source: libcfa/src/concurrency/kernel.cfa@ 933f32f

ADT arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 933f32f was ffe2fad, checked in by Thierry Delisle <tdelisle@…>, 7 years ago

Fixed several warnings in libcfa
  • Property mode set to 100644
File size: 26.1 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 Apr 9 16:11:46 2018
13// Update Count : 24
14//
15
16//C Includes
17#include <stddef.h>
18#include <errno.h>
19#include <string.h>
20extern "C" {
21#include <stdio.h>
22#include <fenv.h>
23#include <sys/resource.h>
24#include <signal.h>
25#include <unistd.h>
26}
27
28//CFA Includes
29#include "time.hfa"
30#include "kernel_private.hfa"
31#include "preemption.hfa"
32#include "startup.hfa"
33
34//Private includes
35#define __CFA_INVOKE_PRIVATE__
36#include "invoke.h"
37
38//-----------------------------------------------------------------------------
39// Some assembly required
40#if defined( __i386 )
41 #define CtxGet( ctx ) \
42 __asm__ volatile ( \
43 "movl %%esp,%0\n"\
44 "movl %%ebp,%1\n"\
45 : "=rm" (ctx.SP),\
46 "=rm" (ctx.FP) \
47 )
48
49 // mxcr : SSE Status and Control bits (control bits are preserved across function calls)
50 // fcw : X87 FPU control word (preserved across function calls)
51 #define __x87_store \
52 uint32_t __mxcr; \
53 uint16_t __fcw; \
54 __asm__ volatile ( \
55 "stmxcsr %0\n" \
56 "fnstcw %1\n" \
57 : "=m" (__mxcr),\
58 "=m" (__fcw) \
59 )
60
61 #define __x87_load \
62 __asm__ volatile ( \
63 "fldcw %1\n" \
64 "ldmxcsr %0\n" \
65 ::"m" (__mxcr),\
66 "m" (__fcw) \
67 )
68
69#elif defined( __x86_64 )
70 #define CtxGet( ctx ) \
71 __asm__ volatile ( \
72 "movq %%rsp,%0\n"\
73 "movq %%rbp,%1\n"\
74 : "=rm" (ctx.SP),\
75 "=rm" (ctx.FP) \
76 )
77
78 #define __x87_store \
79 uint32_t __mxcr; \
80 uint16_t __fcw; \
81 __asm__ volatile ( \
82 "stmxcsr %0\n" \
83 "fnstcw %1\n" \
84 : "=m" (__mxcr),\
85 "=m" (__fcw) \
86 )
87
88 #define __x87_load \
89 __asm__ volatile ( \
90 "fldcw %1\n" \
91 "ldmxcsr %0\n" \
92 :: "m" (__mxcr),\
93 "m" (__fcw) \
94 )
95
96
97#elif defined( __ARM_ARCH )
98#define CtxGet( ctx ) __asm__ ( \
99 "mov %0,%%sp\n" \
100 "mov %1,%%r11\n" \
101 : "=rm" (ctx.SP), "=rm" (ctx.FP) )
102#else
103 #error unknown hardware architecture
104#endif
105
106//-----------------------------------------------------------------------------
107//Start and stop routine for the kernel, declared first to make sure they run first
108static void kernel_startup(void) __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) ));
109static void kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) ));
110
111//-----------------------------------------------------------------------------
112// Kernel storage
113KERNEL_STORAGE(cluster, mainCluster);
114KERNEL_STORAGE(processor, mainProcessor);
115KERNEL_STORAGE(thread_desc, mainThread);
116KERNEL_STORAGE(__stack_t, mainThreadCtx);
117
118cluster * mainCluster;
119processor * mainProcessor;
120thread_desc * mainThread;
121
122extern "C" {
123struct { __dllist_t(cluster) list; __spinlock_t lock; } __cfa_dbg_global_clusters;
124}
125
126size_t __page_size = 0;
127
128//-----------------------------------------------------------------------------
129// Global state
130thread_local struct KernelThreadData kernelTLS __attribute__ ((tls_model ( "initial-exec" ))) = {
131 NULL,
132 NULL,
133 { 1, false, false }
134};
135
136//-----------------------------------------------------------------------------
137// Struct to steal stack
138struct current_stack_info_t {
139 __stack_t * storage; // pointer to stack object
140 void *base; // base of stack
141 void *limit; // stack grows towards stack limit
142 void *context; // address of cfa_context_t
143};
144
145void ?{}( current_stack_info_t & this ) {
146 __stack_context_t ctx;
147 CtxGet( ctx );
148 this.base = ctx.FP;
149
150 rlimit r;
