source: libcfa/src/concurrency/kernel.cfa @ c84b4be

ADTarm-ehast-experimentalenumforall-pointer-decayjacob/cs343-translationnew-astnew-ast-unique-exprpthread-emulationqualifiedEnum
Last change on this file since c84b4be was c84b4be, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

new ready queue seems to work but halting does not, had to be disabled

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[8118303]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
[75f3522]10// Created On       : Tue Jan 17 12:27:26 2017
[6b0b624]11// Last Modified By : Peter A. Buhr
[09d4b22]12// Last Modified On : Thu Dec  5 16:25:52 2019
13// Update Count     : 52
[8118303]14//
15
[2026bb6]16#define __cforall_thread__
17
[8118303]18//C Includes
[c84e80a]19#include <stddef.h>
[214e8da]20#include <errno.h>
[ea8b2f7]21#include <string.h>
[eb2e723]22extern "C" {
[9d944b2]23#include <stdio.h>
[8fcbb4c]24#include <fenv.h>
[eb2e723]25#include <sys/resource.h>
[58b6d1b]26#include <signal.h>
[9d944b2]27#include <unistd.h>
[27f5f71]28#include <limits.h>                                                                             // PTHREAD_STACK_MIN
[1a3040c]29#include <sys/mman.h>                                                                   // mprotect
[eb2e723]30}
[8118303]31
32//CFA Includes
[58b6d1b]33#include "time.hfa"
[73abe95]34#include "kernel_private.hfa"
35#include "preemption.hfa"
36#include "startup.hfa"
[8118303]37
38//Private includes
39#define __CFA_INVOKE_PRIVATE__
40#include "invoke.h"
41
[deca0f5]42//-----------------------------------------------------------------------------
43// Some assembly required
[1805b1b]44#if defined( __i386 )
[deca0f5]45        #define CtxGet( ctx )        \
46                __asm__ volatile (     \
47                        "movl %%esp,%0\n"\
48                        "movl %%ebp,%1\n"\
49                        : "=rm" (ctx.SP),\
50                                "=rm" (ctx.FP) \
51                )
52
53        // mxcr : SSE Status and Control bits (control bits are preserved across function calls)
54        // fcw  : X87 FPU control word (preserved across function calls)
55        #define __x87_store         \
56                uint32_t __mxcr;      \
57                uint16_t __fcw;       \
58                __asm__ volatile (    \
59                        "stmxcsr %0\n"  \
60                        "fnstcw  %1\n"  \
61                        : "=m" (__mxcr),\
62                                "=m" (__fcw)  \
63                )
64
65        #define __x87_load         \
66                __asm__ volatile (   \
67                        "fldcw  %1\n"  \
68                        "ldmxcsr %0\n" \
69                        ::"m" (__mxcr),\
70                                "m" (__fcw)  \
71                )
72
73#elif defined( __x86_64 )
74        #define CtxGet( ctx )        \
75                __asm__ volatile (     \
76                        "movq %%rsp,%0\n"\
77                        "movq %%rbp,%1\n"\
78                        : "=rm" (ctx.SP),\
79                                "=rm" (ctx.FP) \
80                )
81
82        #define __x87_store         \
83                uint32_t __mxcr;      \
84                uint16_t __fcw;       \
85                __asm__ volatile (    \
86                        "stmxcsr %0\n"  \
87                        "fnstcw  %1\n"  \
88                        : "=m" (__mxcr),\
89                                "=m" (__fcw)  \
90                )
91
92        #define __x87_load          \
93                __asm__ volatile (    \
94                        "fldcw  %1\n"   \
95                        "ldmxcsr %0\n"  \
96                        :: "m" (__mxcr),\
97                                "m" (__fcw)  \
98                )
99
100
101#elif defined( __ARM_ARCH )
102#define CtxGet( ctx ) __asm__ ( \
103                "mov %0,%%sp\n"   \
104                "mov %1,%%r11\n"   \
105        : "=rm" (ctx.SP), "=rm" (ctx.FP) )
106#else
107        #error unknown hardware architecture
108#endif
109
110//-----------------------------------------------------------------------------
[2ac095d]111//Start and stop routine for the kernel, declared first to make sure they run first
[c29c342]112static void kernel_startup(void)  __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) ));
113static void kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) ));
[2ac095d]114
[8def349]115//-----------------------------------------------------------------------------
116// Kernel storage
[b2f6113]117KERNEL_STORAGE(cluster,         mainCluster);
118KERNEL_STORAGE(processor,       mainProcessor);
119KERNEL_STORAGE(thread_desc,     mainThread);
120KERNEL_STORAGE(__stack_t,       mainThreadCtx);
[8def349]121
[de6319f]122cluster     * mainCluster;
123processor   * mainProcessor;
[348006f]124thread_desc * mainThread;
[eb2e723]125
[ea8b2f7]126extern "C" {
[1805b1b]127        struct { __dllist_t(cluster) list; __spinlock_t lock; } __cfa_dbg_global_clusters;
[ea8b2f7]128}
[de94a60]129
[b2f6113]130size_t __page_size = 0;
131
