source: libcfa/src/concurrency/kernel.cfa@ 77d601f

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 77d601f was 55d6affb, checked in by Thierry Delisle <tdelisle@…>, 5 years ago

Fixed stupid copy past mistake where I used eventfd_read (wait) instead of eventfd_write (signal).
  • Property mode set to 100644
File size: 23.9 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// kernel.c --
8//
9// Author : Thierry Delisle
10// Created On : Tue Jan 17 12:27:26 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Mon Aug 31 07:08:20 2020
13// Update Count : 71
14//
15
16#define __cforall_thread__
17// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
18
19//C Includes
20#include <errno.h>
21#include <stdio.h>
22#include <signal.h>
23#include <unistd.h>
24extern "C" {
25 #include <sys/eventfd.h>
26}
27
28//CFA Includes
29#include "kernel_private.hfa"
30#include "preemption.hfa"
31
32//Private includes
33#define __CFA_INVOKE_PRIVATE__
34#include "invoke.h"
35
36
37//-----------------------------------------------------------------------------
38// Some assembly required
39#if defined( __i386 )
40 // mxcr : SSE Status and Control bits (control bits are preserved across function calls)
41 // fcw : X87 FPU control word (preserved across function calls)
42 #define __x87_store \
43 uint32_t __mxcr; \
44 uint16_t __fcw; \
45 __asm__ volatile ( \
46 "stmxcsr %0\n" \
47 "fnstcw %1\n" \
48 : "=m" (__mxcr),\
49 "=m" (__fcw) \
50 )
51
52 #define __x87_load \
53 __asm__ volatile ( \
54 "fldcw %1\n" \
55 "ldmxcsr %0\n" \
56 ::"m" (__mxcr),\
57 "m" (__fcw) \
58 )
59
60#elif defined( __x86_64 )
61 #define __x87_store \
62 uint32_t __mxcr; \
63 uint16_t __fcw; \
64 __asm__ volatile ( \
65 "stmxcsr %0\n" \
66 "fnstcw %1\n" \
67 : "=m" (__mxcr),\
68 "=m" (__fcw) \
69 )
70
71 #define __x87_load \
72 __asm__ volatile ( \
73 "fldcw %1\n" \
74 "ldmxcsr %0\n" \
75 :: "m" (__mxcr),\
76 "m" (__fcw) \
77 )
78
79#elif defined( __arm__ )
80 #define __x87_store
81 #define __x87_load
82
83#elif defined( __aarch64__ )
84 #define __x87_store \
85 uint32_t __fpcntl[2]; \
86 __asm__ volatile ( \
87 "mrs x9, FPCR\n" \
88 "mrs x10, FPSR\n" \
89 "stp x9, x10, %0\n" \
90 : "=m" (__fpcntl) : : "x9", "x10" \
91 )
92
93 #define __x87_load \
94 __asm__ volatile ( \
95 "ldp x9, x10, %0\n" \
96 "msr FPSR, x10\n" \
97 "msr FPCR, x9\n" \
98 : "=m" (__fpcntl) : : "x9", "x10" \
99 )
100
101#else
102 #error unsupported hardware architecture
103#endif
104
105extern $thread * mainThread;
106extern processor * mainProcessor;
107
108//-----------------------------------------------------------------------------
109// Kernel Scheduling logic
110static $thread * __next_thread(cluster * this);
111static $thread * __next_thread_slow(cluster * this);
112static void __run_thread(processor * this, $thread * dst);
113static void __wake_one(cluster * cltr);
114
115static void push (__cluster_idles & idles, processor & proc);
116static void remove(__cluster_idles & idles, processor & proc);
117static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles );
118
119extern void __cfa_io_start( processor * );
120extern void __cfa_io_drain( processor * );
121extern void __cfa_io_flush( processor * );
122extern void __cfa_io_stop ( processor * );
123static inline void __maybe_io_drain( processor * );
124
125extern void __disable_interrupts_hard();
126extern void __enable_interrupts_hard();
127
128//=============================================================================================
129// Kernel Scheduling logic
130//=============================================================================================
131//Main of the processor contexts
132void main(processorCtx_t & runner) {
133 // Because of a bug, we couldn't initialized the seed on construction
134 // Do it here
135 __cfaabi_tls.rand_seed ^= rdtscl();
136 __cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
137 __tls_rand_advance_bck();
138
139 processor * this = runner.proc;
140 verify(this);
141
142 __cfa_io_start( this );
143
144 __cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
145 #if !defined(__CFA_NO_STATISTICS__)
146 if( this->print_halts ) {
147 __cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
148 }
149 #endif
150
151 {
152 // Setup preemption data
153 preemption_scope scope = { this };
154
155 #if !defined(__CFA_NO_STATISTICS__)
156 unsigned long long last_tally = rdtscl();
157 #endif
158
159
160 __cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
161
162 $thread * readyThread = 0p;
163 MAIN_LOOP:
164 for() {
165 // Check if there is pending io
166 __maybe_io_drain( this );
167
168 // Try to get the next thread
169 readyThread = __next_thread( this->cltr );
170
171 if( !readyThread ) {
172 __cfa_io_flush( this );
173 readyThread = __next_thread_slow( this->cltr );