151 getrlimit( RLIMIT_STACK, &r);
152 size_t size = r.rlim_cur;
153
154 this.limit = (void *)(((intptr_t)this.base) - size);
155 this.context = &storage_mainThreadCtx;
156}
157
158//-----------------------------------------------------------------------------
159// Main thread construction
160
161void ?{}( coroutine_desc & this, current_stack_info_t * info) with( this ) {
162 stack.storage = info->storage;
163 with(*stack.storage) {
164 limit = info->limit;
165 base = info->base;
166 }
167 __attribute__((may_alias)) intptr_t * istorage = (intptr_t*) &stack.storage;
168 *istorage |= 0x1;
169 name = "Main Thread";
170 state = Start;
171 starter = NULL;
172 last = NULL;
173 cancellation = NULL;
174}
175
176void ?{}( thread_desc & this, current_stack_info_t * info) with( this ) {
177 state = Start;
178 self_cor{ info };
179 curr_cor = &self_cor;
180 curr_cluster = mainCluster;
181 self_mon.owner = &this;
182 self_mon.recursion = 1;
183 self_mon_p = &self_mon;
184 next = NULL;
185
186 node.next = NULL;
187 node.prev = NULL;
188 doregister(curr_cluster, this);
189
190 monitors{ &self_mon_p, 1, (fptr_t)0 };
191}
192
193//-----------------------------------------------------------------------------
194// Processor coroutine
195void ?{}(processorCtx_t & this) {
196
197}
198
199// Construct the processor context of non-main processors
200static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) {
201 (this.__cor){ info };
202 this.proc = proc;
203}
204
205static void start(processor * this);
206void ?{}(processor & this, const char * name, cluster & cltr) with( this ) {
207 this.name = name;
208 this.cltr = &cltr;
209 terminated{ 0 };
210 do_terminate = false;
211 preemption_alarm = NULL;
212 pending_preemption = false;
213 runner.proc = &this;
214
215 idleLock{};
216
217 start( &this );
218}
219
220void ^?{}(processor & this) with( this ){
221 if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
222 __cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this);
223
224 __atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED);
225 wake( &this );
226
227 P( terminated );
228 verify( kernelTLS.this_processor != &this);
229 }
230
231 pthread_join( kernel_thread, NULL );
232}
233
234void ?{}(cluster & this, const char * name, Duration preemption_rate) with( this ) {
235 this.name = name;
236 this.preemption_rate = preemption_rate;
237 ready_queue{};
238 ready_queue_lock{};
239
240 procs{ __get };
241 idles{ __get };
242 threads{ __get };
243
244 doregister(this);
245}
246
247void ^?{}(cluster & this) {
248 unregister(this);
249}
250
251//=============================================================================================
252// Kernel Scheduling logic
253//=============================================================================================
254static void runThread(processor * this, thread_desc * dst);
255static void finishRunning(processor * this);
256static void halt(processor * this);
257
258//Main of the processor contexts
259void main(processorCtx_t & runner) {
260 processor * this = runner.proc;
261 verify(this);
262
263 __cfaabi_dbg_print_safe("Kernel : core %p starting\n", this);
264
265 doregister(this->cltr, this);
266
267 {
268 // Setup preemption data
269 preemption_scope scope = { this };
270
271 __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
272
273 thread_desc * readyThread = NULL;
274 for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ )
275 {
276 readyThread = nextThread( this->cltr );
277
278 if(readyThread)
279 {
280 verify( ! kernelTLS.preemption_state.enabled );
281
282 runThread(this, readyThread);
283
284 verify( ! kernelTLS.preemption_state.enabled );
285
286 //Some actions need to be taken from the kernel
287 finishRunning(this);
288
289 spin_count = 0;
290 }
291 else
292 {
293 // spin(this, &spin_count);
