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 1.62 2005/04/18 01:03:33 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 */
48 typedef struct lwkt_queue *lwkt_queue_t;
49 typedef struct lwkt_token *lwkt_token_t;
50 typedef struct lwkt_tokref *lwkt_tokref_t;
51 typedef struct lwkt_wait *lwkt_wait_t;
52 typedef struct lwkt_cpu_msg *lwkt_cpu_msg_t;
53 typedef struct lwkt_cpu_port *lwkt_cpu_port_t;
54 typedef struct lwkt_rwlock *lwkt_rwlock_t;
55 typedef struct lwkt_ipiq *lwkt_ipiq_t;
56 typedef struct lwkt_cpusync *lwkt_cpusync_t;
57 typedef struct thread *thread_t;
59 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
62 * Differentiation between kernel threads and user threads. Userland
63 * programs which want to access to kernel structures have to define
64 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly
65 * written user programs from getting an LWKT thread that is neither the
66 * kernel nor the user version.
68 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
69 #ifndef _MACHINE_THREAD_H_
70 #include <machine/thread.h> /* md_thread */
72 #ifndef _MACHINE_FRAME_H_
73 #include <machine/frame.h>
80 * Tokens are used to serialize access to information. They are 'soft'
81 * serialization entities that only stay in effect while the thread is
82 * running. If the thread blocks, other threads can run holding the same
83 * tokens. The tokens are reacquired when the original thread resumes.
85 * A thread can depend on its serialization remaining intact through a
86 * preemption. An interrupt which attempts to use the same token as the
87 * thread being preempted will reschedule itself for non-preemptive
88 * operation, so the new token code is capable of interlocking against
89 * interrupts as well as other cpus.
91 * Tokens are managed through a helper reference structure, lwkt_tokref,
92 * which is typically declared on the caller's stack. Multiple tokref's
93 * may reference the same token.
95 typedef struct lwkt_token {
96 struct globaldata *t_cpu; /* the current owner of the token */
97 struct globaldata *t_reqcpu; /* requesting cpu */
98 int t_unused01; /* (used to be generation number) */
101 typedef struct lwkt_tokref {
102 lwkt_token_t tr_tok; /* token in question */
103 __uint32_t tr_magic; /* sanity check */
104 lwkt_tokref_t tr_next; /* linked list */
105 lwkt_tokref_t tr_gdreqnext; /* based at gd_tokreqbase */
106 struct globaldata *tr_reqgd; /* requesting cpu */
109 #define LWKT_TOKREF_MAGIC1 \
110 ((__uint32_t)0x544f4b52) /* normal */
111 #define LWKT_TOKREF_MAGIC2 \
112 ((__uint32_t)0x544f4b53) /* pending req */
113 #define LWKT_TOKREF_INIT(tok) \
114 { tok, LWKT_TOKREF_MAGIC1 }
115 #define LWKT_TOKREF_DECLARE(name, tok) \
116 lwkt_tokref name = LWKT_TOKREF_INIT(tok)
119 * Wait structures deal with blocked threads. Due to the way remote cpus
120 * interact with these structures stable storage must be used.
122 typedef struct lwkt_wait {
123 lwkt_queue wa_waitq; /* list of waiting threads */
124 lwkt_token wa_token; /* who currently owns the list */
129 #define MAXCPUFIFO 16 /* power of 2 */
130 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1)
131 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */
134 * Always cast to ipifunc_t when registering an ipi. The actual ipi function
135 * is called with both the data and an interrupt frame, but the ipi function
136 * that is registered might only declare a data argument.
138 typedef void (*ipifunc_t)(void *arg);
139 typedef void (*ipifunc2_t)(void *arg, struct intrframe *frame);
141 typedef struct lwkt_ipiq {
142 int ip_rindex; /* only written by target cpu */
143 int ip_xindex; /* written by target, indicates completion */
144 int ip_windex; /* only written by source cpu */
145 ipifunc2_t ip_func[MAXCPUFIFO];
146 void *ip_arg[MAXCPUFIFO];
147 u_int ip_npoll; /* synchronization to avoid excess IPIs */
151 * CPU Synchronization structure. See lwkt_cpusync_start() and
152 * lwkt_cpusync_finish() for more information.
154 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll);
155 typedef void (*cpusync_func2_t)(void *data);
157 struct lwkt_cpusync {
158 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */
159 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */
160 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */
163 volatile int cs_count;
168 * The standard message and queue structure used for communications between
169 * cpus. Messages are typically queued via a machine-specific non-linked
170 * FIFO matrix allowing any cpu to send a message to any other cpu without
173 typedef struct lwkt_cpu_msg {
174 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */
175 int cm_code; /* request code if applicable */
176 int cm_cpu; /* reply to cpu */
177 thread_t cm_originator; /* originating thread for wakeup */
183 typedef struct lwkt_rwlock {
190 #define rw_token rw_wait.wa_token
193 * Thread structure. Note that ownership of a thread structure is special
194 * cased and there is no 'token'. A thread is always owned by the cpu
195 * represented by td_gd, any manipulation of the thread by some other cpu
196 * must be done through cpu_*msg() functions. e.g. you could request
197 * ownership of a thread that way, or hand a thread off to another cpu.
