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 1.88 2007/04/25 11:45:28 swildner 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>
53 typedef struct lwkt_queue *lwkt_queue_t;
54 typedef struct lwkt_token *lwkt_token_t;
55 typedef struct lwkt_tokref *lwkt_tokref_t;
56 typedef struct lwkt_cpu_msg *lwkt_cpu_msg_t;
57 typedef struct lwkt_cpu_port *lwkt_cpu_port_t;
58 typedef struct lwkt_ipiq *lwkt_ipiq_t;
59 typedef struct lwkt_cpusync *lwkt_cpusync_t;
60 typedef struct thread *thread_t;
62 typedef TAILQ_HEAD(lwkt_queue, thread) lwkt_queue;
65 * Differentiation between kernel threads and user threads. Userland
66 * programs which want to access to kernel structures have to define
67 * _KERNEL_STRUCTURES. This is a kinda safety valve to prevent badly
68 * written user programs from getting an LWKT thread that is neither the
69 * kernel nor the user version.
71 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
72 #ifndef _MACHINE_THREAD_H_
73 #include <machine/thread.h> /* md_thread */
75 #ifndef _MACHINE_FRAME_H_
76 #include <machine/frame.h>
83 * Tokens are used to serialize access to information. They are 'soft'
84 * serialization entities that only stay in effect while a thread is
85 * running. If the thread blocks, other threads can run holding the same
86 * token(s). The tokens are reacquired when the original thread resumes.
88 * A thread can depend on its serialization remaining intact through a
89 * preemption. An interrupt which attempts to use the same token as the
90 * thread being preempted will reschedule itself for non-preemptive
91 * operation, so the new token code is capable of interlocking against
92 * interrupts as well as other cpus.
94 * Tokens are managed through a helper reference structure, lwkt_tokref,
95 * which is typically declared on the caller's stack. Multiple tokref's
96 * may reference the same token.
98 * We do not actually have to track any information in the token itself
99 * on UP systems. Simply linking the reference into the thread's td_toks
100 * list is sufficient. We still track a global t_globalcount on UP for
101 * debugging purposes.
105 typedef struct lwkt_token {
106 struct spinlock t_spinlock; /* Controls access */
107 struct thread *t_owner; /* The current owner of the token */
108 int t_count; /* Per-thread count */
113 typedef struct lwkt_token {
114 struct spinlock t_unused01;
115 struct thread *t_unused02;
116 int t_globalcount; /* Global reference count */
121 typedef struct lwkt_tokref {
122 lwkt_token_t tr_tok; /* token in question */
123 lwkt_tokref_t tr_next; /* linked list */
124 int tr_state; /* 0 = don't have, 1 = have */
127 #define LWKT_TOKREF_INIT(tok) \
129 #define LWKT_TOKREF_DECLARE(name, tok) \
130 lwkt_tokref name = LWKT_TOKREF_INIT(tok)
132 #define MAXCPUFIFO 16 /* power of 2 */
133 #define MAXCPUFIFO_MASK (MAXCPUFIFO - 1)
134 #define LWKT_MAXTOKENS 16 /* max tokens beneficially held by thread */
137 * Always cast to ipifunc_t when registering an ipi. The actual ipi function
138 * is called with both the data and an interrupt frame, but the ipi function
139 * that is registered might only declare a data argument.
141 typedef void (*ipifunc1_t)(void *arg);
142 typedef void (*ipifunc2_t)(void *arg, int arg2);
143 typedef void (*ipifunc3_t)(void *arg, int arg2, struct intrframe *frame);
145 typedef struct lwkt_ipiq {
146 int ip_rindex; /* only written by target cpu */
147 int ip_xindex; /* written by target, indicates completion */
148 int ip_windex; /* only written by source cpu */
149 ipifunc3_t ip_func[MAXCPUFIFO];
150 void *ip_arg1[MAXCPUFIFO];
151 int ip_arg2[MAXCPUFIFO];
152 u_int ip_npoll; /* synchronization to avoid excess IPIs */
156 * CPU Synchronization structure. See lwkt_cpusync_start() and
157 * lwkt_cpusync_finish() for more information.
159 typedef void (*cpusync_func_t)(lwkt_cpusync_t poll);
160 typedef void (*cpusync_func2_t)(void *data);
162 struct lwkt_cpusync {
163 cpusync_func_t cs_run_func; /* run (tandem w/ acquire) */
164 cpusync_func_t cs_fin1_func; /* fin1 (synchronized) */
165 cpusync_func2_t cs_fin2_func; /* fin2 (tandem w/ release) */
168 volatile int cs_count;
173 * The standard message and queue structure used for communications between
174 * cpus. Messages are typically queued via a machine-specific non-linked
175 * FIFO matrix allowing any cpu to send a message to any other cpu without
178 typedef struct lwkt_cpu_msg {
179 void (*cm_func)(lwkt_cpu_msg_t msg); /* primary dispatch function */
180 int cm_code; /* request code if applicable */
181 int cm_cpu; /* reply to cpu */
182 thread_t cm_originator; /* originating thread for wakeup */
186 * Thread structure. Note that ownership of a thread structure is special
187 * cased and there is no 'token'. A thread is always owned by the cpu
188 * represented by td_gd, any manipulation of the thread by some other cpu
189 * must be done through cpu_*msg() functions. e.g. you could request
190 * ownership of a thread that way, or hand a thread off to another cpu.