294 halt(this);
295 }
296 }
297
298 __cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this);
299 }
300
301 unregister(this->cltr, this);
302
303 V( this->terminated );
304
305 __cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this);
306}
307
308static int * __volatile_errno() __attribute__((noinline));
309static int * __volatile_errno() { asm(""); return &errno; }
310
311// KERNEL ONLY
312// runThread runs a thread by context switching
313// from the processor coroutine to the target thread
314static void runThread(processor * this, thread_desc * thrd_dst) {
315 coroutine_desc * proc_cor = get_coroutine(this->runner);
316
317 // Reset the terminating actions here
318 this->finish.action_code = No_Action;
319
320 // Update global state
321 kernelTLS.this_thread = thrd_dst;
322
323 // set state of processor coroutine to inactive and the thread to active
324 proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
325 thrd_dst->state = Active;
326
327 // set context switch to the thread that the processor is executing
328 verify( thrd_dst->context.SP );
329 CtxSwitch( &proc_cor->context, &thrd_dst->context );
330 // when CtxSwitch returns we are back in the processor coroutine
331
332 // set state of processor coroutine to active and the thread to inactive
333 thrd_dst->state = thrd_dst->state == Halted ? Halted : Inactive;
334 proc_cor->state = Active;
335}
336
337// KERNEL_ONLY
338static void returnToKernel() {
339 coroutine_desc * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
340 thread_desc * thrd_src = kernelTLS.this_thread;
341
342 // set state of current coroutine to inactive
343 thrd_src->state = thrd_src->state == Halted ? Halted : Inactive;
344 proc_cor->state = Active;
345 int local_errno = *__volatile_errno();
346 #if defined( __i386 ) || defined( __x86_64 )
347 __x87_store;
348 #endif
349
350 // set new coroutine that the processor is executing
351 // and context switch to it
352 verify( proc_cor->context.SP );
353 CtxSwitch( &thrd_src->context, &proc_cor->context );
354
355 // set state of new coroutine to active
356 proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
357 thrd_src->state = Active;
358
359 #if defined( __i386 ) || defined( __x86_64 )
360 __x87_load;
361 #endif
362 *__volatile_errno() = local_errno;
363}
364
365// KERNEL_ONLY
366// Once a thread has finished running, some of
367// its final actions must be executed from the kernel
368static void finishRunning(processor * this) with( this->finish ) {
369 verify( ! kernelTLS.preemption_state.enabled );
370 choose( action_code ) {
371 case No_Action:
372 break;
373 case Release:
374 unlock( *lock );
375 case Schedule:
376 ScheduleThread( thrd );
377 case Release_Schedule:
378 unlock( *lock );
379 ScheduleThread( thrd );
380 case Release_Multi:
381 for(int i = 0; i < lock_count; i++) {
382 unlock( *locks[i] );
383 }
384 case Release_Multi_Schedule:
385 for(int i = 0; i < lock_count; i++) {
386 unlock( *locks[i] );
387 }
388 for(int i = 0; i < thrd_count; i++) {
389 ScheduleThread( thrds[i] );
390 }
391 case Callback:
392 callback();
393 default:
394 abort("KERNEL ERROR: Unexpected action to run after thread");
395 }
396}
397
398// KERNEL_ONLY
399// Context invoker for processors
400// This is the entry point for processors (kernel threads)
401// It effectively constructs a coroutine by stealing the pthread stack
402static void * CtxInvokeProcessor(void * arg) {
403 processor * proc = (processor *) arg;
404 kernelTLS.this_processor = proc;
405 kernelTLS.this_thread = NULL;
406 kernelTLS.preemption_state.[enabled, disable_count] = [false, 1];
407 // SKULLDUGGERY: We want to create a context for the processor coroutine
408 // which is needed for the 2-step context switch. However, there is no reason
409 // to waste the perfectly valid stack create by pthread.
