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 1.83 2006/05/29 07:29:15 dillon 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 _MACHINE_THREAD_H_
35 #include <machine/thread.h>
55 typedef struct lwkt_queue *lwkt_queue_t;
56 typedef struct lwkt_token *lwkt_token_t;
57 typedef struct lwkt_tokref *lwkt_tokref_t;
58 typedef struct lwkt_wait *lwkt_wait_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_rwlock *lwkt_rwlock_t;
62 typedef struct lwkt_ipiq *lwkt_ipiq_t;
63 typedef struct lwkt_cpusync *lwkt_cpusync_t;
64 typedef struct thread *thread_t;
66 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
69 * Differentiation between kernel threads and user threads. Userland
70 * programs which want to access to kernel structures have to define
71 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly
72 * written user programs from getting an LWKT thread that is neither the
73 * kernel nor the user version.
75 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
76 #ifndef _MACHINE_THREAD_H_
77 #include <machine/thread.h> /* md_thread */
79 #ifndef _MACHINE_FRAME_H_
80 #include <machine/frame.h>
87 * Tokens are used to serialize access to information. They are 'soft'
88 * serialization entities that only stay in effect while a thread is
89 * running. If the thread blocks, other threads can run holding the same
90 * token(s). The tokens are reacquired when the original thread resumes.
92 * A thread can depend on its serialization remaining intact through a
93 * preemption. An interrupt which attempts to use the same token as the
94 * thread being preempted will reschedule itself for non-preemptive
95 * operation, so the new token code is capable of interlocking against
96 * interrupts as well as other cpus.
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.
102 * We do not actually have to track any information in the token itself
103 * on UP systems. Simply linking the reference into the thread's td_toks
104 * list is sufficient. We still track a global t_globalcount on UP for
105 * debugging purposes.
109 typedef struct lwkt_token {
110 struct spinlock t_spinlock; /* Controls access */
111 struct thread *t_owner; /* The current owner of the token */
112 int t_count; /* Per-thread count */
117 typedef struct lwkt_token {
118 struct spinlock t_unused01;
119 struct thread *t_unused02;
120 int t_globalcount; /* Global reference count */
125 typedef struct lwkt_tokref {
126 lwkt_token_t tr_tok; /* token in question */
127 lwkt_tokref_t tr_next; /* linked list */
128 int tr_state; /* 0 = don't have, 1 = have */
131 #define LWKT_TOKREF_INIT(tok) \
133 #define LWKT_TOKREF_DECLARE(name, tok) \
134 lwkt_tokref name = LWKT_TOKREF_INIT(tok)
137 * Wait structures deal with blocked threads. Due to the way remote cpus
138 * interact with these structures stable storage must be used.
140 typedef struct lwkt_wait {
141 lwkt_queue wa_waitq; /* list of waiting threads */
142 struct spinlock wa_spinlock;
147 #define MAXCPUFIFO 16 /* power of 2 */
148 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1)
149 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */
152 * Always cast to ipifunc_t when registering an ipi. The actual ipi function
153 * is called with both the data and an interrupt frame, but the ipi function
154 * that is registered might only declare a data argument.
156 typedef void (*ipifunc1_t)(void *arg);
157 typedef void (*ipifunc2_t)(void *arg, int arg2);
158 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame);
160 typedef struct lwkt_ipiq {
161 int ip_rindex; /* only written by target cpu */
162 int ip_xindex; /* written by target, indicates completion */
163 int ip_windex; /* only written by source cpu */
164 ipifunc3_t ip_func[MAXCPUFIFO];
165 void *ip_arg1[MAXCPUFIFO];
166 int ip_arg2[MAXCPUFIFO];
167 u_int ip_npoll; /* synchronization to avoid excess IPIs */
171 * CPU Synchronization structure. See lwkt_cpusync_start() and
172 * lwkt_cpusync_finish() for more information.
174 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll);
175 typedef void (*cpusync_func2_t)(void *data);
177 struct lwkt_cpusync {
178 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */
179 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */
180 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */
183 volatile int cs_count;
188 * The standard message and queue structure used for communications between
189 * cpus. Messages are typically queued via a machine-specific non-linked
190 * FIFO matrix allowing any cpu to send a message to any other cpu without
193 typedef struct lwkt_cpu_msg {
194 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */
195 int cm_code; /* request code if applicable */
196 int cm_cpu; /* reply to cpu */
197 thread_t cm_originator; /* originating thread for wakeup */
203 typedef struct lwkt_rwlock {
210 #define rw_spinlock rw_wait.wa_spinlock
213 * Thread structure. Note that ownership of a thread structure is special
214 * cased and there is no 'token'. A thread is always owned by the cpu
215 * represented by td_gd, any manipulation of the thread by some other cpu
216 * must be done through cpu_*msg() functions. e.g. you could request
217 * ownership of a thread that way, or hand a thread off to another cpu.
219 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section,
220 * but this does not effect how the thread is scheduled by LWKT.