[bd98b58]132//-----------------------------------------------------------------------------
133// Global state
[afc2427]134thread_local struct KernelThreadData kernelTLS __attribute__ ((tls_model ( "initial-exec" ))) = {
[1805b1b]135        NULL,                                                                                           // cannot use 0p
[b10affd]136        NULL,
[21184e3]137        { 1, false, false },
138        6u //this should be seeded better but due to a bug calling rdtsc doesn't work
[b10affd]139};
[c84e80a]140
141//-----------------------------------------------------------------------------
[de6319f]142// Struct to steal stack
[8def349]143struct current_stack_info_t {
[1805b1b]144        __stack_t * storage;                                                            // pointer to stack object
145        void * base;                                                                            // base of stack
146        void * limit;                                                                           // stack grows towards stack limit
147        void * context;                                                                         // address of cfa_context_t
[c84e80a]148};
149
[242a902]150void ?{}( current_stack_info_t & this ) {
[b2f6113]151        __stack_context_t ctx;
152        CtxGet( ctx );
153        this.base = ctx.FP;
[8def349]154
155        rlimit r;
[132fad4]156        getrlimit( RLIMIT_STACK, &r);
[69a61d2]157        size_t size = r.rlim_cur;
[8def349]158
[69a61d2]159        this.limit = (void *)(((intptr_t)this.base) - size);
[9236060]160        this.context = &storage_mainThreadCtx;
[8def349]161}
162
[de6319f]163//-----------------------------------------------------------------------------
164// Main thread construction
[8def349]165
[65deb18]166void ?{}( coroutine_desc & this, current_stack_info_t * info) with( this ) {
[b2f6113]167        stack.storage = info->storage;
168        with(*stack.storage) {
169                limit     = info->limit;
170                base      = info->base;
171        }
[ffe2fad]172        __attribute__((may_alias)) intptr_t * istorage = (intptr_t*) &stack.storage;
173        *istorage |= 0x1;
[65deb18]174        name = "Main Thread";
175        state = Start;
[1805b1b]176        starter = 0p;
177        last = 0p;
178        cancellation = 0p;
[8def349]179}
180
[65deb18]181void ?{}( thread_desc & this, current_stack_info_t * info) with( this ) {
[e8e457e]182        state = Start;
[65deb18]183        self_cor{ info };
[82c948c]184        curr_cor = &self_cor;
[de6319f]185        curr_cluster = mainCluster;
[82c948c]186        self_mon.owner = &this;
187        self_mon.recursion = 1;
188        self_mon_p = &self_mon;
[b798713]189        link.next = 0p;
190        link.prev = 0p;
[de94a60]191
[1805b1b]192        node.next = 0p;
193        node.prev = 0p;
[a1a17a7]194        doregister(curr_cluster, this);
[82c948c]195
196        monitors{ &self_mon_p, 1, (fptr_t)0 };
[8def349]197}
[c84e80a]198
[8def349]199//-----------------------------------------------------------------------------
200// Processor coroutine
[de6319f]201void ?{}(processorCtx_t & this) {
[39fea2f]202
[8def349]203}
204
[39fea2f]205// Construct the processor context of non-main processors
[c29c342]206static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) {
[242a902]207        (this.__cor){ info };
208        this.proc = proc;
[8def349]209}
210
[c29c342]211static void start(processor * this);
[de6319f]212void ?{}(processor & this, const char * name, cluster & cltr) with( this ) {
213        this.name = name;
214        this.cltr = &cltr;
[7768b8d]215        id = -1u;
[c40e7c5]216        terminated{ 0 };
217        do_terminate = false;
[1805b1b]218        preemption_alarm = 0p;
[c40e7c5]219        pending_preemption = false;
[094476d]220        runner.proc = &this;
[8def349]221
[85b1deb]222        idleLock{};
[6b4cdd3]223
[242a902]224        start( &this );
[c84e80a]225}
226
[65deb18]227void ^?{}(processor & this) with( this ){
[ea8b2f7]228        if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
[36982fc]229                __cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this);
[85b1deb]230
231                __atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED);
232                wake( &this );
233
[65deb18]234                P( terminated );
[14a61b5]235                verify( kernelTLS.this_processor != &this);
[8def349]236        }
[6b4cdd3]237
[1805b1b]238        pthread_join( kernel_thread, 0p );
[27f5f71]239        free( this.stack );
[8def349]240}
241
[de6319f]242void ?{}(cluster & this, const char * name, Duration preemption_rate) with( this ) {
243        this.name = name;
244        this.preemption_rate = preemption_rate;
[65deb18]245        ready_queue{};
[7768b8d]246        ready_lock{};
[de94a60]247
248        idles{ __get };
[a1a17a7]249        threads{ __get };
[de94a60]250
251        doregister(this);
[8def349]252}
253
[242a902]254void ^?{}(cluster & this) {
[de94a60]255        unregister(this);
[c84e80a]256}
257
