1 /* $NetBSD: lwp.h,v 1.170 2015/03/31 01:10:02 matt Exp $ */
2
3 /*-
4 * Copyright (c) 2001, 2006, 2007, 2008, 2009, 2010
5 * The NetBSD Foundation, Inc.
6 * All rights reserved.
7 *
8 * This code is derived from software contributed to The NetBSD Foundation
9 * by Nathan J. Williams and Andrew Doran.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33 #ifndef _SYS_LWP_H_
34 #define _SYS_LWP_H_
35
36 #if defined(_KERNEL) || defined(_KMEMUSER)
37
38 #include <sys/param.h>
39 #include <sys/time.h>
40 #include <sys/queue.h>
41 #include <sys/callout.h>
42 #include <sys/kcpuset.h>
43 #include <sys/mutex.h>
44 #include <sys/condvar.h>
45 #include <sys/signalvar.h>
46 #include <sys/sched.h>
47 #include <sys/specificdata.h>
48 #include <sys/syncobj.h>
49 #include <sys/resource.h>
50
51 #if defined(_KERNEL)
52 struct lwp;
53 /* forward declare this for <machine/cpu.h> so it can get l_cpu. */
54 static inline struct cpu_info *lwp_getcpu(struct lwp *);
55 #include <machine/cpu.h> /* curcpu() and cpu_info */
56 #endif
57
58 #include <machine/proc.h> /* Machine-dependent proc substruct. */
59
60 /*
61 * Lightweight process. Field markings and the corresponding locks:
62 *
63 * a: proc_lock
64 * c: condition variable interlock, passed to cv_wait()
65 * l: *l_mutex
66 * p: l_proc->p_lock
67 * s: spc_mutex, which may or may not be referenced by l_mutex
68 * S: l_selcluster->sc_lock
69 * (: unlocked, stable
70 * !: unlocked, may only be reliably accessed by the LWP itself
71 *
72 * Fields are clustered together by usage (to increase the likelyhood
73 * of cache hits) and by size (to reduce dead space in the structure).
74 */
75
76 #include <sys/pcu.h>
77
78 struct lockdebug;
79 struct sysent;
80
81 struct lwp {
82 /* Scheduling and overall state. */
83 TAILQ_ENTRY(lwp) l_runq; /* s: run queue */
84 union {
85 void * info; /* s: scheduler-specific structure */
86 u_int timeslice; /* l: time-quantum for SCHED_M2 */
87 } l_sched;
88 struct cpu_info *volatile l_cpu;/* s: CPU we're on if LSONPROC */
89 kmutex_t * volatile l_mutex; /* l: ptr to mutex on sched state */
90 int l_ctxswtch; /* l: performing a context switch */
91 void *l_addr; /* l: PCB address; use lwp_getpcb() */
92 struct mdlwp l_md; /* l: machine-dependent fields. */
93 int l_flag; /* l: misc flag values */
94 int l_stat; /* l: overall LWP status */
95 struct bintime l_rtime; /* l: real time */
96 struct bintime l_stime; /* l: start time (while ONPROC) */
97 u_int l_swtime; /* l: time swapped in or out */
98 u_int l_rticks; /* l: Saved start time of run */
99 u_int l_rticksum; /* l: Sum of ticks spent running */
100 u_int l_slpticks; /* l: Saved start time of sleep */
101 u_int l_slpticksum; /* l: Sum of ticks spent sleeping */
102 int l_biglocks; /* l: biglock count before sleep */
103 int l_class; /* l: scheduling class */
104 int l_kpriority; /* !: has kernel priority boost */
105 pri_t l_kpribase; /* !: kernel priority base level */
106 pri_t l_priority; /* l: scheduler priority */
107 pri_t l_inheritedprio;/* l: inherited priority */
108 SLIST_HEAD(, turnstile) l_pi_lenders; /* l: ts lending us priority */
