source: libcfa/src/concurrency/kernel.cfa@ 71d6bd8

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 71d6bd8 was 57c764c4, checked in by Thierry Delisle <tdelisle@…>, 6 years ago

Fixed typo
  • Property mode set to 100644
File size: 26.6 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 : Thu Jun 20 17:21:23 2019
13// Update Count : 25
14//
15
16#define __cforall_thread__
17
18//C Includes
19#include <stddef.h>
20#include <errno.h>
21#include <string.h>
22extern "C" {
23#include <stdio.h>
24#include <fenv.h>
25#include <sys/resource.h>
26#include <signal.h>
27#include <unistd.h>
28}
29
30//CFA Includes
31#include "time.hfa"
32#include "kernel_private.hfa"
33#include "preemption.hfa"
34#include "startup.hfa"
35
36//Private includes
37#define __CFA_INVOKE_PRIVATE__
38#include "invoke.h"
39
40//-----------------------------------------------------------------------------
41// Some assembly required
42#if defined( __i386 )
43 #define CtxGet( ctx ) \
44 __asm__ volatile ( \
45 "movl %%esp,%0\n"\
46 "movl %%ebp,%1\n"\
47 : "=rm" (ctx.SP),\
48 "=rm" (ctx.FP) \
49 )
50
51 // mxcr : SSE Status and Control bits (control bits are preserved across function calls)
52 // fcw : X87 FPU control word (preserved across function calls)
53 #define __x87_store \
54 uint32_t __mxcr; \
55 uint16_t __fcw; \
56 __asm__ volatile ( \
57 "stmxcsr %0\n" \
58 "fnstcw %1\n" \
59 : "=m" (__mxcr),\
60 "=m" (__fcw) \
61 )
62
63 #define __x87_load \
64 __asm__ volatile ( \
65 "fldcw %1\n" \
66 "ldmxcsr %0\n" \
67 ::"m" (__mxcr),\
68 "m" (__fcw) \
69 )
70
71#elif defined( __x86_64 )
72 #define CtxGet( ctx ) \
73 __asm__ volatile ( \
74 "movq %%rsp,%0\n"\
75 "movq %%rbp,%1\n"\
76 : "=rm" (ctx.SP),\
77 "=rm" (ctx.FP) \
78 )
79
80 #define __x87_store \
81 uint32_t __mxcr; \
82 uint16_t __fcw; \
83 __asm__ volatile ( \
84 "stmxcsr %0\n" \
85 "fnstcw %1\n" \
86 : "=m" (__mxcr),\
87 "=m" (__fcw) \
88 )
89
90 #define __x87_load \
91 __asm__ volatile ( \
92 "fldcw %1\n" \
93 "ldmxcsr %0\n" \
94 :: "m" (__mxcr),\
95 "m" (__fcw) \
96 )
97
98
99#elif defined( __ARM_ARCH )
100#define CtxGet( ctx ) __asm__ ( \
101 "mov %0,%%sp\n" \
102 "mov %1,%%r11\n" \
103 : "=rm" (ctx.SP), "=rm" (ctx.FP) )
104#else
105 #error unknown hardware architecture
106#endif
107
108//-----------------------------------------------------------------------------
109//Start and stop routine for the kernel, declared first to make sure they run first
110static void kernel_startup(void) __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) ));
111static void kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) ));
112
113//-----------------------------------------------------------------------------
114// Kernel storage
115KERNEL_STORAGE(cluster, mainCluster);
116KERNEL_STORAGE(processor, mainProcessor);
117KERNEL_STORAGE(thread_desc, mainThread);
118KERNEL_STORAGE(__stack_t, mainThreadCtx);
119
120cluster * mainCluster;
121processor * mainProcessor;
122thread_desc * mainThread;
123
124extern "C" {
125struct { __dllist_t(cluster) list; __spinlock_t lock; } __cfa_dbg_global_clusters;
126}
127
128size_t __page_size = 0;
129
130//-----------------------------------------------------------------------------
131// Global state
132thread_local struct KernelThreadData kernelTLS __attribute__ ((tls_model ( "initial-exec" ))) = {
133 NULL,
134 NULL,
135 { 1, false, false },
136 6u //this should be seeded better but due to a bug calling rdtsc doesn't work
137};
138
139//-----------------------------------------------------------------------------
140// Struct to steal stack
141struct current_stack_info_t {
142 __stack_t * storage; // pointer to stack object
143 void *base; // base of stack
144 void *limit; // stack grows towards stack limit
145 void *context; // address of cfa_context_t
146};
147
148void ?{}( current_stack_info_t & this ) {
149 __stack_context_t ctx;
150 CtxGet( ctx );
151 this.base = ctx.FP;
