source: libcfa/src/concurrency/kernel.cfa @ 27f5f71

arm-ehjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-expr
Last change on this file since 27f5f71 was 27f5f71, checked in by Peter A. Buhr <pabuhr@…>, 2 years ago

explicitly create stack for pthread thread, change NULL to 0p

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File size: 27.7 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 : Fri Nov 29 17:59:16 2019
13// Update Count     : 35
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#include <limits.h>                                                                             // PTHREAD_STACK_MIN
29}
30
31//CFA Includes
32#include "time.hfa"
33#include "kernel_private.hfa"
34#include "preemption.hfa"
35#include "startup.hfa"
36
37//Private includes
38#define __CFA_INVOKE_PRIVATE__
39#include "invoke.h"
40
41//-----------------------------------------------------------------------------
42// Some assembly required
43#if   defined( __i386 )
44        #define CtxGet( ctx )        \
45                __asm__ volatile (     \
46                        "movl %%esp,%0\n"\
47                        "movl %%ebp,%1\n"\
48                        : "=rm" (ctx.SP),\
49                                "=rm" (ctx.FP) \
50                )
51
52        // mxcr : SSE Status and Control bits (control bits are preserved across function calls)
53        // fcw  : X87 FPU control word (preserved across function calls)
54        #define __x87_store         \
55                uint32_t __mxcr;      \
56                uint16_t __fcw;       \
57                __asm__ volatile (    \
58                        "stmxcsr %0\n"  \
59                        "fnstcw  %1\n"  \
60                        : "=m" (__mxcr),\
61                                "=m" (__fcw)  \
62                )
63
64        #define __x87_load         \
65                __asm__ volatile (   \
66                        "fldcw  %1\n"  \
67                        "ldmxcsr %0\n" \
68                        ::"m" (__mxcr),\
69                                "m" (__fcw)  \
70                )
71
72#elif defined( __x86_64 )
73        #define CtxGet( ctx )        \
74                __asm__ volatile (     \
75                        "movq %%rsp,%0\n"\
76                        "movq %%rbp,%1\n"\
77                        : "=rm" (ctx.SP),\
78                                "=rm" (ctx.FP) \
79                )
80
81        #define __x87_store         \
82                uint32_t __mxcr;      \
83                uint16_t __fcw;       \
84                __asm__ volatile (    \
85                        "stmxcsr %0\n"  \
86                        "fnstcw  %1\n"  \
87                        : "=m" (__mxcr),\
88                                "=m" (__fcw)  \
89                )
90
91        #define __x87_load          \
92                __asm__ volatile (    \
93                        "fldcw  %1\n"   \
94                        "ldmxcsr %0\n"  \
95                        :: "m" (__mxcr),\
96                                "m" (__fcw)  \
97                )
98
99
100#elif defined( __ARM_ARCH )
101#define CtxGet( ctx ) __asm__ ( \
102                "mov %0,%%sp\n"   \
103                "mov %1,%%r11\n"   \
104        : "=rm" (ctx.SP), "=rm" (ctx.FP) )
105#else
106        #error unknown hardware architecture
107#endif
108
109//-----------------------------------------------------------------------------
110//Start and stop routine for the kernel, declared first to make sure they run first
111static void kernel_startup(void)  __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) ));
112static void kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) ));
113
114//-----------------------------------------------------------------------------
115// Kernel storage
116KERNEL_STORAGE(cluster,         mainCluster);
117KERNEL_STORAGE(processor,       mainProcessor);
118KERNEL_STORAGE(thread_desc,     mainThread);
119KERNEL_STORAGE(__stack_t,       mainThreadCtx);
120
121cluster     * mainCluster;
122processor   * mainProcessor;
123thread_desc * mainThread;
124
125extern "C" {
126struct { __dllist_t(cluster) list; __spinlock_t lock; } __cfa_dbg_global_clusters;
127}
128
129size_t __page_size = 0;
130
131//-----------------------------------------------------------------------------
132// Global state
133thread_local struct KernelThreadData kernelTLS __attribute__ ((tls_model ( "initial-exec" ))) = {
134        NULL,
135        NULL,
136        { NULL, 1, false, false },
137        6u //this should be seeded better but due to a bug calling rdtsc doesn't work
138};
139
140//-----------------------------------------------------------------------------
141// Struct to steal stack
142struct current_stack_info_t {
143        __stack_t * storage;            // pointer to stack object
144        void *base;                             // base of stack
