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kernel.cfa@ a468e1e9

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ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum

Last change on this file since a468e1e9 was 6011658, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Fixed abort to no longer deadlock when calling itself recursively. abort now disable interrupts indefinitely.
Property mode set to `100644`
File size: 24.1 KB

Rev	Line
[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
[0190480]	12	// Last Modified On : Mon Aug 31 07:08:20 2020
	13	// Update Count : 71
[8118303]	14	//
	15
[2026bb6]	16	#define __cforall_thread__
[4069faad]	17	// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
[2026bb6]	18
[8118303]	19	//C Includes
[214e8da]	20	#include <errno.h>
[9d944b2]	21	#include <stdio.h>
[58b6d1b]	22	#include <signal.h>
[9d944b2]	23	#include <unistd.h>
[8118303]	24
	25	//CFA Includes
[73abe95]	26	#include "kernel_private.hfa"
	27	#include "preemption.hfa"
[8118303]	28
	29	//Private includes
	30	#define __CFA_INVOKE_PRIVATE__
	31	#include "invoke.h"
	32
[4069faad]	33
[deca0f5]	34	//-----------------------------------------------------------------------------
	35	// Some assembly required
[1805b1b]	36	#if defined( __i386 )
[deca0f5]	37	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	38	// fcw : X87 FPU control word (preserved across function calls)
	39	#define __x87_store \
	40	uint32_t __mxcr; \
	41	uint16_t __fcw; \
	42	__asm__ volatile ( \
	43	"stmxcsr %0\n" \
	44	"fnstcw %1\n" \
	45	: "=m" (__mxcr),\
	46	"=m" (__fcw) \
	47	)
	48
	49	#define __x87_load \
	50	__asm__ volatile ( \
	51	"fldcw %1\n" \
	52	"ldmxcsr %0\n" \
	53	::"m" (__mxcr),\
	54	"m" (__fcw) \
	55	)
	56
	57	#elif defined( __x86_64 )
	58	#define __x87_store \
	59	uint32_t __mxcr; \
	60	uint16_t __fcw; \
	61	__asm__ volatile ( \
	62	"stmxcsr %0\n" \
	63	"fnstcw %1\n" \
	64	: "=m" (__mxcr),\
	65	"=m" (__fcw) \
	66	)
	67
	68	#define __x87_load \
	69	__asm__ volatile ( \
	70	"fldcw %1\n" \
	71	"ldmxcsr %0\n" \
	72	:: "m" (__mxcr),\
	73	"m" (__fcw) \
	74	)
	75
[0190480]	76	#elif defined( __arm__ )
	77	#define __x87_store
	78	#define __x87_load
	79
	80	#elif defined( __aarch64__ )
[74f5c83]	81	#define __x87_store \
	82	uint32_t __fpcntl[2]; \
	83	__asm__ volatile ( \
	84	"mrs x9, FPCR\n" \
	85	"mrs x10, FPSR\n" \
	86	"stp x9, x10, %0\n" \
	87	: "=m" (__fpcntl) : : "x9", "x10" \
	88	)
	89
	90	#define __x87_load \
	91	__asm__ volatile ( \
	92	"ldp x9, x10, %0\n" \
	93	"msr FPSR, x10\n" \
	94	"msr FPCR, x9\n" \
	95	: "=m" (__fpcntl) : : "x9", "x10" \
	96	)
	97
[deca0f5]	98	#else
[0190480]	99	#error unsupported hardware architecture
[deca0f5]	100	#endif
	101
[e660761]	102	extern $thread * mainThread;
	103	extern processor * mainProcessor;
[2ac095d]	104
[92e7631]	105	//-----------------------------------------------------------------------------
	106	// Kernel Scheduling logic
	107	static $thread * __next_thread(cluster * this);
[1eb239e4]	108	static $thread * __next_thread_slow(cluster * this);
[92e7631]	109	static void __run_thread(processor * this, $thread * dst);