152
153 rlimit r;
154 getrlimit( RLIMIT_STACK, &r);
155 size_t size = r.rlim_cur;
156
157 this.limit = (void *)(((intptr_t)this.base) - size);
158 this.context = &storage_mainThreadCtx;
159}
160
161//-----------------------------------------------------------------------------
162// Main thread construction
163
164void ?{}( coroutine_desc & this, current_stack_info_t * info) with( this ) {
165 stack.storage = info->storage;
166 with(*stack.storage) {
167 limit = info->limit;
168 base = info->base;
169 }
170 __attribute__((may_alias)) intptr_t * istorage = (intptr_t*) &stack.storage;
171 *istorage |= 0x1;
172 name = "Main Thread";
173 state = Start;
174 starter = NULL;
175 last = NULL;
176 cancellation = NULL;
177}
178
179void ?{}( thread_desc & this, current_stack_info_t * info) with( this ) {
180 state = Start;
181 self_cor{ info };
182 curr_cor = &self_cor;
183 curr_cluster = mainCluster;
184 self_mon.owner = &this;
185 self_mon.recursion = 1;
186 self_mon_p = &self_mon;
187 next = NULL;
188
189 node.next = NULL;
190 node.prev = NULL;
191 doregister(curr_cluster, this);
192
193 monitors{ &self_mon_p, 1, (fptr_t)0 };
194}
195
196//-----------------------------------------------------------------------------
197// Processor coroutine
198void ?{}(processorCtx_t & this) {
199
200}
201
202// Construct the processor context of non-main processors
203static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) {
204 (this.__cor){ info };
205 this.proc = proc;
206}
207
208static void start(processor * this);
209void ?{}(processor & this, const char * name, cluster & cltr) with( this ) {
210 this.name = name;
211 this.cltr = &cltr;
212 terminated{ 0 };
213 do_terminate = false;
214 preemption_alarm = NULL;
215 pending_preemption = false;
216 runner.proc = &this;
217
218 idleLock{};
219
220 start( &this );
221}
222
223void ^?{}(processor & this) with( this ){
224 if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
225 __cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this);
226
227 __atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED);
228 wake( &this );
229
230 P( terminated );
231 verify( kernelTLS.this_processor != &this);
232 }
233
234 pthread_join( kernel_thread, NULL );
235}
236
237void ?{}(cluster & this, const char * name, Duration preemption_rate) with( this ) {
238 this.name = name;
239 this.preemption_rate = preemption_rate;
240 ready_queue{};
241 ready_queue_lock{};
242
243 procs{ __get };
244 idles{ __get };
245 threads{ __get };
246
247 doregister(this);
248}
249
250void ^?{}(cluster & this) {
251 unregister(this);
252}
253
254//=============================================================================================
255// Kernel Scheduling logic
256//=============================================================================================
257static void runThread(processor * this, thread_desc * dst);
258static void finishRunning(processor * this);
259static void halt(processor * this);
260
261//Main of the processor contexts
262void main(processorCtx_t & runner) {
263 // Because of a bug, we couldn't initialized the seed on construction
264 // Do it here
265 kernelTLS.rand_seed ^= rdtscl();
266
267 processor * this = runner.proc;
268 verify(this);
269
270 __cfaabi_dbg_print_safe("Kernel : core %p starting\n", this);
271
272 doregister(this->cltr, this);
273
274 {
275 // Setup preemption data
276 preemption_scope scope = { this };
277
278 __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
279
280 thread_desc * readyThread = NULL;
281 for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ )
282 {
283 readyThread = nextThread( this->cltr );
284
285 if(readyThread)
286 {
287 verify( ! kernelTLS.preemption_state.enabled );
288
289 runThread(this, readyThread);
290
291 verify( ! kernelTLS.preemption_state.enabled );
292
293 //Some actions need to be taken from the kernel
294 finishRunning(this);
