Context Navigation

kernel.cfa @ ae7be7a

ADTarm-ehast-experimentalenumforall-pointer-decayjacob/cs343-translationnew-astnew-ast-unique-exprpthread-emulationqualifiedEnum

Last change on this file since ae7be7a was ae7be7a, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
Fixed incorrect setting of ready state and added result to previous park information
Property mode set to `100644`
File size: 31.4 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 : Tue Feb 4 13:03:15 2020
13	// Update Count : 58
14	//
15
16	#define __cforall_thread__
17
18	//C Includes
19	#include <stddef.h>
20	#include <errno.h>
21	#include <string.h>
22	extern "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	#include <sys/mman.h> // mprotect
30	}
31
32	//CFA Includes
33	#include "time.hfa"
34	#include "kernel_private.hfa"
35	#include "preemption.hfa"
36	#include "startup.hfa"
37
38	//Private includes
39	#define __CFA_INVOKE_PRIVATE__
40	#include "invoke.h"
41
42	//-----------------------------------------------------------------------------
43	// Some assembly required
44	#if defined( __i386 )
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	//-----------------------------------------------------------------------------
111	//Start and stop routine for the kernel, declared first to make sure they run first
112	static void __kernel_startup (void) __attribute__(( constructor( STARTUP_PRIORITY_KERNEL ) ));
113	static void __kernel_shutdown(void) __attribute__(( destructor ( STARTUP_PRIORITY_KERNEL ) ));
114
115	//-----------------------------------------------------------------------------
116	// Kernel storage
117	KERNEL_STORAGE(cluster, mainCluster);
118	KERNEL_STORAGE(processor, mainProcessor);
119	KERNEL_STORAGE($thread, mainThread);
120	KERNEL_STORAGE(__stack_t, mainThreadCtx);
121
122	cluster * mainCluster;
123	processor * mainProcessor;
124	$thread * mainThread;
125
126	extern "C" {
127	struct { __dllist_t(cluster) list; __spinlock_t lock; } __cfa_dbg_global_clusters;
128	}
129
130	size_t __page_size = 0;
131
132	//-----------------------------------------------------------------------------
133	// Global state
134	thread_local struct KernelThreadData kernelTLS __attribute__ ((tls_model ( "initial-exec" ))) = {
135	NULL, // cannot use 0p
136	NULL,
137	{ 1, false, false },
138	6u //this should be seeded better but due to a bug calling rdtsc doesn't work
139	};
140
141	//-----------------------------------------------------------------------------
142	// Struct to steal stack
143	struct current_stack_info_t {
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
148	};
149
150	void ?{}( current_stack_info_t & this ) {
151	__stack_context_t ctx;
152	CtxGet( ctx );
153	this.base = ctx.FP;
154
155	rlimit r;
156	getrlimit( RLIMIT_STACK, &r);
157	size_t size = r.rlim_cur;
158
159	this.limit = (void *)(((intptr_t)this.base) - size);
160	this.context = &storage_mainThreadCtx;
161	}
162
163	//-----------------------------------------------------------------------------
164	// Main thread construction
165
166	void ?{}( $coroutine & this, current_stack_info_t * info) with( this ) {
167	stack.storage = info->storage;
168	with(*stack.storage) {
169	limit = info->limit;
170	base = info->base;
171	}
172	__attribute__((may_alias)) intptr_t * istorage = (intptr_t*) &stack.storage;
173	*istorage \|= 0x1;
174	name = "Main Thread";
175	state = Start;
176	starter = 0p;
177	last = 0p;
178	cancellation = 0p;
179	}
180
181	void ?{}( $thread & this, current_stack_info_t * info) with( this ) {
182	state = Start;
183	self_cor{ info };
184	curr_cor = &self_cor;
185	curr_cluster = mainCluster;
186	self_mon.owner = &this;
187	self_mon.recursion = 1;
188	self_mon_p = &self_mon;
189	next = 0p;
190
191	node.next = 0p;
192	node.prev = 0p;
193	doregister(curr_cluster, this);
194
195	monitors{ &self_mon_p, 1, (fptr_t)0 };
196	}
197
198	//-----------------------------------------------------------------------------
199	// Processor coroutine
200	void ?{}(processorCtx_t & this) {
201
202	}
203
204	// Construct the processor context of non-main processors
205	static void ?{}(processorCtx_t & this, processor * proc, current_stack_info_t * info) {
206	(this.__cor){ info };
207	this.proc = proc;
208	}
209
210	static void * __invoke_processor(void * arg);
211
