */
136 int ip_xindex
; /* written by target, indicates completion */
137 int ip_windex
; /* only written by source cpu */
138 ipifunc3_t ip_func
[MAXCPUFIFO
];
139 void *ip_arg1
[MAXCPUFIFO
];
140 int ip_arg2
[MAXCPUFIFO
];
141 u_int ip_npoll
; /* synchronization to avoid excess IPIs */
145 * CPU Synchronization structure. See lwkt_cpusync_start() and
146 * lwkt_cpusync_finish() for more information.
148 typedef void (*cpusync_func_t
)(lwkt_cpusync_t poll
);
149 typedef void (*cpusync_func2_t
)(void *data
);
151 struct lwkt_cpusync
{
152 cpusync_func_t cs_run_func
; /* run (tandem w/ acquire) */
153 cpusync_func_t cs_fin1_func
; /* fin1 (synchronized) */
154 cpusync_func2_t cs_fin2_func
; /* fin2 (tandem w/ release) */
157 volatile int cs_count
;
162 * The standard message and queue structure used for communications between
163 * cpus. Messages are typically queued via a machine-specific non-linked
164 * FIFO matrix allowing any cpu to send a message to any other cpu without
167 typedef struct lwkt_cpu_msg
{
168 void (*cm_func
)(lwkt_cpu_msg_t msg
); /* primary dispatch function */
169 int cm_code
; /* request code if applicable */
170 int cm_cpu
; /* reply to cpu */
171 thread_t cm_originator
; /* originating thread for wakeup */
175 * Thread structure. Note that ownership of a thread structure is special
176 * cased and there is no 'token'. A thread is always owned by the cpu
177 * represented by td_gd, any manipulation of the thread by some other cpu
178 * must be done through cpu_*msg() functions. e.g. you could request
179 * ownership of a thread that way, or hand a thread off to another cpu.
181 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section,
182 * but this does not effect how the thread is scheduled by LWKT.
184 * NOTE: td_ucred is synchronized from the p_ucred on user->kernel syscall,
185 * trap, and AST/signal transitions to provide a stable ucred for
186 * (primarily) system calls. This field will be NULL for pure kernel
193 TAILQ_ENTRY(thread
) td_threadq
;
194 TAILQ_ENTRY(thread
) td_allq
;
195 TAILQ_ENTRY(thread
) td_sleepq
;
196 lwkt_port td_msgport
; /* built-in message port for replies */
197 struct lwp
*td_lwp
; /* (optional) associated lwp */
198 struct proc
*td_proc
; /* (optional) associated process */
199 struct pcb
*td_pcb
; /* points to pcb and top of kstack */
200 struct globaldata
*td_gd
; /* associated with this cpu */
201 const char *td_wmesg
; /* string name for blockage */
202 void *td_wchan
; /* waiting on channel */
203 int td_pri
; /* 0-31, 31=highest priority (note 1) */
204 int td_flags
; /* TDF flags */
205 int td_wdomain
; /* domain for wchan address (typ 0) */
206 void (*td_preemptable
)(struct thread
*td
, int critpri
);
207 void (*td_release
)(struct thread
*td
);
208 char *td_kstack
; /* kernel stack */
209 int td_kstack_size
; /* size of kernel stack */
210 char *td_sp
; /* kernel stack pointer for LWKT restore */
211 void (*td_switch
)(struct thread
*ntd
);
212 __uint64_t td_uticks
; /* Statclock hits in user mode (uS) */
213 __uint64_t td_sticks
; /* Statclock hits in system mode (uS) */
214 __uint64_t td_iticks
; /* Statclock hits processing intr (uS) */
215 int td_locks
; /* lockmgr lock debugging */
217 int td_refs
; /* hold position in gd_tdallq / hold free */
218 int td_nest_count
; /* prevent splz nesting */
220 int td_mpcount
; /* MP lock held (count) */
221 int td_cscount
; /* cpu synchronization master */
223 int td_mpcount_unused
; /* filler so size matches */
224 int td_cscount_unused
;
226 struct iosched_data td_iosdata
; /* Dynamic I/O scheduling data */
227 struct timeval td_start
; /* start time for a thread/process */
228 char td_comm
[MAXCOMLEN
+1]; /* typ 16+1 bytes */
229 struct thread
*td_preempted
; /* we preempted this thread */
230 struct ucred
*td_ucred
; /* synchronized from p_ucred */
231 struct caps_kinfo
*td_caps
; /* list of client and server registrations */
232 lwkt_tokref_t td_toks
; /* tokens beneficially held */
233 #ifdef DEBUG_CRIT_SECTIONS
234 #define CRIT_DEBUG_ARRAY_SIZE 32
235 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1)
236 const char *td_crit_debug_array
[CRIT_DEBUG_ARRAY_SIZE
];
237 int td_crit_debug_index
;
238 int td_in_crit_report
;
240 struct md_thread td_mach
;
244 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after
245 * we switch to the new one, which is necessary because LWKTs don't need
246 * to hold the BGL. This flag is used by the exit code and the managed
247 * thread migration code. Note in addition that preemption will cause
248 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
249 * must also check TDF_PREEMPT_LOCK.