174 }
175
176 HALT:
177 if( !readyThread ) {
178 // Don't block if we are done
179 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
180
181 #if !defined(__CFA_NO_STATISTICS__)
182 __tls_stats()->ready.sleep.halts++;
183 #endif
184
185 // Push self to idle stack
186 push(this->cltr->idles, * this);
187
188 // Confirm the ready-queue is empty
189 readyThread = __next_thread_slow( this->cltr );
190 if( readyThread ) {
191 // A thread was found, cancel the halt
192 remove(this->cltr->idles, * this);
193
194 #if !defined(__CFA_NO_STATISTICS__)
195 __tls_stats()->ready.sleep.cancels++;
196 #endif
197
198 // continue the mai loop
199 break HALT;
200 }
201
202 #if !defined(__CFA_NO_STATISTICS__)
203 if(this->print_halts) {
204 __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
205 }
206 #endif
207
208 __cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
209
210 __disable_interrupts_hard();
211 eventfd_t val;
212 eventfd_read( this->idle, &val );
213 __enable_interrupts_hard();
214
215 #if !defined(__CFA_NO_STATISTICS__)
216 if(this->print_halts) {
217 __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
218 }
219 #endif
220
221 // We were woken up, remove self from idle
222 remove(this->cltr->idles, * this);
223
224 // DON'T just proceed, start looking again
225 continue MAIN_LOOP;
226 }
227
228 /* paranoid */ verify( readyThread );
229
230 // Reset io dirty bit
231 this->io.dirty = false;
232
233 // We found a thread run it
234 __run_thread(this, readyThread);
235
236 // Are we done?
237 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
238
239 #if !defined(__CFA_NO_STATISTICS__)
240 unsigned long long curr = rdtscl();
241 if(curr > (last_tally + 500000000)) {
242 __tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
243 last_tally = curr;
244 }
245 #endif
246
247 if(this->io.pending && !this->io.dirty) {
248 __cfa_io_flush( this );
249 }
250 }
251
252 __cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
253 }
254
255 __cfa_io_stop( this );
256
257 post( this->terminated );
258
259
260 if(this == mainProcessor) {
261 // HACK : the coroutine context switch expects this_thread to be set
262 // and it make sense for it to be set in all other cases except here
263 // fake it
264 __cfaabi_tls.this_thread = mainThread;
265 }
266
267 __cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
268}
269
270static int * __volatile_errno() __attribute__((noinline));
271static int * __volatile_errno() { asm(""); return &errno; }
272
273// KERNEL ONLY
274// runThread runs a thread by context switching
275// from the processor coroutine to the target thread
276static void __run_thread(processor * this, $thread * thrd_dst) {
277 /* paranoid */ verify( ! __preemption_enabled() );
278 /* paranoid */ verifyf( thrd_dst->state == Ready || thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
279 /* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
280 __builtin_prefetch( thrd_dst->context.SP );
281
282 __cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
283
284 $coroutine * proc_cor = get_coroutine(this->runner);
285
286 // set state of processor coroutine to inactive
287 verify(proc_cor->state == Active);
288 proc_cor->state = Blocked;
289
290 // Actually run the thread
291 RUNNING: while(true) {
292 thrd_dst->preempted = __NO_PREEMPTION;
293 thrd_dst->state = Active;
294
295 // Update global state
296 kernelTLS().this_thread = thrd_dst;
297
298 /* paranoid */ verify( ! __preemption_enabled() );
299 /* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
300 /* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
301 /* paranoid */ verify( thrd_dst->context.SP );
302 /* paranoid */ verify( thrd_dst->state != Halted );
303 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); // add escape condition if we are setting up the processor
304 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) || thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor
305 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
306
307
308
309 // set context switch to the thread that the processor is executing
310 __cfactx_switch( &proc_cor->context, &thrd_dst->context );
311 // when __cfactx_switch returns we are back in the processor coroutine
312
313 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
314 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst );
315 /* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
316 /* paranoid */ verify( thrd_dst->context.SP );
317 /* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
318 /* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
319 /* paranoid */ verify( ! __preemption_enabled() );
320
321 // Reset global state
322 kernelTLS().this_thread = 0p;
323
324 // We just finished running a thread, there are a few things that could have happened.