212	void ?{}(processor & this, const char name[], cluster & cltr) with( this ) {
213	this.name = name;
214	this.cltr = &cltr;
215	terminated{ 0 };
216	destroyer = 0p;
217	do_terminate = false;
218	preemption_alarm = 0p;
219	pending_preemption = false;
220	runner.proc = &this;
221
222	idleLock{};
223
224	__cfaabi_dbg_print_safe("Kernel : Starting core %p\n", &this);
225
226	this.stack = __create_pthread( &this.kernel_thread, __invoke_processor, (void *)&this );
227
228	__cfaabi_dbg_print_safe("Kernel : core %p started\n", &this);
229	}
230
231	void ^?{}(processor & this) with( this ){
232	if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
233	__cfaabi_dbg_print_safe("Kernel : core %p signaling termination\n", &this);
234
235	__atomic_store_n(&do_terminate, true, __ATOMIC_RELAXED);
236	wake( &this );
237
238	P( terminated );
239	verify( kernelTLS.this_processor != &this);
240	}
241
242	pthread_join( kernel_thread, 0p );
243	free( this.stack );
244	}
245
246	void ?{}(cluster & this, const char name[], Duration preemption_rate) with( this ) {
247	this.name = name;
248	this.preemption_rate = preemption_rate;
249	ready_queue{};
250	ready_queue_lock{};
251
252	procs{ __get };
253	idles{ __get };
254	threads{ __get };
255
256	doregister(this);
257	}
258
259	void ^?{}(cluster & this) {
260	unregister(this);
261	}
262
263	//=============================================================================================
264	// Kernel Scheduling logic
265	//=============================================================================================
266	static $thread * __next_thread(cluster * this);
267	static void __run_thread(processor * this, $thread * dst);
268	static void __halt(processor * this);
269
270	//Main of the processor contexts
271	void main(processorCtx_t & runner) {
272	// Because of a bug, we couldn't initialized the seed on construction
273	// Do it here
274	kernelTLS.rand_seed ^= rdtscl();
275
276	processor * this = runner.proc;
277	verify(this);
278
279	__cfaabi_dbg_print_safe("Kernel : core %p starting\n", this);
280
281	doregister(this->cltr, this);
282
283	{
284	// Setup preemption data
285	preemption_scope scope = { this };
286
287	__cfaabi_dbg_print_safe("Kernel : core %p started\n", this);
288
289	$thread * readyThread = 0p;
290	for( unsigned int spin_count = 0; ! __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST); spin_count++ ) {
291	readyThread = __next_thread( this->cltr );
292
293	if(readyThread) {
294	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
295	/* paranoid */ verifyf( readyThread->state == Blocked \|\| readyThread->state == Start \|\| readyThread->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", readyThread->state, readyThread->preempted);
296	/* paranoid */ verifyf( readyThread->next == 0p, "Expected null got %p", readyThread->next );
297
298	__run_thread(this, readyThread);
299
300	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
301
302	spin_count = 0;
303	} else {
304	// spin(this, &spin_count);
305	__halt(this);
306	}
307	}
308
309	__cfaabi_dbg_print_safe("Kernel : core %p stopping\n", this);
310	}
311
312	unregister(this->cltr, this);
313
314	V( this->terminated );
315
316	__cfaabi_dbg_print_safe("Kernel : core %p terminated\n", this);
317	}
318
319	static int * __volatile_errno() __attribute__((noinline));
320	static int * __volatile_errno() { asm(""); return &errno; }
321
322	// KERNEL ONLY
323	// runThread runs a thread by context switching
324	// from the processor coroutine to the target thread
325	static void __run_thread(processor * this, $thread * thrd_dst) {
326	$coroutine * proc_cor = get_coroutine(this->runner);
327
328	// Update global state
329	kernelTLS.this_thread = thrd_dst;
330
331	// set state of processor coroutine to inactive
332	verify(proc_cor->state == Active);
333	proc_cor->state = Blocked;
334
335	// Actually run the thread
336	RUNNING: while(true) {
337	if(unlikely(thrd_dst->preempted)) {
338	thrd_dst->preempted = __NO_PREEMPTION;
339	verify(thrd_dst->state == Active \|\| thrd_dst->state == Rerun);
340	} else {
341	verify(thrd_dst->state == Start \|\| thrd_dst->state == Primed \|\| thrd_dst->state == Blocked);
342	thrd_dst->state = Active;
343	}
344
345	__cfaabi_dbg_debug_do(
346	thrd_dst->park_stale = true;
347	thrd_dst->unpark_stale = true;