226 TAILQ_ENTRY(thread) td_threadq;
227 TAILQ_ENTRY(thread) td_allq;
228 lwkt_port td_msgport; /* built-in message port for replies */
229 struct lwp *td_lwp; /* (optional) associated lwp */
230 struct proc *td_proc; /* (optional) associated process */
231 struct pcb *td_pcb; /* points to pcb and top of kstack */
232 struct globaldata *td_gd; /* associated with this cpu */
233 const char *td_wmesg; /* string name for blockage */
234 void *td_wchan; /* waiting on channel */
235 int td_pri; /* 0-31, 31=highest priority (note 1) */
236 int td_flags; /* TDF flags */
237 int td_wdomain; /* domain for wchan address (typ 0) */
238 void (*td_preemptable)(struct thread *td, int critpri);
239 void (*td_release)(struct thread *td);
240 char *td_kstack; /* kernel stack */
241 int td_kstack_size; /* size of kernel stack */
242 char *td_sp; /* kernel stack pointer for LWKT restore */
243 void (*td_switch)(struct thread *ntd);
244 lwkt_wait_t td_wait; /* thread sitting on wait structure */
245 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */
246 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */
247 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */
248 int td_locks; /* lockmgr lock debugging */
250 int td_refs; /* hold position in gd_tdallq / hold free */
251 int td_nest_count; /* prevent splz nesting */
253 int td_mpcount; /* MP lock held (count) */
254 int td_cscount; /* cpu synchronization master */
256 int td_mpcount_unused; /* filler so size matches */
257 int td_cscount_unused;
259 struct timeval td_start; /* start time for a thread/process */
260 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
261 struct thread *td_preempted; /* we preempted this thread */
262 struct caps_kinfo *td_caps; /* list of client and server registrations */
263 lwkt_tokref_t td_toks; /* tokens beneficially held */
264 #ifdef DEBUG_CRIT_SECTIONS
265 #define CRIT_DEBUG_ARRAY_SIZE 32
266 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1)
267 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE];
268 int td_crit_debug_index;
269 int td_in_crit_report;
271 struct md_thread td_mach;
275 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after
276 * we switch to the new one, which is necessary because LWKTs don't need
277 * to hold the BGL. This flag is used by the exit code and the managed
278 * thread migration code. Note in addition that preemption will cause
279 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
280 * must also check TDF_PREEMPT_LOCK.
282 * LWKT threads stay on their (per-cpu) run queue while running, not to
283 * be confused with user processes which are removed from the user scheduling
284 * run queue while actually running.
286 * td_threadq can represent the thread on one of three queues... the LWKT
287 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem
288 * does not allow a thread to be scheduled if it already resides on some
291 #define TDF_RUNNING 0x0001 /* thread still active */
292 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */
293 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */
294 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */
295 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */
296 #define TDF_MIGRATING 0x0020 /* thread is being migrated */
297 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */
298 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */
300 #define TDF_SYSTHREAD 0x0100 /* system thread */
301 #define TDF_ALLOCATED_THREAD 0x0200 /* zalloc allocated thread */
302 #define TDF_ALLOCATED_STACK 0x0400 /* zalloc allocated stack */
303 #define TDF_VERBOSE 0x0800 /* verbose on exit */
304 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */
305 #define TDF_STOPREQ 0x2000 /* suspend_kproc */
306 #define TDF_WAKEREQ 0x4000 /* resume_kproc */
307 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */
308 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */
309 #define TDF_NORESCHED 0x00020000 /* Do not reschedule on wake */
310 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */
311 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */
312 #define TDF_BLOCKQ 0x00100000 /* on block queue */
313 #define TDF_MPSAFE 0x00200000 /* (thread creation) */
314 #define TDF_EXITING 0x00400000 /* thread exiting */
317 * Thread priorities. Typically only one thread from any given
318 * user process scheduling queue is on the LWKT run queue at a time.
319 * Remember that there is one LWKT run queue per cpu.
321 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
322 * causes interrupts to be masked as they occur. When this occurs a
323 * rollup flag will be set in mycpu->gd_reqflags.
325 #define TDPRI_IDLE_THREAD 0 /* the idle thread */
326 #define TDPRI_USER_IDLE 4 /* user scheduler idle */
327 #define TDPRI_USER_NORM 6 /* user scheduler normal */
328 #define TDPRI_USER_REAL 8 /* user scheduler real time */
329 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */
330 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */
331 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */
332 #define TDPRI_SOFT_NORM 14 /* kernel / normal */
333 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */
334 #define TDPRI_EXITING 19 /* exiting thread */
335 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */
336 #define TDPRI_INT_LOW 27 /* low priority interrupt */
337 #define TDPRI_INT_MED 28 /* medium priority interrupt */
338 #define TDPRI_INT_HIGH 29 /* high priority interrupt */
341 #define TDPRI_MASK 31
342 #define TDPRI_CRIT 32 /* high bits of td_pri used for crit */
345 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE)
348 #define CACHE_NTHREADS 6
350 #define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT)
354 extern struct vm_zone *thread_zone;
359 * Applies both to the kernel and to liblwkt.