109 uint64_t l_ncsw; /* l: total context switches */
110 uint64_t l_nivcsw; /* l: involuntary context switches */
111 u_int l_cpticks; /* (: Ticks of CPU time */
112 fixpt_t l_pctcpu; /* p: %cpu during l_swtime */
113 fixpt_t l_estcpu; /* l: cpu time for SCHED_4BSD */
114 psetid_t l_psid; /* l: assigned processor-set ID */
115 struct cpu_info *l_target_cpu; /* l: target CPU to migrate */
116 struct lwpctl *l_lwpctl; /* p: lwpctl block kernel address */
117 struct lcpage *l_lcpage; /* p: lwpctl containing page */
118 kcpuset_t *l_affinity; /* l: CPU set for affinity */
119
120 /* Synchronisation. */
121 struct turnstile *l_ts; /* l: current turnstile */
122 struct syncobj *l_syncobj; /* l: sync object operations set */
123 TAILQ_ENTRY(lwp) l_sleepchain; /* l: sleep queue */
124 wchan_t l_wchan; /* l: sleep address */
125 const char *l_wmesg; /* l: reason for sleep */
126 struct sleepq *l_sleepq; /* l: current sleep queue */
127 int l_sleeperr; /* !: error before unblock */
128 u_int l_slptime; /* l: time since last blocked */
129 callout_t l_timeout_ch; /* !: callout for tsleep */
130 u_int l_emap_gen; /* !: emap generation number */
131 kcondvar_t l_waitcv; /* a: vfork() wait */
132
133 #if PCU_UNIT_COUNT > 0
134 struct cpu_info * volatile l_pcu_cpu[PCU_UNIT_COUNT];
135 uint32_t l_pcu_valid;
136 #endif
137
138 /* Process level and global state, misc. */
139 LIST_ENTRY(lwp) l_list; /* a: entry on list of all LWPs */
140 void *l_ctxlink; /* p: uc_link {get,set}context */
141 struct proc *l_proc; /* p: parent process */
142 LIST_ENTRY(lwp) l_sibling; /* p: entry on proc's list of LWPs */
143 lwpid_t l_waiter; /* p: first LWP waiting on us */
144 lwpid_t l_waitingfor; /* p: specific LWP we are waiting on */
145 int l_prflag; /* p: process level flags */
146 u_int l_refcnt; /* p: reference count on this LWP */
147 lwpid_t l_lid; /* (: LWP identifier; local to proc */
148 char *l_name; /* (: name, optional */
149
150 /* State of select() or poll(). */
151 int l_selflag; /* S: polling state flags */
152 SLIST_HEAD(,selinfo) l_selwait; /* S: descriptors waited on */
153 int l_selret; /* S: return value of select/poll */
154 uintptr_t l_selrec; /* !: argument for selrecord() */
155 struct selcluster *l_selcluster;/* !: associated cluster data */
156 void * l_selbits; /* (: select() bit-field */
157 size_t l_selni; /* (: size of a single bit-field */
158
159 /* Signals. */
160 int l_sigrestore; /* p: need to restore old sig mask */
161 sigset_t l_sigwaitset; /* p: signals being waited for */
162 kcondvar_t l_sigcv; /* p: for sigsuspend() */
163 struct ksiginfo *l_sigwaited; /* p: delivered signals from set */
164 sigpend_t *l_sigpendset; /* p: XXX issignal()/postsig() baton */
165 LIST_ENTRY(lwp) l_sigwaiter; /* p: chain on list of waiting LWPs */
166 stack_t l_sigstk; /* p: sp & on stack state variable */
167 sigset_t l_sigmask; /* p: signal mask */
168 sigpend_t l_sigpend; /* p: signals to this LWP */
169 sigset_t l_sigoldmask; /* p: mask for sigpause */
170
171 /* Private data. */
172 specificdata_reference
173 l_specdataref; /* !: subsystem lwp-specific data */
