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kernel.cfa@ 3e1a705

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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 3e1a705 was 8464edf, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
'print_stats_now' now pulls stats from processors.
Property mode set to `100644`
File size: 29.7 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>
[dddb3dd0]	24	extern "C" {
	25	#include <sys/eventfd.h>
	26	}
[8118303]	27
	28	//CFA Includes
[73abe95]	29	#include "kernel_private.hfa"
	30	#include "preemption.hfa"
[8118303]	31
	32	//Private includes
	33	#define __CFA_INVOKE_PRIVATE__
	34	#include "invoke.h"
	35
[89eff25]	36	#if !defined(__CFA_NO_STATISTICS__)
	37	#define __STATS( ...) __VA_ARGS__
	38	#else
	39	#define __STATS( ...)
	40	#endif
[4069faad]	41
[deca0f5]	42	//-----------------------------------------------------------------------------
	43	// Some assembly required
[1805b1b]	44	#if defined( __i386 )
[deca0f5]	45	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	46	// fcw : X87 FPU control word (preserved across function calls)
	47	#define __x87_store \
	48	uint32_t __mxcr; \
	49	uint16_t __fcw; \
	50	__asm__ volatile ( \
	51	"stmxcsr %0\n" \
	52	"fnstcw %1\n" \
	53	: "=m" (__mxcr),\
	54	"=m" (__fcw) \
	55	)
	56
	57	#define __x87_load \
	58	__asm__ volatile ( \
	59	"fldcw %1\n" \
	60	"ldmxcsr %0\n" \
	61	::"m" (__mxcr),\
	62	"m" (__fcw) \
	63	)
	64
	65	#elif defined( __x86_64 )
	66	#define __x87_store \
	67	uint32_t __mxcr; \
	68	uint16_t __fcw; \
	69	__asm__ volatile ( \
	70	"stmxcsr %0\n" \
	71	"fnstcw %1\n" \
	72	: "=m" (__mxcr),\
	73	"=m" (__fcw) \
	74	)
	75
	76	#define __x87_load \
	77	__asm__ volatile ( \
	78	"fldcw %1\n" \
	79	"ldmxcsr %0\n" \
	80	:: "m" (__mxcr),\
	81	"m" (__fcw) \
	82	)
	83
[0190480]	84	#elif defined( __arm__ )
	85	#define __x87_store
	86	#define __x87_load
	87
	88	#elif defined( __aarch64__ )
[74f5c83]	89	#define __x87_store \
	90	uint32_t __fpcntl[2]; \
	91	__asm__ volatile ( \
	92	"mrs x9, FPCR\n" \
	93	"mrs x10, FPSR\n" \
	94	"stp x9, x10, %0\n" \
	95	: "=m" (__fpcntl) : : "x9", "x10" \
	96	)
	97
	98	#define __x87_load \
	99	__asm__ volatile ( \
	100	"ldp x9, x10, %0\n" \
	101	"msr FPSR, x10\n" \
	102	"msr FPCR, x9\n" \
	103	: "=m" (__fpcntl) : : "x9", "x10" \
	104	)
	105
[deca0f5]	106	#else
[0190480]	107	#error unsupported hardware architecture
[deca0f5]	108	#endif
	109
[e660761]	110	extern $thread * mainThread;
	111	extern processor * mainProcessor;
[2ac095d]	112
[92e7631]	113	//-----------------------------------------------------------------------------
	114	// Kernel Scheduling logic
	115	static $thread * __next_thread(cluster * this);
[1eb239e4]	116	static $thread * __next_thread_slow(cluster * this);
[c6c7e6c]	117	static inline bool __must_unpark( $thread * thrd ) __attribute((nonnull(1)));
[92e7631]	118	static void __run_thread(processor * this, $thread * dst);
[e873838]	119	static void __wake_one(cluster * cltr);
[1eb239e4]	120
[6a9b12b]	121	static void mark_idle (__cluster_proc_list & idles, processor & proc);
	122	static void mark_awake(__cluster_proc_list & idles, processor & proc);
	123	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list idles );
[1eb239e4]	124
[dddb3dd0]	125	extern void __cfa_io_start( processor * );
[c1c95b1]	126	extern bool __cfa_io_drain( processor * );
[dddb3dd0]	127	extern void __cfa_io_flush( processor * );
	128	extern void __cfa_io_stop ( processor * );
[c1c95b1]	129	static inline bool __maybe_io_drain( processor * );
[dddb3dd0]	130
	131	extern void __disable_interrupts_hard();
	132	extern void __enable_interrupts_hard();
[c84e80a]	133
[a3821fa]	134	static inline void __disable_interrupts_checked() {
	135	/* paranoid */ verify( __preemption_enabled() );
	136	disable_interrupts();
	137	/* paranoid */ verify( ! __preemption_enabled() );
	138	}
	139