[e873838]	110	static void __wake_one(cluster * cltr);
[1eb239e4]	111
	112	static void push (__cluster_idles & idles, processor & proc);
	113	static void remove(__cluster_idles & idles, processor & proc);
	114	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles );
	115
[c84e80a]	116
[75f3522]	117	//=============================================================================================
	118	// Kernel Scheduling logic
	119	//=============================================================================================
[8fcbb4c]	120	//Main of the processor contexts
[83a071f9]	121	void main(processorCtx_t & runner) {
[21184e3]	122	// Because of a bug, we couldn't initialized the seed on construction
	123	// Do it here
[8fc652e0]	124	__cfaabi_tls.rand_seed ^= rdtscl();
	125	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	126	__tls_rand_advance_bck();
[21184e3]	127
[83a071f9]	128	processor * this = runner.proc;
[094476d]	129	verify(this);
[c81ebf9]	130
[4069faad]	131	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	132	#if !defined(__CFA_NO_STATISTICS__)
	133	if( this->print_halts ) {
	134	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
	135	}
	136	#endif
[b798713]	137
[75f3522]	138	{
[c81ebf9]	139	// Setup preemption data
	140	preemption_scope scope = { this };
	141
[4069faad]	142	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	143
[ac2b598]	144	$thread * readyThread = 0p;
[1eb239e4]	145	MAIN_LOOP:
	146	for() {
[92e7631]	147	// Try to get the next thread
[8c50aed]	148	readyThread = __next_thread( this->cltr );
[75f3522]	149
[1eb239e4]	150	if( !readyThread ) {
	151	readyThread = __next_thread_slow( this->cltr );
	152	}
[4e6fb8e]	153
[1eb239e4]	154	HALT:
	155	if( !readyThread ) {
	156	// Don't block if we are done
	157	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	158
[1eb239e4]	159	#if !defined(__CFA_NO_STATISTICS__)
	160	__tls_stats()->ready.sleep.halts++;
	161	#endif
[398e8e9]	162
[1eb239e4]	163	// Push self to idle stack
	164	push(this->cltr->idles, * this);
[398e8e9]	165
[1eb239e4]	166	// Confirm the ready-queue is empty
	167	readyThread = __next_thread_slow( this->cltr );
	168	if( readyThread ) {
	169	// A thread was found, cancel the halt
	170	remove(this->cltr->idles, * this);
	171
	172	#if !defined(__CFA_NO_STATISTICS__)
	173	__tls_stats()->ready.sleep.cancels++;
	174	#endif
	175
	176	// continue the mai loop
	177	break HALT;
	178	}
	179
	180	#if !defined(__CFA_NO_STATISTICS__)
	181	if(this->print_halts) {
	182	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
	183	}
	184	#endif
	185
	186	wait( this->idle );
	187
	188	#if !defined(__CFA_NO_STATISTICS__)
	189	if(this->print_halts) {
	190	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
	191	}
	192	#endif
	193
	194	// We were woken up, remove self from idle
	195	remove(this->cltr->idles, * this);
	196
	197	// DON'T just proceed, start looking again
	198	continue MAIN_LOOP;
[64a7146]	199	}
[1eb239e4]	200
	201	/* paranoid */ verify( readyThread );
	202
	203	// We found a thread run it
	204	__run_thread(this, readyThread);
	205
	206	// Are we done?