174 struct timespec l_ktrcsw; /* !: for ktrace CSW trace XXX */
175 void *l_private; /* !: svr4-style lwp-private data */
176 struct lwp *l_switchto; /* !: mi_switch: switch to this LWP */
177 struct kauth_cred *l_cred; /* !: cached credentials */
178 struct filedesc *l_fd; /* !: cached copy of proc::p_fd */
179 void *l_emuldata; /* !: kernel lwp-private data */
180 u_int l_cv_signalled; /* c: restarted by cv_signal() */
181 u_short l_shlocks; /* !: lockdebug: shared locks held */
182 u_short l_exlocks; /* !: lockdebug: excl. locks held */
183 u_short l_unused; /* !: unused */
184 u_short l_blcnt; /* !: count of kernel_lock held */
185 int l_nopreempt; /* !: don't preempt me! */
186 u_int l_dopreempt; /* s: kernel preemption pending */
187 int l_pflag; /* !: LWP private flags */
188 int l_dupfd; /* !: side return from cloning devs XXX */
189 const struct sysent * volatile l_sysent;/* !: currently active syscall */
190 struct rusage l_ru; /* !: accounting information */
191 uint64_t l_pfailtime; /* !: for kernel preemption */
192 uintptr_t l_pfailaddr; /* !: for kernel preemption */
193 uintptr_t l_pfaillock; /* !: for kernel preemption */
194 _TAILQ_HEAD(,struct lockdebug,volatile) l_ld_locks;/* !: locks held by LWP */
195 int l_tcgen; /* !: for timecounter removal */
196
197 /* These are only used by 'options SYSCALL_TIMES'. */
198 uint32_t l_syscall_time; /* !: time epoch for current syscall */
199 uint64_t *l_syscall_counter; /* !: counter for current process */
200
201 struct kdtrace_thread *l_dtrace; /* (: DTrace-specific data. */
202 };
203
204 /*
205 * UAREA_PCB_OFFSET: an offset of PCB structure in the uarea. MD code may
206 * define it in <machine/proc.h>, to indicate a different uarea layout.
207 */
208 #ifndef UAREA_PCB_OFFSET
209 #define UAREA_PCB_OFFSET 0
210 #endif
211
212 LIST_HEAD(lwplist, lwp); /* A list of LWPs. */
213
214 #ifdef _KERNEL
215 extern struct lwplist alllwp; /* List of all LWPs. */
216 extern lwp_t lwp0; /* LWP for proc0. */
217 extern int maxlwp __read_mostly; /* max number of lwps */
218 #ifndef MAXLWP
219 #define MAXLWP 2048
220 #endif
221 #ifndef __HAVE_CPU_MAXLWP
222 #define cpu_maxlwp() MAXLWP
223 #endif
224 #endif
225
226 #endif /* _KERNEL || _KMEMUSER */
227
228 /* These flags are kept in l_flag. */
229 #define LW_IDLE 0x00000001 /* Idle lwp. */
230 #define LW_LWPCTL 0x00000002 /* Adjust lwpctl in userret */
231 #define LW_SINTR 0x00000080 /* Sleep is interruptible. */
232 #define LW_SYSTEM 0x00000200 /* Kernel thread */
233 #define LW_WSUSPEND 0x00020000 /* Suspend before return to user */
234 #define LW_BATCH 0x00040000 /* LWP tends to hog CPU */
235 #define LW_WCORE 0x00080000 /* Stop for core dump on return to user */
236 #define LW_WEXIT 0x00100000 /* Exit before return to user */
237 #define LW_PENDSIG 0x01000000 /* Pending signal for us */
238 #define LW_CANCELLED 0x02000000 /* tsleep should not sleep */
239 #define LW_WREBOOT 0x08000000 /* System is rebooting, please suspend */
240 #define LW_UNPARKED 0x10000000 /* Unpark op pending */
241 #define LW_RUMP_CLEAR 0x40000000 /* Clear curlwp in RUMP scheduler */