145        void *limit;                    // stack grows towards stack limit
146        void *context;                  // address of cfa_context_t
147};
148
149void ?{}( current_stack_info_t & this ) {
150        __stack_context_t ctx;
151        CtxGet( ctx );
152        this.base = ctx.FP;
153
154        rlimit r;
155        getrlimit( RLIMIT_STACK, &r);
156        size_t size = r.rlim_cur;
157
158        this.limit = (void *)(((intptr_t)this.base) - size);
159        this.context = &storage_mainThreadCtx;
160}
161
162//-----------------------------------------------------------------------------
163// Main thread construction
164
165void ?{}( coroutine_desc & this, current_stack_info_t * info) with( this ) {
166        stack.storage = info->storage;
167        with(*stack.storage) {
168                limit     = info->limit;
169                base      = info->base;
170        }
171        __attribute__((may_alias)) intptr_t * istorage = (intptr_t*) &stack.storage;
172        *istorage |= 0x1;
173        name = "Main Thread";
174        state = Start;
175        starter = NULL;
176        last = NULL;
177        cancellation = NULL;
178}
179
180void ?{}( thread_desc & this, current_stack_info_t * info) with( this ) {
181        state = Start;
182        self_cor{ info };
183        curr_cor = &self_cor;
184        curr_cluster = mainCluster;
185        self_mon.owner = &this;
186        self_mon.recursion = 1;
187        self_mon_p = &self_mon;
188        next = NULL;
189
190        node.next = NULL;
191        node.prev = NULL;
192        doregister(curr_cluster, this);
193
194        monitors{ &self_mon_p, 1, (fptr_t)0 };
195}
196
197//-----------------------------------------------------------------------------
198// Processor coroutine
199void ?{}(processorCtx_t & this) {
200
201}
202
203// Construct the processor context of non-main processors
204static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) {
205        (this.__cor){ info };
206        this.proc = proc;
207}
208
209static void start(processor * this);
210void ?{}(processor & this, const char * name, cluster & cltr) with( this ) {
211        this.name = name;
212        this.cltr = &cltr;
213        terminated{ 0 };
214        do_terminate = false;
215        preemption_alarm = NULL;
216        pending_preemption = false;
217        runner.proc = &this;
218
219        idleLock{};
220
221        start( &this );
222}
223
224void ^?{}(processor & this) with( this ){
225        if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
226                __cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this);
227
228                __atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED);
229                wake( &this );
230
231                P( terminated );
232                verify( kernelTLS.this_processor != &this);
233        }
234
235        pthread_join( kernel_thread, NULL );
236        free( this.stack );
237}
238
239void ?{}(cluster & this, const char * name, Duration preemption_rate) with( this ) {
240        this.name = name;
241        this.preemption_rate = preemption_rate;
242        ready_queue{};
243        ready_queue_lock{};
244
245        procs{ __get };
246        idles{ __get };
247        threads{ __get };
248
249        doregister(this);
250}
251
252void ^?{}(cluster & this) {
253        unregister(this);
254}
255
256//=============================================================================================
257// Kernel Scheduling logic
258//=============================================================================================
259static void runThread(processor * this, thread_desc * dst);
260static void finishRunning(processor * this);
261static void halt(processor * this);
262
263//Main of the processor contexts
264void main(processorCtx_t & runner) {
265        // Because of a bug, we couldn't initialized the seed on construction
266        // Do it here
267        kernelTLS.rand_seed ^= rdtscl();
268
269        processor * this = runner.proc;
270        verify(this);
271
272        __cfaabi_dbg_print_safe("Kernel : core %p starting\n", this);
273
274        doregister(this->cltr, this);
275
276        {
277                // Setup preemption data
278                preemption_scope scope = { this };
279
280                __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
281
282                thread_desc * readyThread = NULL;
283                for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ )
284                {
285                        readyThread = nextThread( this->cltr );
286
287                        if(readyThread)
288                        {
289                                verify( ! kernelTLS.preemption_state.enabled );
290
291                                runThread(this, readyThread);
292
293                                verify( ! kernelTLS.preemption_state.enabled );
294