295
296 spin_count = 0;
297 }
298 else
299 {
300 // spin(this, &spin_count);
301 halt(this);
302 }
303 }
304
305 __cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this);
306 }
307
308 unregister(this->cltr, this);
309
310 V( this->terminated );
311
312 __cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this);
313}
314
315static int * __volatile_errno() __attribute__((noinline));
316static int * __volatile_errno() { asm(""); return &errno; }
317
318// KERNEL ONLY
319// runThread runs a thread by context switching
320// from the processor coroutine to the target thread
321static void runThread(processor * this, thread_desc * thrd_dst) {
322 coroutine_desc * proc_cor = get_coroutine(this->runner);
323
324 // Reset the terminating actions here
325 this->finish.action_code = No_Action;
326
327 // Update global state
328 kernelTLS.this_thread = thrd_dst;
329
330 // set state of processor coroutine to inactive and the thread to active
331 proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
332 thrd_dst->state = Active;
333
334 // set context switch to the thread that the processor is executing
335 verify( thrd_dst->context.SP );
336 CtxSwitch( &proc_cor->context, &thrd_dst->context );
337 // when CtxSwitch returns we are back in the processor coroutine
338
339 // set state of processor coroutine to active and the thread to inactive
340 thrd_dst->state = thrd_dst->state == Halted ? Halted : Inactive;
341 proc_cor->state = Active;
342}
343
344// KERNEL_ONLY
345static void returnToKernel() {
346 coroutine_desc * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
347 thread_desc * thrd_src = kernelTLS.this_thread;
348
349 // set state of current coroutine to inactive
350 thrd_src->state = thrd_src->state == Halted ? Halted : Inactive;
351 proc_cor->state = Active;
352 int local_errno = *__volatile_errno();
353 #if defined( __i386 ) || defined( __x86_64 )
354 __x87_store;
355 #endif
356
357 // set new coroutine that the processor is executing
358 // and context switch to it
359 verify( proc_cor->context.SP );
360 CtxSwitch( &thrd_src->context, &proc_cor->context );
361
362 // set state of new coroutine to active
363 proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
364 thrd_src->state = Active;
365
366 #if defined( __i386 ) || defined( __x86_64 )
367 __x87_load;
368 #endif
369 *__volatile_errno() = local_errno;
370}
371
372// KERNEL_ONLY
373// Once a thread has finished running, some of
374// its final actions must be executed from the kernel
375static void finishRunning(processor * this) with( this->finish ) {
376 verify( ! kernelTLS.preemption_state.enabled );
377 choose( action_code ) {
378 case No_Action:
379 break;
380 case Release:
381 unlock( *lock );
382 case Schedule:
383 ScheduleThread( thrd );
384 case Release_Schedule:
385 unlock( *lock );
386 ScheduleThread( thrd );
387 case Release_Multi:
388 for(int i = 0; i < lock_count; i++) {
389 unlock( *locks[i] );
390 }
391 case Release_Multi_Schedule:
392 for(int i = 0; i < lock_count; i++) {
393 unlock( *locks[i] );
394 }
395 for(int i = 0; i < thrd_count; i++) {
396 ScheduleThread( thrds[i] );
397 }
398 case Callback:
399 callback();
400 default:
401 abort("KERNEL ERROR: Unexpected action to run after thread");
402 }
403}
404
405// KERNEL_ONLY
406// Context invoker for processors
407// This is the entry point for processors (kernel threads)
408// It effectively constructs a coroutine by stealing the pthread stack
409static void * CtxInvokeProcessor(void * arg) {
410 processor * proc = (processor *) arg;
411 kernelTLS.this_processor = proc;
412 kernelTLS.this_thread = NULL;
413 kernelTLS.preemption_state.[enabled, disable_count] = [false, 1];
414 // SKULLDUGGERY: We want to create a context for the processor coroutine
415 // which is needed for the 2-step context switch. However, there is no reason
416 // to waste the perfectly valid stack create by pthread.