192 * NOTE: td_pri is bumped by TDPRI_CRIT when entering a critical section,
193 * but this does not effect how the thread is scheduled by LWKT.
199 TAILQ_ENTRY(thread) td_threadq;
200 TAILQ_ENTRY(thread) td_allq;
201 lwkt_port td_msgport; /* built-in message port for replies */
202 struct lwp *td_lwp; /* (optional) associated lwp */
203 struct proc *td_proc; /* (optional) associated process */
204 struct pcb *td_pcb; /* points to pcb and top of kstack */
205 struct globaldata *td_gd; /* associated with this cpu */
206 const char *td_wmesg; /* string name for blockage */
207 void *td_wchan; /* waiting on channel */
208 int td_pri; /* 0-31, 31=highest priority (note 1) */
209 int td_flags; /* TDF flags */
210 int td_wdomain; /* domain for wchan address (typ 0) */
211 void (*td_preemptable)(struct thread *td, int critpri);
212 void (*td_release)(struct thread *td);
213 char *td_kstack; /* kernel stack */
214 int td_kstack_size; /* size of kernel stack */
215 char *td_sp; /* kernel stack pointer for LWKT restore */
216 void (*td_switch)(struct thread *ntd);
217 __uint64_t td_uticks; /* Statclock hits in user mode (uS) */
218 __uint64_t td_sticks; /* Statclock hits in system mode (uS) */
219 __uint64_t td_iticks; /* Statclock hits processing intr (uS) */
220 int td_locks; /* lockmgr lock debugging */
222 int td_refs; /* hold position in gd_tdallq / hold free */
223 int td_nest_count; /* prevent splz nesting */
225 int td_mpcount; /* MP lock held (count) */
226 int td_cscount; /* cpu synchronization master */
228 int td_mpcount_unused; /* filler so size matches */
229 int td_cscount_unused;
231 struct timeval td_start; /* start time for a thread/process */
232 char td_comm[MAXCOMLEN+1]; /* typ 16+1 bytes */
233 struct thread *td_preempted; /* we preempted this thread */
234 struct caps_kinfo *td_caps; /* list of client and server registrations */
235 lwkt_tokref_t td_toks; /* tokens beneficially held */
236 #ifdef DEBUG_CRIT_SECTIONS
237 #define CRIT_DEBUG_ARRAY_SIZE 32
238 #define CRIT_DEBUG_ARRAY_MASK (CRIT_DEBUG_ARRAY_SIZE - 1)
239 const char *td_crit_debug_array[CRIT_DEBUG_ARRAY_SIZE];
240 int td_crit_debug_index;
241 int td_in_crit_report;
243 struct md_thread td_mach;
247 * Thread flags. Note that TDF_RUNNING is cleared on the old thread after
248 * we switch to the new one, which is necessary because LWKTs don't need
249 * to hold the BGL. This flag is used by the exit code and the managed
250 * thread migration code. Note in addition that preemption will cause
251 * TDF_RUNNING to be cleared temporarily, so any code checking TDF_RUNNING
252 * must also check TDF_PREEMPT_LOCK.
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 * td_threadq can represent the thread on one of three queues... the LWKT
259 * run queue, a tsleep queue, or an lwkt blocking queue. The LWKT subsystem
260 * does not allow a thread to be scheduled if it already resides on some
263 #define TDF_RUNNING 0x0001 /* thread still active */
264 #define TDF_RUNQ 0x0002 /* on an LWKT run queue */
265 #define TDF_PREEMPT_LOCK 0x0004 /* I have been preempted */
266 #define TDF_PREEMPT_DONE 0x0008 /* acknowledge preemption complete */
267 #define TDF_IDLE_NOHLT 0x0010 /* we need to spin */
268 #define TDF_MIGRATING 0x0020 /* thread is being migrated */
269 #define TDF_SINTR 0x0040 /* interruptability hint for 'ps' */
270 #define TDF_TSLEEPQ 0x0080 /* on a tsleep wait queue */
272 #define TDF_SYSTHREAD 0x0100 /* system thread */
273 #define TDF_ALLOCATED_THREAD 0x0200 /* zalloc allocated thread */
274 #define TDF_ALLOCATED_STACK 0x0400 /* zalloc allocated stack */
275 #define TDF_VERBOSE 0x0800 /* verbose on exit */
276 #define TDF_DEADLKTREAT 0x1000 /* special lockmgr deadlock treatment */
277 #define TDF_STOPREQ 0x2000 /* suspend_kproc */
278 #define TDF_WAKEREQ 0x4000 /* resume_kproc */
279 #define TDF_TIMEOUT 0x8000 /* tsleep timeout */
280 #define TDF_INTTHREAD 0x00010000 /* interrupt thread */
281 #define TDF_NORESCHED 0x00020000 /* Do not reschedule on wake */
282 #define TDF_BLOCKED 0x00040000 /* Thread is blocked */
283 #define TDF_PANICWARN 0x00080000 /* panic warning in switch */
284 #define TDF_BLOCKQ 0x00100000 /* on block queue */
285 #define TDF_MPSAFE 0x00200000 /* (thread creation) */
286 #define TDF_EXITING 0x00400000 /* thread exiting */
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)
327 extern struct vm_zone *thread_zone;
332 * Applies both to the kernel and to liblwkt.