	140	static inline void __enable_interrupts_checked( bool poll = true ) {
	141	/* paranoid */ verify( ! __preemption_enabled() );
	142	enable_interrupts( poll );
	143	/* paranoid */ verify( __preemption_enabled() );
	144	}
	145
[75f3522]	146	//=============================================================================================
	147	// Kernel Scheduling logic
	148	//=============================================================================================
[8fcbb4c]	149	//Main of the processor contexts
[83a071f9]	150	void main(processorCtx_t & runner) {
[21184e3]	151	// Because of a bug, we couldn't initialized the seed on construction
	152	// Do it here
[8fc652e0]	153	__cfaabi_tls.rand_seed ^= rdtscl();
	154	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	155	__tls_rand_advance_bck();
[21184e3]	156
[83a071f9]	157	processor * this = runner.proc;
[094476d]	158	verify(this);
[c81ebf9]	159
[dddb3dd0]	160	__cfa_io_start( this );
	161
[4069faad]	162	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	163	#if !defined(__CFA_NO_STATISTICS__)
	164	if( this->print_halts ) {
[c993b15]	165	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->unique_id, this->name, (void*)this);
[28d73c1]	166	}
	167	#endif
[b798713]	168
[75f3522]	169	{
[c81ebf9]	170	// Setup preemption data
	171	preemption_scope scope = { this };
	172
[a5e7233]	173	// if we need to run some special setup, now is the time to do it.
	174	if(this->init.thrd) {
	175	this->init.thrd->curr_cluster = this->cltr;
	176	__run_thread(this, this->init.thrd);
	177	}
[325e6ea]	178
[4069faad]	179	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	180
[ac2b598]	181	$thread * readyThread = 0p;
[1eb239e4]	182	MAIN_LOOP:
	183	for() {
[34b2796]	184	#if 1
[dddb3dd0]	185	// Check if there is pending io
	186	__maybe_io_drain( this );
	187
[92e7631]	188	// Try to get the next thread
[8c50aed]	189	readyThread = __next_thread( this->cltr );
[75f3522]	190
[1eb239e4]	191	if( !readyThread ) {
[dddb3dd0]	192	__cfa_io_flush( this );
[1eb239e4]	193	readyThread = __next_thread_slow( this->cltr );
	194	}
[4e6fb8e]	195
[1eb239e4]	196	HALT:
	197	if( !readyThread ) {
	198	// Don't block if we are done
	199	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	200
[1eb239e4]	201	#if !defined(__CFA_NO_STATISTICS__)
	202	__tls_stats()->ready.sleep.halts++;
	203	#endif
[398e8e9]	204
[1eb239e4]	205	// Push self to idle stack
[6a9b12b]	206	mark_idle(this->cltr->procs, * this);
[398e8e9]	207
[1eb239e4]	208	// Confirm the ready-queue is empty
	209	readyThread = __next_thread_slow( this->cltr );
	210	if( readyThread ) {
	211	// A thread was found, cancel the halt
[6a9b12b]	212	mark_awake(this->cltr->procs, * this);
[1eb239e4]	213
	214	#if !defined(__CFA_NO_STATISTICS__)
	215	__tls_stats()->ready.sleep.cancels++;
	216	#endif
	217
	218	// continue the mai loop
	219	break HALT;
	220	}
	221
	222	#if !defined(__CFA_NO_STATISTICS__)
	223	if(this->print_halts) {
[c993b15]	224	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
[1eb239e4]	225	}
	226	#endif
	227
[dddb3dd0]	228	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	229
	230	__disable_interrupts_hard();
	231	eventfd_t val;
	232	eventfd_read( this->idle, &val );
	233	__enable_interrupts_hard();
[1eb239e4]	234
	235	#if !defined(__CFA_NO_STATISTICS__)
	236	if(this->print_halts) {
[c993b15]	237	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
[1eb239e4]	238	}
	239	#endif
	240
	241	// We were woken up, remove self from idle
[6a9b12b]	242	mark_awake(this->cltr->procs, * this);
[1eb239e4]	243
	244	// DON'T just proceed, start looking again
	245	continue MAIN_LOOP;
[64a7146]	246	}
[1eb239e4]	247
	248	/* paranoid */ verify( readyThread );
	249
[dddb3dd0]	250	// Reset io dirty bit
	251	this->io.dirty = false;
	252
[1eb239e4]	253	// We found a thread run it
	254	__run_thread(this, readyThread);
	255
	256	// Are we done?
