source: libcfa/src/concurrency/kernel.cfa@ 8c3a0336

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 8c3a0336 was deca0f5, checked in by tdelisle <tdelisle@…>, 7 years ago

x87 and SSE flags are now only saved by threads
  • 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 *((intptr_t*)&stack.storage) |= 0x1;
168 name = "Main Thread";
169 state = Start;
170 starter = NULL;
171 last = NULL;
172 cancellation = NULL;
173}
174
175void ?{}( thread_desc & this, current_stack_info_t * info) with( this ) {
176 state = Start;
177 self_cor{ info };
178 curr_cor = &self_cor;
179 curr_cluster = mainCluster;
180 self_mon.owner = &this;
181 self_mon.recursion = 1;
182 self_mon_p = &self_mon;
183 next = NULL;
184
185 node.next = NULL;
186 node.prev = NULL;
187 doregister(curr_cluster, this);
188
189 monitors{ &self_mon_p, 1, (fptr_t)0 };
190}
191
192//-----------------------------------------------------------------------------
193// Processor coroutine
194void ?{}(processorCtx_t & this) {
195
196}
197
198// Construct the processor context of non-main processors
199static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) {
200 (this.__cor){ info };
201 this.proc = proc;
202}
203
204static void start(processor * this);
205void ?{}(processor & this, const char * name, cluster & cltr) with( this ) {
206 this.name = name;
207 this.cltr = &cltr;
208 terminated{ 0 };
209 do_terminate = false;
210 preemption_alarm = NULL;
211 pending_preemption = false;
212 runner.proc = &this;
213
214 idleLock{};
215
216 start( &this );
217}
218
219void ^?{}(processor & this) with( this ){
220 if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
221 __cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this);
222
223 __atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED);
224 wake( &this );
225
226 P( terminated );
227 verify( kernelTLS.this_processor != &this);
228 }
229
230 pthread_join( kernel_thread, NULL );
231}
232
233void ?{}(cluster & this, const char * name, Duration preemption_rate) with( this ) {
234 this.name = name;
235 this.preemption_rate = preemption_rate;
236 ready_queue{};
237 ready_queue_lock{};
238
239 procs{ __get };
240 idles{ __get };
241 threads{ __get };
242
243 doregister(this);
244}
245
246void ^?{}(cluster & this) {
247 unregister(this);
248}
249
250//=============================================================================================
251// Kernel Scheduling logic
252//=============================================================================================
253static void runThread(processor * this, thread_desc * dst);
254static void finishRunning(processor * this);
255static void halt(processor * this);
256
257//Main of the processor contexts
258void main(processorCtx_t & runner) {
259 processor * this = runner.proc;
260 verify(this);
261
262 __cfaabi_dbg_print_safe("Kernel : core %p starting\n", this);
263
264 doregister(this->cltr, this);
265
266 {
267 // Setup preemption data
268 preemption_scope scope = { this };
269
270 __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
271
272 thread_desc * readyThread = NULL;
273 for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ )
274 {
275 readyThread = nextThread( this->cltr );
276
277 if(readyThread)
278 {
279 verify( ! kernelTLS.preemption_state.enabled );
280
281 runThread(this, readyThread);
282
283 verify( ! kernelTLS.preemption_state.enabled );
284
285 //Some actions need to be taken from the kernel
286 finishRunning(this);
287
288 spin_count = 0;
289 }
290 else
291 {
292 // spin(this, &spin_count);
293 halt(this);
294 }
295 }
296
297 __cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this);
298 }
299
300 unregister(this->cltr, this);
301
302 V( this->terminated );
303
304 __cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this);
305}
306
307static int * __volatile_errno() __attribute__((noinline));
308static int * __volatile_errno() { asm(""); return &errno; }
309
310// KERNEL ONLY
311// runThread runs a thread by context switching