[75f3522]258//=============================================================================================
259// Kernel Scheduling logic
260//=============================================================================================
[c29c342]261static void runThread(processor * this, thread_desc * dst);
262static void finishRunning(processor * this);
263static void halt(processor * this);
264
[8fcbb4c]265//Main of the processor contexts
[83a071f9]266void main(processorCtx_t & runner) {
[21184e3]267        // Because of a bug, we couldn't initialized the seed on construction
268        // Do it here
[7768b8d]269        kernelTLS.rand_seed ^= rdtscl();
[21184e3]270
[83a071f9]271        processor * this = runner.proc;
[094476d]272        verify(this);
[c81ebf9]273
[36982fc]274        __cfaabi_dbg_print_safe("Kernel : core %p starting\n", this);
[8118303]275
[7768b8d]276        // register the processor unless it's the main thread which is handled in the boot sequence
[b798713]277        if(this != mainProcessor) {
[7768b8d]278                this->id = doregister(this->cltr, this);
[b798713]279                ready_queue_grow( this->cltr );
280        }
281
[de94a60]282
[75f3522]283        {
[c81ebf9]284                // Setup preemption data
285                preemption_scope scope = { this };
286
[36982fc]287                __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
[8118303]288
[1805b1b]289                thread_desc * readyThread = 0p;
[1a3040c]290                for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ ) {
[c81ebf9]291                        readyThread = nextThread( this->cltr );
[75f3522]292
[1a3040c]293                        if(readyThread) {
[14a61b5]294                                verify( ! kernelTLS.preemption_state.enabled );
[4e6fb8e]295
[c81ebf9]296                                runThread(this, readyThread);
[75f3522]297
[14a61b5]298                                verify( ! kernelTLS.preemption_state.enabled );
[4e6fb8e]299
[c81ebf9]300                                //Some actions need to be taken from the kernel
301                                finishRunning(this);
302
303                                spin_count = 0;
[1a3040c]304                        } else {
[ea8b2f7]305                                // spin(this, &spin_count);
306                                halt(this);
[c81ebf9]307                        }
308                }
309
[36982fc]310                __cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this);
[c84e80a]311        }
[8118303]312
[4cedd9f]313        V( this->terminated );
[bdeba0b]314
[b798713]315
[7768b8d]316        // unregister the processor unless it's the main thread which is handled in the boot sequence
[b798713]317        if(this != mainProcessor) {
318                ready_queue_shrink( this->cltr );
[7768b8d]319                unregister(this->cltr, this);
[b798713]320        }
[7768b8d]321
[36982fc]322        __cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this);
[b798713]323
324        stats_tls_tally(this->cltr);
[c84e80a]325}
326
[5c1a531]327static int * __volatile_errno() __attribute__((noinline));
328static int * __volatile_errno() { asm(""); return &errno; }
329
[14a61b5]330// KERNEL ONLY
[1c273d0]331// runThread runs a thread by context switching
332// from the processor coroutine to the target thread
[e8e457e]333static void runThread(processor * this, thread_desc * thrd_dst) {
[094476d]334        coroutine_desc * proc_cor = get_coroutine(this->runner);
[1c273d0]335
[14a61b5]336        // Reset the terminating actions here
[db6f06a]337        this->finish.action_code = No_Action;
[8fcbb4c]338
[14a61b5]339        // Update global state
[e8e457e]340        kernelTLS.this_thread = thrd_dst;
341
342        // set state of processor coroutine to inactive and the thread to active
343        proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
344        thrd_dst->state = Active;
345
346        // set context switch to the thread that the processor is executing
347        verify( thrd_dst->context.SP );
348        CtxSwitch( &proc_cor->context, &thrd_dst->context );
349        // when CtxSwitch returns we are back in the processor coroutine
[75f3522]350
[e8e457e]351        // set state of processor coroutine to active and the thread to inactive
352        thrd_dst->state = thrd_dst->state == Halted ? Halted : Inactive;
353        proc_cor->state = Active;
[75f3522]354}
355
[14a61b5]356// KERNEL_ONLY
[c29c342]357static void returnToKernel() {
[14a61b5]358        coroutine_desc * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
[e8e457e]359        thread_desc * thrd_src = kernelTLS.this_thread;
360
361        // set state of current coroutine to inactive
362        thrd_src->state = thrd_src->state == Halted ? Halted : Inactive;
363        proc_cor->state = Active;
[5c1a531]364        int local_errno = *__volatile_errno();
[deca0f5]365        #if defined( __i386 ) || defined( __x86_64 )
366                __x87_store;
367        #endif
[e8e457e]368