	257	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	258
[dddb3dd0]	259	if(this->io.pending && !this->io.dirty) {
	260	__cfa_io_flush( this );
	261	}
[89eff25]	262
[34b2796]	263	#else
	264
	265	SEARCH: {
	266	/* paranoid */ verify( ! __preemption_enabled() );
	267	/* paranoid */ verify( kernelTLS().this_proc_id );
	268
	269	// First, lock the scheduler since we are searching for a thread
	270	ready_schedule_lock();
	271
	272	// Try to get the next thread
	273	readyThread = pop_fast( this->cltr );
	274	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	275
	276	// If we can't find a thread, might as well flush any outstanding I/O
	277	if(this->io.pending) { __cfa_io_flush( this ); }
	278
	279	// Spin a little on I/O, just in case
	280	for(25) {
	281	__maybe_io_drain( this );
	282	readyThread = pop_fast( this->cltr );
	283	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	284	}
	285
	286	// no luck, try stealing a few times
	287	for(25) {
	288	if( __maybe_io_drain( this ) ) {
	289	readyThread = pop_fast( this->cltr );
	290	} else {
	291	readyThread = pop_slow( this->cltr );
	292	}
	293	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	294	}
	295
	296	// still no luck, search for a thread
	297	readyThread = pop_search( this->cltr );
	298	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	299
	300	// Don't block if we are done
	301	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	302
	303	__STATS( __tls_stats()->ready.sleep.halts++; )
	304
	305	// Push self to idle stack
	306	ready_schedule_unlock();
	307	mark_idle(this->cltr->procs, * this);
	308	ready_schedule_lock();
	309
	310	// Confirm the ready-queue is empty
	311	__maybe_io_drain( this );
	312	readyThread = pop_search( this->cltr );
	313	ready_schedule_unlock();
	314
	315	if( readyThread ) {
	316	// A thread was found, cancel the halt
	317	mark_awake(this->cltr->procs, * this);
	318
	319	__STATS( __tls_stats()->ready.sleep.cancels++; )
	320
	321	// continue the main loop
	322	break SEARCH;
	323	}
	324
	325	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl()); )
	326	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	327
	328	// __disable_interrupts_hard();
	329	eventfd_t val;
	330	eventfd_read( this->idle, &val );
	331	// __enable_interrupts_hard();
	332
	333	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl()); )
	334
	335	// We were woken up, remove self from idle
	336	mark_awake(this->cltr->procs, * this);
	337
	338	// DON'T just proceed, start looking again
	339	continue MAIN_LOOP;
	340	}
	341
	342	RUN_THREAD:
	343	/* paranoid */ verify( kernelTLS().this_proc_id );
	344	/* paranoid */ verify( ! __preemption_enabled() );
	345	/* paranoid */ verify( readyThread );
	346
	347	// Reset io dirty bit
	348	this->io.dirty = false;
	349
	350	// We found a thread run it
	351	__run_thread(this, readyThread);
	352
	353	// Are we done?
