source: libcfa/src/concurrency/kernel.cfa @ d4e68a6

arm-ehjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-expr
Last change on this file since d4e68a6 was d4e68a6, checked in by Peter A. Buhr <pabuhr@…>, 3 years ago

move location of active_xxx routines, and counter for number processors on a cluster

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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//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        cltr->nthreads += 1;
910        push_front(cltr->threads, thrd);
911        unlock    (cltr->thread_list_lock);
912}
913
914void unregister( cluster * cltr, thread_desc & thrd ) {
915        lock  (cltr->thread_list_lock __cfaabi_dbg_ctx2);
916        remove(cltr->threads, thrd );
917        cltr->nthreads -= 1;
918        unlock(cltr->thread_list_lock);
919}
920
921void doregister( cluster * cltr, processor * proc ) {
922        lock      (cltr->proc_list_lock __cfaabi_dbg_ctx2);
923        cltr->nprocessors += 1;
924        push_front(cltr->procs, *proc);
925        unlock    (cltr->proc_list_lock);
926}
927
928void unregister( cluster * cltr, processor * proc ) {
929        lock  (cltr->proc_list_lock __cfaabi_dbg_ctx2);
930        remove(cltr->procs, *proc );
931        cltr->nprocessors -= 1;
932        unlock(cltr->proc_list_lock);
933}
934
935//-----------------------------------------------------------------------------
936// Debug
937__cfaabi_dbg_debug_do(
938        extern "C" {
939                void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) {
940                        this.prev_name = prev_name;
941                        this.prev_thrd = kernelTLS.this_thread;
942                }
943        }
944)
945// Local Variables: //
946// mode: c //
947// tab-width: 4 //
948// End: //
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