369        // set new coroutine that the processor is executing
370        // and context switch to it
371        verify( proc_cor->context.SP );
372        CtxSwitch( &thrd_src->context, &proc_cor->context );
373
374        // set state of new coroutine to active
375        proc_cor->state = proc_cor->state == Halted ? Halted : Inactive;
376        thrd_src->state = Active;
[deca0f5]377
378        #if defined( __i386 ) || defined( __x86_64 )
379                __x87_load;
380        #endif
[5c1a531]381        *__volatile_errno() = local_errno;
[82c948c]382}
383
[14a61b5]384// KERNEL_ONLY
[1c273d0]385// Once a thread has finished running, some of
[75f3522]386// its final actions must be executed from the kernel
[c29c342]387static void finishRunning(processor * this) with( this->finish ) {
[09800e9]388        verify( ! kernelTLS.preemption_state.enabled );
389        choose( action_code ) {
390        case No_Action:
391                break;
392        case Release:
[65deb18]393                unlock( *lock );
[09800e9]394        case Schedule:
[65deb18]395                ScheduleThread( thrd );
[09800e9]396        case Release_Schedule:
[65deb18]397                unlock( *lock );
398                ScheduleThread( thrd );
[09800e9]399        case Release_Multi:
[65deb18]400                for(int i = 0; i < lock_count; i++) {
401                        unlock( *locks[i] );
[0c78741]402                }
[09800e9]403        case Release_Multi_Schedule:
[65deb18]404                for(int i = 0; i < lock_count; i++) {
405                        unlock( *locks[i] );
[0c78741]406                }
[65deb18]407                for(int i = 0; i < thrd_count; i++) {
408                        ScheduleThread( thrds[i] );
[0c78741]409                }
[09800e9]410        case Callback:
411                callback();
412        default:
413                abort("KERNEL ERROR: Unexpected action to run after thread");
[8fcbb4c]414        }
[c84e80a]415}
416
[14a61b5]417// KERNEL_ONLY
[0c92c9f]418// Context invoker for processors
419// This is the entry point for processors (kernel threads)
420// It effectively constructs a coroutine by stealing the pthread stack
[c29c342]421static void * CtxInvokeProcessor(void * arg) {
[8def349]422        processor * proc = (processor *) arg;
[14a61b5]423        kernelTLS.this_processor = proc;
[1805b1b]424        kernelTLS.this_thread    = 0p;
[14a61b5]425        kernelTLS.preemption_state.[enabled, disable_count] = [false, 1];
[8def349]426        // SKULLDUGGERY: We want to create a context for the processor coroutine
427        // which is needed for the 2-step context switch. However, there is no reason
[1c273d0]428        // to waste the perfectly valid stack create by pthread.
[8def349]429        current_stack_info_t info;
[b2f6113]430        __stack_t ctx;
431        info.storage = &ctx;
[094476d]432        (proc->runner){ proc, &info };
[8def349]433
[b2f6113]434        __cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
[8fcbb4c]435
[0c92c9f]436        //Set global state
[1805b1b]437        kernelTLS.this_thread = 0p;
[8def349]438
439        //We now have a proper context from which to schedule threads
[094476d]440        __cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx);
[8def349]441
[1c273d0]442        // SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't
443        // resume it to start it like it normally would, it will just context switch
444        // back to here. Instead directly call the main since we already are on the
[8def349]445        // appropriate stack.
[094476d]446        get_coroutine(proc->runner)->state = Active;
447        main( proc->runner );
448        get_coroutine(proc->runner)->state = Halted;
[8def349]449
[0c92c9f]450        // Main routine of the core returned, the core is now fully terminated
[094476d]451        __cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner);
[8def349]452
[1805b1b]453        return 0p;
[c84e80a]454}
455
[1805b1b]456static void Abort( int ret, const char * func ) {
[1a3040c]457        if ( ret ) {                                                                            // pthread routines return errno values
[1805b1b]458                abort( "%s : internal error, error(%d) %s.", func, ret, strerror( ret ) );
[27f5f71]459        } // if
[1805b1b]460} // Abort
461
462void * create_pthread( pthread_t * pthread, void * (*start)(void *), void * arg ) {
463        pthread_attr_t attr;
464
465        Abort( pthread_attr_init( &attr ), "pthread_attr_init" ); // initialize attribute
466
[27f5f71]467        size_t stacksize;
[09d4b22]468        // default stack size, normally defined by shell limit
[1a3040c]469        Abort( pthread_attr_getstacksize( &attr, &stacksize ), "pthread_attr_getstacksize" );
[27f5f71]470        assert( stacksize >= PTHREAD_STACK_MIN );
[1a3040c]471
[09d4b22]472        void * stack;
473        __cfaabi_dbg_debug_do(
474                stack = memalign( __page_size, stacksize + __page_size );
475                // pthread has no mechanism to create the guard page in user supplied stack.