312// from the processor coroutine to the target thread
313static void runThread(processor * this, thread_desc * thrd_dst) {
314 coroutine_desc * proc_cor = get_coroutine(this->runner);
315
316 // Reset the terminating actions here
317 this->finish.action_code = No_Action;
318
319 // Update global state
320 kernelTLS.this_thread = thrd_dst;
321
322 // set state of processor coroutine to inactive and the thread to active
323 proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
324 thrd_dst->state = Active;
325
326 // set context switch to the thread that the processor is executing
327 verify( thrd_dst->context.SP );
328 CtxSwitch( &proc_cor->context, &thrd_dst->context );
329 // when CtxSwitch returns we are back in the processor coroutine
330
331 // set state of processor coroutine to active and the thread to inactive
332 thrd_dst->state = thrd_dst->state == Halted ? Halted : Inactive;
333 proc_cor->state = Active;
334}
335
336// KERNEL_ONLY
337static void returnToKernel() {
338 coroutine_desc * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
339 thread_desc * thrd_src = kernelTLS.this_thread;
340
341 // set state of current coroutine to inactive
342 thrd_src->state = thrd_src->state == Halted ? Halted : Inactive;
343 proc_cor->state = Active;
344 int local_errno = *__volatile_errno();
345 #if defined( __i386 ) || defined( __x86_64 )
346 __x87_store;
347 #endif
348
349 // set new coroutine that the processor is executing
350 // and context switch to it
351 verify( proc_cor->context.SP );
352 CtxSwitch( &thrd_src->context, &proc_cor->context );
353
354 // set state of new coroutine to active
355 proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
356 thrd_src->state = Active;
357
358 #if defined( __i386 ) || defined( __x86_64 )
359 __x87_load;
360 #endif
361 *__volatile_errno() = local_errno;
362}
363
364// KERNEL_ONLY
365// Once a thread has finished running, some of
366// its final actions must be executed from the kernel
367static void finishRunning(processor * this) with( this->finish ) {
368 verify( ! kernelTLS.preemption_state.enabled );
369 choose( action_code ) {
370 case No_Action:
371 break;
372 case Release:
373 unlock( *lock );
374 case Schedule:
375 ScheduleThread( thrd );
376 case Release_Schedule:
377 unlock( *lock );
378 ScheduleThread( thrd );
379 case Release_Multi:
380 for(int i = 0; i < lock_count; i++) {
381 unlock( *locks[i] );
382 }
383 case Release_Multi_Schedule:
384 for(int i = 0; i < lock_count; i++) {
385 unlock( *locks[i] );
386 }
387 for(int i = 0; i < thrd_count; i++) {
388 ScheduleThread( thrds[i] );
389 }
390 case Callback:
391 callback();
392 default:
393 abort("KERNEL ERROR: Unexpected action to run after thread");
394 }
395}
396
397// KERNEL_ONLY
398// Context invoker for processors
399// This is the entry point for processors (kernel threads)
400// It effectively constructs a coroutine by stealing the pthread stack
401static void * CtxInvokeProcessor(void * arg) {
402 processor * proc = (processor *) arg;
403 kernelTLS.this_processor = proc;
404 kernelTLS.this_thread = NULL;
405 kernelTLS.preemption_state.[enabled, disable_count] = [false, 1];
406 // SKULLDUGGERY: We want to create a context for the processor coroutine
407 // which is needed for the 2-step context switch. However, there is no reason
408 // to waste the perfectly valid stack create by pthread.
409 current_stack_info_t info;
410 __stack_t ctx;
411 info.storage = &ctx;
412 (proc->runner){ proc, &info };
413
414 __cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
415
416 //Set global state
417 kernelTLS.this_thread = NULL;
418
419 //We now have a proper context from which to schedule threads
420 __cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx);
421
422 // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't
423 // resume it to start it like it normally would, it will just context switch
424 // back to here. Instead directly call the main since we already are on the
425 // appropriate stack.