199 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section,
200 * but this does not effect how the thread is scheduled by LWKT.
206 TAILQ_ENTRY(thread) td_threadq;
207 TAILQ_ENTRY(thread) td_allq;
208 lwkt_port td_msgport; /* built-in message port for replies */
209 struct proc *td_proc; /* (optional) associated process */
210 struct pcb *td_pcb; /* points to pcb and top of kstack */
211 struct globaldata *td_gd; /* associated with this cpu */
212 const char *td_wmesg; /* string name for blockage */
213 void *td_wchan; /* waiting on channel */
214 int td_pri; /* 0-31, 31=highest priority (note 1) */
215 int td_flags; /* TDF flags */
216 int td_wdomain; /* domain for wchan address (typ 0) */
217 void (*td_preemptable)(struct thread *td, int critpri);
218 void (*td_release)(struct thread *td);
220 struct md_intr_info *intdata;
222 char *td_kstack; /* kernel stack */
223 int td_kstack_size; /* size of kernel stack */
224 char *td_sp; /* kernel stack pointer for LWKT restore */
225 void (*td_switch)(struct thread *ntd);
226 lwkt_wait_t td_wait; /* thread sitting on wait structure */
227 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */
228 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */
229 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */
230 int td_locks; /* lockmgr lock debugging YYY */
231 int td_refs; /* hold position in gd_tdallq / hold free */
232 int td_nest_count; /* prevent splz nesting */
234 int td_mpcount; /* MP lock held (count) */
235 int td_cscount; /* cpu synchronization master */
237 int td_mpcount_unused; /* filler so size matches */
238 int td_cscount_unused;
240 struct timeval td_start; /* start time for a thread/process */
241 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
242 struct thread *td_preempted; /* we preempted this thread */
243 struct caps_kinfo *td_caps; /* list of client and server registrations */
244 lwkt_tokref_t td_toks; /* tokens beneficially held */
245 struct md_thread td_mach;
249 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after
250 * we switch to the new one, which is necessary because LWKTs don't need
251 * to hold the BGL. This flag is used by the exit code and the managed
252 * thread migration code.
254 * LWKT threads stay on their (per-cpu) run queue while running, not to
255 * be confused with user processes which are removed from the user scheduling
256 * run queue while actually running.
258 #define TDF_RUNNING 0x0001 /* thread still active */
259 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */
260 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */
261 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */
262 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */
263 #define TDF_MIGRATING 0x0020 /* thread is being migrated */
264 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */
266 #define TDF_SYSTHREAD 0x0100 /* system thread */
267 #define TDF_ALLOCATED_THREAD 0x0200 /* zalloc allocated thread */
268 #define TDF_ALLOCATED_STACK 0x0400 /* zalloc allocated stack */
269 #define TDF_VERBOSE 0x0800 /* verbose on exit */
270 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */
271 #define TDF_STOPREQ 0x2000 /* suspend_kproc */
272 #define TDF_WAKEREQ 0x4000 /* resume_kproc */
273 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */
274 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */
275 #define TDF_NORESCHED 0x00020000 /* Do not reschedule on wake */
276 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */
279 * Thread priorities. Typically only one thread from any given
280 * user process scheduling queue is on the LWKT run queue at a time.
281 * Remember that there is one LWKT run queue per cpu.
283 * Critical sections are handled by bumping td_pri above TDPRI_MAX, which
284 * causes interrupts to be masked as they occur. When this occurs a
285 * rollup flag will be set in mycpu->gd_reqflags.
287 #define TDPRI_IDLE_THREAD 0 /* the idle thread */
288 #define TDPRI_USER_IDLE 4 /* user scheduler idle */
289 #define TDPRI_USER_NORM 6 /* user scheduler normal */
290 #define TDPRI_USER_REAL 8 /* user scheduler real time */
291 #define TDPRI_KERN_LPSCHED 9 /* scheduler helper for userland sch */
292 #define TDPRI_KERN_USER 10 /* kernel / block in syscall */
293 #define TDPRI_KERN_DAEMON 12 /* kernel daemon (pageout, etc) */
294 #define TDPRI_SOFT_NORM 14 /* kernel / normal */
295 #define TDPRI_SOFT_TIMER 16 /* kernel / timer */
296 #define TDPRI_EXITING 19 /* exiting thread */
297 #define TDPRI_INT_SUPPORT 20 /* kernel / high priority support */
298 #define TDPRI_INT_LOW 27 /* low priority interrupt */
299 #define TDPRI_INT_MED 28 /* medium priority interrupt */
300 #define TDPRI_INT_HIGH 29 /* high priority interrupt */
303 #define TDPRI_MASK 31
304 #define TDPRI_CRIT 32 /* high bits of td_pri used for crit */
307 #define LWKT_THREAD_STACK (UPAGES * PAGE_SIZE)
310 #define CACHE_NTHREADS 6
312 #define IN_CRITICAL_SECT(td) ((td)->td_pri >= TDPRI_CRIT)
316 extern struct vm_zone *thread_zone;
321 * Applies both to the kernel and to liblwkt.