410 current_stack_info_t info;
411 __stack_t ctx;
412 info.storage = &ctx;
413 (proc->runner){ proc, &info };
414
415 __cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
416
417 //Set global state
418 kernelTLS.this_thread = NULL;
419
420 //We now have a proper context from which to schedule threads
421 __cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx);
422
423 // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't
424 // resume it to start it like it normally would, it will just context switch
425 // back to here. Instead directly call the main since we already are on the
426 // appropriate stack.
427 get_coroutine(proc->runner)->state = Active;
428 main( proc->runner );
429 get_coroutine(proc->runner)->state = Halted;
430
431 // Main routine of the core returned, the core is now fully terminated
432 __cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner);
433
434 return NULL;
435}
436
437static void start(processor * this) {
438 __cfaabi_dbg_print_safe("Kernel : Starting core %p\n", this);
439
440 pthread_create( &this->kernel_thread, NULL, CtxInvokeProcessor, (void*)this );
441
442 __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
443}
444
445// KERNEL_ONLY
446void kernel_first_resume( processor * this ) {
447 thread_desc * src = mainThread;
448 coroutine_desc * dst = get_coroutine(this->runner);
449
450 verify( ! kernelTLS.preemption_state.enabled );
451
452 __stack_prepare( &dst->stack, 65000 );
453 CtxStart(&this->runner, CtxInvokeCoroutine);
454
455 verify( ! kernelTLS.preemption_state.enabled );
456
457 dst->last = &src->self_cor;
458 dst->starter = dst->starter ? dst->starter : &src->self_cor;
459
460 // set state of current coroutine to inactive
461 src->state = src->state == Halted ? Halted : Inactive;
462
463 // context switch to specified coroutine
464 verify( dst->context.SP );
465 CtxSwitch( &src->context, &dst->context );
466 // when CtxSwitch returns we are back in the src coroutine
467
468 // set state of new coroutine to active
469 src->state = Active;
470
471 verify( ! kernelTLS.preemption_state.enabled );
472}
473
474// KERNEL_ONLY
475void kernel_last_resume( processor * this ) {
476 coroutine_desc * src = &mainThread->self_cor;
477 coroutine_desc * dst = get_coroutine(this->runner);
478
479 verify( ! kernelTLS.preemption_state.enabled );
480 verify( dst->starter == src );
481 verify( dst->context.SP );
482
483 // context switch to the processor
484 CtxSwitch( &src->context, &dst->context );
485}
486
487//-----------------------------------------------------------------------------
488// Scheduler routines
489
490// KERNEL ONLY
491void ScheduleThread( thread_desc * thrd ) {
492 verify( thrd );
493 verify( thrd->state != Halted );
494
495 verify( ! kernelTLS.preemption_state.enabled );
496
497 verifyf( thrd->next == NULL, "Expected null got %p", thrd->next );
498
499 with( *thrd->curr_cluster ) {
500 lock ( ready_queue_lock __cfaabi_dbg_ctx2 );
501 bool was_empty = !(ready_queue != 0);
502 append( ready_queue, thrd );
503 unlock( ready_queue_lock );
504
505 if(was_empty) {
506 lock (proc_list_lock __cfaabi_dbg_ctx2);
507 if(idles) {
508 wake_fast(idles.head);
509 }
510 unlock (proc_list_lock);
511 }
512 else if( struct processor * idle = idles.head ) {
513 wake_fast(idle);
514 }
515
516 }
517
518 verify( ! kernelTLS.preemption_state.enabled );
519}
520
521// KERNEL ONLY
522thread_desc * nextThread(cluster * this) with( *this ) {
523 verify( ! kernelTLS.preemption_state.enabled );
524 lock( ready_queue_lock __cfaabi_dbg_ctx2 );
525 thread_desc * head = pop_head( ready_queue );
526 unlock( ready_queue_lock );
527 verify( ! kernelTLS.preemption_state.enabled );
528 return head;
529}
530
531void BlockInternal() {
532 disable_interrupts();
533 verify( ! kernelTLS.preemption_state.enabled );
534 returnToKernel();
535 verify( ! kernelTLS.preemption_state.enabled );
536 enable_interrupts( __cfaabi_dbg_ctx );
537}
538
539void BlockInternal( __spinlock_t * lock ) {
540 disable_interrupts();
541 with( *kernelTLS.this_processor ) {
542 finish.action_code = Release;