348	)
349
350	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
351	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) \|\| thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); // add escape condition if we are setting up the processor
352	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) \|\| thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor
353
354	// set context switch to the thread that the processor is executing
355	verify( thrd_dst->context.SP );
356	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
357	// when __cfactx_switch returns we are back in the processor coroutine
358
359	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst );
360	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
361	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
362
363
364	// We just finished running a thread, there are a few things that could have happened.
365	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
366	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
367	// 4 - Preempted
368	// In case 1, we may have won a race so we can't write to the state again.
369	// In case 2, we lost the race so we now own the thread.
370
371	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
372	// The thread was preempted, reschedule it and reset the flag
373	__schedule_thread( thrd_dst );
374	break RUNNING;
375	}
376
377	// set state of processor coroutine to active and the thread to inactive
378	static_assert(sizeof(thrd_dst->state) == sizeof(int));
379	enum coroutine_state old_state = __atomic_exchange_n(&thrd_dst->state, Blocked, __ATOMIC_SEQ_CST);
380	__cfaabi_dbg_debug_do( thrd_dst->park_result = old_state; )
381	switch(old_state) {
382	case Halted:
383	// The thread has halted, it should never be scheduled/run again, leave it back to Halted and move on
384	thrd_dst->state = Halted;
385
386	// We may need to wake someone up here since
387	unpark( this->destroyer __cfaabi_dbg_ctx2 );
388	this->destroyer = 0p;
389	break RUNNING;
390	case Active:
391	// This is case 1, the regular case, nothing more is needed
392	break RUNNING;
393	case Rerun:
394	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
395	// In this case, just run it again.
396	continue RUNNING;
397	default:
398	// This makes no sense, something is wrong abort
399	abort("Finished running a thread that was Blocked/Start/Primed %d\n", old_state);
400	}
401	}
402
403	// Just before returning to the processor, set the processor coroutine to active
404	proc_cor->state = Active;
405	kernelTLS.this_thread = 0p;
406	}
407
408	// KERNEL_ONLY
409	void returnToKernel() {
410	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
411	$coroutine * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
412	$thread * thrd_src = kernelTLS.this_thread;
413
414	// Run the thread on this processor
415	{
416	int local_errno = *__volatile_errno();
417	#if defined( __i386 ) \|\| defined( __x86_64 )
418	__x87_store;
419	#endif
420	verify( proc_cor->context.SP );
421	__cfactx_switch( &thrd_src->context, &proc_cor->context );
422	#if defined( __i386 ) \|\| defined( __x86_64 )
423	__x87_load;
424	#endif
425	*__volatile_errno() = local_errno;
426	}
427
428	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
429	/* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) < ((uintptr_t)__get_stack(thrd_src->curr_cor)->base ), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too small.\n", thrd_src );
430	/* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) > ((uintptr_t)__get_stack(thrd_src->curr_cor)->limit), "ERROR : Returning $thread %p has been corrupted.\n StackPointer too large.\n", thrd_src );
431	}
432
433	// KERNEL_ONLY
434	// Context invoker for processors
435	// This is the entry point for processors (kernel threads)
436	// It effectively constructs a coroutine by stealing the pthread stack
437	static void * __invoke_processor(void * arg) {
438	processor * proc = (processor *) arg;
439	kernelTLS.this_processor = proc;
440	kernelTLS.this_thread = 0p;
441	kernelTLS.preemption_state.[enabled, disable_count] = [false, 1];
442	// SKULLDUGGERY: We want to create a context for the processor coroutine
443	// which is needed for the 2-step context switch. However, there is no reason
444	// to waste the perfectly valid stack create by pthread.