242 #define LW_RUMP_QEXIT 0x80000000 /* LWP should exit ASAP */
243
244 /* The second set of flags is kept in l_pflag. */
245 #define LP_KTRACTIVE 0x00000001 /* Executing ktrace operation */
246 #define LP_KTRCSW 0x00000002 /* ktrace context switch marker */
247 #define LP_KTRCSWUSER 0x00000004 /* ktrace context switch marker */
248 #define LP_PIDLID 0x00000008 /* free LID from PID space on exit */
249 #define LP_OWEUPC 0x00000010 /* Owe user profiling tick */
250 #define LP_MPSAFE 0x00000020 /* Starts life without kernel_lock */
251 #define LP_INTR 0x00000040 /* Soft interrupt handler */
252 #define LP_SYSCTLWRITE 0x00000080 /* sysctl write lock held */
253 #define LP_MUSTJOIN 0x00000100 /* Must join kthread on exit */
254 #define LP_VFORKWAIT 0x00000200 /* Waiting at vfork() for a child */
255 #define LP_TIMEINTR 0x00010000 /* Time this soft interrupt */
256 #define LP_RUNNING 0x20000000 /* Active on a CPU */
257 #define LP_BOUND 0x80000000 /* Bound to a CPU */
258
259 /* The third set is kept in l_prflag. */
260 #define LPR_DETACHED 0x00800000 /* Won't be waited for. */
261 #define LPR_CRMOD 0x00000100 /* Credentials modified */
262
263 /*
264 * Mask indicating that there is "exceptional" work to be done on return to
265 * user.
266 */
267 #define LW_USERRET \
268 (LW_WEXIT | LW_PENDSIG | LW_WREBOOT | LW_WSUSPEND | LW_WCORE | LW_LWPCTL)
269
270 /*
271 * Status values.
272 *
273 * A note about LSRUN and LSONPROC: LSRUN indicates that a process is
274 * runnable but *not* yet running, i.e. is on a run queue. LSONPROC
275 * indicates that the process is actually executing on a CPU, i.e.
276 * it is no longer on a run queue.
277 */
278 #define LSIDL 1 /* Process being created by fork. */
279 #define LSRUN 2 /* Currently runnable. */
280 #define LSSLEEP 3 /* Sleeping on an address. */
281 #define LSSTOP 4 /* Process debugging or suspension. */
282 #define LSZOMB 5 /* Awaiting collection by parent. */
283 /* unused, for source compatibility with NetBSD 4.0 and earlier. */
284 #define LSDEAD 6 /* Process is almost a zombie. */
285 #define LSONPROC 7 /* Process is currently on a CPU. */
286 #define LSSUSPENDED 8 /* Not running, not signalable. */
287
288 #if defined(_KERNEL) || defined(_KMEMUSER)
289 static inline void *
lwp_getpcb(struct lwp * l)290 lwp_getpcb(struct lwp *l)
291 {
292
293 return l->l_addr;
294 }
295 #endif /* _KERNEL || _KMEMUSER */
296
297 #ifdef _KERNEL
298 #define LWP_CACHE_CREDS(l, p) \
299 do { \
300 (void)p; \
301 if (__predict_false((l)->l_prflag & LPR_CRMOD)) \
302 lwp_update_creds(l); \
303 } while (/* CONSTCOND */ 0)
304
305 void lwpinit(void);
306 void lwp0_init(void);
307 void lwp_sys_init(void);
308
309 void lwp_startup(lwp_t *, lwp_t *);
310 void startlwp(void *);
311
312 int lwp_locked(lwp_t *, kmutex_t *);
313 void lwp_setlock(lwp_t *, kmutex_t *);
314 void lwp_unlock_to(lwp_t *, kmutex_t *);
315 int lwp_trylock(lwp_t *);
316 void lwp_addref(lwp_t *);
317 void lwp_delref(lwp_t *);
318 void lwp_delref2(lwp_t *);
319 void lwp_drainrefs(lwp_t *);
320 bool lwp_alive(lwp_t *);
321 lwp_t *lwp_find_first(proc_t *);
322