295                                //Some actions need to be taken from the kernel
296                                finishRunning(this);
297
298                                spin_count = 0;
299                        }
300                        else
301                        {
302                                // spin(this, &spin_count);
303                                halt(this);
304                        }
305                }
306
307                __cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this);
308        }
309
310        unregister(this->cltr, this);
311
312        V( this->terminated );
313
314        __cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this);
315}
316
317static int * __volatile_errno() __attribute__((noinline));
318static int * __volatile_errno() { asm(""); return &errno; }
319
320// KERNEL ONLY
321// runThread runs a thread by context switching
322// from the processor coroutine to the target thread
323static void runThread(processor * this, thread_desc * thrd_dst) {
324        coroutine_desc * proc_cor = get_coroutine(this->runner);
325
326        // Reset the terminating actions here
327        this->finish.action_code = No_Action;
328
329        // Update global state
330        kernelTLS.this_thread = thrd_dst;
331
332        // set state of processor coroutine to inactive and the thread to active
333        proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
334        thrd_dst->state = Active;
335
336        // set context switch to the thread that the processor is executing
337        verify( thrd_dst->context.SP );
338        CtxSwitch( &proc_cor->context, &thrd_dst->context );
339        // when CtxSwitch returns we are back in the processor coroutine
340
341        // set state of processor coroutine to active and the thread to inactive
342        thrd_dst->state = thrd_dst->state == Halted ? Halted : Inactive;
343        proc_cor->state = Active;
344}
345
346// KERNEL_ONLY
347static void returnToKernel() {
348        coroutine_desc * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
349        thread_desc * thrd_src = kernelTLS.this_thread;
350
351        // set state of current coroutine to inactive
352        thrd_src->state = thrd_src->state == Halted ? Halted : Inactive;
353        proc_cor->state = Active;
354        int local_errno = *__volatile_errno();
355        #if defined( __i386 ) || defined( __x86_64 )
356                __x87_store;
357        #endif
358
359        // set new coroutine that the processor is executing
360        // and context switch to it
361        verify( proc_cor->context.SP );
362        CtxSwitch( &thrd_src->context, &proc_cor->context );
363
364        // set state of new coroutine to active
365        proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
366        thrd_src->state = Active;
367
368        #if defined( __i386 ) || defined( __x86_64 )
369                __x87_load;
370        #endif
371        *__volatile_errno() = local_errno;
372}
373
374// KERNEL_ONLY
375// Once a thread has finished running, some of
376// its final actions must be executed from the kernel
377static void finishRunning(processor * this) with( this->finish ) {
378        verify( ! kernelTLS.preemption_state.enabled );
379        choose( action_code ) {
380        case No_Action:
381                break;
382        case Release:
383                unlock( *lock );
384        case Schedule:
385                ScheduleThread( thrd );
386        case Release_Schedule:
387                unlock( *lock );
388                ScheduleThread( thrd );
389        case Release_Multi:
390                for(int i = 0; i < lock_count; i++) {
391                        unlock( *locks[i] );
392                }
393        case Release_Multi_Schedule:
394                for(int i = 0; i < lock_count; i++) {
395                        unlock( *locks[i] );
396                }
397                for(int i = 0; i < thrd_count; i++) {
398                        ScheduleThread( thrds[i] );
399                }
400        case Callback:
401                callback();
402        default:
403                abort("KERNEL ERROR: Unexpected action to run after thread");
404        }
405}
406
407// KERNEL_ONLY
408// Context invoker for processors
409// This is the entry point for processors (kernel threads)
410// It effectively constructs a coroutine by stealing the pthread stack
411static void * CtxInvokeProcessor(void * arg) {
412        processor * proc = (processor *) arg;
413        kernelTLS.this_processor = proc;
414        kernelTLS.this_thread    = NULL;
415        kernelTLS.preemption_state.[enabled, disable_count] = [false, 1];
416        // SKULLDUGGERY: We want to create a context for the processor coroutine
417        // which is needed for the 2-step context switch. However, there is no reason
418        // to waste the perfectly valid stack create by pthread.