	354	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	355
	356	#if !defined(__CFA_NO_STATISTICS__)
	357	unsigned long long curr = rdtscl();
	358	if(curr > (last_tally + 500000000)) {
	359	__tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
	360	last_tally = curr;
	361	}
	362	#endif
	363
	364	if(this->io.pending && !this->io.dirty) {
	365	__cfa_io_flush( this );
	366	}
	367
	368	ready_schedule_lock();
	369	__maybe_io_drain( this );
	370	ready_schedule_unlock();
	371	#endif
[c81ebf9]	372	}
	373
[4069faad]	374	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	375	}
[8118303]	376
[dddb3dd0]	377	__cfa_io_stop( this );
	378
[454f478]	379	post( this->terminated );
[bdeba0b]	380
[28d73c1]	381	if(this == mainProcessor) {
[6a490b2]	382	// HACK : the coroutine context switch expects this_thread to be set
	383	// and it make sense for it to be set in all other cases except here
	384	// fake it
[8fc652e0]	385	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	386	}
[7768b8d]	387
[4069faad]	388	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	389	}
	390
[5c1a531]	391	static int * __volatile_errno() __attribute__((noinline));
	392	static int * __volatile_errno() { asm(""); return &errno; }
	393
[14a61b5]	394	// KERNEL ONLY
[1c273d0]	395	// runThread runs a thread by context switching
	396	// from the processor coroutine to the target thread
[ac2b598]	397	static void __run_thread(processor * this, $thread * thrd_dst) {
[8fc652e0]	398	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	399	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	400	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	401	__builtin_prefetch( thrd_dst->context.SP );
	402
[dddb3dd0]	403	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	404
[ac2b598]	405	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	406
[9f575ea]	407	// set state of processor coroutine to inactive
	408	verify(proc_cor->state == Active);
[ae7be7a]	409	proc_cor->state = Blocked;
[e8e457e]	410
[9f575ea]	411	// Actually run the thread
[3381ed7]	412	RUNNING: while(true) {
[ff79d5e]	413	thrd_dst->preempted = __NO_PREEMPTION;
	414	thrd_dst->state = Active;
[e8e457e]	415
[58d64a4]	416	// Update global state
[8fc652e0]	417	kernelTLS().this_thread = thrd_dst;
[75f3522]	418
[8fc652e0]	419	/* paranoid */ verify( ! __preemption_enabled() );
	420	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	421	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	422	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	423	/* paranoid */ verify( thrd_dst->state != Halted );
[210b8b3]	424	/* 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
	425	/* 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]	426	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	427
[3381ed7]	428
[58d64a4]	429
[9f575ea]	430	// set context switch to the thread that the processor is executing
[c7a900a]	431	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	432	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	433
[ac12f1f]	434	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[210b8b3]	435	/* 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 );
	436	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
[b4b63e8]	437	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	438	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	439	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	440	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	441
[58d64a4]	442	// Reset global state
[8fc652e0]	443	kernelTLS().this_thread = 0p;
[3381ed7]	444
	445	// We just finished running a thread, there are a few things that could have happened.
	446	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	447	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	448	// 4 - Preempted
	449	// In case 1, we may have won a race so we can't write to the state again.
	450	// In case 2, we lost the race so we now own the thread.
	451
	452	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	453	// The thread was preempted, reschedule it and reset the flag
[254ad1b]	454	schedule_thread$( thrd_dst );
[3381ed7]	455	break RUNNING;
	456	}
[75f3522]	457
[3ea8ad1]	458	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	459	// The thread has halted, it should never be scheduled/run again
[5afb49a]	460	// finish the thread
	461	__thread_finish( thrd_dst );
[ff79d5e]	462	break RUNNING;
	463	}
	464
	465	/* paranoid */ verify( thrd_dst->state == Active );
	466	thrd_dst->state = Blocked;
	467
[3381ed7]	468	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	469	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	470	switch(old_ticket) {
[6a77224]	471	case TICKET_RUNNING:
[3381ed7]	472	// This is case 1, the regular case, nothing more is needed
	473	break RUNNING;
[6a77224]	474	case TICKET_UNBLOCK:
[ec43cf9]	475	#if !defined(__CFA_NO_STATISTICS__)
	476	__tls_stats()->ready.threads.threads++;
[73f4d08]	477	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	478	#endif
[3381ed7]	479	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	480	// In this case, just run it again.