251 * LWKT threads stay on their (per-cpu) run queue while running, not to
252 * be confused with user processes which are removed from the user scheduling
253 * run queue while actually running.
255 * td_threadq can represent the thread on one of three queues... the LWKT
256 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem
257 * does not allow a thread to be scheduled if it already resides on some
260 #define TDF_RUNNING 0x0001 /* thread still active */
261 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */
262 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */
263 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */
264 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */
265 #define TDF_MIGRATING 0x0020 /* thread is being migrated */
266 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */
267 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */
269 #define TDF_SYSTHREAD 0x0100 /* allocations may use reserve */
270 #define TDF_ALLOCATED_THREAD 0x0200 /* objcache allocated thread */
271 #define TDF_ALLOCATED_STACK 0x0400 /* objcache allocated stack */
272 #define TDF_VERBOSE 0x0800 /* verbose on exit */
273 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */
274 #define TDF_STOPREQ 0x2000 /* suspend_kproc */
275 #define TDF_WAKEREQ 0x4000 /* resume_kproc */
276 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */
277 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */
278 #define TDF_TSLEEP_DESCHEDULED 0x00020000 /* tsleep core deschedule */
279 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */
280 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */
281 #define TDF_BLOCKQ 0x00100000 /* on block queue */
282 #define TDF_MPSAFE 0x00200000 /* (thread creation) */
283 #define TDF_EXITING 0x00400000 /* thread exiting */
284 #define TDF_USINGFP 0x00800000 /* thread using fp coproc */
285 #define TDF_KERNELFP 0x01000000 /* kernel using fp coproc */
286 #define TDF_NETWORK 0x02000000 /* network proto thread */
289 * Thread priorities. Typically only one thread from any given
290 * user process scheduling queue is on the LWKT run queue at a time.
291 * Remember that there is one LWKT run queue per cpu.
293 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
294 * causes interrupts to be masked as they occur. When this occurs a
295 * rollup flag will be set in mycpu->gd_reqflags.
