4 * Implements inline procedure support for the LWKT subsystem.
6 * Generally speaking these routines only operate on threads associated
7 * with the current cpu. For example, a higher priority thread pending
8 * on a different cpu will not be immediately scheduled by a yield() on
11 * $DragonFly: src/sys/sys/thread2.h,v 1.28 2006/12/23 00:27:03 swildner Exp $
14 #ifndef _SYS_THREAD2_H_
15 #define _SYS_THREAD2_H_
19 #error "This file should not be included by userland programs."
24 * Userland will have its own globaldata which it includes prior to this.
27 #include <sys/systm.h>
29 #ifndef _SYS_GLOBALDATA_H_
30 #include <sys/globaldata.h>
32 #ifndef _MACHINE_CPUFUNC_H_
33 #include <machine/cpufunc.h>
37 * Is a token held by the specified thread?
40 _lwkt_token_held(lwkt_token_t tok, thread_t td)
42 return (tok->t_ref >= &td->td_toks_base &&
43 tok->t_ref < td->td_toks_stop);
47 * Critical section debugging
49 #ifdef DEBUG_CRIT_SECTIONS
50 #define __DEBUG_CRIT_ARG__ const char *id
51 #define __DEBUG_CRIT_ADD_ARG__ , const char *id
52 #define __DEBUG_CRIT_PASS_ARG__ , id
53 #define __DEBUG_CRIT_ENTER(td) _debug_crit_enter((td), id)
54 #define __DEBUG_CRIT_EXIT(td) _debug_crit_exit((td), id)
55 #define crit_enter() _crit_enter(mycpu, __FUNCTION__)
56 #define crit_enter_id(id) _crit_enter(mycpu, id)
57 #define crit_enter_gd(curgd) _crit_enter((curgd), __FUNCTION__)
58 #define crit_enter_quick(curtd) _crit_enter_quick((curtd), __FUNCTION__)
59 #define crit_enter_hard() _crit_enter_hard(mycpu, __FUNCTION__)
60 #define crit_enter_hard_gd(curgd) _crit_enter_hard((curgd), __FUNCTION__)
61 #define crit_exit() _crit_exit(mycpu, __FUNCTION__)
62 #define crit_exit_id(id) _crit_exit(mycpu, id)
63 #define crit_exit_gd(curgd) _crit_exit((curgd), __FUNCTION__)
64 #define crit_exit_quick(curtd) _crit_exit_quick((curtd), __FUNCTION__)
65 #define crit_exit_hard() _crit_exit_hard(mycpu, __FUNCTION__)
66 #define crit_exit_hard_gd(curgd) _crit_exit_hard((curgd), __FUNCTION__)
67 #define crit_exit_noyield(curtd) _crit_exit_noyield((curtd),__FUNCTION__)
69 #define __DEBUG_CRIT_ARG__ void
70 #define __DEBUG_CRIT_ADD_ARG__
71 #define __DEBUG_CRIT_PASS_ARG__
72 #define __DEBUG_CRIT_ENTER(td)
73 #define __DEBUG_CRIT_EXIT(td)
74 #define crit_enter() _crit_enter(mycpu)
75 #define crit_enter_id(id) _crit_enter(mycpu)
76 #define crit_enter_gd(curgd) _crit_enter((curgd))
77 #define crit_enter_quick(curtd) _crit_enter_quick((curtd))
78 #define crit_enter_hard() _crit_enter_hard(mycpu)
79 #define crit_enter_hard_gd(curgd) _crit_enter_hard((curgd))
80 #define crit_exit() crit_exit_wrapper()
81 #define crit_exit_id(id) _crit_exit(mycpu)
82 #define crit_exit_gd(curgd) _crit_exit((curgd))
83 #define crit_exit_quick(curtd) _crit_exit_quick((curtd))
84 #define crit_exit_hard() _crit_exit_hard(mycpu)
85 #define crit_exit_hard_gd(curgd) _crit_exit_hard((curgd))
86 #define crit_exit_noyield(curtd) _crit_exit_noyield((curtd))
89 extern void crit_exit_wrapper(__DEBUG_CRIT_ARG__);
92 * Track crit_enter()/crit_exit() pairs and warn on mismatches.
94 #ifdef DEBUG_CRIT_SECTIONS
97 _debug_crit_enter(thread_t td, const char *id)
99 int wi = td->td_crit_debug_index;
101 td->td_crit_debug_array[wi & CRIT_DEBUG_ARRAY_MASK] = id;
102 ++td->td_crit_debug_index;
106 _debug_crit_exit(thread_t td, const char *id)
111 wi = td->td_crit_debug_index - 1;
112 if ((gid = td->td_crit_debug_array[wi & CRIT_DEBUG_ARRAY_MASK]) != id) {
113 if (td->td_in_crit_report == 0) {
114 td->td_in_crit_report = 1;
115 kprintf("crit_exit(%s) expected id %s\n", id, gid);
116 td->td_in_crit_report = 0;
119 --td->td_crit_debug_index;
125 * Critical sections prevent preemption, but allowing explicit blocking
126 * and thread switching. Any interrupt occuring while in a critical
127 * section is made pending and returns immediately. Interrupts are not
128 * physically disabled.