419        current_stack_info_t info;
420        __stack_t ctx;
421        info.storage = &ctx;
422        (proc->runner){ proc, &info };
423
424        __cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
425
426        //Set global state
427        kernelTLS.this_thread    = NULL;
428
429        //We now have a proper context from which to schedule threads
430        __cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx);
431
432        // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't
433        // resume it to start it like it normally would, it will just context switch
434        // back to here. Instead directly call the main since we already are on the
435        // appropriate stack.
436        get_coroutine(proc->runner)->state = Active;
437        main( proc->runner );
438        get_coroutine(proc->runner)->state = Halted;
439
440        // Main routine of the core returned, the core is now fully terminated
441        __cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner);
442
443        return NULL;
444}
445
446static void start(processor * this) {
447        __cfaabi_dbg_print_safe("Kernel : Starting core %p\n", this);
448
449        pthread_attr_t attr;
450        int ret;
451        ret = pthread_attr_init( &attr );                                       // initialize attribute
452        if ( ret ) {
453                abort( "%s : internal error, pthread_attr_init failed, error(%d) %s.", __PRETTY_FUNCTION__, ret, strerror( ret ) );
454        } // if
455
456        size_t stacksize;
457        ret = pthread_attr_getstacksize( &attr, &stacksize ); // default stack size, normally defined by shell limit
458        if ( ret ) {
459                abort( "%s : internal error, pthread_attr_getstacksize failed, error(%d) %s.", __PRETTY_FUNCTION__, ret, strerror( ret ) );
460        } // if
461        assert( stacksize >= PTHREAD_STACK_MIN );
462
463        this->stack = malloc( stacksize );
464        ret = pthread_attr_setstack( &attr, this->stack, stacksize );
465        if ( ret ) {
466                abort( "%s : internal error, pthread_attr_setstack failed, error(%d) %s.", __PRETTY_FUNCTION__, ret, strerror( ret ) );
467        } // if
468
469        ret = pthread_create( &this->kernel_thread, &attr, CtxInvokeProcessor, (void *)this );
470        if ( ret ) {
471                abort( "%s : internal error, pthread_create failed, error(%d) %s.", __PRETTY_FUNCTION__, ret, strerror( ret ) );
472        } // if
473//      pthread_create( &this->kernel_thread, NULL, CtxInvokeProcessor, (void*)this );
474
475        __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
476}
477
478// KERNEL_ONLY
479void kernel_first_resume( processor * this ) {
480        thread_desc * src = mainThread;
481        coroutine_desc * dst = get_coroutine(this->runner);
482
483        verify( ! kernelTLS.preemption_state.enabled );
484
485        __stack_prepare( &dst->stack, 65000 );
486        CtxStart(&this->runner, CtxInvokeCoroutine);
487
488        verify( ! kernelTLS.preemption_state.enabled );
489
490        dst->last = &src->self_cor;
491        dst->starter = dst->starter ? dst->starter : &src->self_cor;
492
493        // set state of current coroutine to inactive
494        src->state = src->state == Halted ? Halted : Inactive;
495
496        // context switch to specified coroutine
497        verify( dst->context.SP );
498        CtxSwitch( &src->context, &dst->context );
499        // when CtxSwitch returns we are back in the src coroutine
500
501        // set state of new coroutine to active
502        src->state = Active;
503
504        verify( ! kernelTLS.preemption_state.enabled );
505}
506
507// KERNEL_ONLY
508void kernel_last_resume( processor * this ) {
509        coroutine_desc * src = &mainThread->self_cor;
510        coroutine_desc * dst = get_coroutine(this->runner);
511
512        verify( ! kernelTLS.preemption_state.enabled );
513        verify( dst->starter == src );
514        verify( dst->context.SP );
515
516        // context switch to the processor
517        CtxSwitch( &src->context, &dst->context );
518}
519