445	current_stack_info_t info;
446	__stack_t ctx;
447	info.storage = &ctx;
448	(proc->runner){ proc, &info };
449
450	__cfaabi_dbg_print_safe("Coroutine : created stack %p\n", get_coroutine(proc->runner)->stack.storage);
451
452	//Set global state
453	kernelTLS.this_thread = 0p;
454
455	//We now have a proper context from which to schedule threads
456	__cfaabi_dbg_print_safe("Kernel : core %p created (%p, %p)\n", proc, &proc->runner, &ctx);
457
458	// SKULLDUGGERY: Since the coroutine doesn't have its own stack, we can't
459	// resume it to start it like it normally would, it will just context switch
460	// back to here. Instead directly call the main since we already are on the
461	// appropriate stack.
462	get_coroutine(proc->runner)->state = Active;
463	main( proc->runner );
464	get_coroutine(proc->runner)->state = Halted;
465
466	// Main routine of the core returned, the core is now fully terminated
467	__cfaabi_dbg_print_safe("Kernel : core %p main ended (%p)\n", proc, &proc->runner);
468
469	return 0p;
470	}
471
472	static void Abort( int ret, const char func[] ) {
473	if ( ret ) { // pthread routines return errno values
474	abort( "%s : internal error, error(%d) %s.", func, ret, strerror( ret ) );
475	} // if
476	} // Abort
477
478	void * __create_pthread( pthread_t * pthread, void * (start)(void ), void * arg ) {
479	pthread_attr_t attr;
480
481	Abort( pthread_attr_init( &attr ), "pthread_attr_init" ); // initialize attribute
482
483	size_t stacksize;
484	// default stack size, normally defined by shell limit
485	Abort( pthread_attr_getstacksize( &attr, &stacksize ), "pthread_attr_getstacksize" );
486	assert( stacksize >= PTHREAD_STACK_MIN );
487
488	void * stack;
489	__cfaabi_dbg_debug_do(
490	stack = memalign( __page_size, stacksize + __page_size );
491	// pthread has no mechanism to create the guard page in user supplied stack.
492	if ( mprotect( stack, __page_size, PROT_NONE ) == -1 ) {
493	abort( "mprotect : internal error, mprotect failure, error(%d) %s.", errno, strerror( errno ) );
494	} // if
495	);
496	__cfaabi_dbg_no_debug_do(
497	stack = malloc( stacksize );
498	);
499
500	Abort( pthread_attr_setstack( &attr, stack, stacksize ), "pthread_attr_setstack" );
501
502	Abort( pthread_create( pthread, &attr, start, arg ), "pthread_create" );
503	return stack;
504	}
505
506	// KERNEL_ONLY
507	static void __kernel_first_resume( processor * this ) {
508	$thread * src = mainThread;
509	$coroutine * dst = get_coroutine(this->runner);
510
511	verify( ! kernelTLS.preemption_state.enabled );
512
513	kernelTLS.this_thread->curr_cor = dst;
514	__stack_prepare( &dst->stack, 65000 );
515	__cfactx_start(main, dst, this->runner, __cfactx_invoke_coroutine);
516
517	verify( ! kernelTLS.preemption_state.enabled );
518
519	dst->last = &src->self_cor;
520	dst->starter = dst->starter ? dst->starter : &src->self_cor;
521
522	// set state of current coroutine to inactive
523	src->state = src->state == Halted ? Halted : Blocked;
524
525	// context switch to specified coroutine
526	verify( dst->context.SP );
527	__cfactx_switch( &src->context, &dst->context );
528	// when __cfactx_switch returns we are back in the src coroutine
529
530	mainThread->curr_cor = &mainThread->self_cor;
531
532	// set state of new coroutine to active
533	src->state = Active;
534
535	verify( ! kernelTLS.preemption_state.enabled );
536	}
537
538	// KERNEL_ONLY
539	static void __kernel_last_resume( processor * this ) {
540	$coroutine * src = &mainThread->self_cor;
541	$coroutine * dst = get_coroutine(this->runner);
542
543	verify( ! kernelTLS.preemption_state.enabled );
544	verify( dst->starter == src );
545	verify( dst->context.SP );
546
547	// context switch to the processor
548	__cfactx_switch( &src->context, &dst->context );
549	}
550
551	//-----------------------------------------------------------------------------