417 current_stack_info_t info;
418 __stack_t ctx;
419 info.storage = &ctx;
420 (proc->runner){ proc, &info };
421
422 __cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
423
424 //Set global state
425 kernelTLS.this_thread = NULL;
426
427 //We now have a proper context from which to schedule threads
428 __cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx);
429
430 // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't
431 // resume it to start it like it normally would, it will just context switch
432 // back to here. Instead directly call the main since we already are on the
433 // appropriate stack.
434 get_coroutine(proc->runner)->state = Active;
435 main( proc->runner );
436 get_coroutine(proc->runner)->state = Halted;
437
438 // Main routine of the core returned, the core is now fully terminated
439 __cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner);
440
441 return NULL;
442}
443
444static void start(processor * this) {
445 __cfaabi_dbg_print_safe("Kernel : Starting core %p\n", this);
446
447 pthread_create( &this->kernel_thread, NULL, CtxInvokeProcessor, (void*)this );
448
449 __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
450}
451
452// KERNEL_ONLY
453void kernel_first_resume( processor * this ) {
454 thread_desc * src = mainThread;
455 coroutine_desc * dst = get_coroutine(this->runner);
456
457 verify( ! kernelTLS.preemption_state.enabled );
458
459 __stack_prepare( &dst->stack, 65000 );
460 CtxStart(&this->runner, CtxInvokeCoroutine);
461
462 verify( ! kernelTLS.preemption_state.enabled );
463
464 dst->last = &src->self_cor;
465 dst->starter = dst->starter ? dst->starter : &src->self_cor;
466
467 // set state of current coroutine to inactive
468 src->state = src->state == Halted ? Halted : Inactive;
469
470 // context switch to specified coroutine
471 verify( dst->context.SP );
472 CtxSwitch( &src->context, &dst->context );
473 // when CtxSwitch returns we are back in the src coroutine
474
475 // set state of new coroutine to active
476 src->state = Active;
477
478 verify( ! kernelTLS.preemption_state.enabled );
479}
480
481// KERNEL_ONLY
482void kernel_last_resume( processor * this ) {
483 coroutine_desc * src = &mainThread->self_cor;
484 coroutine_desc * dst = get_coroutine(this->runner);
485
486 verify( ! kernelTLS.preemption_state.enabled );
487 verify( dst->starter == src );
488 verify( dst->context.SP );
489
490 // context switch to the processor
491 CtxSwitch( &src->context, &dst->context );
492}
493
494//-----------------------------------------------------------------------------
495// Scheduler routines
496
497// KERNEL ONLY
498void ScheduleThread( thread_desc * thrd ) {
499 verify( thrd );
500 verify( thrd->state != Halted );
501
502 verify( ! kernelTLS.preemption_state.enabled );
503
504 verifyf( thrd->next == NULL, "Expected null got %p", thrd->next );
505
506 with( *thrd->curr_cluster ) {
507 lock ( ready_queue_lock __cfaabi_dbg_ctx2 );
508 bool was_empty = !(ready_queue != 0);
509 append( ready_queue, thrd );
510 unlock( ready_queue_lock );
511
512 if(was_empty) {
513 lock (proc_list_lock __cfaabi_dbg_ctx2);
514 if(idles) {
515 wake_fast(idles.head);
516 }
517 unlock (proc_list_lock);
518 }
519 else if( struct processor * idle = idles.head ) {
520 wake_fast(idle);
521 }
522
523 }
524
525 verify( ! kernelTLS.preemption_state.enabled );
526}
527
528// KERNEL ONLY
529thread_desc * nextThread(cluster * this) with( *this ) {
530 verify( ! kernelTLS.preemption_state.enabled );
531 lock( ready_queue_lock __cfaabi_dbg_ctx2 );
532 thread_desc * head = pop_head( ready_queue );
533 unlock( ready_queue_lock );
534 verify( ! kernelTLS.preemption_state.enabled );
535 return head;
536}
537
538void BlockInternal() {
539 disable_interrupts();
540 verify( ! kernelTLS.preemption_state.enabled );
541 returnToKernel();
542 verify( ! kernelTLS.preemption_state.enabled );
543 enable_interrupts( __cfaabi_dbg_ctx );
544}
545
546void BlockInternal( __spinlock_t * lock ) {
547 disable_interrupts();
548 with( *kernelTLS.this_processor ) {
549 finish.action_code = Release;
550 finish.lock = lock;
551 }
552