520//-----------------------------------------------------------------------------
521// Scheduler routines
522
523// KERNEL ONLY
524void ScheduleThread( thread_desc * thrd ) {
525        verify( thrd );
526        verify( thrd->state != Halted );
527
528        verify( ! kernelTLS.preemption_state.enabled );
529
530        verifyf( thrd->next == NULL, "Expected null got %p", thrd->next );
531
532        with( *thrd->curr_cluster ) {
533                lock  ( ready_queue_lock __cfaabi_dbg_ctx2 );
534                bool was_empty = !(ready_queue != 0);
535                append( ready_queue, thrd );
536                unlock( ready_queue_lock );
537
538                if(was_empty) {
539                        lock      (proc_list_lock __cfaabi_dbg_ctx2);
540                        if(idles) {
541                                wake_fast(idles.head);
542                        }
543                        unlock    (proc_list_lock);
544                }
545                else if( struct processor * idle = idles.head ) {
546                        wake_fast(idle);
547                }
548
549        }
550
551        verify( ! kernelTLS.preemption_state.enabled );
552}
553
554// KERNEL ONLY
555thread_desc * nextThread(cluster * this) with( *this ) {
556        verify( ! kernelTLS.preemption_state.enabled );
557        lock( ready_queue_lock __cfaabi_dbg_ctx2 );
558        thread_desc * head = pop_head( ready_queue );
559        unlock( ready_queue_lock );
560        verify( ! kernelTLS.preemption_state.enabled );
561        return head;
562}
563
564void BlockInternal() {
565        disable_interrupts();
566        verify( ! kernelTLS.preemption_state.enabled );
567        returnToKernel();
568        verify( ! kernelTLS.preemption_state.enabled );
569        enable_interrupts( __cfaabi_dbg_ctx );
570}
571
572void BlockInternal( __spinlock_t * lock ) {
573        disable_interrupts();
574        with( *kernelTLS.this_processor ) {
575                finish.action_code = Release;
576                finish.lock        = lock;
577        }
578
579        verify( ! kernelTLS.preemption_state.enabled );
580        returnToKernel();
581        verify( ! kernelTLS.preemption_state.enabled );
582
583        enable_interrupts( __cfaabi_dbg_ctx );
584}
585
586void BlockInternal( thread_desc * thrd ) {
587        disable_interrupts();
588        with( * kernelTLS.this_processor ) {
589                finish.action_code = Schedule;
590                finish.thrd        = thrd;
591        }
592
593        verify( ! kernelTLS.preemption_state.enabled );
594        returnToKernel();
595        verify( ! kernelTLS.preemption_state.enabled );
596
597        enable_interrupts( __cfaabi_dbg_ctx );
598}
599
600void BlockInternal( __spinlock_t * lock, thread_desc * thrd ) {
601        assert(thrd);
602        disable_interrupts();
603        with( * kernelTLS.this_processor ) {
604                finish.action_code = Release_Schedule;
605                finish.lock        = lock;
606                finish.thrd        = thrd;
607        }
608
609        verify( ! kernelTLS.preemption_state.enabled );
610        returnToKernel();
611        verify( ! kernelTLS.preemption_state.enabled );
612
613        enable_interrupts( __cfaabi_dbg_ctx );
614}
615
616void BlockInternal(__spinlock_t * locks [], unsigned short count) {
617        disable_interrupts();
618        with( * kernelTLS.this_processor ) {
619                finish.action_code = Release_Multi;
620                finish.locks       = locks;
621                finish.lock_count  = count;
622        }
623
624        verify( ! kernelTLS.preemption_state.enabled );
625        returnToKernel();
626        verify( ! kernelTLS.preemption_state.enabled );
627
628        enable_interrupts( __cfaabi_dbg_ctx );
629}
630
631void BlockInternal(__spinlock_t * locks [], unsigned short lock_count, thread_desc * thrds [], unsigned short thrd_count) {
632        disable_interrupts();
633        with( *kernelTLS.this_processor ) {
634                finish.action_code = Release_Multi_Schedule;
635                finish.locks       = locks;
636                finish.lock_count  = lock_count;