	481	continue RUNNING;
	482	default:
	483	// This makes no sense, something is wrong abort
[ff79d5e]	484	abort();
[3381ed7]	485	}
[9f575ea]	486	}
[e8e457e]	487
[9f575ea]	488	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	489	proc_cor->state = Active;
[1eb239e4]	490
[dddb3dd0]	491	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	492
[ec43cf9]	493	#if !defined(__CFA_NO_STATISTICS__)
	494	__tls_stats()->ready.threads.threads--;
[73f4d08]	495	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	496	#endif
	497
[8fc652e0]	498	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	499	}
	500
[14a61b5]	501	// KERNEL_ONLY
[b0c7419]	502	void returnToKernel() {
[8fc652e0]	503	/* paranoid */ verify( ! __preemption_enabled() );
	504	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	505	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	506
[89eff25]	507	__STATS( thrd_src->last_proc = kernelTLS().this_processor; )
[29cb302]	508
[9f575ea]	509	// Run the thread on this processor
	510	{
	511	int local_errno = *__volatile_errno();
	512	#if defined( __i386 ) \|\| defined( __x86_64 )
	513	__x87_store;
	514	#endif
[b4b63e8]	515	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	516	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	517	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	518	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	519	#if defined( __i386 ) \|\| defined( __x86_64 )
	520	__x87_load;
	521	#endif
	522	*__volatile_errno() = local_errno;
[8fcbb4c]	523	}
[deca0f5]	524
[29cb302]	525	#if !defined(__CFA_NO_STATISTICS__)
[89eff25]	526	/* paranoid */ verify( thrd_src->last_proc != 0p );
	527	if(thrd_src->last_proc != kernelTLS().this_processor) {
[29cb302]	528	__tls_stats()->ready.threads.migration++;
	529	}
	530	#endif
	531
[8fc652e0]	532	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	533	/* 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 );
	534	/* 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]	535	}
	536
[8def349]	537	//-----------------------------------------------------------------------------
	538	// Scheduler routines
[14a61b5]	539	// KERNEL ONLY
[e9c0b4c]	540	static void __schedule_thread( $thread * thrd ) {
[8fc652e0]	541	/* paranoid */ verify( ! __preemption_enabled() );
[254ad1b]	542	/* paranoid */ verify( ready_schedule_islocked());
[6a490b2]	543	/* paranoid */ verify( thrd );
	544	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	545	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	546	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	547	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	548	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	549	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	550	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	551	/* paranoid */ #endif
[6a490b2]	552	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	553	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	554
[9f575ea]	555
[ae7be7a]	556	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	557
[ec43cf9]	558	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	559	struct cluster * cl = thrd->curr_cluster;
[89eff25]	560	__STATS(bool outside = thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	561
[254ad1b]	562	// push the thread to the cluster ready-queue
	563	push( cl, thrd );
[32a8b61]	564
[254ad1b]	565	// variable thrd is no longer safe to use
[734908c]	566	thrd = 0xdeaddeaddeaddeadp;
[32a8b61]	567
[254ad1b]	568	// wake the cluster using the save variable.