553 verify( ! kernelTLS.preemption_state.enabled );
554 returnToKernel();
555 verify( ! kernelTLS.preemption_state.enabled );
556
557 enable_interrupts( __cfaabi_dbg_ctx );
558}
559
560void BlockInternal( thread_desc * thrd ) {
561 disable_interrupts();
562 with( * kernelTLS.this_processor ) {
563 finish.action_code = Schedule;
564 finish.thrd = thrd;
565 }
566
567 verify( ! kernelTLS.preemption_state.enabled );
568 returnToKernel();
569 verify( ! kernelTLS.preemption_state.enabled );
570
571 enable_interrupts( __cfaabi_dbg_ctx );
572}
573
574void BlockInternal( __spinlock_t * lock, thread_desc * thrd ) {
575 assert(thrd);
576 disable_interrupts();
577 with( * kernelTLS.this_processor ) {
578 finish.action_code = Release_Schedule;
579 finish.lock = lock;
580 finish.thrd = thrd;
581 }
582
583 verify( ! kernelTLS.preemption_state.enabled );
584 returnToKernel();
585 verify( ! kernelTLS.preemption_state.enabled );
586
587 enable_interrupts( __cfaabi_dbg_ctx );
588}
589
590void BlockInternal(__spinlock_t * locks [], unsigned short count) {
591 disable_interrupts();
592 with( * kernelTLS.this_processor ) {
593 finish.action_code = Release_Multi;
594 finish.locks = locks;
595 finish.lock_count = count;
596 }
597
598 verify( ! kernelTLS.preemption_state.enabled );
599 returnToKernel();
600 verify( ! kernelTLS.preemption_state.enabled );
601
602 enable_interrupts( __cfaabi_dbg_ctx );
603}
604
605void BlockInternal(__spinlock_t * locks [], unsigned short lock_count, thread_desc * thrds [], unsigned short thrd_count) {
606 disable_interrupts();
607 with( *kernelTLS.this_processor ) {
608 finish.action_code = Release_Multi_Schedule;
609 finish.locks = locks;
610 finish.lock_count = lock_count;
611 finish.thrds = thrds;
612 finish.thrd_count = thrd_count;
613 }
614
615 verify( ! kernelTLS.preemption_state.enabled );
616 returnToKernel();
617 verify( ! kernelTLS.preemption_state.enabled );
618
619 enable_interrupts( __cfaabi_dbg_ctx );
620}
621
622void BlockInternal(__finish_callback_fptr_t callback) {
623 disable_interrupts();
624 with( *kernelTLS.this_processor ) {
625 finish.action_code = Callback;
626 finish.callback = callback;
627 }
628
629 verify( ! kernelTLS.preemption_state.enabled );
630 returnToKernel();
631 verify( ! kernelTLS.preemption_state.enabled );
632
633 enable_interrupts( __cfaabi_dbg_ctx );
634}
635
636// KERNEL ONLY
637void LeaveThread(__spinlock_t * lock, thread_desc * thrd) {
638 verify( ! kernelTLS.preemption_state.enabled );
639 with( * kernelTLS.this_processor ) {
640 finish.action_code = thrd ? Release_Schedule : Release;
641 finish.lock = lock;
642 finish.thrd = thrd;
643 }
644
645 returnToKernel();
646}
647
648//=============================================================================================
649// Kernel Setup logic
650//=============================================================================================
651//-----------------------------------------------------------------------------
652// Kernel boot procedures
653static void kernel_startup(void) {
654 verify( ! kernelTLS.preemption_state.enabled );
655 __cfaabi_dbg_print_safe("Kernel : Starting\n");
656
657 __page_size = sysconf( _SC_PAGESIZE );
658
659 __cfa_dbg_global_clusters.list{ __get };
660 __cfa_dbg_global_clusters.lock{};
661
662 // Initialize the main cluster
663 mainCluster = (cluster *)&storage_mainCluster;
664 (*mainCluster){"Main Cluster"};
665
666 __cfaabi_dbg_print_safe("Kernel : Main cluster ready\n");
667
668 // Start by initializing the main thread
669 // SKULLDUGGERY: the mainThread steals the process main thread
670 // which will then be scheduled by the mainProcessor normally
671 mainThread = (thread_desc *)&storage_mainThread;
672 current_stack_info_t info;
673 info.storage = (__stack_t*)&storage_mainThreadCtx;
674 (*mainThread){ &info };
675
676 __cfaabi_dbg_print_safe("Kernel : Main thread ready\n");
677
678
679
680 // Construct the processor context of the main processor
681 void ?{}(processorCtx_t & this, processor * proc) {
682 (this.__cor){ "Processor" };
683 this.__cor.starter = NULL;
684 this.proc = proc;
685 }
686
687 void ?{}(processor & this) with( this ) {