325 // 1 - Regular case : the thread has blocked and now one has scheduled it yet.
326 // 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
327 // 4 - Preempted
328 // In case 1, we may have won a race so we can't write to the state again.
329 // In case 2, we lost the race so we now own the thread.
330
331 if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
332 // The thread was preempted, reschedule it and reset the flag
333 __schedule_thread( thrd_dst );
334 break RUNNING;
335 }
336
337 if(unlikely(thrd_dst->state == Halting)) {
338 // The thread has halted, it should never be scheduled/run again
339 // finish the thread
340 __thread_finish( thrd_dst );
341 break RUNNING;
342 }
343
344 /* paranoid */ verify( thrd_dst->state == Active );
345 thrd_dst->state = Blocked;
346
347 // set state of processor coroutine to active and the thread to inactive
348 int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
349 switch(old_ticket) {
350 case TICKET_RUNNING:
351 // This is case 1, the regular case, nothing more is needed
352 break RUNNING;
353 case TICKET_UNBLOCK:
354 // This is case 2, the racy case, someone tried to run this thread before it finished blocking
355 // In this case, just run it again.
356 continue RUNNING;
357 default:
358 // This makes no sense, something is wrong abort
359 abort();
360 }
361 }
362
363 // Just before returning to the processor, set the processor coroutine to active
364 proc_cor->state = Active;
365
366 __cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
367
368 /* paranoid */ verify( ! __preemption_enabled() );
369}
370
371// KERNEL_ONLY
372void returnToKernel() {
373 /* paranoid */ verify( ! __preemption_enabled() );
374 $coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
375 $thread * thrd_src = kernelTLS().this_thread;
376
377 #if !defined(__CFA_NO_STATISTICS__)
378 struct processor * last_proc = kernelTLS().this_processor;
379 #endif
380
381 // Run the thread on this processor
382 {
383 int local_errno = *__volatile_errno();
384 #if defined( __i386 ) || defined( __x86_64 )
385 __x87_store;
386 #endif
387 /* paranoid */ verify( proc_cor->context.SP );
388 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
389 __cfactx_switch( &thrd_src->context, &proc_cor->context );
390 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
391 #if defined( __i386 ) || defined( __x86_64 )
392 __x87_load;
393 #endif
394 *__volatile_errno() = local_errno;
395 }
396
397 #if !defined(__CFA_NO_STATISTICS__)
398 if(last_proc != kernelTLS().this_processor) {
399 __tls_stats()->ready.threads.migration++;
400 }
401 #endif
402
403 /* paranoid */ verify( ! __preemption_enabled() );
404 /* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) < ((uintptr_t)__get_stack(thrd_src->curr_cor)->base ), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too small.\n", thrd_src );
405 /* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) > ((uintptr_t)__get_stack(thrd_src->curr_cor)->limit), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too large.\n", thrd_src );
406}
407
408//-----------------------------------------------------------------------------
409// Scheduler routines
410// KERNEL ONLY
411void __schedule_thread( $thread * thrd ) {
412 /* paranoid */ verify( ! __preemption_enabled() );
413 /* paranoid */ verify( kernelTLS().this_proc_id );
414 /* paranoid */ verify( thrd );
415 /* paranoid */ verify( thrd->state != Halted );
416 /* paranoid */ verify( thrd->curr_cluster );
417 /* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
418 /* paranoid */ if( thrd->state == Blocked || thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
419 "Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
420 /* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
421 "Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
422 /* paranoid */ #endif
423 /* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
424 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
425
426
427 if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
428
429 ready_schedule_lock();
430 // Dereference the thread now because once we push it, there is not guaranteed it's still valid.
431 struct cluster * cl = thrd->curr_cluster;
432
433 // push the thread to the cluster ready-queue
434 push( cl, thrd );
435
436 // variable thrd is no longer safe to use
437
438 // wake the cluster using the save variable.