323 int lwp_wait(lwp_t *, lwpid_t, lwpid_t *, bool);
324 void lwp_continue(lwp_t *);
325 void lwp_unsleep(lwp_t *, bool);
326 void lwp_unstop(lwp_t *);
327 void lwp_exit(lwp_t *);
328 void lwp_exit_switchaway(lwp_t *) __dead;
329 int lwp_suspend(lwp_t *, lwp_t *);
330 int lwp_create1(lwp_t *, const void *, size_t, u_long, lwpid_t *);
331 void lwp_update_creds(lwp_t *);
332 void lwp_migrate(lwp_t *, struct cpu_info *);
333 lwp_t * lwp_find2(pid_t, lwpid_t);
334 lwp_t * lwp_find(proc_t *, int);
335 void lwp_userret(lwp_t *);
336 void lwp_need_userret(lwp_t *);
337 void lwp_free(lwp_t *, bool, bool);
338 uint64_t lwp_pctr(void);
339 int lwp_setprivate(lwp_t *, void *);
340 int do_lwp_create(lwp_t *, void *, u_long, lwpid_t *);
341
342 void lwpinit_specificdata(void);
343 int lwp_specific_key_create(specificdata_key_t *, specificdata_dtor_t);
344 void lwp_specific_key_delete(specificdata_key_t);
345 void lwp_initspecific(lwp_t *);
346 void lwp_finispecific(lwp_t *);
347 void *lwp_getspecific(specificdata_key_t);
348 #if defined(_LWP_API_PRIVATE)
349 void *_lwp_getspecific_by_lwp(lwp_t *, specificdata_key_t);
350 #endif
351 void lwp_setspecific(specificdata_key_t, void *);
352
353 /* Syscalls. */
354 int lwp_park(clockid_t, int, struct timespec *, const void *);
355 int lwp_unpark(lwpid_t, const void *);
356
357 /* DDB. */
358 void lwp_whatis(uintptr_t, void (*)(const char *, ...) __printflike(1, 2));
359
360 /*
361 * Lock an LWP. XXX _MODULE
362 */
363 static inline void
lwp_lock(lwp_t * l)364 lwp_lock(lwp_t *l)
365 {
366 kmutex_t *old = l->l_mutex;
367
368 /*
369 * Note: mutex_spin_enter() will have posted a read barrier.
370 * Re-test l->l_mutex. If it has changed, we need to try again.
371 */
372 mutex_spin_enter(old);
373 while (__predict_false(l->l_mutex != old)) {
374 mutex_spin_exit(old);
375 old = l->l_mutex;
376 mutex_spin_enter(old);
377 }
378 }
379
380 /*
381 * Unlock an LWP. XXX _MODULE
382 */
383 static inline void
lwp_unlock(lwp_t * l)384 lwp_unlock(lwp_t *l)
385 {
386 mutex_spin_exit(l->l_mutex);
387 }
388
389 static inline void
lwp_changepri(lwp_t * l,pri_t pri)390 lwp_changepri(lwp_t *l, pri_t pri)
391 {
392 KASSERT(mutex_owned(l->l_mutex));
393
394 if (l->l_priority == pri)
395 return;
396
397 (*l->l_syncobj->sobj_changepri)(l, pri);
398 KASSERT(l->l_priority == pri);
399 }
400
401 static inline void
lwp_lendpri(lwp_t * l,pri_t pri)402 lwp_lendpri(lwp_t *l, pri_t pri)
403 {
404 KASSERT(mutex_owned(l->l_mutex));
405
406 if (l->l_inheritedprio == pri)
407 return;
408
409 (*l->l_syncobj->sobj_lendpri)(l, pri);
410 KASSERT(l->l_inheritedprio == pri);
411 }
412
413 static inline pri_t
lwp_eprio(lwp_t * l)414 lwp_eprio(lwp_t *l)
415 {
416 pri_t pri;
417
418 pri = l->l_priority;
419 if ((l->l_flag & LW_SYSTEM) == 0 && l->l_kpriority && pri < PRI_KERNEL)
420 pri = (pri >> 1) + l->l_kpribase;
421 return MAX(l->l_inheritedprio, pri);
422 }
423
424 int lwp_create(lwp_t *, struct proc *, vaddr_t, int,
425 void *, size_t, void (*)(void *), void *, lwp_t **, int);
426
427 /*
428 * XXX _MODULE
429 * We should provide real stubs for the below that modules can use.
