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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 299b8b28 was 34b2796, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
Changed comments to ifdef
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File size: 29.1 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>
[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
[89eff25]	173	__STATS( unsigned long long last_tally = rdtscl(); )
[325e6ea]	174
[a5e7233]	175	// if we need to run some special setup, now is the time to do it.
	176	if(this->init.thrd) {
	177	this->init.thrd->curr_cluster = this->cltr;
	178	__run_thread(this, this->init.thrd);
	179	}
[325e6ea]	180
[4069faad]	181	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	182
[ac2b598]	183	$thread * readyThread = 0p;
[1eb239e4]	184	MAIN_LOOP:
	185	for() {
[34b2796]	186	#if 1
[dddb3dd0]	187	// Check if there is pending io
	188	__maybe_io_drain( this );
	189
[92e7631]	190	// Try to get the next thread
[8c50aed]	191	readyThread = __next_thread( this->cltr );
[75f3522]	192
[1eb239e4]	193	if( !readyThread ) {
[dddb3dd0]	194	__cfa_io_flush( this );
[1eb239e4]	195	readyThread = __next_thread_slow( this->cltr );
	196	}
[4e6fb8e]	197
[1eb239e4]	198	HALT:
	199	if( !readyThread ) {
	200	// Don't block if we are done
	201	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	202
[1eb239e4]	203	#if !defined(__CFA_NO_STATISTICS__)
	204	__tls_stats()->ready.sleep.halts++;
	205	#endif
[398e8e9]	206
[1eb239e4]	207	// Push self to idle stack
[6a9b12b]	208	mark_idle(this->cltr->procs, * this);
[398e8e9]	209
[1eb239e4]	210	// Confirm the ready-queue is empty
	211	readyThread = __next_thread_slow( this->cltr );
	212	if( readyThread ) {
	213	// A thread was found, cancel the halt
[6a9b12b]	214	mark_awake(this->cltr->procs, * this);
[1eb239e4]	215
	216	#if !defined(__CFA_NO_STATISTICS__)
	217	__tls_stats()->ready.sleep.cancels++;
	218	#endif
	219
	220	// continue the mai loop
	221	break HALT;
	222	}
	223
	224	#if !defined(__CFA_NO_STATISTICS__)
	225	if(this->print_halts) {
[c993b15]	226	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
[1eb239e4]	227	}
	228	#endif
	229
[dddb3dd0]	230	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	231
	232	__disable_interrupts_hard();
	233	eventfd_t val;
	234	eventfd_read( this->idle, &val );
	235	__enable_interrupts_hard();
[1eb239e4]	236
	237	#if !defined(__CFA_NO_STATISTICS__)
	238	if(this->print_halts) {
[c993b15]	239	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
[1eb239e4]	240	}
	241	#endif
	242
	243	// We were woken up, remove self from idle
[6a9b12b]	244	mark_awake(this->cltr->procs, * this);
[1eb239e4]	245
	246	// DON'T just proceed, start looking again
	247	continue MAIN_LOOP;
[64a7146]	248	}
[1eb239e4]	249
	250	/* paranoid */ verify( readyThread );
	251
[dddb3dd0]	252	// Reset io dirty bit
	253	this->io.dirty = false;
	254
[1eb239e4]	255	// We found a thread run it
	256	__run_thread(this, readyThread);
	257
	258	// Are we done?
	259	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	260
	261	#if !defined(__CFA_NO_STATISTICS__)
	262	unsigned long long curr = rdtscl();
	263	if(curr > (last_tally + 500000000)) {
	264	__tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
	265	last_tally = curr;
	266	}
	267	#endif
[dddb3dd0]	268
	269	if(this->io.pending && !this->io.dirty) {
	270	__cfa_io_flush( this );
	271	}
[89eff25]	272
[34b2796]	273	#else
	274
	275	SEARCH: {
	276	/* paranoid */ verify( ! __preemption_enabled() );
	277	/* paranoid */ verify( kernelTLS().this_proc_id );
	278
	279	// First, lock the scheduler since we are searching for a thread
	280	ready_schedule_lock();
	281
	282	// Try to get the next thread
	283	readyThread = pop_fast( this->cltr );
	284	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	285
	286	// If we can't find a thread, might as well flush any outstanding I/O
	287	if(this->io.pending) { __cfa_io_flush( this ); }
	288
	289	// Spin a little on I/O, just in case
	290	for(25) {
	291	__maybe_io_drain( this );
	292	readyThread = pop_fast( this->cltr );
	293	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	294	}
	295
	296	// no luck, try stealing a few times
	297	for(25) {
	298	if( __maybe_io_drain( this ) ) {
	299	readyThread = pop_fast( this->cltr );
	300	} else {
	301	readyThread = pop_slow( this->cltr );
	302	}
	303	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	304	}
	305
	306	// still no luck, search for a thread
	307	readyThread = pop_search( this->cltr );
	308	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	309
	310	// Don't block if we are done
	311	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	312
	313	__STATS( __tls_stats()->ready.sleep.halts++; )
	314
	315	// Push self to idle stack
	316	ready_schedule_unlock();
	317	mark_idle(this->cltr->procs, * this);
	318	ready_schedule_lock();
	319
	320	// Confirm the ready-queue is empty
	321	__maybe_io_drain( this );
	322	readyThread = pop_search( this->cltr );
	323	ready_schedule_unlock();
	324
	325	if( readyThread ) {
	326	// A thread was found, cancel the halt
	327	mark_awake(this->cltr->procs, * this);
	328
	329	__STATS( __tls_stats()->ready.sleep.cancels++; )
	330
	331	// continue the main loop
	332	break SEARCH;
	333	}
	334
	335	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl()); )
	336	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	337
	338	// __disable_interrupts_hard();
	339	eventfd_t val;
	340	eventfd_read( this->idle, &val );
	341	// __enable_interrupts_hard();
	342
	343	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl()); )
	344
	345	// We were woken up, remove self from idle
	346	mark_awake(this->cltr->procs, * this);
	347
	348	// DON'T just proceed, start looking again
	349	continue MAIN_LOOP;
	350	}
	351
	352	RUN_THREAD:
	353	/* paranoid */ verify( kernelTLS().this_proc_id );
	354	/* paranoid */ verify( ! __preemption_enabled() );
	355	/* paranoid */ verify( readyThread );
	356
	357	// Reset io dirty bit
	358	this->io.dirty = false;
	359
	360	// We found a thread run it
	361	__run_thread(this, readyThread);
	362
	363	// Are we done?