476                if ( mprotect( stack, __page_size, PROT_NONE ) == -1 ) {
477                        abort( "mprotect : internal error, mprotect failure, error(%d) %s.", errno, strerror( errno ) );
478                } // if
479        );
480        __cfaabi_dbg_no_debug_do(
481                stack = malloc( stacksize );
482        );
[1a3040c]483
[f80f840]484        Abort( pthread_attr_setstack( &attr, stack, stacksize ), "pthread_attr_setstack" );
[27f5f71]485
[1805b1b]486        Abort( pthread_create( pthread, &attr, start, arg ), "pthread_create" );
487        return stack;
[c84e80a]488}
489
[c29c342]490static void start(processor * this) {
[36982fc]491        __cfaabi_dbg_print_safe("Kernel : Starting core %p\n", this);
[82ff5845]492
[1805b1b]493        this->stack = create_pthread( &this->kernel_thread, CtxInvokeProcessor, (void *)this );
[eb2e723]494
[36982fc]495        __cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
[eb2e723]496}
497
[14a61b5]498// KERNEL_ONLY
[e8e457e]499void kernel_first_resume( processor * this ) {
500        thread_desc * src = mainThread;
[094476d]501        coroutine_desc * dst = get_coroutine(this->runner);
[b69ea6b]502
[14a61b5]503        verify( ! kernelTLS.preemption_state.enabled );
[b69ea6b]504
[b2f6113]505        __stack_prepare( &dst->stack, 65000 );
[094476d]506        CtxStart(&this->runner, CtxInvokeCoroutine);
[b69ea6b]507
[14a61b5]508        verify( ! kernelTLS.preemption_state.enabled );
[b69ea6b]509
[e8e457e]510        dst->last = &src->self_cor;
511        dst->starter = dst->starter ? dst->starter : &src->self_cor;
[b69ea6b]512
513        // set state of current coroutine to inactive
514        src->state = src->state == Halted ? Halted : Inactive;
515
516        // context switch to specified coroutine
[69a61d2]517        verify( dst->context.SP );
[b2f6113]518        CtxSwitch( &src->context, &dst->context );
[b69ea6b]519        // when CtxSwitch returns we are back in the src coroutine
520
521        // set state of new coroutine to active
522        src->state = Active;
523
[14a61b5]524        verify( ! kernelTLS.preemption_state.enabled );
[b69ea6b]525}
526
[e8e457e]527// KERNEL_ONLY
528void kernel_last_resume( processor * this ) {
529        coroutine_desc * src = &mainThread->self_cor;
530        coroutine_desc * dst = get_coroutine(this->runner);
531
532        verify( ! kernelTLS.preemption_state.enabled );
533        verify( dst->starter == src );
534        verify( dst->context.SP );
535
536        // context switch to the processor
537        CtxSwitch( &src->context, &dst->context );
538}
539
[8def349]540//-----------------------------------------------------------------------------
541// Scheduler routines
[14a61b5]542
543// KERNEL ONLY
[348006f]544void ScheduleThread( thread_desc * thrd ) {
[135b431]545        verify( thrd );
[e8e457e]546        verify( thrd->state != Halted );
[1c273d0]547
[14a61b5]548        verify( ! kernelTLS.preemption_state.enabled );
[690f13c]549
[f80f840]550        verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[1c273d0]551
[6b4cdd3]552
[b798713]553        ready_schedule_lock(thrd->curr_cluster, kernelTLS.this_processor);
554                bool was_empty = push( thrd->curr_cluster, thrd );
555        ready_schedule_unlock(thrd->curr_cluster, kernelTLS.this_processor);
556
557        with( *thrd->curr_cluster ) {
[c84b4be]558                // if(was_empty) {
559                //      lock      (proc_list_lock __cfaabi_dbg_ctx2);
560                //      if(idles) {
561                //              wake_fast(idles.head);
562                //      }
563                //      unlock    (proc_list_lock);
564                // }
565                // else if( struct processor * idle = idles.head ) {
566                //      wake_fast(idle);
567                // }
[65deb18]568        }
[1c273d0]569
[14a61b5]570        verify( ! kernelTLS.preemption_state.enabled );
[db6f06a]571}
572
[14a61b5]573// KERNEL ONLY
[65deb18]574thread_desc * nextThread(cluster * this) with( *this ) {
[14a61b5]575        verify( ! kernelTLS.preemption_state.enabled );
[7768b8d]576
[b798713]577        ready_schedule_lock(this, kernelTLS.this_processor);
578                thread_desc * head = pop( this );
579        ready_schedule_unlock(this, kernelTLS.this_processor);
[7768b8d]580
[14a61b5]581        verify( ! kernelTLS.preemption_state.enabled );
[db6f06a]582        return head;
[eb2e723]583}
584
[82ff5845]585void BlockInternal() {
586        disable_interrupts();
[14a61b5]587        verify( ! kernelTLS.preemption_state.enabled );
[82c948c]588        returnToKernel();
[14a61b5]589        verify( ! kernelTLS.preemption_state.enabled );
[36982fc]590        enable_interrupts( __cfaabi_dbg_ctx );
[75f3522]591}
592
[ea7d2b0]593void BlockInternal( __spinlock_t * lock ) {
[82ff5845]594        disable_interrupts();
[14a61b5]595        with( *kernelTLS.this_processor ) {
[de6319f]596                finish.action_code = Release;
597                finish.lock        = lock;
598        }
[0b33412]599
[afd550c]600        verify( ! kernelTLS.preemption_state.enabled );
[82c948c]601        returnToKernel();
[afd550c]602        verify( ! kernelTLS.preemption_state.enabled );
[0b33412]603
[36982fc]604        enable_interrupts( __cfaabi_dbg_ctx );
[db6f06a]605}
606
[82ff5845]607void BlockInternal( thread_desc * thrd ) {
608        disable_interrupts();
[14a61b5]609        with( * kernelTLS.this_processor ) {
[de6319f]610                finish.action_code = Schedule;
611                finish.thrd        = thrd;
612        }
[0b33412]613
[14a61b5]614        verify( ! kernelTLS.preemption_state.enabled );
[82c948c]615        returnToKernel();
[14a61b5]616        verify( ! kernelTLS.preemption_state.enabled );
[0b33412]617
[36982fc]618        enable_interrupts( __cfaabi_dbg_ctx );
[db6f06a]619}
620
[ea7d2b0]621void BlockInternal( __spinlock_t * lock, thread_desc * thrd ) {
[97e3296]622        assert(thrd);
[82ff5845]623        disable_interrupts();
[14a61b5]624        with( * kernelTLS.this_processor ) {
[de6319f]625                finish.action_code = Release_Schedule;
626                finish.lock        = lock;