543 finish.lock = lock;
544 }
545
546 verify( ! kernelTLS.preemption_state.enabled );
547 returnToKernel();
548 verify( ! kernelTLS.preemption_state.enabled );
549
550 enable_interrupts( __cfaabi_dbg_ctx );
551}
552
553void BlockInternal( thread_desc * thrd ) {
554 disable_interrupts();
555 with( * kernelTLS.this_processor ) {
556 finish.action_code = Schedule;
557 finish.thrd = thrd;
558 }
559
560 verify( ! kernelTLS.preemption_state.enabled );
561 returnToKernel();
562 verify( ! kernelTLS.preemption_state.enabled );
563
564 enable_interrupts( __cfaabi_dbg_ctx );
565}
566
567void BlockInternal( __spinlock_t * lock, thread_desc * thrd ) {
568 assert(thrd);
569 disable_interrupts();
570 with( * kernelTLS.this_processor ) {
571 finish.action_code = Release_Schedule;
572 finish.lock = lock;
573 finish.thrd = thrd;
574 }
575
576 verify( ! kernelTLS.preemption_state.enabled );
577 returnToKernel();
578 verify( ! kernelTLS.preemption_state.enabled );
579
580 enable_interrupts( __cfaabi_dbg_ctx );
581}
582
583void BlockInternal(__spinlock_t * locks [], unsigned short count) {
584 disable_interrupts();
585 with( * kernelTLS.this_processor ) {
586 finish.action_code = Release_Multi;
587 finish.locks = locks;
588 finish.lock_count = count;
589 }
590
591 verify( ! kernelTLS.preemption_state.enabled );
592 returnToKernel();
593 verify( ! kernelTLS.preemption_state.enabled );
594
595 enable_interrupts( __cfaabi_dbg_ctx );
596}
597
598void BlockInternal(__spinlock_t * locks [], unsigned short lock_count, thread_desc * thrds [], unsigned short thrd_count) {
599 disable_interrupts();
600 with( *kernelTLS.this_processor ) {
601 finish.action_code = Release_Multi_Schedule;
602 finish.locks = locks;
603 finish.lock_count = lock_count;
604 finish.thrds = thrds;
605 finish.thrd_count = thrd_count;
606 }
607
608 verify( ! kernelTLS.preemption_state.enabled );
609 returnToKernel();
610 verify( ! kernelTLS.preemption_state.enabled );
611
612 enable_interrupts( __cfaabi_dbg_ctx );
613}
614
615void BlockInternal(__finish_callback_fptr_t callback) {
616 disable_interrupts();
617 with( *kernelTLS.this_processor ) {
618 finish.action_code = Callback;
619 finish.callback = callback;
620 }
621
622 verify( ! kernelTLS.preemption_state.enabled );
623 returnToKernel();
624 verify( ! kernelTLS.preemption_state.enabled );
625
626 enable_interrupts( __cfaabi_dbg_ctx );
627}
628
629// KERNEL ONLY
630void LeaveThread(__spinlock_t * lock, thread_desc * thrd) {
631 verify( ! kernelTLS.preemption_state.enabled );
632 with( * kernelTLS.this_processor ) {
633 finish.action_code = thrd ? Release_Schedule : Release;
634 finish.lock = lock;
635 finish.thrd = thrd;
636 }
637
638 returnToKernel();
639}
640
641//=============================================================================================
642// Kernel Setup logic
643//=============================================================================================
644//-----------------------------------------------------------------------------
645// Kernel boot procedures
646static void kernel_startup(void) {
647 verify( ! kernelTLS.preemption_state.enabled );
648 __cfaabi_dbg_print_safe("Kernel : Starting\n");
649
650 __page_size = sysconf( _SC_PAGESIZE );
651
652 __cfa_dbg_global_clusters.list{ __get };
653 __cfa_dbg_global_clusters.lock{};
654
655 // Initialize the main cluster
656 mainCluster = (cluster *)&storage_mainCluster;
657 (*mainCluster){"Main Cluster"};
658
659 __cfaabi_dbg_print_safe("Kernel : Main cluster ready\n");
660
661 // Start by initializing the main thread
662 // SKULLDUGGERY: the mainThread steals the process main thread
663 // which will then be scheduled by the mainProcessor normally
664 mainThread = (thread_desc *)&storage_mainThread;
665 current_stack_info_t info;
666 info.storage = (__stack_t*)&storage_mainThreadCtx;
667 (*mainThread){ &info };
668
669 __cfaabi_dbg_print_safe("Kernel : Main thread ready\n");
670
671
672
673 // Construct the processor context of the main processor
674 void ?{}(processorCtx_t & this, processor * proc) {
675 (this.__cor){ "Processor" };