637                finish.thrds       = thrds;
638                finish.thrd_count  = thrd_count;
639        }
640
641        verify( ! kernelTLS.preemption_state.enabled );
642        returnToKernel();
643        verify( ! kernelTLS.preemption_state.enabled );
644
645        enable_interrupts( __cfaabi_dbg_ctx );
646}
647
648void BlockInternal(__finish_callback_fptr_t callback) {
649        disable_interrupts();
650        with( *kernelTLS.this_processor ) {
651                finish.action_code = Callback;
652                finish.callback    = callback;
653        }
654
655        verify( ! kernelTLS.preemption_state.enabled );
656        returnToKernel();
657        verify( ! kernelTLS.preemption_state.enabled );
658
659        enable_interrupts( __cfaabi_dbg_ctx );
660}
661
662// KERNEL ONLY
663void LeaveThread(__spinlock_t * lock, thread_desc * thrd) {
664        verify( ! kernelTLS.preemption_state.enabled );
665        with( * kernelTLS.this_processor ) {
666                finish.action_code = thrd ? Release_Schedule : Release;
667                finish.lock        = lock;
668                finish.thrd        = thrd;
669        }
670
671        returnToKernel();
672}
673
674//=============================================================================================
675// Kernel Setup logic
676//=============================================================================================
677//-----------------------------------------------------------------------------
678// Kernel boot procedures
679static void kernel_startup(void) {
680        verify( ! kernelTLS.preemption_state.enabled );
681        __cfaabi_dbg_print_safe("Kernel : Starting\n");
682
683        __page_size = sysconf( _SC_PAGESIZE );
684
685        __cfa_dbg_global_clusters.list{ __get };
686        __cfa_dbg_global_clusters.lock{};
687
688        // Initialize the main cluster
689        mainCluster = (cluster *)&storage_mainCluster;
690        (*mainCluster){"Main Cluster"};
691
692        __cfaabi_dbg_print_safe("Kernel : Main cluster ready\n");
693
694        // Start by initializing the main thread
695        // SKULLDUGGERY: the mainThread steals the process main thread
696        // which will then be scheduled by the mainProcessor normally
697        mainThread = (thread_desc *)&storage_mainThread;
698        current_stack_info_t info;
699        info.storage = (__stack_t*)&storage_mainThreadCtx;
700        (*mainThread){ &info };
701
702        __cfaabi_dbg_print_safe("Kernel : Main thread ready\n");
703
704
705
706        // Construct the processor context of the main processor
707        void ?{}(processorCtx_t & this, processor * proc) {
708                (this.__cor){ "Processor" };
709                this.__cor.starter = NULL;
710                this.proc = proc;
711        }
712
713        void ?{}(processor & this) with( this ) {
714                name = "Main Processor";
715                cltr = mainCluster;
716                terminated{ 0 };
717                do_terminate = false;
718                preemption_alarm = NULL;
719                pending_preemption = false;
720                kernel_thread = pthread_self();
721
722                runner{ &this };
723                __cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner);
724        }
725
726        // Initialize the main processor and the main processor ctx
727        // (the coroutine that contains the processing control flow)
728        mainProcessor = (processor *)&storage_mainProcessor;
729        (*mainProcessor){};
730
731        //initialize the global state variables
732        kernelTLS.this_processor = mainProcessor;
733        kernelTLS.this_thread    = mainThread;
734
735        // Enable preemption
736        kernel_start_preemption();
737
738        // Add the main thread to the ready queue
739        // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
740        ScheduleThread(mainThread);
741
742        // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
743        // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that
744        // mainThread is on the ready queue when this call is made.