297 #define TDPRI_IDLE_THREAD 0 /* the idle thread */
298 #define TDPRI_USER_SCHEDULER 2 /* user scheduler helper */
299 #define TDPRI_USER_IDLE 4 /* user scheduler idle */
300 #define TDPRI_USER_NORM 6 /* user scheduler normal */
301 #define TDPRI_USER_REAL 8 /* user scheduler real time */
302 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */
303 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */
304 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */
305 #define TDPRI_SOFT_NORM 14 /* kernel / normal */
306 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */
307 #define TDPRI_EXITING 19 /* exiting thread */
308 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */
309 #define TDPRI_INT_LOW 27 /* low priority interrupt */
310 #define TDPRI_INT_MED 28 /* medium priority interrupt */
311 #define TDPRI_INT_HIGH 29 /* high priority interrupt */
314 #define TDPRI_MASK 31
315 #define TDPRI_CRIT 32 /* high bits of td_pri used for crit */
318 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE)
321 #define CACHE_NTHREADS 6
323 #define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT)
325 extern void lwkt_init(void);
326 extern struct thread
*lwkt_alloc_thread(struct thread
*, int, int, int);
327 extern void lwkt_init_thread(struct thread
*, void *, int, int,
328 struct globaldata
*);
329 extern void lwkt_set_comm(thread_t
, const char *, ...);
330 extern void lwkt_wait_free(struct thread
*);
331 extern void lwkt_free_thread(struct thread
*);
332 extern void lwkt_gdinit(struct globaldata
*);
333 extern void lwkt_switch(void);
334 extern void lwkt_preempt(thread_t
, int);
335 extern void lwkt_schedule(thread_t
);
336 extern void lwkt_schedule_noresched(thread_t
);
337 extern void lwkt_schedule_self(thread_t
);
338 extern void lwkt_deschedule(thread_t
);
339 extern void lwkt_deschedule_self(thread_t
);
340 extern void lwkt_yield(void);
341 extern void lwkt_user_yield(void);
342 extern void lwkt_token_wait(void);
343 extern void lwkt_hold(thread_t
);
344 extern void lwkt_rele(thread_t
);
345 extern void lwkt_passive_release(thread_t
);
347 extern void lwkt_gettoken(lwkt_tokref_t
, lwkt_token_t
);
348 extern int lwkt_trytoken(lwkt_tokref_t
, lwkt_token_t
);
349 extern void lwkt_gettokref(lwkt_tokref_t
);
350 extern int lwkt_trytokref(lwkt_tokref_t
);
351 extern void lwkt_reltoken(lwkt_tokref_t
);
352 extern int lwkt_getalltokens(thread_t
);
353 extern void lwkt_relalltokens(thread_t
);
354 extern void lwkt_drain_token_requests(void);
355 extern void lwkt_token_init(lwkt_token_t
);
356 extern void lwkt_token_uninit(lwkt_token_t
);
358 extern void lwkt_token_pool_init(void);
359 extern lwkt_token_t
lwkt_token_pool_lookup(void *);
360 extern void lwkt_getpooltoken(lwkt_tokref_t
, void *);
362 extern void lwkt_setpri(thread_t
, int);
363 extern void lwkt_setpri_initial(thread_t
, int);
364 extern void lwkt_setpri_self(int);
365 extern int lwkt_check_resched(thread_t
);
366 extern void lwkt_setcpu_self(struct globaldata
*);
367 extern void lwkt_migratecpu(int);
371 extern void lwkt_giveaway(struct thread
*);
372 extern void lwkt_acquire(struct thread
*);
373 extern int lwkt_send_ipiq3(struct globaldata
*, ipifunc3_t
, void *, int);
374 extern int lwkt_send_ipiq3_passive(struct globaldata
*, ipifunc3_t
,
376 extern int lwkt_send_ipiq3_nowait(struct globaldata
*, ipifunc3_t
,
378 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t
, void *, int);
379 extern int lwkt_send_ipiq3_mask(cpumask_t
, ipifunc3_t
, void *, int);
380 extern void lwkt_wait_ipiq(struct globaldata
*, int);
381 extern int lwkt_seq_ipiq(struct globaldata
*);
382 extern void lwkt_process_ipiq(void);
384 extern void lwkt_process_ipiq_frame(struct intrframe
*);
386 extern void lwkt_smp_stopped(void);
387 extern void lwkt_synchronize_ipiqs(const char *);
391 extern void lwkt_cpusync_simple(cpumask_t
, cpusync_func_t
, void *);
392 extern void lwkt_cpusync_fastdata(cpumask_t
, cpusync_func2_t
, void *);
393 extern void lwkt_cpusync_start(cpumask_t
, lwkt_cpusync_t
);
394 extern void lwkt_cpusync_add(cpumask_t
, lwkt_cpusync_t
);
395 extern void lwkt_cpusync_finish(lwkt_cpusync_t
);
397 extern void crit_panic(void);
398 extern struct lwp
*lwkt_preempted_proc(void);
400 extern int lwkt_create (void (*func
)(void *), void *, struct thread
**,
401 struct thread
*, int, int, const char *, ...);
402 extern void lwkt_exit (void) __dead2
;
403 extern void lwkt_remove_tdallq (struct thread
*);