676 this.__cor.starter = NULL;
677 this.proc = proc;
678 }
679
680 void ?{}(processor & this) with( this ) {
681 name = "Main Processor";
682 cltr = mainCluster;
683 terminated{ 0 };
684 do_terminate = false;
685 preemption_alarm = NULL;
686 pending_preemption = false;
687 kernel_thread = pthread_self();
688
689 runner{ &this };
690 __cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner);
691 }
692
693 // Initialize the main processor and the main processor ctx
694 // (the coroutine that contains the processing control flow)
695 mainProcessor = (processor *)&storage_mainProcessor;
696 (*mainProcessor){};
697
698 //initialize the global state variables
699 kernelTLS.this_processor = mainProcessor;
700 kernelTLS.this_thread = mainThread;
701
702 // Enable preemption
703 kernel_start_preemption();
704
705 // Add the main thread to the ready queue
706 // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
707 ScheduleThread(mainThread);
708
709 // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
710 // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that
711 // mainThread is on the ready queue when this call is made.
712 kernel_first_resume( kernelTLS.this_processor );
713
714
715
716 // THE SYSTEM IS NOW COMPLETELY RUNNING
717 __cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n");
718
719 verify( ! kernelTLS.preemption_state.enabled );
720 enable_interrupts( __cfaabi_dbg_ctx );
721 verify( TL_GET( preemption_state.enabled ) );
722}
723
724static void kernel_shutdown(void) {
725 __cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n");
726
727 verify( TL_GET( preemption_state.enabled ) );
728 disable_interrupts();
729 verify( ! kernelTLS.preemption_state.enabled );
730
731 // SKULLDUGGERY: Notify the mainProcessor it needs to terminates.
732 // When its coroutine terminates, it return control to the mainThread
733 // which is currently here
734 __atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE);
735 kernel_last_resume( kernelTLS.this_processor );
736 mainThread->self_cor.state = Halted;
737
738 // THE SYSTEM IS NOW COMPLETELY STOPPED
739
740 // Disable preemption
741 kernel_stop_preemption();
742
743 // Destroy the main processor and its context in reverse order of construction
744 // These were manually constructed so we need manually destroy them
745 ^(mainProcessor->runner){};
746 ^(mainProcessor){};
747
748 // Final step, destroy the main thread since it is no longer needed
749 // Since we provided a stack to this taxk it will not destroy anything
750 ^(mainThread){};
751
752 ^(__cfa_dbg_global_clusters.list){};
753 ^(__cfa_dbg_global_clusters.lock){};
754
755 __cfaabi_dbg_print_safe("Kernel : Shutdown complete\n");
756}
757
758//=============================================================================================
759// Kernel Quiescing
760//=============================================================================================
761static void halt(processor * this) with( *this ) {
762 // verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) );
763
764 with( *cltr ) {
765 lock (proc_list_lock __cfaabi_dbg_ctx2);
766 remove (procs, *this);
767 push_front(idles, *this);
768 unlock (proc_list_lock);
769 }
770
771 __cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
772
773 wait( idleLock );
774
775 __cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this);
776
777 with( *cltr ) {
778 lock (proc_list_lock __cfaabi_dbg_ctx2);
779 remove (idles, *this);
780 push_front(procs, *this);
781 unlock (proc_list_lock);
782 }
783}
784
785//=============================================================================================
786// Unexpected Terminating logic
787//=============================================================================================
788static __spinlock_t kernel_abort_lock;
789static bool kernel_abort_called = false;
790
791void * kernel_abort(void) __attribute__ ((__nothrow__)) {
792 // abort cannot be recursively entered by the same or different processors because all signal handlers return when
793 // the globalAbort flag is true.