426 get_coroutine(proc->runner)->state = Active;
427 main( proc->runner );
428 get_coroutine(proc->runner)->state = Halted;
429
430 // Main routine of the core returned, the core is now fully terminated
431 __cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner);
432
433 return NULL;
434}
435
436static void start(processor * this) {
437 __cfaabi_dbg_print_safe("Kernel : Starting core %p\n", this);
438
439 pthread_create( &this->kernel_thread, NULL, CtxInvokeProcessor, (void*)this );
440
441 __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
442}
443
444// KERNEL_ONLY
445void kernel_first_resume( processor * this ) {
446 thread_desc * src = mainThread;
447 coroutine_desc * dst = get_coroutine(this->runner);
448
449 verify( ! kernelTLS.preemption_state.enabled );
450
451 __stack_prepare( &dst->stack, 65000 );
452 CtxStart(&this->runner, CtxInvokeCoroutine);
453
454 verify( ! kernelTLS.preemption_state.enabled );
455
456 dst->last = &src->self_cor;
457 dst->starter = dst->starter ? dst->starter : &src->self_cor;
458
459 // set state of current coroutine to inactive
460 src->state = src->state == Halted ? Halted : Inactive;
461
462 // context switch to specified coroutine
463 verify( dst->context.SP );
464 CtxSwitch( &src->context, &dst->context );
465 // when CtxSwitch returns we are back in the src coroutine
466
467 // set state of new coroutine to active
468 src->state = Active;
469
470 verify( ! kernelTLS.preemption_state.enabled );
471}
472
473// KERNEL_ONLY
474void kernel_last_resume( processor * this ) {
475 coroutine_desc * src = &mainThread->self_cor;
476 coroutine_desc * dst = get_coroutine(this->runner);
477
478 verify( ! kernelTLS.preemption_state.enabled );
479 verify( dst->starter == src );
480 verify( dst->context.SP );
481
482 // context switch to the processor
483 CtxSwitch( &src->context, &dst->context );
484}
485
486//-----------------------------------------------------------------------------
487// Scheduler routines
488
489// KERNEL ONLY
490void ScheduleThread( thread_desc * thrd ) {
491 verify( thrd );
492 verify( thrd->state != Halted );
493
494 verify( ! kernelTLS.preemption_state.enabled );
495
496 verifyf( thrd->next == NULL, "Expected null got %p", thrd->next );
497
498 with( *thrd->curr_cluster ) {
499 lock ( ready_queue_lock __cfaabi_dbg_ctx2 );
500 bool was_empty = !(ready_queue != 0);
501 append( ready_queue, thrd );
502 unlock( ready_queue_lock );
503
504 if(was_empty) {
505 lock (proc_list_lock __cfaabi_dbg_ctx2);
506 if(idles) {
507 wake_fast(idles.head);
508 }
509 unlock (proc_list_lock);
510 }
511 else if( struct processor * idle = idles.head ) {
512 wake_fast(idle);
513 }
514
515 }
516
517 verify( ! kernelTLS.preemption_state.enabled );
518}
519
520// KERNEL ONLY
521thread_desc * nextThread(cluster * this) with( *this ) {
522 verify( ! kernelTLS.preemption_state.enabled );
523 lock( ready_queue_lock __cfaabi_dbg_ctx2 );
524 thread_desc * head = pop_head( ready_queue );
525 unlock( ready_queue_lock );
526 verify( ! kernelTLS.preemption_state.enabled );
527 return head;
528}
529
530void BlockInternal() {
531 disable_interrupts();
532 verify( ! kernelTLS.preemption_state.enabled );
533 returnToKernel();
534 verify( ! kernelTLS.preemption_state.enabled );
535 enable_interrupts( __cfaabi_dbg_ctx );
536}
537
538void BlockInternal( __spinlock_t * lock ) {
539 disable_interrupts();
540 with( *kernelTLS.this_processor ) {
541 finish.action_code = Release;
542 finish.lock = lock;
543 }
544
545 verify( ! kernelTLS.preemption_state.enabled );
546 returnToKernel();
547 verify( ! kernelTLS.preemption_state.enabled );
548
549 enable_interrupts( __cfaabi_dbg_ctx );
550}
551
552void BlockInternal( thread_desc * thrd ) {
553 disable_interrupts();
554 with( * kernelTLS.this_processor ) {
555 finish.action_code = Schedule;
556 finish.thrd = thrd;
557 }
558
559 verify( ! kernelTLS.preemption_state.enabled );