361 extern struct thread *lwkt_alloc_thread(struct thread *template, int stksize,
363 extern void lwkt_init_thread(struct thread *td, void *stack, int stksize,
364 int flags, struct globaldata *gd);
365 extern void lwkt_set_comm(thread_t td, const char *ctl, ...);
366 extern void lwkt_wait_free(struct thread *td);
367 extern void lwkt_free_thread(struct thread *td);
368 extern void lwkt_wait_init(struct lwkt_wait *w);
369 extern void lwkt_gdinit(struct globaldata *gd);
370 extern void lwkt_switch(void);
371 extern void lwkt_preempt(thread_t ntd, int critpri);
372 extern void lwkt_schedule(thread_t td);
373 extern void lwkt_schedule_self(thread_t td);
374 extern void lwkt_deschedule(thread_t td);
375 extern void lwkt_deschedule_self(thread_t td);
376 extern void lwkt_yield(void);
377 extern void lwkt_yield_quick(void);
378 extern void lwkt_token_wait(void);
379 extern void lwkt_hold(thread_t td);
380 extern void lwkt_rele(thread_t td);
382 extern void lwkt_block(lwkt_wait_t w, const char *wmesg, int *gen);
383 extern void lwkt_signal(lwkt_wait_t w, int count);
385 extern void lwkt_gettoken(lwkt_tokref_t ref, lwkt_token_t tok);
386 extern int lwkt_trytoken(lwkt_tokref_t ref, lwkt_token_t tok);
387 extern void lwkt_gettokref(lwkt_tokref_t ref);
388 extern int lwkt_trytokref(lwkt_tokref_t ref);
389 extern void lwkt_reltoken(lwkt_tokref_t ref);
390 extern int lwkt_getalltokens(thread_t td);
391 extern void lwkt_relalltokens(thread_t td);
392 extern void lwkt_drain_token_requests(void);
393 extern void lwkt_token_init(lwkt_token_t tok);
394 extern void lwkt_token_uninit(lwkt_token_t tok);
396 extern void lwkt_token_pool_init(void);
397 extern lwkt_token_t lwkt_token_pool_get(void *ptraddr);
399 extern void lwkt_rwlock_init(lwkt_rwlock_t lock);
400 extern void lwkt_rwlock_uninit(lwkt_rwlock_t lock);
401 extern void lwkt_exlock(lwkt_rwlock_t lock, const char *wmesg);
402 extern void lwkt_shlock(lwkt_rwlock_t lock, const char *wmesg);
403 extern void lwkt_exunlock(lwkt_rwlock_t lock);
404 extern void lwkt_shunlock(lwkt_rwlock_t lock);
406 extern void lwkt_setpri(thread_t td, int pri);
407 extern void lwkt_setpri_self(int pri);
408 extern int lwkt_checkpri_self(void);
409 extern void lwkt_setcpu_self(struct globaldata *rgd);
410 extern void lwkt_migratecpu(int cpuid);
414 extern void lwkt_giveaway(struct thread *);
415 extern void lwkt_acquire(struct thread *);
416 extern int lwkt_send_ipiq3(struct globaldata *targ, ipifunc3_t func,
417 void *arg1, int arg2);
418 extern int lwkt_send_ipiq3_passive(struct globaldata *targ, ipifunc3_t func,
419 void *arg1, int arg2);
420 extern int lwkt_send_ipiq3_nowait(struct globaldata *targ, ipifunc3_t func,
421 void *arg1, int arg2);
422 extern int lwkt_send_ipiq3_bycpu(int dcpu, ipifunc3_t func,
423 void *arg1, int arg2);
424 extern int lwkt_send_ipiq3_mask(cpumask_t mask, ipifunc3_t func,
425 void *arg1, int arg2);
426 extern void lwkt_wait_ipiq(struct globaldata *targ, int seq);
427 extern int lwkt_seq_ipiq(struct globaldata *targ);
428 extern void lwkt_process_ipiq(void);
430 extern void lwkt_process_ipiq_frame(struct intrframe frame);
432 extern void lwkt_smp_stopped(void);
436 extern void lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *data);
437 extern void lwkt_cpusync_fastdata(cpumask_t mask, cpusync_func2_t func, void *data);
438 extern void lwkt_cpusync_start(cpumask_t mask, lwkt_cpusync_t poll);
439 extern void lwkt_cpusync_add(cpumask_t mask, lwkt_cpusync_t poll);
440 extern void lwkt_cpusync_finish(lwkt_cpusync_t poll);
442 extern void crit_panic(void);
443 extern struct lwp *lwkt_preempted_proc(void);
445 extern int lwkt_create (void (*func)(void *), void *arg, struct thread **ptd,
446 struct thread *template, int tdflags, int cpu,
447 const char *ctl, ...);
448 extern void lwkt_exit (void) __dead2;
449 extern void lwkt_mp_lock_contested(void);