688 name = "Main Processor";
689 cltr = mainCluster;
690 terminated{ 0 };
691 do_terminate = false;
692 preemption_alarm = NULL;
693 pending_preemption = false;
694 kernel_thread = pthread_self();
695
696 runner{ &this };
697 __cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner);
698 }
699
700 // Initialize the main processor and the main processor ctx
701 // (the coroutine that contains the processing control flow)
702 mainProcessor = (processor *)&storage_mainProcessor;
703 (*mainProcessor){};
704
705 //initialize the global state variables
706 kernelTLS.this_processor = mainProcessor;
707 kernelTLS.this_thread = mainThread;
708
709 // Enable preemption
710 kernel_start_preemption();
711
712 // Add the main thread to the ready queue
713 // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
714 ScheduleThread(mainThread);
715
716 // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
717 // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that
718 // mainThread is on the ready queue when this call is made.
719 kernel_first_resume( kernelTLS.this_processor );
720
721
722
723 // THE SYSTEM IS NOW COMPLETELY RUNNING
724 __cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n");
725
726 verify( ! kernelTLS.preemption_state.enabled );
727 enable_interrupts( __cfaabi_dbg_ctx );
728 verify( TL_GET( preemption_state.enabled ) );
729}
730
731static void kernel_shutdown(void) {
732 __cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n");
733
734 verify( TL_GET( preemption_state.enabled ) );
735 disable_interrupts();
736 verify( ! kernelTLS.preemption_state.enabled );
737
738 // SKULLDUGGERY: Notify the mainProcessor it needs to terminates.
739 // When its coroutine terminates, it return control to the mainThread
740 // which is currently here
741 __atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE);
742 kernel_last_resume( kernelTLS.this_processor );
743 mainThread->self_cor.state = Halted;
744
745 // THE SYSTEM IS NOW COMPLETELY STOPPED
746
747 // Disable preemption
748 kernel_stop_preemption();
749
750 // Destroy the main processor and its context in reverse order of construction
751 // These were manually constructed so we need manually destroy them
752 ^(mainProcessor->runner){};
753 ^(mainProcessor){};
754
755 // Final step, destroy the main thread since it is no longer needed
756 // Since we provided a stack to this taxk it will not destroy anything
757 ^(mainThread){};
758
759 ^(__cfa_dbg_global_clusters.list){};
760 ^(__cfa_dbg_global_clusters.lock){};
761
762 __cfaabi_dbg_print_safe("Kernel : Shutdown complete\n");
763}
764
765//=============================================================================================
766// Kernel Quiescing
767//=============================================================================================
768static void halt(processor * this) with( *this ) {
769 // verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) );
770
771 with( *cltr ) {
772 lock (proc_list_lock __cfaabi_dbg_ctx2);
773 remove (procs, *this);
774 push_front(idles, *this);
775 unlock (proc_list_lock);
776 }
777
778 __cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
779
780 wait( idleLock );
781
782 __cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this);
783
784 with( *cltr ) {
785 lock (proc_list_lock __cfaabi_dbg_ctx2);
786 remove (idles, *this);
787 push_front(procs, *this);
788 unlock (proc_list_lock);
789 }
790}
791
792//=============================================================================================
793// Unexpected Terminating logic
794//=============================================================================================
795static __spinlock_t kernel_abort_lock;
796static bool kernel_abort_called = false;
797
798void * kernel_abort(void) __attribute__ ((__nothrow__)) {
799 // abort cannot be recursively entered by the same or different processors because all signal handlers return when
800 // the globalAbort flag is true.
801 lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
802
803 // first task to abort ?
804 if ( kernel_abort_called ) { // not first task to abort ?