627                finish.thrd        = thrd;
628        }
[0b33412]629
[14a61b5]630        verify( ! kernelTLS.preemption_state.enabled );
[82c948c]631        returnToKernel();
[14a61b5]632        verify( ! kernelTLS.preemption_state.enabled );
[0b33412]633
[36982fc]634        enable_interrupts( __cfaabi_dbg_ctx );
[eb2e723]635}
636
[ea7d2b0]637void BlockInternal(__spinlock_t * locks [], unsigned short count) {
[82ff5845]638        disable_interrupts();
[14a61b5]639        with( * kernelTLS.this_processor ) {
[de6319f]640                finish.action_code = Release_Multi;
641                finish.locks       = locks;
642                finish.lock_count  = count;
643        }
[0b33412]644
[14a61b5]645        verify( ! kernelTLS.preemption_state.enabled );
[82c948c]646        returnToKernel();
[14a61b5]647        verify( ! kernelTLS.preemption_state.enabled );
[0b33412]648
[36982fc]649        enable_interrupts( __cfaabi_dbg_ctx );
[0c78741]650}
651
[ea7d2b0]652void BlockInternal(__spinlock_t * locks [], unsigned short lock_count, thread_desc * thrds [], unsigned short thrd_count) {
[82ff5845]653        disable_interrupts();
[14a61b5]654        with( *kernelTLS.this_processor ) {
[de6319f]655                finish.action_code = Release_Multi_Schedule;
656                finish.locks       = locks;
657                finish.lock_count  = lock_count;
658                finish.thrds       = thrds;
659                finish.thrd_count  = thrd_count;
660        }
[0b33412]661
[14a61b5]662        verify( ! kernelTLS.preemption_state.enabled );
[82c948c]663        returnToKernel();
[14a61b5]664        verify( ! kernelTLS.preemption_state.enabled );
[0b33412]665
[36982fc]666        enable_interrupts( __cfaabi_dbg_ctx );
[0c78741]667}
668
[09800e9]669void BlockInternal(__finish_callback_fptr_t callback) {
670        disable_interrupts();
671        with( *kernelTLS.this_processor ) {
672                finish.action_code = Callback;
673                finish.callback    = callback;
674        }
675
676        verify( ! kernelTLS.preemption_state.enabled );
677        returnToKernel();
678        verify( ! kernelTLS.preemption_state.enabled );
679
680        enable_interrupts( __cfaabi_dbg_ctx );
681}
682
[14a61b5]683// KERNEL ONLY
[ea7d2b0]684void LeaveThread(__spinlock_t * lock, thread_desc * thrd) {
[14a61b5]685        verify( ! kernelTLS.preemption_state.enabled );
686        with( * kernelTLS.this_processor ) {
[de6319f]687                finish.action_code = thrd ? Release_Schedule : Release;
688                finish.lock        = lock;
689                finish.thrd        = thrd;
690        }
[f2b12406]691
[82c948c]692        returnToKernel();
[f2b12406]693}
694
[fa21ac9]695//=============================================================================================
696// Kernel Setup logic
697//=============================================================================================
[eb2e723]698//-----------------------------------------------------------------------------
699// Kernel boot procedures
[c29c342]700static void kernel_startup(void) {
[14a61b5]701        verify( ! kernelTLS.preemption_state.enabled );
[36982fc]702        __cfaabi_dbg_print_safe("Kernel : Starting\n");
[eb2e723]703
[b2f6113]704        __page_size = sysconf( _SC_PAGESIZE );
705
[ea8b2f7]706        __cfa_dbg_global_clusters.list{ __get };
707        __cfa_dbg_global_clusters.lock{};
[de94a60]708
[de6319f]709        // Initialize the main cluster
710        mainCluster = (cluster *)&storage_mainCluster;
711        (*mainCluster){"Main Cluster"};
712
713        __cfaabi_dbg_print_safe("Kernel : Main cluster ready\n");
714
[eb2e723]715        // Start by initializing the main thread
[1c273d0]716        // SKULLDUGGERY: the mainThread steals the process main thread
[969b3fe]717        // which will then be scheduled by the mainProcessor normally
718        mainThread = (thread_desc *)&storage_mainThread;
[8fcbb4c]719        current_stack_info_t info;
[b2f6113]720        info.storage = (__stack_t*)&storage_mainThreadCtx;
[83a071f9]721        (*mainThread){ &info };
[eb2e723]722
[36982fc]723        __cfaabi_dbg_print_safe("Kernel : Main thread ready\n");
[fa21ac9]724
[bd98b58]725
[de6319f]726
727        // Construct the processor context of the main processor
728        void ?{}(processorCtx_t & this, processor * proc) {
729                (this.__cor){ "Processor" };
[1805b1b]730                this.__cor.starter = 0p;
[de6319f]731                this.proc = proc;
732        }
733
734        void ?{}(processor & this) with( this ) {
735                name = "Main Processor";
736                cltr = mainCluster;
737                terminated{ 0 };
738                do_terminate = false;
[1805b1b]739                preemption_alarm = 0p;
[de6319f]740                pending_preemption = false;
741                kernel_thread = pthread_self();
[7768b8d]742                id = -1u;
[de6319f]743
744                runner{ &this };
745                __cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner);
746        }
[fa21ac9]747
[969b3fe]748        // Initialize the main processor and the main processor ctx
[eb2e723]749        // (the coroutine that contains the processing control flow)
[969b3fe]750        mainProcessor = (processor *)&storage_mainProcessor;
[de6319f]751        (*mainProcessor){};
[eb2e723]752
[7768b8d]753        mainProcessor->id = doregister(mainCluster, mainProcessor);
754
[dcb42b8]755        //initialize the global state variables
[14a61b5]756        kernelTLS.this_processor = mainProcessor;
757        kernelTLS.this_thread    = mainThread;
[eb2e723]758
[82ff5845]759        // Enable preemption
760        kernel_start_preemption();
761
[969b3fe]762        // Add the main thread to the ready queue
763        // once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
764        ScheduleThread(mainThread);
765
766        // SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
[dcb42b8]767        // context. Hence, the main thread does not begin through CtxInvokeThread, like all other threads. The trick here is that
[1c273d0]768        // mainThread is on the ready queue when this call is made.