552	// Scheduler routines
553	// KERNEL ONLY
554	void __schedule_thread( $thread * thrd ) with( *thrd->curr_cluster ) {
555	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
556	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
557	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
558	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
559	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active \|\| thrd->state == Rerun,
560	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
561	/* paranoid */ #endif
562	/* paranoid */ verifyf( thrd->next == 0p, "Expected null got %p", thrd->next );
563
564	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
565
566	lock ( ready_queue_lock __cfaabi_dbg_ctx2 );
567	bool was_empty = !(ready_queue != 0);
568	append( ready_queue, thrd );
569	unlock( ready_queue_lock );
570
571	if(was_empty) {
572	lock (proc_list_lock __cfaabi_dbg_ctx2);
573	if(idles) {
574	wake_fast(idles.head);
575	}
576	unlock (proc_list_lock);
577	}
578	else if( struct processor * idle = idles.head ) {
579	wake_fast(idle);
580	}
581
582	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
583	}
584
585	// KERNEL ONLY
586	static $thread * __next_thread(cluster * this) with( *this ) {
587	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
588
589	lock( ready_queue_lock __cfaabi_dbg_ctx2 );
590	$thread * head = pop_head( ready_queue );
591	unlock( ready_queue_lock );
592
593	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
594	return head;
595	}
596
597	void unpark( $thread * thrd __cfaabi_dbg_ctx_param2 ) {
598	if( !thrd ) return;
599
600	disable_interrupts();
601	static_assert(sizeof(thrd->state) == sizeof(int));
602
603	// record activity
604	__cfaabi_dbg_record_thrd( *thrd, false, caller );
605
606	enum coroutine_state old_state = __atomic_exchange_n(&thrd->state, Rerun, __ATOMIC_SEQ_CST);
607	__cfaabi_dbg_debug_do( thrd->unpark_result = old_state; )
608	switch(old_state) {
609	case Active:
610	// Wake won the race, the thread will reschedule/rerun itself
611	break;
612	case Blocked:
613	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
614
615	// Wake lost the race,
616	thrd->state = Blocked;
617	__schedule_thread( thrd );
618	break;
619	case Rerun:
620	abort("More than one thread attempted to schedule thread %p\n", thrd);
621	break;
622	case Halted:
623	case Start:
624	case Primed:
625	default:
626	// This makes no sense, something is wrong abort
627	abort();
628	}
629	enable_interrupts( __cfaabi_dbg_ctx );
630	}
631
632	void park( __cfaabi_dbg_ctx_param ) {
633	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
634	disable_interrupts();
635	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
636	/* paranoid */ verify( kernelTLS.this_thread->preempted == __NO_PREEMPTION );
637
638	// record activity
639	__cfaabi_dbg_record_thrd( *kernelTLS.this_thread, true, caller );
640
641	returnToKernel();
642
643	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
644	enable_interrupts( __cfaabi_dbg_ctx );
645	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
646
647	}
648
649	// KERNEL ONLY
650	void __leave_thread() {
651	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
652	returnToKernel();
653	abort();
654	}
655
656	// KERNEL ONLY
657	bool force_yield( __Preemption_Reason reason ) {
658	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
659	disable_interrupts();
660	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
661
662	$thread * thrd = kernelTLS.this_thread;
663	/* paranoid */ verify(thrd->state == Active \|\| thrd->state == Rerun);
664
665	// SKULLDUGGERY: It is possible that we are preempting this thread just before
666	// it was going to park itself. If that is the case and it is already using the
667	// intrusive fields then we can't use them to preempt the thread
668	// If that is the case, abandon the preemption.