334 extern struct thread *lwkt_alloc_thread(struct thread *, int, int, int);
335 extern void lwkt_init_thread(struct thread *, void *, int, int,
336 struct globaldata *);
337 extern void lwkt_set_comm(thread_t, const char *, ...);
338 extern void lwkt_wait_free(struct thread *);
339 extern void lwkt_free_thread(struct thread *);
340 extern void lwkt_gdinit(struct globaldata *);
341 extern void lwkt_switch(void);
342 extern void lwkt_preempt(thread_t, int);
343 extern void lwkt_schedule(thread_t);
344 extern void lwkt_schedule_self(thread_t);
345 extern void lwkt_deschedule(thread_t);
346 extern void lwkt_deschedule_self(thread_t);
347 extern void lwkt_yield(void);
348 extern void lwkt_yield_quick(void);
349 extern void lwkt_token_wait(void);
350 extern void lwkt_hold(thread_t);
351 extern void lwkt_rele(thread_t);
353 extern void lwkt_gettoken(lwkt_tokref_t, lwkt_token_t);
354 extern int lwkt_trytoken(lwkt_tokref_t, lwkt_token_t);
355 extern void lwkt_gettokref(lwkt_tokref_t);
356 extern int lwkt_trytokref(lwkt_tokref_t);
357 extern void lwkt_reltoken(lwkt_tokref_t);
358 extern int lwkt_getalltokens(thread_t);
359 extern void lwkt_relalltokens(thread_t);
360 extern void lwkt_drain_token_requests(void);
361 extern void lwkt_token_init(lwkt_token_t);
362 extern void lwkt_token_uninit(lwkt_token_t);
364 extern void lwkt_token_pool_init(void);
365 extern lwkt_token_t lwkt_token_pool_get(void *);
367 extern void lwkt_setpri(thread_t, int);
368 extern void lwkt_setpri_self(int);
369 extern int lwkt_checkpri_self(void);
370 extern void lwkt_setcpu_self(struct globaldata *);
371 extern void lwkt_migratecpu(int);
375 extern void lwkt_giveaway(struct thread *);
376 extern void lwkt_acquire(struct thread *);
377 extern int lwkt_send_ipiq3(struct globaldata *, ipifunc3_t, void *, int);
378 extern int lwkt_send_ipiq3_passive(struct globaldata *, ipifunc3_t,
380 extern int lwkt_send_ipiq3_nowait(struct globaldata *, ipifunc3_t,
382 extern int lwkt_send_ipiq3_bycpu(int, ipifunc3_t, void *, int);
383 extern int lwkt_send_ipiq3_mask(cpumask_t, ipifunc3_t, void *, int);
384 extern void lwkt_wait_ipiq(struct globaldata *, int);
385 extern int lwkt_seq_ipiq(struct globaldata *);
386 extern void lwkt_process_ipiq(void);
388 extern void lwkt_process_ipiq_frame(struct intrframe *);
390 extern void lwkt_smp_stopped(void);
394 extern void lwkt_cpusync_simple(cpumask_t, cpusync_func_t, void *);
395 extern void lwkt_cpusync_fastdata(cpumask_t, cpusync_func2_t, void *);
396 extern void lwkt_cpusync_start(cpumask_t, lwkt_cpusync_t);
397 extern void lwkt_cpusync_add(cpumask_t, lwkt_cpusync_t);
398 extern void lwkt_cpusync_finish(lwkt_cpusync_t);
400 extern void crit_panic(void);
401 extern struct lwp *lwkt_preempted_proc(void);
403 extern int lwkt_create (void (*func)(void *), void *, struct thread **,
404 struct thread *, int, int, const char *, ...);
405 extern void lwkt_exit (void) __dead2;
406 extern void lwkt_remove_tdallq (struct thread *);
407 extern void lwkt_mp_lock_contested(void);