[14a61b5]769        kernel_first_resume( kernelTLS.this_processor );
[eb2e723]770
[dcb42b8]771
772
773        // THE SYSTEM IS NOW COMPLETELY RUNNING
[36982fc]774        __cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n");
[82ff5845]775
[14a61b5]776        verify( ! kernelTLS.preemption_state.enabled );
[36982fc]777        enable_interrupts( __cfaabi_dbg_ctx );
[afd550c]778        verify( TL_GET( preemption_state.enabled ) );
[eb2e723]779}
780
[c29c342]781static void kernel_shutdown(void) {
[36982fc]782        __cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n");
[eb2e723]783
[afd550c]784        verify( TL_GET( preemption_state.enabled ) );
[4e6fb8e]785        disable_interrupts();
[14a61b5]786        verify( ! kernelTLS.preemption_state.enabled );
[4e6fb8e]787
[969b3fe]788        // SKULLDUGGERY: Notify the mainProcessor it needs to terminates.
[dcb42b8]789        // When its coroutine terminates, it return control to the mainThread
790        // which is currently here
[ea8b2f7]791        __atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE);
[e8e457e]792        kernel_last_resume( kernelTLS.this_processor );
[ea8b2f7]793        mainThread->self_cor.state = Halted;
[eb2e723]794
[dcb42b8]795        // THE SYSTEM IS NOW COMPLETELY STOPPED
[eb2e723]796
[82ff5845]797        // Disable preemption
798        kernel_stop_preemption();
799
[7768b8d]800        unregister(mainCluster, mainProcessor);
801
[969b3fe]802        // Destroy the main processor and its context in reverse order of construction
[dcb42b8]803        // These were manually constructed so we need manually destroy them
[b798713]804        void ^?{}(processor & this) with( this ) {
805                //don't join the main thread here, that wouldn't make any sense
806                __cfaabi_dbg_print_safe("Kernel : destroyed main processor context %p\n", &runner);
807        }
808
[7768b8d]809        ^(*mainProcessor){};
[eb2e723]810
[dcb42b8]811        // Final step, destroy the main thread since it is no longer needed
[7768b8d]812        // Since we provided a stack to this task it will not destroy anything
813        ^(*mainThread){};
814
815        ^(*mainCluster){};
[eb2e723]816
[ea8b2f7]817        ^(__cfa_dbg_global_clusters.list){};
818        ^(__cfa_dbg_global_clusters.lock){};
[a1a17a7]819
[36982fc]820        __cfaabi_dbg_print_safe("Kernel : Shutdown complete\n");
[9d944b2]821}
822
[14a61b5]823//=============================================================================================
824// Kernel Quiescing
825//=============================================================================================
[c29c342]826static void halt(processor * this) with( *this ) {
[c84b4be]827        // // verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) );
[ea8b2f7]828
[c84b4be]829        // with( *cltr ) {
830        //      lock      (proc_list_lock __cfaabi_dbg_ctx2);
831        //      push_front(idles, *this);
832        //      unlock    (proc_list_lock);
833        // }
[14a61b5]834
[c84b4be]835        // __cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
[14a61b5]836
[c84b4be]837        // wait( idleLock );
[14a61b5]838
[c84b4be]839        // __cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this);
[14a61b5]840
[c84b4be]841        // with( *cltr ) {
842        //      lock      (proc_list_lock __cfaabi_dbg_ctx2);
843        //      remove    (idles, *this);
844        //      unlock    (proc_list_lock);
845        // }
[6b4cdd3]846}
847
[dbe9b08]848//=============================================================================================
849// Unexpected Terminating logic
850//=============================================================================================
[ea7d2b0]851static __spinlock_t kernel_abort_lock;
[9d944b2]852static bool kernel_abort_called = false;
853
[afd550c]854void * kernel_abort(void) __attribute__ ((__nothrow__)) {
[9d944b2]855        // abort cannot be recursively entered by the same or different processors because all signal handlers return when
856        // the globalAbort flag is true.
[36982fc]857        lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
[9d944b2]858
859        // first task to abort ?