	207	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	208	}
	209
[4069faad]	210	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	211	}
[8118303]	212
[4cedd9f]	213	V( this->terminated );
[bdeba0b]	214
[28d73c1]	215	if(this == mainProcessor) {
[6a490b2]	216	// HACK : the coroutine context switch expects this_thread to be set
	217	// and it make sense for it to be set in all other cases except here
	218	// fake it
[8fc652e0]	219	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	220	}
[7768b8d]	221
[4069faad]	222	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	223	}
	224
[5c1a531]	225	static int * __volatile_errno() __attribute__((noinline));
	226	static int * __volatile_errno() { asm(""); return &errno; }
	227
[14a61b5]	228	// KERNEL ONLY
[1c273d0]	229	// runThread runs a thread by context switching
	230	// from the processor coroutine to the target thread
[ac2b598]	231	static void __run_thread(processor * this, $thread * thrd_dst) {
[8fc652e0]	232	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	233	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	234	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	235	__builtin_prefetch( thrd_dst->context.SP );
	236
[ac2b598]	237	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	238
[9f575ea]	239	// set state of processor coroutine to inactive
	240	verify(proc_cor->state == Active);
[ae7be7a]	241	proc_cor->state = Blocked;
[e8e457e]	242
[9f575ea]	243	// Actually run the thread
[3381ed7]	244	RUNNING: while(true) {
[ff79d5e]	245	thrd_dst->preempted = __NO_PREEMPTION;
	246	thrd_dst->state = Active;
[e8e457e]	247
[58d64a4]	248	// Update global state
[8fc652e0]	249	kernelTLS().this_thread = thrd_dst;
[75f3522]	250
[8fc652e0]	251	/* paranoid */ verify( ! __preemption_enabled() );
	252	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	253	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	254	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	255	/* paranoid */ verify( thrd_dst->state != Halted );
[210b8b3]	256	/* 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
	257	/* 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
[ac12f1f]	258	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	259
[3381ed7]	260
[58d64a4]	261
[9f575ea]	262	// set context switch to the thread that the processor is executing
[c7a900a]	263	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	264	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	265
[ac12f1f]	266	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[210b8b3]	267	/* 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 );
	268	/* 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 );
[b4b63e8]	269	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	270	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	271	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	272	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	273
[58d64a4]	274	// Reset global state
[8fc652e0]	275	kernelTLS().this_thread = 0p;
[3381ed7]	276
	277	// We just finished running a thread, there are a few things that could have happened.
	278	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	279	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	280	// 4 - Preempted
	281	// In case 1, we may have won a race so we can't write to the state again.
	282	// In case 2, we lost the race so we now own the thread.
	283
	284	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	285	// The thread was preempted, reschedule it and reset the flag
[e873838]	286	__schedule_thread( thrd_dst );
[3381ed7]	287	break RUNNING;
	288	}
[75f3522]	289
[3ea8ad1]	290	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	291	// The thread has halted, it should never be scheduled/run again
[5afb49a]	292	// finish the thread
	293	__thread_finish( thrd_dst );
[ff79d5e]	294	break RUNNING;
	295	}
	296
	297	/* paranoid */ verify( thrd_dst->state == Active );
	298	thrd_dst->state = Blocked;
	299
[3381ed7]	300	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	301	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	302	switch(old_ticket) {
[6a77224]	303	case TICKET_RUNNING:
[3381ed7]	304	// This is case 1, the regular case, nothing more is needed
	305	break RUNNING;
[6a77224]	306	case TICKET_UNBLOCK:
[3381ed7]	307	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	308	// In this case, just run it again.
	309	continue RUNNING;
	310	default:
	311	// This makes no sense, something is wrong abort
[ff79d5e]	312	abort();
[3381ed7]	313	}
[9f575ea]	314	}
[e8e457e]	315
[9f575ea]	316	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	317	proc_cor->state = Active;
[1eb239e4]	318
[8fc652e0]	319	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	320	}
	321
[14a61b5]	322	// KERNEL_ONLY
[b0c7419]	323	void returnToKernel() {
[8fc652e0]	324	/* paranoid */ verify( ! __preemption_enabled() );
	325	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	326	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	327
[29cb302]	328	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	329	struct processor * last_proc = kernelTLS().this_processor;
[29cb302]	330	#endif
	331
[9f575ea]	332	// Run the thread on this processor
	333	{
	334	int local_errno = *__volatile_errno();