669	bool preempted = false;
670	if(thrd->next == 0p) {
671	preempted = true;
672	thrd->preempted = reason;
673	returnToKernel();
674	}
675
676	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
677	enable_interrupts_noPoll();
678	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
679
680	return preempted;
681	}
682
683	//=============================================================================================
684	// Kernel Setup logic
685	//=============================================================================================
686	//-----------------------------------------------------------------------------
687	// Kernel boot procedures
688	static void __kernel_startup(void) {
689	verify( ! kernelTLS.preemption_state.enabled );
690	__cfaabi_dbg_print_safe("Kernel : Starting\n");
691
692	__page_size = sysconf( _SC_PAGESIZE );
693
694	__cfa_dbg_global_clusters.list{ __get };
695	__cfa_dbg_global_clusters.lock{};
696
697	// Initialize the main cluster
698	mainCluster = (cluster *)&storage_mainCluster;
699	(*mainCluster){"Main Cluster"};
700
701	__cfaabi_dbg_print_safe("Kernel : Main cluster ready\n");
702
703	// Start by initializing the main thread
704	// SKULLDUGGERY: the mainThread steals the process main thread
705	// which will then be scheduled by the mainProcessor normally
706	mainThread = ($thread *)&storage_mainThread;
707	current_stack_info_t info;
708	info.storage = (__stack_t*)&storage_mainThreadCtx;
709	(*mainThread){ &info };
710
711	__cfaabi_dbg_print_safe("Kernel : Main thread ready\n");
712
713
714
715	// Construct the processor context of the main processor
716	void ?{}(processorCtx_t & this, processor * proc) {
717	(this.__cor){ "Processor" };
718	this.__cor.starter = 0p;
719	this.proc = proc;
720	}
721
722	void ?{}(processor & this) with( this ) {
723	name = "Main Processor";
724	cltr = mainCluster;
725	terminated{ 0 };
726	do_terminate = false;
727	preemption_alarm = 0p;
728	pending_preemption = false;
729	kernel_thread = pthread_self();
730
731	runner{ &this };
732	__cfaabi_dbg_print_safe("Kernel : constructed main processor context %p\n", &runner);
733	}
734
735	// Initialize the main processor and the main processor ctx
736	// (the coroutine that contains the processing control flow)
737	mainProcessor = (processor *)&storage_mainProcessor;
738	(*mainProcessor){};
739
740	//initialize the global state variables
741	kernelTLS.this_processor = mainProcessor;
742	kernelTLS.this_thread = mainThread;
743
744	// Enable preemption
745	kernel_start_preemption();
746
747	// Add the main thread to the ready queue
748	// once resume is called on mainProcessor->runner the mainThread needs to be scheduled like any normal thread
749	__schedule_thread(mainThread);
750
751	// SKULLDUGGERY: Force a context switch to the main processor to set the main thread's context to the current UNIX
752	// context. Hence, the main thread does not begin through __cfactx_invoke_thread, like all other threads. The trick here is that
753	// mainThread is on the ready queue when this call is made.