560 returnToKernel();
561 verify( ! kernelTLS.preemption_state.enabled );
562
563 enable_interrupts( __cfaabi_dbg_ctx );
564}
565
566void BlockInternal( __spinlock_t * lock, thread_desc * thrd ) {
567 assert(thrd);
568 disable_interrupts();
569 with( * kernelTLS.this_processor ) {
570 finish.action_code = Release_Schedule;
571 finish.lock = lock;
572 finish.thrd = thrd;
573 }
574
575 verify( ! kernelTLS.preemption_state.enabled );
576 returnToKernel();
577 verify( ! kernelTLS.preemption_state.enabled );
578
579 enable_interrupts( __cfaabi_dbg_ctx );
580}
581
582void BlockInternal(__spinlock_t * locks [], unsigned short count) {
583 disable_interrupts();
584 with( * kernelTLS.this_processor ) {
585 finish.action_code = Release_Multi;
586 finish.locks = locks;
587 finish.lock_count = count;
588 }
589
590 verify( ! kernelTLS.preemption_state.enabled );
591 returnToKernel();
592 verify( ! kernelTLS.preemption_state.enabled );
593
594 enable_interrupts( __cfaabi_dbg_ctx );
595}
596
597void BlockInternal(__spinlock_t * locks [], unsigned short lock_count, thread_desc * thrds [], unsigned short thrd_count) {
598 disable_interrupts();
599 with( *kernelTLS.this_processor ) {
600 finish.action_code = Release_Multi_Schedule;
601 finish.locks = locks;
602 finish.lock_count = lock_count;
603 finish.thrds = thrds;
604 finish.thrd_count = thrd_count;
605 }
606
607 verify( ! kernelTLS.preemption_state.enabled );
608 returnToKernel();
609 verify( ! kernelTLS.preemption_state.enabled );
610
611 enable_interrupts( __cfaabi_dbg_ctx );
612}
613
614void BlockInternal(__finish_callback_fptr_t callback) {
615 disable_interrupts();
616 with( *kernelTLS.this_processor ) {
617 finish.action_code = Callback;
618 finish.callback = callback;
619 }
620
621 verify( ! kernelTLS.preemption_state.enabled );
622 returnToKernel();
623 verify( ! kernelTLS.preemption_state.enabled );
624
625 enable_interrupts( __cfaabi_dbg_ctx );
626}
627
628// KERNEL ONLY
629void LeaveThread(__spinlock_t * lock, thread_desc * thrd) {
630 verify( ! kernelTLS.preemption_state.enabled );
631 with( * kernelTLS.this_processor ) {
632 finish.action_code = thrd ? Release_Schedule : Release;
633 finish.lock = lock;
634 finish.thrd = thrd;
635 }
636
637 returnToKernel();
638}
639
640//=============================================================================================
641// Kernel Setup logic
642//=============================================================================================
643//-----------------------------------------------------------------------------
644// Kernel boot procedures
645static void kernel_startup(void) {
646 verify( ! kernelTLS.preemption_state.enabled );
647 __cfaabi_dbg_print_safe("Kernel : Starting\n");
648
649 __page_size = sysconf( _SC_PAGESIZE );
650
651 __cfa_dbg_global_clusters.list{ __get };
652 __cfa_dbg_global_clusters.lock{};
653
654 // Initialize the main cluster
655 mainCluster = (cluster *)&storage_mainCluster;
656 (*mainCluster){"Main Cluster"};
657
658 __cfaabi_dbg_print_safe("Kernel : Main cluster ready\n");
659
660 // Start by initializing the main thread
661 // SKULLDUGGERY: the mainThread steals the process main thread
662 // which will then be scheduled by the mainProcessor normally
663 mainThread = (thread_desc *)&storage_mainThread;
664 current_stack_info_t info;
665 info.storage = (__stack_t*)&storage_mainThreadCtx;
666 (*mainThread){ &info };
667
668 __cfaabi_dbg_print_safe("Kernel : Main thread ready\n");
669
670
671
672 // Construct the processor context of the main processor
673 void ?{}(processorCtx_t & this, processor * proc) {
674 (this.__cor){ "Processor" };
675 this.__cor.starter = NULL;
676 this.proc = proc;
677 }
678
679 void ?{}(processor & this) with( this ) {
680 name = "Main Processor";
681 cltr = mainCluster;
682 terminated{ 0 };
683 do_terminate = false;
684 preemption_alarm = NULL;
685 pending_preemption = false;