	335	#if defined( __i386 ) \|\| defined( __x86_64 )
	336	__x87_store;
	337	#endif
[b4b63e8]	338	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	339	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	340	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	341	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	342	#if defined( __i386 ) \|\| defined( __x86_64 )
	343	__x87_load;
	344	#endif
	345	*__volatile_errno() = local_errno;
[8fcbb4c]	346	}
[deca0f5]	347
[29cb302]	348	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	349	if(last_proc != kernelTLS().this_processor) {
[29cb302]	350	__tls_stats()->ready.threads.migration++;
	351	}
	352	#endif
	353
[8fc652e0]	354	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	355	/* 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 );
	356	/* 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 );
[c84e80a]	357	}
	358
[8def349]	359	//-----------------------------------------------------------------------------
	360	// Scheduler routines
[14a61b5]	361	// KERNEL ONLY
[e873838]	362	void __schedule_thread( $thread * thrd ) {
[8fc652e0]	363	/* paranoid */ verify( ! __preemption_enabled() );
[9d6e1b8a]	364	/* paranoid */ verify( kernelTLS().this_proc_id );
[6a490b2]	365	/* paranoid */ verify( thrd );
	366	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	367	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	368	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	369	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	370	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	371	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	372	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	373	/* paranoid */ #endif
[6a490b2]	374	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	375	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	376
[9f575ea]	377
[ae7be7a]	378	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	379
[e873838]	380	ready_schedule_lock();
[32a8b61]	381	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	382	struct cluster * cl = thrd->curr_cluster;
	383
	384	// push the thread to the cluster ready-queue
	385	push( cl, thrd );
	386
	387	// variable thrd is no longer safe to use
	388
	389	// wake the cluster using the save variable.
	390	__wake_one( cl );
[e873838]	391	ready_schedule_unlock();
[1c273d0]	392
[8fc652e0]	393	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	394	}
	395
[14a61b5]	396	// KERNEL ONLY
[1eb239e4]	397	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	398	/* paranoid */ verify( ! __preemption_enabled() );
	399	/* paranoid */ verify( kernelTLS().this_proc_id );
[7768b8d]	400
[e873838]	401	ready_schedule_lock();
[1eb239e4]	402	$thread * thrd = pop( this );
[e873838]	403	ready_schedule_unlock();
[7768b8d]	404
[8fc652e0]	405	/* paranoid */ verify( kernelTLS().this_proc_id );
	406	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	407	return thrd;
[eb2e723]	408	}
	409
[64a7146]	410	// KERNEL ONLY
[1eb239e4]	411	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	412	/* paranoid */ verify( ! __preemption_enabled() );
	413	/* paranoid */ verify( kernelTLS().this_proc_id );
[64a7146]	414
[e873838]	415	ready_schedule_lock();
[1eb239e4]	416	$thread * thrd = pop_slow( this );
[e873838]	417	ready_schedule_unlock();
[64a7146]	418
[8fc652e0]	419	/* paranoid */ verify( kernelTLS().this_proc_id );
	420	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	421	return thrd;
[64a7146]	422	}
	423
[e873838]	424	void unpark( $thread * thrd ) {
	425	if( !thrd ) return;
	426
[ff79d5e]	427	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	428	switch(old_ticket) {
[6a77224]	429	case TICKET_RUNNING:
[3381ed7]	430	// Wake won the race, the thread will reschedule/rerun itself
	431	break;
[6a77224]	432	case TICKET_BLOCKED:
[3381ed7]	433	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	434	/* paranoid */ verify( thrd->state == Blocked );
[0b33412]	435
[8fc652e0]	436	{
	437	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	438	bool full = publicTLS_get(this_proc_id)->full_proc;
	439	if(full) disable_interrupts();
	440
	441	/* paranoid */ verify( ! __preemption_enabled() );
	442
	443	// Wake lost the race,
	444	__schedule_thread( thrd );
	445
	446	/* paranoid */ verify( ! __preemption_enabled() );
	447
	448	if(full) enable_interrupts( __cfaabi_dbg_ctx );
	449	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	450	}
	451
[3381ed7]	452	break;
	453	default:
	454	// This makes no sense, something is wrong abort
[7ee8153]	455	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	456	}
[eb2e723]	457	}
	458
[e235429]	459	void park( void ) {
[8fc652e0]	460	/* paranoid */ verify( __preemption_enabled() );
[82ff5845]	461	disable_interrupts();
[8fc652e0]	462	/* paranoid */ verify( ! __preemption_enabled() );
	463	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
[0b33412]	464
[82c948c]	465	returnToKernel();
[0b33412]	466
[8fc652e0]	467	/* paranoid */ verify( ! __preemption_enabled() );
[36982fc]	468	enable_interrupts( __cfaabi_dbg_ctx );
[8fc652e0]	469	/* paranoid */ verify( __preemption_enabled() );
[0c78741]	470
	471	}
[09800e9]	472
[5afb49a]	473	extern "C" {
	474	// Leave the thread monitor
	475	// last routine called by a thread.