754	__kernel_first_resume( kernelTLS.this_processor );
755
756
757
758	// THE SYSTEM IS NOW COMPLETELY RUNNING
759	__cfaabi_dbg_print_safe("Kernel : Started\n--------------------------------------------------\n\n");
760
761	verify( ! kernelTLS.preemption_state.enabled );
762	enable_interrupts( __cfaabi_dbg_ctx );
763	verify( TL_GET( preemption_state.enabled ) );
764	}
765
766	static void __kernel_shutdown(void) {
767	__cfaabi_dbg_print_safe("\n--------------------------------------------------\nKernel : Shutting down\n");
768
769	verify( TL_GET( preemption_state.enabled ) );
770	disable_interrupts();
771	verify( ! kernelTLS.preemption_state.enabled );
772
773	// SKULLDUGGERY: Notify the mainProcessor it needs to terminates.
774	// When its coroutine terminates, it return control to the mainThread
775	// which is currently here
776	__atomic_store_n(&mainProcessor->do_terminate, true, __ATOMIC_RELEASE);
777	__kernel_last_resume( kernelTLS.this_processor );
778	mainThread->self_cor.state = Halted;
779
780	// THE SYSTEM IS NOW COMPLETELY STOPPED
781
782	// Disable preemption
783	kernel_stop_preemption();
784
785	// Destroy the main processor and its context in reverse order of construction
786	// These were manually constructed so we need manually destroy them
787	^(*mainProcessor){};
788
789	// Final step, destroy the main thread since it is no longer needed
790	// Since we provided a stack to this taxk it will not destroy anything
791	/* paranoid / verify(mainThread->self_cor.stack.storage == (__stack_t)(((uintptr_t)&storage_mainThreadCtx)\| 0x1));
792	^(*mainThread){};
793
794	^(__cfa_dbg_global_clusters.list){};
795	^(__cfa_dbg_global_clusters.lock){};
796
797	__cfaabi_dbg_print_safe("Kernel : Shutdown complete\n");
798	}
799
800	//=============================================================================================
801	// Kernel Quiescing
802	//=============================================================================================
803	static void __halt(processor * this) with( *this ) {
804	// verify( ! __atomic_load_n(&do_terminate, __ATOMIC_SEQ_CST) );
805
806	with( *cltr ) {
807	lock (proc_list_lock __cfaabi_dbg_ctx2);
808	remove (procs, *this);
809	push_front(idles, *this);
810	unlock (proc_list_lock);
811	}
812
813	__cfaabi_dbg_print_safe("Kernel : Processor %p ready to sleep\n", this);
814
815	wait( idleLock );
816
817	__cfaabi_dbg_print_safe("Kernel : Processor %p woke up and ready to run\n", this);
818
819	with( *cltr ) {
820	lock (proc_list_lock __cfaabi_dbg_ctx2);
821	remove (idles, *this);
822	push_front(procs, *this);
823	unlock (proc_list_lock);
824	}
825	}
826
827	//=============================================================================================
828	// Unexpected Terminating logic
829	//=============================================================================================
830	static __spinlock_t kernel_abort_lock;
831	static bool kernel_abort_called = false;
832
833	void * kernel_abort(void) __attribute__ ((__nothrow__)) {
834	// abort cannot be recursively entered by the same or different processors because all signal handlers return when
835	// the globalAbort flag is true.
836	lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
837
838	// first task to abort ?
839	if ( kernel_abort_called ) { // not first task to abort ?