430 */
431
432 static inline void
spc_lock(struct cpu_info * ci)433 spc_lock(struct cpu_info *ci)
434 {
435 mutex_spin_enter(ci->ci_schedstate.spc_mutex);
436 }
437
438 static inline void
spc_unlock(struct cpu_info * ci)439 spc_unlock(struct cpu_info *ci)
440 {
441 mutex_spin_exit(ci->ci_schedstate.spc_mutex);
442 }
443
444 static inline void
spc_dlock(struct cpu_info * ci1,struct cpu_info * ci2)445 spc_dlock(struct cpu_info *ci1, struct cpu_info *ci2)
446 {
447 struct schedstate_percpu *spc1 = &ci1->ci_schedstate;
448 struct schedstate_percpu *spc2 = &ci2->ci_schedstate;
449
450 KASSERT(ci1 != ci2);
451 if (ci1 < ci2) {
452 mutex_spin_enter(spc1->spc_mutex);
453 mutex_spin_enter(spc2->spc_mutex);
454 } else {
455 mutex_spin_enter(spc2->spc_mutex);
456 mutex_spin_enter(spc1->spc_mutex);
457 }
458 }
459
460 /*
461 * Allow machine-dependent code to override curlwp in <machine/cpu.h> for
462 * its own convenience. Otherwise, we declare it as appropriate.
463 */
464 #if !defined(curlwp)
465 #if defined(MULTIPROCESSOR)
466 #define curlwp curcpu()->ci_curlwp /* Current running LWP */
467 #else
468 extern struct lwp *curlwp; /* Current running LWP */
469 #endif /* MULTIPROCESSOR */
470 #endif /* ! curlwp */
471 #define curproc (curlwp->l_proc)
472
473 /*
474 * This provide a way for <machine/cpu.h> to get l_cpu for curlwp before
475 * struct lwp is defined.
476 */
477 static inline struct cpu_info *
lwp_getcpu(struct lwp * l)478 lwp_getcpu(struct lwp *l)
479 {
480 return l->l_cpu;
481 }
482
483 static inline bool
CURCPU_IDLE_P(void)484 CURCPU_IDLE_P(void)
485 {
486 struct cpu_info *ci = curcpu();
487 return ci->ci_data.cpu_onproc == ci->ci_data.cpu_idlelwp;
488 }
489
490 /*
491 * Disable and re-enable preemption. Only for low-level kernel
492 * use. Device drivers and anything that could potentially be
493 * compiled as a module should use kpreempt_disable() and
494 * kpreempt_enable().
495 */
496 static inline void
KPREEMPT_DISABLE(lwp_t * l)497 KPREEMPT_DISABLE(lwp_t *l)
498 {
499
500 KASSERT(l == curlwp);
501 l->l_nopreempt++;
502 __insn_barrier();
503 }
504
505 static inline void
KPREEMPT_ENABLE(lwp_t * l)506 KPREEMPT_ENABLE(lwp_t *l)
507 {
508
509 KASSERT(l == curlwp);
510 KASSERT(l->l_nopreempt > 0);
511 __insn_barrier();
512 if (--l->l_nopreempt != 0)
513 return;
514 __insn_barrier();
515 if (__predict_false(l->l_dopreempt))
516 kpreempt(0);
517 __insn_barrier();
518 }
519
520 /* For lwp::l_dopreempt */
521 #define DOPREEMPT_ACTIVE 0x01
522 #define DOPREEMPT_COUNTED 0x02
523
524 #endif /* _KERNEL */
525
526 /* Flags for _lwp_create(), as per Solaris. */
527 #define LWP_DETACHED 0x00000040
528 #define LWP_SUSPENDED 0x00000080
529
530 /* Kernel-internal flags for LWP creation. */
531 #define LWP_PIDLID 0x40000000
532 #define LWP_VFORK 0x80000000
533
534 #endif /* !_SYS_LWP_H_ */
535