686 kernel_thread = pthread_self();
687
688 runner{ &this };
689 __cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner);
690 }
691
692 // Initialize the main processor and the main processor ctx
693 // (the coroutine that contains the processing control flow)
694 mainProcessor = (processor *)&storage_mainProcessor;
695 (*mainProcessor){};
696
697 //initialize the global state variables
698 kernelTLS.this_processor = mainProcessor;
699 kernelTLS.this_thread = mainThread;
700
701 // Enable preemption
702 kernel_start_preemption();
703
704 // Add the main thread to the ready queue
705 // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
706 ScheduleThread(mainThread);
707
708 // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
709 // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that
710 // mainThread is on the ready queue when this call is made.
711 kernel_first_resume( kernelTLS.this_processor );
712
713
714
715 // THE SYSTEM IS NOW COMPLETELY RUNNING
716 __cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n");
717
718 verify( ! kernelTLS.preemption_state.enabled );
719 enable_interrupts( __cfaabi_dbg_ctx );
720 verify( TL_GET( preemption_state.enabled ) );
721}
722
723static void kernel_shutdown(void) {
724 __cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n");
725
726 verify( TL_GET( preemption_state.enabled ) );
727 disable_interrupts();
728 verify( ! kernelTLS.preemption_state.enabled );
729
730 // SKULLDUGGERY: Notify the mainProcessor it needs to terminates.
731 // When its coroutine terminates, it return control to the mainThread
732 // which is currently here
733 __atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE);
734 kernel_last_resume( kernelTLS.this_processor );
735 mainThread->self_cor.state = Halted;
736
737 // THE SYSTEM IS NOW COMPLETELY STOPPED
738
739 // Disable preemption
740 kernel_stop_preemption();
741
742 // Destroy the main processor and its context in reverse order of construction
743 // These were manually constructed so we need manually destroy them
744 ^(mainProcessor->runner){};
745 ^(mainProcessor){};
746
747 // Final step, destroy the main thread since it is no longer needed
748 // Since we provided a stack to this taxk it will not destroy anything
749 ^(mainThread){};
750
751 ^(__cfa_dbg_global_clusters.list){};
752 ^(__cfa_dbg_global_clusters.lock){};
753
754 __cfaabi_dbg_print_safe("Kernel : Shutdown complete\n");
755}
756
757//=============================================================================================
758// Kernel Quiescing
759//=============================================================================================
760static void halt(processor * this) with( *this ) {
761 // verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) );
762
763 with( *cltr ) {
764 lock (proc_list_lock __cfaabi_dbg_ctx2);
765 remove (procs, *this);
766 push_front(idles, *this);
767 unlock (proc_list_lock);
768 }
769
770 __cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
771
772 wait( idleLock );
773
774 __cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this);
775
776 with( *cltr ) {
777 lock (proc_list_lock __cfaabi_dbg_ctx2);
778 remove (idles, *this);
779 push_front(procs, *this);
780 unlock (proc_list_lock);
781 }
782}
783
784//=============================================================================================
785// Unexpected Terminating logic
786//=============================================================================================
787static __spinlock_t kernel_abort_lock;
788static bool kernel_abort_called = false;
789
790void * kernel_abort(void) __attribute__ ((__nothrow__)) {
791 // abort cannot be recursively entered by the same or different processors because all signal handlers return when
792 // the globalAbort flag is true.
793 lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
794
795 // first task to abort ?