805 unlock( kernel_abort_lock );
806
807 sigset_t mask;
808 sigemptyset( &mask );
809 sigaddset( &mask, SIGALRM ); // block SIGALRM signals
810 sigsuspend( &mask ); // block the processor to prevent further damage during abort
811 _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
812 }
813 else {
814 kernel_abort_called = true;
815 unlock( kernel_abort_lock );
816 }
817
818 return kernelTLS.this_thread;
819}
820
821void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
822 thread_desc * thrd = kernel_data;
823
824 if(thrd) {
825 int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
826 __cfaabi_dbg_bits_write( abort_text, len );
827
828 if ( &thrd->self_cor != thrd->curr_cor ) {
829 len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
830 __cfaabi_dbg_bits_write( abort_text, len );
831 }
832 else {
833 __cfaabi_dbg_bits_write( ".\n", 2 );
834 }
835 }
836 else {
837 int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
838 __cfaabi_dbg_bits_write( abort_text, len );
839 }
840}
841
842int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
843 return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
844}
845
846static __spinlock_t kernel_debug_lock;
847
848extern "C" {
849 void __cfaabi_dbg_bits_acquire() {
850 lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
851 }
852
853 void __cfaabi_dbg_bits_release() {
854 unlock( kernel_debug_lock );
855 }
856}
857
858//=============================================================================================
859// Kernel Utilities
860//=============================================================================================
861//-----------------------------------------------------------------------------
862// Locks
863void ?{}( semaphore & this, int count = 1 ) {
864 (this.lock){};
865 this.count = count;
866 (this.waiting){};
867}
868void ^?{}(semaphore & this) {}
869
870void P(semaphore & this) with( this ){
871 lock( lock __cfaabi_dbg_ctx2 );
872 count -= 1;
873 if ( count < 0 ) {
874 // queue current task
875 append( waiting, kernelTLS.this_thread );
876
877 // atomically release spin lock and block
878 BlockInternal( &lock );
879 }
880 else {
881 unlock( lock );
882 }
883}
884
885void V(semaphore & this) with( this ) {
886 thread_desc * thrd = NULL;
887 lock( lock __cfaabi_dbg_ctx2 );
888 count += 1;
889 if ( count <= 0 ) {
890 // remove task at head of waiting list
891 thrd = pop_head( waiting );
892 }
893
894 unlock( lock );
895
896 // make new owner
897 WakeThread( thrd );
898}
899
900//-----------------------------------------------------------------------------
901// Global Queues
902void doregister( cluster & cltr ) {
903 lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
904 push_front( __cfa_dbg_global_clusters.list, cltr );
905 unlock ( __cfa_dbg_global_clusters.lock );
906}
907
908void unregister( cluster & cltr ) {
909 lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
910 remove( __cfa_dbg_global_clusters.list, cltr );
911 unlock( __cfa_dbg_global_clusters.lock );
912}
913
914void doregister( cluster * cltr, thread_desc & thrd ) {
915 lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
916 cltr->nthreads += 1;
917 push_front(cltr->threads, thrd);
918 unlock (cltr->thread_list_lock);
919}
920
921void unregister( cluster * cltr, thread_desc & thrd ) {
922 lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
923 remove(cltr->threads, thrd );
924 cltr->nthreads -= 1;
925 unlock(cltr->thread_list_lock);
926}
927
928void doregister( cluster * cltr, processor * proc ) {
929 lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
930 cltr->nprocessors += 1;
931 push_front(cltr->procs, *proc);
932 unlock (cltr->proc_list_lock);
933}
934
935void unregister( cluster * cltr, processor * proc ) {
936 lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
937 remove(cltr->procs, *proc );
938 cltr->nprocessors -= 1;
939 unlock(cltr->proc_list_lock);
940}
941
942//-----------------------------------------------------------------------------
943// Debug
944__cfaabi_dbg_debug_do(
945 extern "C" {
946 void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) {
947 this.prev_name = prev_name;
948 this.prev_thrd = kernelTLS.this_thread;
949 }
950 }
951)
952
953//-----------------------------------------------------------------------------
954// Debug
955bool threading_enabled(void) {
956 return true;
957}
958// Local Variables: //
959// mode: c //
960// tab-width: 4 //
961// End: //
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