[de94a60]860        if ( kernel_abort_called ) {                    // not first task to abort ?
[ea7d2b0]861                unlock( kernel_abort_lock );
[1c273d0]862
[9d944b2]863                sigset_t mask;
864                sigemptyset( &mask );
[de94a60]865                sigaddset( &mask, SIGALRM );            // block SIGALRM signals
866                sigsuspend( &mask );                    // block the processor to prevent further damage during abort
867                _exit( EXIT_FAILURE );                  // if processor unblocks before it is killed, terminate it
868        }
869        else {
870                kernel_abort_called = true;
871                unlock( kernel_abort_lock );
[9d944b2]872        }
873
[14a61b5]874        return kernelTLS.this_thread;
[9d944b2]875}
876
877void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
878        thread_desc * thrd = kernel_data;
879
[de94a60]880        if(thrd) {
881                int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]882                __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]883
[212c2187]884                if ( &thrd->self_cor != thrd->curr_cor ) {
885                        len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]886                        __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]887                }
888                else {
[1c40091]889                        __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]890                }
[1c273d0]891        }
[9d944b2]892        else {
[de94a60]893                int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]894                __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]895        }
896}
897
[2b8bc41]898int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
[14a61b5]899        return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]900}
901
[de94a60]902static __spinlock_t kernel_debug_lock;
903
[9d944b2]904extern "C" {
[1c40091]905        void __cfaabi_bits_acquire() {
[36982fc]906                lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]907        }
908
[1c40091]909        void __cfaabi_bits_release() {
[ea7d2b0]910                unlock( kernel_debug_lock );
[9d944b2]911        }
[8118303]912}
913
[fa21ac9]914//=============================================================================================
915// Kernel Utilities
916//=============================================================================================
[bd98b58]917//-----------------------------------------------------------------------------
918// Locks
[242a902]919void  ?{}( semaphore & this, int count = 1 ) {
920        (this.lock){};
921        this.count = count;
922        (this.waiting){};
[db6f06a]923}
[242a902]924void ^?{}(semaphore & this) {}
[db6f06a]925
[65deb18]926void P(semaphore & this) with( this ){
927        lock( lock __cfaabi_dbg_ctx2 );
928        count -= 1;
929        if ( count < 0 ) {
[bdeba0b]930                // queue current task
[14a61b5]931                append( waiting, kernelTLS.this_thread );
[bdeba0b]932
933                // atomically release spin lock and block
[65deb18]934                BlockInternal( &lock );
[8def349]935        }
[4e6fb8e]936        else {
[65deb18]937            unlock( lock );
[4e6fb8e]938        }
[bd98b58]939}
940
[65deb18]941void V(semaphore & this) with( this ) {
[1805b1b]942        thread_desc * thrd = 0p;
[65deb18]943        lock( lock __cfaabi_dbg_ctx2 );
944        count += 1;
945        if ( count <= 0 ) {
[bdeba0b]946                // remove task at head of waiting list
[65deb18]947                thrd = pop_head( waiting );
[bd98b58]948        }
[bdeba0b]949
[65deb18]950        unlock( lock );
[bdeba0b]951
952        // make new owner
953        WakeThread( thrd );
[bd98b58]954}
955
[f7d6bb0]956//-----------------------------------------------------------------------------
[de94a60]957// Global Queues
958void doregister( cluster     & cltr ) {
[ea8b2f7]959        lock      ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
960        push_front( __cfa_dbg_global_clusters.list, cltr );
961        unlock    ( __cfa_dbg_global_clusters.lock );
[de94a60]962}
[f7d6bb0]963
[de94a60]964void unregister( cluster     & cltr ) {
[ea8b2f7]965        lock  ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
966        remove( __cfa_dbg_global_clusters.list, cltr );
967        unlock( __cfa_dbg_global_clusters.lock );
[de94a60]968}
[f7d6bb0]969
[a1a17a7]970void doregister( cluster * cltr, thread_desc & thrd ) {
971        lock      (cltr->thread_list_lock __cfaabi_dbg_ctx2);
[d4e68a6]972        cltr->nthreads += 1;
[a1a17a7]973        push_front(cltr->threads, thrd);
974        unlock    (cltr->thread_list_lock);
975}
976
977void unregister( cluster * cltr, thread_desc & thrd ) {
978        lock  (cltr->thread_list_lock __cfaabi_dbg_ctx2);
979        remove(cltr->threads, thrd );
[d4e68a6]980        cltr->nthreads -= 1;
[a1a17a7]981        unlock(cltr->thread_list_lock);
982}
[9181f1d]983
[de94a60]984//-----------------------------------------------------------------------------
985// Debug
986__cfaabi_dbg_debug_do(
[1997b4e]987        extern "C" {
988                void __cfaabi_dbg_record(__spinlock_t & this, const char * prev_name) {
989                        this.prev_name = prev_name;
990                        this.prev_thrd = kernelTLS.this_thread;
991                }
[9181f1d]992        }
[f7d6bb0]993)
[2026bb6]994
995//-----------------------------------------------------------------------------
996// Debug
997bool threading_enabled(void) {
998        return true;
999}
[8118303]1000// Local Variables: //
1001// mode: c //
1002// tab-width: 4 //
1003// End: //
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