	569	__wake_one( cl );
[1c273d0]	570
[ec43cf9]	571	#if !defined(__CFA_NO_STATISTICS__)
	572	if( kernelTLS().this_stats ) {
	573	__tls_stats()->ready.threads.threads++;
[89eff25]	574	if(outside) {
	575	__tls_stats()->ready.threads.extunpark++;
	576	}
[73f4d08]	577	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", kernelTLS().this_processor );
[ec43cf9]	578	}
	579	else {
	580	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	581	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[73f4d08]	582	__push_stat( cl->stats, cl->stats->ready.threads.threads, true, "Cluster", cl );
[ec43cf9]	583	}
	584	#endif
	585
[254ad1b]	586	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	587	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	588	}
	589
[254ad1b]	590	void schedule_thread$( $thread * thrd ) {
	591	ready_schedule_lock();
	592	__schedule_thread( thrd );
	593	ready_schedule_unlock();
	594	}
	595
[14a61b5]	596	// KERNEL ONLY
[1eb239e4]	597	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	598	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	599
[e873838]	600	ready_schedule_lock();
[431cd4f]	601	$thread * thrd = pop_fast( this );
[e873838]	602	ready_schedule_unlock();
[7768b8d]	603
[8fc652e0]	604	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	605	return thrd;
[eb2e723]	606	}
	607
[64a7146]	608	// KERNEL ONLY
[1eb239e4]	609	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	610	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	611
[e873838]	612	ready_schedule_lock();
[fc59df78]	613	$thread * thrd;
	614	for(25) {
	615	thrd = pop_slow( this );
	616	if(thrd) goto RET;
	617	}
	618	thrd = pop_search( this );
	619
	620	RET:
[e873838]	621	ready_schedule_unlock();
[64a7146]	622
[8fc652e0]	623	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	624	return thrd;
[64a7146]	625	}
	626
[c6c7e6c]	627	static inline bool __must_unpark( $thread * thrd ) {
[ff79d5e]	628	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	629	switch(old_ticket) {
[6a77224]	630	case TICKET_RUNNING:
[3381ed7]	631	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	632	return false;
[6a77224]	633	case TICKET_BLOCKED:
[3381ed7]	634	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	635	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	636	return true;
[3381ed7]	637	default:
	638	// This makes no sense, something is wrong abort
[7ee8153]	639	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	640	}
[eb2e723]	641	}
	642
[e9c0b4c]	643	void __kernel_unpark( $thread * thrd ) {
	644	/* paranoid */ verify( ! __preemption_enabled() );
	645	/* paranoid */ verify( ready_schedule_islocked());
	646
	647	if( !thrd ) return;
	648
	649	if(__must_unpark(thrd)) {
	650	// Wake lost the race,
	651	__schedule_thread( thrd );
	652	}
	653
	654	/* paranoid */ verify( ready_schedule_islocked());
	655	/* paranoid */ verify( ! __preemption_enabled() );
	656	}
	657
[c6c7e6c]	658	void unpark( $thread * thrd ) {
	659	if( !thrd ) return;
[0b33412]	660
[c6c7e6c]	661	if(__must_unpark(thrd)) {
	662	disable_interrupts();
[a3821fa]	663	// Wake lost the race,
[254ad1b]	664	schedule_thread$( thrd );
[a3821fa]	665	enable_interrupts(false);
[de6319f]	666	}
[eb2e723]	667	}
[0b33412]	668
[e235429]	669	void park( void ) {
[a3821fa]	670	__disable_interrupts_checked();
	671	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	672	returnToKernel();
	673	__enable_interrupts_checked();
[0c78741]	674
	675	}
[09800e9]	676
[5afb49a]	677	extern "C" {
	678	// Leave the thread monitor
	679	// last routine called by a thread.
	680	// Should never return
	681	void __cfactx_thrd_leave() {
[8fc652e0]	682	$thread * thrd = active_thread();
[5afb49a]	683	$monitor * this = &thrd->self_mon;
	684
	685	// Lock the monitor now
	686	lock( this->lock __cfaabi_dbg_ctx2 );
	687
	688	disable_interrupts();
	689
[9d6e1b8a]	690	/* paranoid */ verify( ! __preemption_enabled() );
	691	/* paranoid */ verify( thrd->state == Active );
	692	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	693	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	694	/* paranoid */ verify( thrd->context.SP );
	695	/* 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 );
	696	/* 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 );
	697
[3ea8ad1]	698	thrd->state = Halting;
[58688bf]	699	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	700	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	701	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	702
	703	// Leave the thread
	704	returnToKernel();
	705
	706	// Control flow should never reach here!