	476	// Should never return
	477	void __cfactx_thrd_leave() {
[8fc652e0]	478	$thread * thrd = active_thread();
[5afb49a]	479	$monitor * this = &thrd->self_mon;
	480
	481	// Lock the monitor now
	482	lock( this->lock __cfaabi_dbg_ctx2 );
	483
	484	disable_interrupts();
	485
[9d6e1b8a]	486	/* paranoid */ verify( ! __preemption_enabled() );
	487	/* paranoid */ verify( thrd->state == Active );
	488	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	489	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	490	/* paranoid */ verify( thrd->context.SP );
	491	/* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) > ((uintptr_t)__get_stack(thrd->curr_cor)->limit), "ERROR : $thread %p has been corrupted.\n StackPointer too large.\n", thrd );
	492	/* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) < ((uintptr_t)__get_stack(thrd->curr_cor)->base ), "ERROR : $thread %p has been corrupted.\n StackPointer too small.\n", thrd );
	493
[3ea8ad1]	494	thrd->state = Halting;
[58688bf]	495	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	496	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	497	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	498
	499	// Leave the thread
	500	returnToKernel();
	501
	502	// Control flow should never reach here!
[9d6e1b8a]	503	abort();
[5afb49a]	504	}
[09800e9]	505	}
	506
[14a61b5]	507	// KERNEL ONLY
[3381ed7]	508	bool force_yield( __Preemption_Reason reason ) {
[8fc652e0]	509	/* paranoid */ verify( __preemption_enabled() );
[09800e9]	510	disable_interrupts();
[8fc652e0]	511	/* paranoid */ verify( ! __preemption_enabled() );
[09800e9]	512
[8fc652e0]	513	$thread * thrd = kernelTLS().this_thread;
[ff79d5e]	514	/* paranoid */ verify(thrd->state == Active);
[3381ed7]	515
	516	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	517	// it was going to park itself. If that is the case and it is already using the
	518	// intrusive fields then we can't use them to preempt the thread
	519	// If that is the case, abandon the preemption.
	520	bool preempted = false;
[504a7dc]	521	if(thrd->link.next == 0p) {
[3381ed7]	522	preempted = true;
	523	thrd->preempted = reason;
	524	returnToKernel();
[de6319f]	525	}
[f2b12406]	526
[8fc652e0]	527	/* paranoid */ verify( ! __preemption_enabled() );
[3381ed7]	528	enable_interrupts_noPoll();
[8fc652e0]	529	/* paranoid */ verify( __preemption_enabled() );
[f2b12406]	530
[3381ed7]	531	return preempted;
[f2b12406]	532	}
	533
[14a61b5]	534	//=============================================================================================
[92e7631]	535	// Kernel Idle Sleep
[14a61b5]	536	//=============================================================================================
[64a7146]	537	// Wake a thread from the front if there are any
[e873838]	538	static void __wake_one(cluster * this) {
[8fc652e0]	539	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	540	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	541
[64a7146]	542	// Check if there is a sleeping processor
[1eb239e4]	543	processor * p;
	544	unsigned idle;
	545	unsigned total;
	546	[idle, total, p] = query(this->idles);
[14a61b5]	547
[64a7146]	548	// If no one is sleeping, we are done
[1eb239e4]	549	if( idle == 0 ) return;
[14a61b5]	550
[64a7146]	551	// We found a processor, wake it up
	552	post( p->idle );
[14a61b5]	553
[1eb239e4]	554	#if !defined(__CFA_NO_STATISTICS__)
	555	__tls_stats()->ready.sleep.wakes++;
	556	#endif
	557
[e873838]	558	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	559	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	560
	561	return;
[64a7146]	562	}
[14a61b5]	563
[64a7146]	564	// Unconditionnaly wake a thread
[1eb239e4]	565	void __wake_proc(processor * this) {
