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 * Critical section debugging
39 #ifdef DEBUG_CRIT_SECTIONS
40 #define __DEBUG_CRIT_ARG__ const char *id
41 #define __DEBUG_CRIT_ADD_ARG__ , const char *id
42 #define __DEBUG_CRIT_PASS_ARG__ , id
43 #define __DEBUG_CRIT_ENTER(td) _debug_crit_enter((td), id)
44 #define __DEBUG_CRIT_EXIT(td) _debug_crit_exit((td), id)
45 #define crit_enter() _crit_enter(mycpu, __FUNCTION__)
46 #define crit_enter_id(id) _crit_enter(mycpu, id)
47 #define crit_enter_gd(curgd) _crit_enter((curgd), __FUNCTION__)
48 #define crit_enter_quick(curtd) _crit_enter_quick((curtd), __FUNCTION__)
49 #define crit_enter_hard() _crit_enter_hard(mycpu, __FUNCTION__)
50 #define crit_enter_hard_gd(curgd) _crit_enter_hard((curgd), __FUNCTION__)
51 #define crit_exit() _crit_exit(mycpu, __FUNCTION__)
52 #define crit_exit_id(id) _crit_exit(mycpu, id)
53 #define crit_exit_gd(curgd) _crit_exit((curgd), __FUNCTION__)
54 #define crit_exit_quick(curtd) _crit_exit_quick((curtd), __FUNCTION__)
55 #define crit_exit_hard() _crit_exit_hard(mycpu, __FUNCTION__)
56 #define crit_exit_hard_gd(curgd) _crit_exit_hard((curgd), __FUNCTION__)
57 #define crit_exit_noyield(curtd) _crit_exit_noyield((curtd),__FUNCTION__)
59 #define __DEBUG_CRIT_ARG__ void
60 #define __DEBUG_CRIT_ADD_ARG__
61 #define __DEBUG_CRIT_PASS_ARG__
62 #define __DEBUG_CRIT_ENTER(td)
63 #define __DEBUG_CRIT_EXIT(td)
64 #define crit_enter() _crit_enter(mycpu)
65 #define crit_enter_id(id) _crit_enter(mycpu)
66 #define crit_enter_gd(curgd) _crit_enter((curgd))
67 #define crit_enter_quick(curtd) _crit_enter_quick((curtd))
68 #define crit_enter_hard() _crit_enter_hard(mycpu)
69 #define crit_enter_hard_gd(curgd) _crit_enter_hard((curgd))
70 #define crit_exit() _crit_exit(mycpu)
71 #define crit_exit_id(id) _crit_exit(mycpu)
72 #define crit_exit_gd(curgd) _crit_exit((curgd))
73 #define crit_exit_quick(curtd) _crit_exit_quick((curtd))
74 #define crit_exit_hard() _crit_exit_hard(mycpu)
75 #define crit_exit_hard_gd(curgd) _crit_exit_hard((curgd))
76 #define crit_exit_noyield(curtd) _crit_exit_noyield((curtd))
80 * Track crit_enter()/crit_exit() pairs and warn on mismatches.
82 #ifdef DEBUG_CRIT_SECTIONS
85 _debug_crit_enter(thread_t td, const char *id)
87 int wi = td->td_crit_debug_index;
89 td->td_crit_debug_array[wi & CRIT_DEBUG_ARRAY_MASK] = id;
90 ++td->td_crit_debug_index;
94 _debug_crit_exit(thread_t td, const char *id)
99 wi = td->td_crit_debug_index - 1;
100 if ((gid = td->td_crit_debug_array[wi & CRIT_DEBUG_ARRAY_MASK]) != id) {
101 if (td->td_in_crit_report == 0) {
102 td->td_in_crit_report = 1;
103 kprintf("crit_exit(%s) expected id %s\n", id, gid);
104 td->td_in_crit_report = 0;
107 --td->td_crit_debug_index;
113 * Critical sections prevent preemption, but allowing explicit blocking
114 * and thread switching. Any interrupt occuring while in a critical
115 * section is made pending and returns immediately. Interrupts are not
116 * physically disabled.
118 * Hard critical sections prevent preemption and disallow any blocking
119 * or thread switching, and in addition will assert on any blockable
120 * operation (acquire token not already held, lockmgr, mutex ops, or
121 * splz). Spinlocks can still be used in hard sections.
123 * All critical section routines only operate on the current thread.
124 * Passed gd or td arguments are simply optimizations when mycpu or
125 * curthread is already available to the caller.