[9d6e1b8a]	707	abort();
[5afb49a]	708	}
[09800e9]	709	}
	710
[14a61b5]	711	// KERNEL ONLY
[3381ed7]	712	bool force_yield( __Preemption_Reason reason ) {
[a3821fa]	713	__disable_interrupts_checked();
	714	$thread * thrd = kernelTLS().this_thread;
	715	/* paranoid */ verify(thrd->state == Active);
	716
	717	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	718	// it was going to park itself. If that is the case and it is already using the
	719	// intrusive fields then we can't use them to preempt the thread
	720	// If that is the case, abandon the preemption.
	721	bool preempted = false;
	722	if(thrd->link.next == 0p) {
	723	preempted = true;
	724	thrd->preempted = reason;
	725	returnToKernel();
	726	}
	727	__enable_interrupts_checked( false );
[3381ed7]	728	return preempted;
[f2b12406]	729	}
	730
[14a61b5]	731	//=============================================================================================
[92e7631]	732	// Kernel Idle Sleep
[14a61b5]	733	//=============================================================================================
[64a7146]	734	// Wake a thread from the front if there are any
[e873838]	735	static void __wake_one(cluster * this) {
[8fc652e0]	736	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	737	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	738
[64a7146]	739	// Check if there is a sleeping processor
[1eb239e4]	740	processor * p;
	741	unsigned idle;
	742	unsigned total;
[6a9b12b]	743	[idle, total, p] = query_idles(this->procs);
[14a61b5]	744
[64a7146]	745	// If no one is sleeping, we are done
[1eb239e4]	746	if( idle == 0 ) return;
[14a61b5]	747
[64a7146]	748	// We found a processor, wake it up
[dddb3dd0]	749	eventfd_t val;
	750	val = 1;
	751	eventfd_write( p->idle, val );
[14a61b5]	752
[1eb239e4]	753	#if !defined(__CFA_NO_STATISTICS__)
[5cb51502]	754	if( kernelTLS().this_stats ) {
	755	__tls_stats()->ready.sleep.wakes++;
	756	}
	757	else {
	758	__atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
	759	}
[1eb239e4]	760	#endif
	761
[e873838]	762	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	763	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	764
	765	return;
[64a7146]	766	}
[14a61b5]	767
[64a7146]	768	// Unconditionnaly wake a thread
[1eb239e4]	769	void __wake_proc(processor * this) {
[64a7146]	770	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	771
[a3821fa]	772	__disable_interrupts_checked();
[8fc652e0]	773	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	774	eventfd_t val;
	775	val = 1;
[55d6affb]	776	eventfd_write( this->idle, val );
[a3821fa]	777	__enable_interrupts_checked();
[92e7631]	778	}
	779
[6a9b12b]	780	static void mark_idle(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	781	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	782	lock( this );
	783	this.idle++;
	784	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	785	remove(proc);
[6a9b12b]	786	insert_first(this.idles, proc);
[1eb239e4]	787	unlock( this );
[8fc652e0]	788	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	789	}
[8e16177]	790
[6a9b12b]	791	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	792	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	793	lock( this );
	794	this.idle--;
	795	/* paranoid */ verify( this.idle >= 0 );
	796	remove(proc);
[fc59b580]	797	insert_last(this.actives, proc);
[1eb239e4]	798	unlock( this );
[8fc652e0]	799	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	800	}
[c34ebf2]	801
[6a9b12b]	802	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list this ) {
	803	/* paranoid */ verify( ! __preemption_enabled() );
	804	/* paranoid */ verify( ready_schedule_islocked() );
	805
[1eb239e4]	806	for() {
	807	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	808	if( 1 == (l % 2) ) { Pause(); continue; }
	809	unsigned idle = this.idle;
	810	unsigned total = this.total;
[6a9b12b]	811	processor * proc = &this.idles`first;
[7fdae38]	812	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	813	asm volatile("": : :"memory");
[1eb239e4]	814	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	815	return [idle, total, proc];
	816	}
[6a9b12b]	817
	818	/* paranoid */ verify( ready_schedule_islocked() );
	819	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	820	}
	821
[dbe9b08]	822	//=============================================================================================
	823	// Unexpected Terminating logic