[64a7146]	566	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	567
[64a7146]	568	disable_interrupts();
[8fc652e0]	569	/* paranoid */ verify( ! __preemption_enabled() );
[58d64a4]	570	post( this->idle );
[64a7146]	571	enable_interrupts( __cfaabi_dbg_ctx );
[92e7631]	572	}
	573
[1eb239e4]	574	static void push (__cluster_idles & this, processor & proc) {
[8fc652e0]	575	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	576	lock( this );
	577	this.idle++;
	578	/* paranoid */ verify( this.idle <= this.total );
[8e16177]	579
[1eb239e4]	580	insert_first(this.list, proc);
	581	unlock( this );
[8fc652e0]	582	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	583	}
[8e16177]	584
[1eb239e4]	585	static void remove(__cluster_idles & this, processor & proc) {
[8fc652e0]	586	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	587	lock( this );
	588	this.idle--;
	589	/* paranoid */ verify( this.idle >= 0 );
[c34ebf2]	590
[1eb239e4]	591	remove(proc);
	592	unlock( this );
[8fc652e0]	593	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	594	}
[c34ebf2]	595
[1eb239e4]	596	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
	597	for() {
	598	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	599	if( 1 == (l % 2) ) { Pause(); continue; }
	600	unsigned idle = this.idle;
	601	unsigned total = this.total;
	602	processor * proc = &this.list`first;
[7fdae38]	603	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	604	asm volatile("": : :"memory");
[1eb239e4]	605	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	606	return [idle, total, proc];
	607	}
[6b4cdd3]	608	}
	609
[dbe9b08]	610	//=============================================================================================
	611	// Unexpected Terminating logic
	612	//=============================================================================================
[ea7d2b0]	613	static __spinlock_t kernel_abort_lock;
[9d944b2]	614	static bool kernel_abort_called = false;
	615
[afd550c]	616	void * kernel_abort(void) __attribute__ ((__nothrow__)) {
[9d944b2]	617	// abort cannot be recursively entered by the same or different processors because all signal handlers return when
	618	// the globalAbort flag is true.
[36982fc]	619	lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
[9d944b2]	620
[6011658]	621	// disable interrupts, it no longer makes sense to try to interrupt this processor
	622	disable_interrupts();
	623
[9d944b2]	624	// first task to abort ?
[de94a60]	625	if ( kernel_abort_called ) { // not first task to abort ?
[ea7d2b0]	626	unlock( kernel_abort_lock );
[1c273d0]	627
[9d944b2]	628	sigset_t mask;
	629	sigemptyset( &mask );
[de94a60]	630	sigaddset( &mask, SIGALRM ); // block SIGALRM signals
[8a13c47]	631	sigaddset( &mask, SIGUSR1 ); // block SIGALRM signals
	632	sigsuspend( &mask ); // block the processor to prevent further damage during abort
	633	_exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
[de94a60]	634	}
	635	else {
	636	kernel_abort_called = true;
	637	unlock( kernel_abort_lock );
[9d944b2]	638	}
	639
[8fc652e0]	640	return __cfaabi_tls.this_thread;
[9d944b2]	641	}
	642
	643	void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
[b81fd95]	644	$thread * thrd = ( $thread * ) kernel_data;
[9d944b2]	645
[de94a60]	646	if(thrd) {
	647	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	648	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	649
[212c2187]	650	if ( &thrd->self_cor != thrd->curr_cor ) {
	651	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	652	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	653	}
	654	else {
[1c40091]	655	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	656	}
[1c273d0]	657	}
[9d944b2]	658	else {