794 lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
795
796 // first task to abort ?
797 if ( kernel_abort_called ) { // not first task to abort ?
798 unlock( kernel_abort_lock );
799
800 sigset_t mask;
801 sigemptyset( &mask );
802 sigaddset( &mask, SIGALRM ); // block SIGALRM signals
803 sigsuspend( &mask ); // block the processor to prevent further damage during abort
804 _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
805 }
806 else {
807 kernel_abort_called = true;
808 unlock( kernel_abort_lock );
809 }
810
811 return kernelTLS.this_thread;
812}
813
814void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
815 thread_desc * thrd = kernel_data;
816
817 if(thrd) {
818 int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
819 __cfaabi_dbg_bits_write( abort_text, len );
820
821 if ( &thrd->self_cor != thrd->curr_cor ) {
822 len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
823 __cfaabi_dbg_bits_write( abort_text, len );
824 }
825 else {
826 __cfaabi_dbg_bits_write( ".\n", 2 );
827 }
828 }
829 else {
830 int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
831 __cfaabi_dbg_bits_write( abort_text, len );
832 }
833}
834
835int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
836 return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
837}
838
839static __spinlock_t kernel_debug_lock;
840
841extern "C" {
842 void __cfaabi_dbg_bits_acquire() {
843 lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
844 }
845
846 void __cfaabi_dbg_bits_release() {
847 unlock( kernel_debug_lock );
848 }
849}
850
851//=============================================================================================
852// Kernel Utilities
853//=============================================================================================
854//-----------------------------------------------------------------------------
855// Locks
856void ?{}( semaphore & this, int count = 1 ) {
857 (this.lock){};
858 this.count = count;
859 (this.waiting){};
860}
861void ^?{}(semaphore & this) {}
862
863void P(semaphore & this) with( this ){
864 lock( lock __cfaabi_dbg_ctx2 );
865 count -= 1;
866 if ( count < 0 ) {
867 // queue current task
868 append( waiting, kernelTLS.this_thread );
869
870 // atomically release spin lock and block
871 BlockInternal( &lock );
872 }
873 else {
874 unlock( lock );
875 }
876}
877
878void V(semaphore & this) with( this ) {
879 thread_desc * thrd = NULL;
880 lock( lock __cfaabi_dbg_ctx2 );
881 count += 1;
882 if ( count <= 0 ) {
883 // remove task at head of waiting list
884 thrd = pop_head( waiting );
885 }
886
887 unlock( lock );
888
889 // make new owner
890 WakeThread( thrd );
891}
892
893//-----------------------------------------------------------------------------
894// Global Queues
895void doregister( cluster & cltr ) {
896 lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
897 push_front( __cfa_dbg_global_clusters.list, cltr );
898 unlock ( __cfa_dbg_global_clusters.lock );
899}
900
901void unregister( cluster & cltr ) {
902 lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
903 remove( __cfa_dbg_global_clusters.list, cltr );
904 unlock( __cfa_dbg_global_clusters.lock );
905}
906
907void doregister( cluster * cltr, thread_desc & thrd ) {
908 lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
909 push_front(cltr->threads, thrd);
910 unlock (cltr->thread_list_lock);
911}
912
913void unregister( cluster * cltr, thread_desc & thrd ) {
914 lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
915 remove(cltr->threads, thrd );
916 unlock(cltr->thread_list_lock);
917}
918
919void doregister( cluster * cltr, processor * proc ) {
920 lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
921 push_front(cltr->procs, *proc);
922 unlock (cltr->proc_list_lock);
923}
924
925void unregister( cluster * cltr, processor * proc ) {
926 lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
927 remove(cltr->procs, *proc );
928 unlock(cltr->proc_list_lock);
929}
930
931//-----------------------------------------------------------------------------
932// Debug
933__cfaabi_dbg_debug_do(
934 extern "C" {
935 void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) {
936 this.prev_name = prev_name;
937 this.prev_thrd = kernelTLS.this_thread;
938 }
939 }
940)
941// Local Variables: //
942// mode: c //
943// tab-width: 4 //
944// End: //
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