745        kernel_first_resume( kernelTLS.this_processor );
746
747
748
749        // THE SYSTEM IS NOW COMPLETELY RUNNING
750        __cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n");
751
752        verify( ! kernelTLS.preemption_state.enabled );
753        enable_interrupts( __cfaabi_dbg_ctx );
754        verify( TL_GET( preemption_state.enabled ) );
755}
756
757static void kernel_shutdown(void) {
758        __cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n");
759
760        verify( TL_GET( preemption_state.enabled ) );
761        disable_interrupts();
762        verify( ! kernelTLS.preemption_state.enabled );
763
764        // SKULLDUGGERY: Notify the mainProcessor it needs to terminates.
765        // When its coroutine terminates, it return control to the mainThread
766        // which is currently here
767        __atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE);
768        kernel_last_resume( kernelTLS.this_processor );
769        mainThread->self_cor.state = Halted;
770
771        // THE SYSTEM IS NOW COMPLETELY STOPPED
772
773        // Disable preemption
774        kernel_stop_preemption();
775
776        // Destroy the main processor and its context in reverse order of construction
777        // These were manually constructed so we need manually destroy them
778        ^(mainProcessor->runner){};
779        ^(mainProcessor){};
780
781        // Final step, destroy the main thread since it is no longer needed
782        // Since we provided a stack to this taxk it will not destroy anything
783        ^(mainThread){};
784
785        ^(__cfa_dbg_global_clusters.list){};
786        ^(__cfa_dbg_global_clusters.lock){};
787
788        __cfaabi_dbg_print_safe("Kernel : Shutdown complete\n");
789}
790
791//=============================================================================================
792// Kernel Quiescing
793//=============================================================================================
794static void halt(processor * this) with( *this ) {
795        // verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) );
796
797        with( *cltr ) {
798                lock      (proc_list_lock __cfaabi_dbg_ctx2);
799                remove    (procs, *this);
800                push_front(idles, *this);
801                unlock    (proc_list_lock);
802        }
803
804        __cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
805
806        wait( idleLock );
807
808        __cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this);
809
810        with( *cltr ) {
811                lock      (proc_list_lock __cfaabi_dbg_ctx2);
812                remove    (idles, *this);
813                push_front(procs, *this);
814                unlock    (proc_list_lock);
815        }
816}
817
818//=============================================================================================
819// Unexpected Terminating logic
820//=============================================================================================
821static __spinlock_t kernel_abort_lock;
822static bool kernel_abort_called = false;
823
824void * kernel_abort(void) __attribute__ ((__nothrow__)) {
825        // abort cannot be recursively entered by the same or different processors because all signal handlers return when
826        // the globalAbort flag is true.
827        lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
828
829        // first task to abort ?
830        if ( kernel_abort_called ) {                    // not first task to abort ?