323 extern struct thread *lwkt_alloc_thread(struct thread *template, int stksize,
325 extern void lwkt_init_thread(struct thread *td, void *stack, int stksize,
326 int flags, struct globaldata *gd);
327 extern void lwkt_set_comm(thread_t td, const char *ctl, ...);
328 extern void lwkt_wait_free(struct thread *td);
329 extern void lwkt_free_thread(struct thread *td);
330 extern void lwkt_wait_init(struct lwkt_wait *w);
331 extern void lwkt_gdinit(struct globaldata *gd);
332 extern void lwkt_switch(void);
333 extern void lwkt_preempt(thread_t ntd, int critpri);
334 extern void lwkt_schedule(thread_t td);
335 extern void lwkt_schedule_self(thread_t td);
336 extern void lwkt_deschedule(thread_t td);
337 extern void lwkt_deschedule_self(thread_t td);
338 extern void lwkt_acquire(thread_t td);
339 extern void lwkt_yield(void);
340 extern void lwkt_yield_quick(void);
341 extern void lwkt_token_wait(void);
342 extern void lwkt_hold(thread_t td);
343 extern void lwkt_rele(thread_t td);
345 extern void lwkt_block(lwkt_wait_t w, const char *wmesg, int *gen);
346 extern void lwkt_signal(lwkt_wait_t w, int count);
348 extern int lwkt_havetoken(lwkt_token_t tok);
349 extern int lwkt_havetokref(lwkt_tokref_t xref);
350 extern void lwkt_gettoken(lwkt_tokref_t ref, lwkt_token_t tok);
351 extern int lwkt_trytoken(lwkt_tokref_t ref, lwkt_token_t tok);
352 extern void lwkt_gettokref(lwkt_tokref_t ref);
353 extern int lwkt_trytokref(lwkt_tokref_t ref);
354 extern void lwkt_reltoken(lwkt_tokref_t ref);
355 extern int lwkt_chktokens(thread_t td);
356 extern void lwkt_drain_token_requests(void);
357 extern void lwkt_token_init(lwkt_token_t tok);
358 extern void lwkt_token_uninit(lwkt_token_t tok);
360 extern void lwkt_token_pool_init(void);
361 extern lwkt_token_t lwkt_token_pool_get(void *ptraddr);
363 extern void lwkt_rwlock_init(lwkt_rwlock_t lock);
364 extern void lwkt_rwlock_uninit(lwkt_rwlock_t lock);
365 extern void lwkt_exlock(lwkt_rwlock_t lock, const char *wmesg);
366 extern void lwkt_shlock(lwkt_rwlock_t lock, const char *wmesg);
367 extern void lwkt_exunlock(lwkt_rwlock_t lock);
368 extern void lwkt_shunlock(lwkt_rwlock_t lock);
370 extern void lwkt_setpri(thread_t td, int pri);
371 extern void lwkt_setpri_self(int pri);
372 extern int lwkt_checkpri_self(void);
373 extern void lwkt_setcpu_self(struct globaldata *rgd);
374 extern int lwkt_send_ipiq(struct globaldata *targ, ipifunc_t func, void *arg);
375 extern int lwkt_send_ipiq_passive(struct globaldata *targ, ipifunc_t func, void *arg);
376 extern int lwkt_send_ipiq_nowait(struct globaldata *targ, ipifunc_t func, void *arg);
377 extern int lwkt_send_ipiq_bycpu(int dcpu, ipifunc_t func, void *arg);
378 extern int lwkt_send_ipiq_mask(cpumask_t mask, ipifunc_t func, void *arg);
379 extern void lwkt_wait_ipiq(struct globaldata *targ, int seq);
380 extern int lwkt_seq_ipiq(struct globaldata *targ);
381 extern void lwkt_process_ipiq(void);
383 extern void lwkt_process_ipiq_frame(struct intrframe frame);
385 extern void lwkt_cpusync_simple(cpumask_t mask, cpusync_func_t func, void *data);
386 extern void lwkt_cpusync_fastdata(cpumask_t mask, cpusync_func2_t func, void *data);
387 extern void lwkt_cpusync_start(cpumask_t mask, lwkt_cpusync_t poll);
388 extern void lwkt_cpusync_add(cpumask_t mask, lwkt_cpusync_t poll);
389 extern void lwkt_cpusync_finish(lwkt_cpusync_t poll);
390 extern void crit_panic(void);
391 extern struct proc *lwkt_preempted_proc(void);
393 extern int lwkt_create (void (*func)(void *), void *arg, struct thread **ptd,
394 struct thread *template, int tdflags, int cpu,
395 const char *ctl, ...);
396 extern void lwkt_exit (void) __dead2;