439 __wake_one( cl );
440 ready_schedule_unlock();
441
442 /* paranoid */ verify( ! __preemption_enabled() );
443}
444
445// KERNEL ONLY
446static inline $thread * __next_thread(cluster * this) with( *this ) {
447 /* paranoid */ verify( ! __preemption_enabled() );
448 /* paranoid */ verify( kernelTLS().this_proc_id );
449
450 ready_schedule_lock();
451 $thread * thrd = pop( this );
452 ready_schedule_unlock();
453
454 /* paranoid */ verify( kernelTLS().this_proc_id );
455 /* paranoid */ verify( ! __preemption_enabled() );
456 return thrd;
457}
458
459// KERNEL ONLY
460static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
461 /* paranoid */ verify( ! __preemption_enabled() );
462 /* paranoid */ verify( kernelTLS().this_proc_id );
463
464 ready_schedule_lock();
465 $thread * thrd = pop_slow( this );
466 ready_schedule_unlock();
467
468 /* paranoid */ verify( kernelTLS().this_proc_id );
469 /* paranoid */ verify( ! __preemption_enabled() );
470 return thrd;
471}
472
473void unpark( $thread * thrd ) {
474 if( !thrd ) return;
475
476 int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
477 switch(old_ticket) {
478 case TICKET_RUNNING:
479 // Wake won the race, the thread will reschedule/rerun itself
480 break;
481 case TICKET_BLOCKED:
482 /* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
483 /* paranoid */ verify( thrd->state == Blocked );
484
485 {
486 /* paranoid */ verify( publicTLS_get(this_proc_id) );
487 bool full = publicTLS_get(this_proc_id)->full_proc;
488 if(full) disable_interrupts();
489
490 /* paranoid */ verify( ! __preemption_enabled() );
491
492 // Wake lost the race,
493 __schedule_thread( thrd );
494
495 /* paranoid */ verify( ! __preemption_enabled() );
496
497 if(full) enable_interrupts( __cfaabi_dbg_ctx );
498 /* paranoid */ verify( publicTLS_get(this_proc_id) );
499 }
500
501 break;
502 default:
503 // This makes no sense, something is wrong abort
504 abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
505 }
506}
507
508void park( void ) {
509 /* paranoid */ verify( __preemption_enabled() );
510 disable_interrupts();
511 /* paranoid */ verify( ! __preemption_enabled() );
512 /* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
513
514 returnToKernel();
515
516 /* paranoid */ verify( ! __preemption_enabled() );
517 enable_interrupts( __cfaabi_dbg_ctx );
518 /* paranoid */ verify( __preemption_enabled() );
519
520}
521
522extern "C" {
523 // Leave the thread monitor
524 // last routine called by a thread.
525 // Should never return
526 void __cfactx_thrd_leave() {
527 $thread * thrd = active_thread();
528 $monitor * this = &thrd->self_mon;
529
530 // Lock the monitor now
531 lock( this->lock __cfaabi_dbg_ctx2 );
532
533 disable_interrupts();
534
535 /* paranoid */ verify( ! __preemption_enabled() );
536 /* paranoid */ verify( thrd->state == Active );
537 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
538 /* paranoid */ verify( kernelTLS().this_thread == thrd );
539 /* paranoid */ verify( thrd->context.SP );
540 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) > ((uintptr_t)__get_stack(thrd->curr_cor)->limit), "ERROR : $thread %p has been corrupted.\n StackPointer too large.\n", thrd );
541 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) < ((uintptr_t)__get_stack(thrd->curr_cor)->base ), "ERROR : $thread %p has been corrupted.\n StackPointer too small.\n", thrd );
542
543 thrd->state = Halting;
544 if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
545 if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
546 if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
547
548 // Leave the thread
549 returnToKernel();
550
551 // Control flow should never reach here!
552 abort();
553 }
554}
555
556// KERNEL ONLY
557bool force_yield( __Preemption_Reason reason ) {
558 /* paranoid */ verify( __preemption_enabled() );
559 disable_interrupts();
560 /* paranoid */ verify( ! __preemption_enabled() );
561
562 $thread * thrd = kernelTLS().this_thread;
563 /* paranoid */ verify(thrd->state == Active);
564
565 // SKULLDUGGERY: It is possible that we are preempting this thread just before
566 // it was going to park itself. If that is the case and it is already using the
567 // intrusive fields then we can't use them to preempt the thread
568 // If that is the case, abandon the preemption.