796 if ( kernel_abort_called ) { // not first task to abort ?
797 unlock( kernel_abort_lock );
798
799 sigset_t mask;
800 sigemptyset( &mask );
801 sigaddset( &mask, SIGALRM ); // block SIGALRM signals
802 sigsuspend( &mask ); // block the processor to prevent further damage during abort
803 _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
804 }
805 else {
806 kernel_abort_called = true;
807 unlock( kernel_abort_lock );
808 }
809
810 return kernelTLS.this_thread;
811}
812
813void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
814 thread_desc * thrd = kernel_data;
815
816 if(thrd) {
817 int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
818 __cfaabi_dbg_bits_write( abort_text, len );
819
820 if ( &thrd->self_cor != thrd->curr_cor ) {
821 len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
822 __cfaabi_dbg_bits_write( abort_text, len );
823 }
824 else {
825 __cfaabi_dbg_bits_write( ".\n", 2 );
826 }
827 }
828 else {
829 int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
830 __cfaabi_dbg_bits_write( abort_text, len );
831 }
832}
833
834int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
835 return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
836}
837
838static __spinlock_t kernel_debug_lock;
839
840extern "C" {
841 void __cfaabi_dbg_bits_acquire() {
842 lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
843 }
844
845 void __cfaabi_dbg_bits_release() {
846 unlock( kernel_debug_lock );
847 }
848}
849
850//=============================================================================================
851// Kernel Utilities
852//=============================================================================================
853//-----------------------------------------------------------------------------
854// Locks
855void ?{}( semaphore & this, int count = 1 ) {
856 (this.lock){};
857 this.count = count;
858 (this.waiting){};
859}
860void ^?{}(semaphore & this) {}
861
862void P(semaphore & this) with( this ){
863 lock( lock __cfaabi_dbg_ctx2 );
864 count -= 1;
865 if ( count < 0 ) {
866 // queue current task
867 append( waiting, kernelTLS.this_thread );
868
869 // atomically release spin lock and block
870 BlockInternal( &lock );
871 }
872 else {
873 unlock( lock );
874 }
875}
876
877void V(semaphore & this) with( this ) {
878 thread_desc * thrd = NULL;
879 lock( lock __cfaabi_dbg_ctx2 );
880 count += 1;
881 if ( count <= 0 ) {
882 // remove task at head of waiting list
883 thrd = pop_head( waiting );
884 }
885
886 unlock( lock );
887
888 // make new owner
889 WakeThread( thrd );
890}
891
892//-----------------------------------------------------------------------------
893// Global Queues
894void doregister( cluster & cltr ) {
895 lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
896 push_front( __cfa_dbg_global_clusters.list, cltr );
897 unlock ( __cfa_dbg_global_clusters.lock );
898}
899
900void unregister( cluster & cltr ) {
901 lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
902 remove( __cfa_dbg_global_clusters.list, cltr );
903 unlock( __cfa_dbg_global_clusters.lock );
904}
905
906void doregister( cluster * cltr, thread_desc & thrd ) {
907 lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
908 push_front(cltr->threads, thrd);
909 unlock (cltr->thread_list_lock);
910}
911
912void unregister( cluster * cltr, thread_desc & thrd ) {
913 lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
914 remove(cltr->threads, thrd );
915 unlock(cltr->thread_list_lock);
916}
917
918void doregister( cluster * cltr, processor * proc ) {
919 lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
920 push_front(cltr->procs, *proc);
921 unlock (cltr->proc_list_lock);
922}
923
924void unregister( cluster * cltr, processor * proc ) {
925 lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
926 remove(cltr->procs, *proc );
927 unlock(cltr->proc_list_lock);
928}
929
930//-----------------------------------------------------------------------------
931// Debug
932__cfaabi_dbg_debug_do(
933 extern "C" {
934 void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) {
935 this.prev_name = prev_name;
936 this.prev_thrd = kernelTLS.this_thread;
937 }
938 }
939)
940// Local Variables: //
941// mode: c //
942// tab-width: 4 //
943// End: //
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