831                unlock( kernel_abort_lock );
832
833                sigset_t mask;
834                sigemptyset( &mask );
835                sigaddset( &mask, SIGALRM );            // block SIGALRM signals
836                sigsuspend( &mask );                    // block the processor to prevent further damage during abort
837                _exit( EXIT_FAILURE );                  // if processor unblocks before it is killed, terminate it
838        }
839        else {
840                kernel_abort_called = true;
841                unlock( kernel_abort_lock );
842        }
843
844        return kernelTLS.this_thread;
845}
846
847void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
848        thread_desc * thrd = kernel_data;
849
850        if(thrd) {
851                int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
852                __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
853
854                if ( &thrd->self_cor != thrd->curr_cor ) {
855                        len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
856                        __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
857                }
858                else {
859                        __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
860                }
861        }
862        else {
863                int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
864                __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
865        }
866}
867
868int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
869        return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
870}
871
872static __spinlock_t kernel_debug_lock;
873
874extern "C" {
875        void __cfaabi_bits_acquire() {
876                lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
877        }
878
879        void __cfaabi_bits_release() {
880                unlock( kernel_debug_lock );
881        }
882}
883
884//=============================================================================================
885// Kernel Utilities
886//=============================================================================================
887//-----------------------------------------------------------------------------
888// Locks
889void  ?{}( semaphore & this, int count = 1 ) {
890        (this.lock){};
891        this.count = count;
892        (this.waiting){};
893}
894void ^?{}(semaphore & this) {}
895
896void P(semaphore & this) with( this ){
897        lock( lock __cfaabi_dbg_ctx2 );
898        count -= 1;
899        if ( count < 0 ) {
900                // queue current task
901                append( waiting, kernelTLS.this_thread );
902
903                // atomically release spin lock and block
904                BlockInternal( &lock );
905        }
906        else {
907            unlock( lock );
908        }
909}
910
911void V(semaphore & this) with( this ) {
912        thread_desc * thrd = NULL;
913        lock( lock __cfaabi_dbg_ctx2 );
914        count += 1;
915        if ( count <= 0 ) {
916                // remove task at head of waiting list
917                thrd = pop_head( waiting );
918        }
919
920        unlock( lock );
921
922        // make new owner
923        WakeThread( thrd );
924}
925
926//-----------------------------------------------------------------------------
927// Global Queues
928void doregister( cluster     & cltr ) {
929        lock      ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
930        push_front( __cfa_dbg_global_clusters.list, cltr );
931        unlock    ( __cfa_dbg_global_clusters.lock );
932}
933
934void unregister( cluster     & cltr ) {
935        lock  ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
936        remove( __cfa_dbg_global_clusters.list, cltr );
937        unlock( __cfa_dbg_global_clusters.lock );
938}
939
940void doregister( cluster * cltr, thread_desc & thrd ) {
941        lock      (cltr->thread_list_lock __cfaabi_dbg_ctx2);
942        cltr->nthreads += 1;
943        push_front(cltr->threads, thrd);
944        unlock    (cltr->thread_list_lock);
945}
946
947void unregister( cluster * cltr, thread_desc & thrd ) {
948        lock  (cltr->thread_list_lock __cfaabi_dbg_ctx2);
949        remove(cltr->threads, thrd );
950        cltr->nthreads -= 1;
951        unlock(cltr->thread_list_lock);
952}
953
954void doregister( cluster * cltr, processor * proc ) {
955        lock      (cltr->proc_list_lock __cfaabi_dbg_ctx2);
956        cltr->nprocessors += 1;
957        push_front(cltr->procs, *proc);
958        unlock    (cltr->proc_list_lock);
959}
960
961void unregister( cluster * cltr, processor * proc ) {
962        lock  (cltr->proc_list_lock __cfaabi_dbg_ctx2);
963        remove(cltr->procs, *proc );
964        cltr->nprocessors -= 1;
965        unlock(cltr->proc_list_lock);
966}
967
968//-----------------------------------------------------------------------------
969// Debug
970__cfaabi_dbg_debug_do(
971        extern "C" {
972                void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) {
973                        this.prev_name = prev_name;
974                        this.prev_thrd = kernelTLS.this_thread;
975                }
976        }
977)
978
979//-----------------------------------------------------------------------------
980// Debug
981bool threading_enabled(void) {
982        return true;
983}
984// Local Variables: //
985// mode: c //
986// tab-width: 4 //
987// End: //
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