569 bool preempted = false;
570 if(thrd->link.next == 0p) {
571 preempted = true;
572 thrd->preempted = reason;
573 returnToKernel();
574 }
575
576 /* paranoid */ verify( ! __preemption_enabled() );
577 enable_interrupts_noPoll();
578 /* paranoid */ verify( __preemption_enabled() );
579
580 return preempted;
581}
582
583//=============================================================================================
584// Kernel Idle Sleep
585//=============================================================================================
586// Wake a thread from the front if there are any
587static void __wake_one(cluster * this) {
588 /* paranoid */ verify( ! __preemption_enabled() );
589 /* paranoid */ verify( ready_schedule_islocked() );
590
591 // Check if there is a sleeping processor
592 processor * p;
593 unsigned idle;
594 unsigned total;
595 [idle, total, p] = query(this->idles);
596
597 // If no one is sleeping, we are done
598 if( idle == 0 ) return;
599
600 // We found a processor, wake it up
601 eventfd_t val;
602 val = 1;
603 eventfd_write( p->idle, val );
604
605 #if !defined(__CFA_NO_STATISTICS__)
606 __tls_stats()->ready.sleep.wakes++;
607 #endif
608
609 /* paranoid */ verify( ready_schedule_islocked() );
610 /* paranoid */ verify( ! __preemption_enabled() );
611
612 return;
613}
614
615// Unconditionnaly wake a thread
616void __wake_proc(processor * this) {
617 __cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
618
619 disable_interrupts();
620 /* paranoid */ verify( ! __preemption_enabled() );
621 eventfd_t val;
622 val = 1;
623 eventfd_write( this->idle, val );
624 enable_interrupts( __cfaabi_dbg_ctx );
625}
626
627static void push (__cluster_idles & this, processor & proc) {
628 /* paranoid */ verify( ! __preemption_enabled() );
629 lock( this );
630 this.idle++;
631 /* paranoid */ verify( this.idle <= this.total );
632
633 insert_first(this.list, proc);
634 unlock( this );
635 /* paranoid */ verify( ! __preemption_enabled() );
636}
637
638static void remove(__cluster_idles & this, processor & proc) {
639 /* paranoid */ verify( ! __preemption_enabled() );
640 lock( this );
641 this.idle--;
642 /* paranoid */ verify( this.idle >= 0 );
643
644 remove(proc);
645 unlock( this );
646 /* paranoid */ verify( ! __preemption_enabled() );
647}
648
649static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
650 for() {
651 uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
652 if( 1 == (l % 2) ) { Pause(); continue; }
653 unsigned idle = this.idle;
654 unsigned total = this.total;
655 processor * proc = &this.list`first;
656 // Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
657 asm volatile("": : :"memory");
658 if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
659 return [idle, total, proc];
660 }
661}
662
663//=============================================================================================
664// Unexpected Terminating logic
665//=============================================================================================
666void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
667 $thread * thrd = __cfaabi_tls.this_thread;
668
669 if(thrd) {
670 int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
671 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
672
673 if ( &thrd->self_cor != thrd->curr_cor ) {
674 len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
675 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
676 }
677 else {
678 __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
679 }
680 }
681 else {
682 int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
683 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
684 }
685}
686
687int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
688 return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
689}
690
691static __spinlock_t kernel_debug_lock;
692
693extern "C" {
694 void __cfaabi_bits_acquire() {
695 lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
696 }
697
698 void __cfaabi_bits_release() {
699 unlock( kernel_debug_lock );
700 }
701}
702
703//=============================================================================================
704// Kernel Utilities
705//=============================================================================================
706#if defined(CFA_HAVE_LINUX_IO_URING_H)
707#include "io/types.hfa"
708#endif
709
710static inline void __maybe_io_drain( processor * proc ) {
711 #if defined(CFA_HAVE_LINUX_IO_URING_H)
712 __cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
713
714 // Check if we should drain the queue
715 $io_context * ctx = proc->io.ctx;
716 unsigned head = *ctx->cq.head;
717 unsigned tail = *ctx->cq.tail;
718 if(head != tail) __cfa_io_drain( proc );
719 #endif
720}
721
722//-----------------------------------------------------------------------------
723// Debug
724__cfaabi_dbg_debug_do(
725 extern "C" {
726 void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
727 this.prev_name = prev_name;
728 this.prev_thrd = kernelTLS().this_thread;
729 }
730 }
731)
732
733//-----------------------------------------------------------------------------
734// Debug
735bool threading_enabled(void) __attribute__((const)) {
736 return true;
737}
738
739//-----------------------------------------------------------------------------
740// Statistics
741#if !defined(__CFA_NO_STATISTICS__)
742 void print_halts( processor & this ) {
743 this.print_halts = true;
744 }
745
746 void print_stats_now( cluster & this, int flags ) {
747 __print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
748 }
749
750 extern int __print_alarm_stats;
751 void print_alarm_stats() {
752 __print_alarm_stats = -1;
753 }
754#endif
755// Local Variables: //
756// mode: c //
757// tab-width: 4 //
758// End: //
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