132 _crit_enter_quick(thread_t td __DEBUG_CRIT_ADD_ARG__)
135 __DEBUG_CRIT_ENTER(td);
140 _crit_enter(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
142 _crit_enter_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
146 _crit_enter_hard(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
148 _crit_enter_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
149 ++gd->gd_intr_nesting_level;
156 * NOTE: Conditionalizing just gd_reqflags, a case which is virtually
157 * never true regardless of crit_count, should result in 100%
158 * optimal code execution. We don't check crit_count because
159 * it just bloats the inline and does not improve performance.
162 _crit_exit_noyield(thread_t td __DEBUG_CRIT_ADD_ARG__)
164 __DEBUG_CRIT_EXIT(td);
167 if (__predict_false(td->td_critcount < 0))
170 cpu_ccfence(); /* prevent compiler reordering */
174 _crit_exit_quick(thread_t td __DEBUG_CRIT_ADD_ARG__)
176 _crit_exit_noyield(td __DEBUG_CRIT_PASS_ARG__);
177 if (__predict_false(td->td_gd->gd_reqflags & RQF_IDLECHECK_MASK))
182 _crit_exit(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
184 _crit_exit_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
188 _crit_exit_hard(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
190 --gd->gd_intr_nesting_level;
191 _crit_exit_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
195 crit_test(thread_t td)
197 return(td->td_critcount);
201 * Return whether any threads are runnable, whether they meet mp_lock
202 * requirements or not.
207 return (TAILQ_FIRST(&mycpu->gd_tdrunq) != NULL);
211 lwkt_getpri(thread_t td)
217 lwkt_getpri_self(void)
219 return(lwkt_getpri(curthread));
223 * Reduce our priority in preparation for a return to userland. If
224 * our passive release function was still in place, our priority was
225 * never raised and does not need to be reduced.
227 * See also lwkt_passive_release() and platform/blah/trap.c
230 lwkt_passive_recover(thread_t td)
232 if (td->td_release == NULL)
233 lwkt_setpri_self(TDPRI_USER_NORM);
234 td->td_release = NULL;
240 * IPIQ messaging wrappers. IPIQ remote functions are passed three arguments:
241 * a void * pointer, an integer, and a pointer to the trap frame (or NULL if
242 * the trap frame is not known). However, we wish to provide opaque
243 * interfaces for simpler callbacks... the basic IPI messaging function as
244 * used by the kernel takes a single argument.
247 lwkt_send_ipiq(globaldata_t target, ipifunc1_t func, void *arg)
249 return(lwkt_send_ipiq3(target, (ipifunc3_t)func, arg, 0));
253 lwkt_send_ipiq2(globaldata_t target, ipifunc2_t func, void *arg1, int arg2)
255 return(lwkt_send_ipiq3(target, (ipifunc3_t)func, arg1, arg2));
259 lwkt_send_ipiq_mask(u_int32_t mask, ipifunc1_t func, void *arg)
261 return(lwkt_send_ipiq3_mask(mask, (ipifunc3_t)func, arg, 0));
265 lwkt_send_ipiq2_mask(u_int32_t mask, ipifunc2_t func, void *arg1, int arg2)
267 return(lwkt_send_ipiq3_mask(mask, (ipifunc3_t)func, arg1, arg2));
271 lwkt_send_ipiq_nowait(globaldata_t target, ipifunc1_t func, void *arg)
273 return(lwkt_send_ipiq3_nowait(target, (ipifunc3_t)func, arg, 0));
277 lwkt_send_ipiq2_nowait(globaldata_t target, ipifunc2_t func,
278 void *arg1, int arg2)
280 return(lwkt_send_ipiq3_nowait(target, (ipifunc3_t)func, arg1, arg2));
284 lwkt_send_ipiq_passive(globaldata_t target, ipifunc1_t func, void *arg)
286 return(lwkt_send_ipiq3_passive(target, (ipifunc3_t)func, arg, 0));
290 lwkt_send_ipiq2_passive(globaldata_t target, ipifunc2_t func,
291 void *arg1, int arg2)
293 return(lwkt_send_ipiq3_passive(target, (ipifunc3_t)func, arg1, arg2));
297 lwkt_send_ipiq_bycpu(int dcpu, ipifunc1_t func, void *arg)
299 return(lwkt_send_ipiq3_bycpu(dcpu, (ipifunc3_t)func, arg, 0));
303 lwkt_send_ipiq2_bycpu(int dcpu, ipifunc2_t func, void *arg1, int arg2)
305 return(lwkt_send_ipiq3_bycpu(dcpu, (ipifunc3_t)func, arg1, arg2));
310 #endif /* _SYS_THREAD2_H_ */