[de94a60]	659	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	660	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	661	}
	662	}
	663
[2b8bc41]	664	int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
[8fc652e0]	665	return get_coroutine(kernelTLS().this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	666	}
	667
[de94a60]	668	static __spinlock_t kernel_debug_lock;
	669
[9d944b2]	670	extern "C" {
[1c40091]	671	void __cfaabi_bits_acquire() {
[36982fc]	672	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	673	}
	674
[1c40091]	675	void __cfaabi_bits_release() {
[ea7d2b0]	676	unlock( kernel_debug_lock );
[9d944b2]	677	}
[8118303]	678	}
	679
[fa21ac9]	680	//=============================================================================================
	681	// Kernel Utilities
	682	//=============================================================================================
[bd98b58]	683	//-----------------------------------------------------------------------------
	684	// Locks
[242a902]	685	void ?{}( semaphore & this, int count = 1 ) {
	686	(this.lock){};
	687	this.count = count;
	688	(this.waiting){};
[db6f06a]	689	}
[242a902]	690	void ^?{}(semaphore & this) {}
[db6f06a]	691
[71c8b7e]	692	bool P(semaphore & this) with( this ){
[65deb18]	693	lock( lock __cfaabi_dbg_ctx2 );
	694	count -= 1;
	695	if ( count < 0 ) {
[bdeba0b]	696	// queue current task
[8fc652e0]	697	append( waiting, active_thread() );
[bdeba0b]	698
	699	// atomically release spin lock and block
[3381ed7]	700	unlock( lock );
[e235429]	701	park();
[71c8b7e]	702	return true;
[8def349]	703	}
[4e6fb8e]	704	else {
[65deb18]	705	unlock( lock );
[71c8b7e]	706	return false;
[4e6fb8e]	707	}
[bd98b58]	708	}
	709
[f0ce5f4]	710	bool V(semaphore & this) with( this ) {
[ac2b598]	711	$thread * thrd = 0p;
[65deb18]	712	lock( lock __cfaabi_dbg_ctx2 );
	713	count += 1;
	714	if ( count <= 0 ) {
[bdeba0b]	715	// remove task at head of waiting list
[65deb18]	716	thrd = pop_head( waiting );
[bd98b58]	717	}
[bdeba0b]	718
[65deb18]	719	unlock( lock );
[bdeba0b]	720
	721	// make new owner
[e235429]	722	unpark( thrd );
[f0ce5f4]	723
[d384787]	724	return thrd != 0p;
	725	}
	726
	727	bool V(semaphore & this, unsigned diff) with( this ) {
	728	$thread * thrd = 0p;
	729	lock( lock __cfaabi_dbg_ctx2 );
	730	int release = max(-count, (int)diff);
	731	count += diff;
	732	for(release) {
[e235429]	733	unpark( pop_head( waiting ) );
[d384787]	734	}
	735
	736	unlock( lock );
	737
[f0ce5f4]	738	return thrd != 0p;
[bd98b58]	739	}
	740
[de94a60]	741	//-----------------------------------------------------------------------------
	742	// Debug
	743	__cfaabi_dbg_debug_do(
[1997b4e]	744	extern "C" {
[ae66348]	745	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	746	this.prev_name = prev_name;
[8fc652e0]	747	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	748	}
[9181f1d]	749	}
[f7d6bb0]	750	)
[2026bb6]	751
	752	//-----------------------------------------------------------------------------
	753	// Debug
[8c50aed]	754	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	755	return true;
	756	}
[c34ebf2]	757
	758	//-----------------------------------------------------------------------------
	759	// Statistics
	760	#if !defined(__CFA_NO_STATISTICS__)
	761	void print_halts( processor & this ) {
	762	this.print_halts = true;
	763	}
[58688bf]	764
	765	void print_stats_now( cluster & this, int flags ) {
[1b033b8]	766	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	767	}
	768
	769	extern int __print_alarm_stats;
	770	void print_alarm_stats() {
	771	__print_alarm_stats = -1;
[58688bf]	772	}
[c34ebf2]	773	#endif
[8118303]	774	// Local Variables: //
	775	// mode: c //
	776	// tab-width: 4 //
	777	// End: //

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