130 * Hard critical sections prevent preemption and disallow any blocking
131 * or thread switching, and in addition will assert on any blockable
132 * operation (acquire token not already held, lockmgr, mutex ops, or
133 * splz). Spinlocks can still be used in hard sections.
135 * All critical section routines only operate on the current thread.
136 * Passed gd or td arguments are simply optimizations when mycpu or
137 * curthread is already available to the caller.
144 _crit_enter_quick(thread_t td __DEBUG_CRIT_ADD_ARG__)
147 __DEBUG_CRIT_ENTER(td);
152 _crit_enter(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
154 _crit_enter_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
158 _crit_enter_hard(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
160 _crit_enter_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
161 ++gd->gd_intr_nesting_level;
168 * NOTE: Conditionalizing just gd_reqflags, a case which is virtually
169 * never true regardless of crit_count, should result in 100%
170 * optimal code execution. We don't check crit_count because
171 * it just bloats the inline and does not improve performance.
173 * NOTE: This can produce a considerable amount of code despite the
174 * relatively few lines of code so the non-debug case typically
175 * just wraps it in a real function, crit_exit_wrapper().
178 _crit_exit_noyield(thread_t td __DEBUG_CRIT_ADD_ARG__)
180 __DEBUG_CRIT_EXIT(td);
183 if (__predict_false(td->td_critcount < 0))
186 cpu_ccfence(); /* prevent compiler reordering */
190 _crit_exit_quick(thread_t td __DEBUG_CRIT_ADD_ARG__)
192 _crit_exit_noyield(td __DEBUG_CRIT_PASS_ARG__);
193 if (__predict_false(td->td_gd->gd_reqflags & RQF_IDLECHECK_MASK))
198 _crit_exit(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
200 _crit_exit_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
204 _crit_exit_hard(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
206 --gd->gd_intr_nesting_level;
207 _crit_exit_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
211 crit_test(thread_t td)
213 return(td->td_critcount);
217 * Return whether any threads are runnable.
222 return (TAILQ_FIRST(&mycpu->gd_tdrunq) != NULL);
226 lwkt_getpri(thread_t td)
232 lwkt_getpri_self(void)
234 return(lwkt_getpri(curthread));
238 * Reduce our priority in preparation for a return to userland. If
239 * our passive release function was still in place, our priority was
240 * never raised and does not need to be reduced.
242 * See also lwkt_passive_release() and platform/blah/trap.c
245 lwkt_passive_recover(thread_t td)
247 if (td->td_release == NULL)
248 lwkt_setpri_self(TDPRI_USER_NORM);
249 td->td_release = NULL;
255 * IPIQ messaging wrappers. IPIQ remote functions are passed three arguments:
256 * a void * pointer, an integer, and a pointer to the trap frame (or NULL if
257 * the trap frame is not known). However, we wish to provide opaque
258 * interfaces for simpler callbacks... the basic IPI messaging function as
259 * used by the kernel takes a single argument.
262 lwkt_send_ipiq(globaldata_t target, ipifunc1_t func, void *arg)
264 return(lwkt_send_ipiq3(target, (ipifunc3_t)func, arg, 0));
268 lwkt_send_ipiq2(globaldata_t target, ipifunc2_t func, void *arg1, int arg2)
270 return(lwkt_send_ipiq3(target, (ipifunc3_t)func, arg1, arg2));
274 lwkt_send_ipiq_mask(cpumask_t mask, ipifunc1_t func, void *arg)
276 return(lwkt_send_ipiq3_mask(mask, (ipifunc3_t)func, arg, 0));
280 lwkt_send_ipiq2_mask(cpumask_t mask, ipifunc2_t func, void *arg1, int arg2)
282 return(lwkt_send_ipiq3_mask(mask, (ipifunc3_t)func, arg1, arg2));
286 lwkt_send_ipiq_nowait(globaldata_t target, ipifunc1_t func, void *arg)
288 return(lwkt_send_ipiq3_nowait(target, (ipifunc3_t)func, arg, 0));
292 lwkt_send_ipiq2_nowait(globaldata_t target, ipifunc2_t func,
293 void *arg1, int arg2)
295 return(lwkt_send_ipiq3_nowait(target, (ipifunc3_t)func, arg1, arg2));
299 lwkt_send_ipiq_passive(globaldata_t target, ipifunc1_t func, void *arg)
301 return(lwkt_send_ipiq3_passive(target, (ipifunc3_t)func, arg, 0));
305 lwkt_send_ipiq2_passive(globaldata_t target, ipifunc2_t func,
306 void *arg1, int arg2)
308 return(lwkt_send_ipiq3_passive(target, (ipifunc3_t)func, arg1, arg2));
312 lwkt_send_ipiq_bycpu(int dcpu, ipifunc1_t func, void *arg)
314 return(lwkt_send_ipiq3_bycpu(dcpu, (ipifunc3_t)func, arg, 0));
318 lwkt_send_ipiq2_bycpu(int dcpu, ipifunc2_t func, void *arg1, int arg2)
320 return(lwkt_send_ipiq3_bycpu(dcpu, (ipifunc3_t)func, arg1, arg2));
325 #endif /* _SYS_THREAD2_H_ */