	824	//=============================================================================================
[92bfda0]	825	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
	826	$thread * thrd = __cfaabi_tls.this_thread;
[9d944b2]	827
[de94a60]	828	if(thrd) {
	829	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	830	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	831
[212c2187]	832	if ( &thrd->self_cor != thrd->curr_cor ) {
	833	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	834	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	835	}
	836	else {
[1c40091]	837	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	838	}
[1c273d0]	839	}
[9d944b2]	840	else {
[de94a60]	841	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	842	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	843	}
	844	}
	845
[92bfda0]	846	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	847	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	848	}
	849
[de94a60]	850	static __spinlock_t kernel_debug_lock;
	851
[9d944b2]	852	extern "C" {
[1c40091]	853	void __cfaabi_bits_acquire() {
[36982fc]	854	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	855	}
	856
[1c40091]	857	void __cfaabi_bits_release() {
[ea7d2b0]	858	unlock( kernel_debug_lock );
[9d944b2]	859	}
[8118303]	860	}
	861
[fa21ac9]	862	//=============================================================================================
	863	// Kernel Utilities
	864	//=============================================================================================
[dddb3dd0]	865	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	866	#include "io/types.hfa"
	867	#endif
	868
[c1c95b1]	869	static inline bool __maybe_io_drain( processor * proc ) {
[e9c0b4c]	870	bool ret = false;
[dddb3dd0]	871	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	872	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	873
	874	// Check if we should drain the queue
	875	$io_context * ctx = proc->io.ctx;
	876	unsigned head = *ctx->cq.head;
	877	unsigned tail = *ctx->cq.tail;
[c1c95b1]	878	if(head == tail) return false;
[b7fd2db6]	879	ready_schedule_lock();
[e9c0b4c]	880	ret = __cfa_io_drain( proc );
[b7fd2db6]	881	ready_schedule_unlock();
[dddb3dd0]	882	#endif
[e9c0b4c]	883	return ret;
[dddb3dd0]	884	}
	885
[de94a60]	886	//-----------------------------------------------------------------------------
	887	// Debug
	888	__cfaabi_dbg_debug_do(
[1997b4e]	889	extern "C" {
[ae66348]	890	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	891	this.prev_name = prev_name;
[8fc652e0]	892	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	893	}
[9181f1d]	894	}
[f7d6bb0]	895	)
[2026bb6]	896
	897	//-----------------------------------------------------------------------------
	898	// Debug
[8c50aed]	899	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	900	return true;
	901	}
[c34ebf2]	902
	903	//-----------------------------------------------------------------------------
	904	// Statistics
	905	#if !defined(__CFA_NO_STATISTICS__)
	906	void print_halts( processor & this ) {
	907	this.print_halts = true;
	908	}
[58688bf]	909
[8464edf]	910	static void crawl_list( cluster * cltr, dlist(processor, processor) & list, unsigned count ) {
	911	/* paranoid */ verify( cltr->stats );
	912
	913	processor * it = &list`first;
	914	for(unsigned i = 0; i < count; i++) {
	915	/* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
	916	/* paranoid */ verify( it->local_data->this_stats );
	917	__tally_stats( cltr->stats, it->local_data->this_stats );
	918	it = &(*it)`next;
	919	}
	920	}
	921
	922	void crawl_cluster_stats( cluster & this ) {
	923	// Stop the world, otherwise stats could get really messed-up
	924	// this doesn't solve all problems but does solve many
	925	// so it's probably good enough
	926	uint_fast32_t last_size = ready_mutate_lock();
	927
	928	crawl_list(&this, this.procs.actives, this.procs.total - this.procs.idle);
	929	crawl_list(&this, this.procs.idles , this.procs.idle );
	930
	931	// Unlock the RWlock
	932	ready_mutate_unlock( last_size );
	933	}
	934
	935
[58688bf]	936	void print_stats_now( cluster & this, int flags ) {
[8464edf]	937	crawl_cluster_stats( this );
[1b033b8]	938	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	939	}
[c34ebf2]	940	#endif
[8118303]	941	// Local Variables: //
	942	// mode: c //
	943	// tab-width: 4 //
	944	// End: //

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