840	unlock( kernel_abort_lock );
841
842	sigset_t mask;
843	sigemptyset( &mask );
844	sigaddset( &mask, SIGALRM ); // block SIGALRM signals
845	sigaddset( &mask, SIGUSR1 ); // block SIGALRM signals
846	sigsuspend( &mask ); // block the processor to prevent further damage during abort
847	_exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
848	}
849	else {
850	kernel_abort_called = true;
851	unlock( kernel_abort_lock );
852	}
853
854	return kernelTLS.this_thread;
855	}
856
857	void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
858	$thread * thrd = kernel_data;
859
860	if(thrd) {
861	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
862	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
863
864	if ( &thrd->self_cor != thrd->curr_cor ) {
865	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
866	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
867	}
868	else {
869	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
870	}
871	}
872	else {
873	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
874	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
875	}
876	}
877
878	int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
879	return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
880	}
881
882	static __spinlock_t kernel_debug_lock;
883
884	extern "C" {
885	void __cfaabi_bits_acquire() {
886	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
887	}
888
889	void __cfaabi_bits_release() {
890	unlock( kernel_debug_lock );
891	}
892	}
893
894	//=============================================================================================
895	// Kernel Utilities
896	//=============================================================================================
897	//-----------------------------------------------------------------------------
898	// Locks
899	void ?{}( semaphore & this, int count = 1 ) {
900	(this.lock){};
901	this.count = count;
902	(this.waiting){};
903	}
904	void ^?{}(semaphore & this) {}
905
906	void P(semaphore & this) with( this ){
907	lock( lock __cfaabi_dbg_ctx2 );
908	count -= 1;
909	if ( count < 0 ) {
910	// queue current task
911	append( waiting, kernelTLS.this_thread );
912
913	// atomically release spin lock and block
914	unlock( lock );
915	park( __cfaabi_dbg_ctx );
916	}
917	else {
918	unlock( lock );
919	}
920	}
921
922	void V(semaphore & this) with( this ) {
923	$thread * thrd = 0p;
924	lock( lock __cfaabi_dbg_ctx2 );
925	count += 1;
926	if ( count <= 0 ) {
927	// remove task at head of waiting list
928	thrd = pop_head( waiting );
929	}
930
931	unlock( lock );
932
933	// make new owner
934	unpark( thrd __cfaabi_dbg_ctx2 );
935	}
936
937	//-----------------------------------------------------------------------------
938	// Global Queues
939	void doregister( cluster & cltr ) {
940	lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
941	push_front( __cfa_dbg_global_clusters.list, cltr );
942	unlock ( __cfa_dbg_global_clusters.lock );
943	}
944
945	void unregister( cluster & cltr ) {
946	lock ( __cfa_dbg_global_clusters.lock __cfaabi_dbg_ctx2);
947	remove( __cfa_dbg_global_clusters.list, cltr );
948	unlock( __cfa_dbg_global_clusters.lock );
949	}
950
951	void doregister( cluster * cltr, $thread & thrd ) {
952	lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
953	cltr->nthreads += 1;
954	push_front(cltr->threads, thrd);
955	unlock (cltr->thread_list_lock);
956	}
957
958	void unregister( cluster * cltr, $thread & thrd ) {
959	lock (cltr->thread_list_lock __cfaabi_dbg_ctx2);
960	remove(cltr->threads, thrd );
961	cltr->nthreads -= 1;
962	unlock(cltr->thread_list_lock);
963	}
964
965	void doregister( cluster * cltr, processor * proc ) {
966	lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
967	cltr->nprocessors += 1;
968	push_front(cltr->procs, *proc);
969	unlock (cltr->proc_list_lock);
970	}
971
972	void unregister( cluster * cltr, processor * proc ) {
973	lock (cltr->proc_list_lock __cfaabi_dbg_ctx2);
974	remove(cltr->procs, *proc );
975	cltr->nprocessors -= 1;
976	unlock(cltr->proc_list_lock);
977	}
978
979	//-----------------------------------------------------------------------------
980	// Debug
981	__cfaabi_dbg_debug_do(
982	extern "C" {
983	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
984	this.prev_name = prev_name;
985	this.prev_thrd = kernelTLS.this_thread;
986	}
987
988	void __cfaabi_dbg_record_thrd($thread & this, bool park, const char prev_name[]) {
989	if(park) {
990	this.prev_park = prev_name;
991	this.park_stale = false;
992	}
993	else {
994	this.prev_unpark = prev_name;
995	this.unpark_stale = false;
996	}
997	}
998	}
999	)
1000
1001	//-----------------------------------------------------------------------------
1002	// Debug
1003	bool threading_enabled(void) __attribute__((const)) {
1004	return true;
1005	}
1006	// Local Variables: //
1007	// mode: c //
1008	// tab-width: 4 //
1009	// End: //

Note: See TracBrowser for help on using the repository browser.

Download in other formats:

Original Format