	364	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	365
	366	#if !defined(__CFA_NO_STATISTICS__)
	367	unsigned long long curr = rdtscl();
	368	if(curr > (last_tally + 500000000)) {
	369	__tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
	370	last_tally = curr;
	371	}
	372	#endif
	373
	374	if(this->io.pending && !this->io.dirty) {
	375	__cfa_io_flush( this );
	376	}
	377
	378	ready_schedule_lock();
	379	__maybe_io_drain( this );
	380	ready_schedule_unlock();
	381	#endif
[c81ebf9]	382	}
	383
[4069faad]	384	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	385	}
[8118303]	386
[dddb3dd0]	387	__cfa_io_stop( this );
	388
[454f478]	389	post( this->terminated );
[bdeba0b]	390
[28d73c1]	391	if(this == mainProcessor) {
[6a490b2]	392	// HACK : the coroutine context switch expects this_thread to be set
	393	// and it make sense for it to be set in all other cases except here
	394	// fake it
[8fc652e0]	395	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	396	}
[7768b8d]	397
[4069faad]	398	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	399	}
	400
[5c1a531]	401	static int * __volatile_errno() __attribute__((noinline));
	402	static int * __volatile_errno() { asm(""); return &errno; }
	403
[14a61b5]	404	// KERNEL ONLY
[1c273d0]	405	// runThread runs a thread by context switching
	406	// from the processor coroutine to the target thread
[ac2b598]	407	static void __run_thread(processor * this, $thread * thrd_dst) {
[8fc652e0]	408	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	409	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	410	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	411	__builtin_prefetch( thrd_dst->context.SP );
	412
[dddb3dd0]	413	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	414
[ac2b598]	415	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	416
[9f575ea]	417	// set state of processor coroutine to inactive
	418	verify(proc_cor->state == Active);
[ae7be7a]	419	proc_cor->state = Blocked;
[e8e457e]	420
[9f575ea]	421	// Actually run the thread
[3381ed7]	422	RUNNING: while(true) {
[ff79d5e]	423	thrd_dst->preempted = __NO_PREEMPTION;
	424	thrd_dst->state = Active;
[e8e457e]	425
[58d64a4]	426	// Update global state
[8fc652e0]	427	kernelTLS().this_thread = thrd_dst;
[75f3522]	428
[8fc652e0]	429	/* paranoid */ verify( ! __preemption_enabled() );
	430	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	431	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	432	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	433	/* paranoid */ verify( thrd_dst->state != Halted );
[210b8b3]	434	/* 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
	435	/* 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]	436	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	437
[3381ed7]	438
[58d64a4]	439
[9f575ea]	440	// set context switch to the thread that the processor is executing
[c7a900a]	441	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	442	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	443
[ac12f1f]	444	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[210b8b3]	445	/* 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 );
	446	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
[b4b63e8]	447	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	448	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	449	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	450	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	451
[58d64a4]	452	// Reset global state
[8fc652e0]	453	kernelTLS().this_thread = 0p;
[3381ed7]	454
	455	// We just finished running a thread, there are a few things that could have happened.
	456	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	457	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	458	// 4 - Preempted
	459	// In case 1, we may have won a race so we can't write to the state again.
	460	// In case 2, we lost the race so we now own the thread.
	461
	462	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	463	// The thread was preempted, reschedule it and reset the flag
[254ad1b]	464	schedule_thread$( thrd_dst );
[3381ed7]	465	break RUNNING;
	466	}
[75f3522]	467
[3ea8ad1]	468	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	469	// The thread has halted, it should never be scheduled/run again
[5afb49a]	470	// finish the thread
	471	__thread_finish( thrd_dst );
[ff79d5e]	472	break RUNNING;
	473	}
	474
	475	/* paranoid */ verify( thrd_dst->state == Active );
	476	thrd_dst->state = Blocked;
	477
[3381ed7]	478	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	479	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	480	switch(old_ticket) {
[6a77224]	481	case TICKET_RUNNING:
[3381ed7]	482	// This is case 1, the regular case, nothing more is needed
	483	break RUNNING;
[6a77224]	484	case TICKET_UNBLOCK:
[ec43cf9]	485	#if !defined(__CFA_NO_STATISTICS__)
	486	__tls_stats()->ready.threads.threads++;
[73f4d08]	487	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	488	#endif
[3381ed7]	489	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	490	// In this case, just run it again.
	491	continue RUNNING;
	492	default:
	493	// This makes no sense, something is wrong abort
[ff79d5e]	494	abort();
[3381ed7]	495	}
[9f575ea]	496	}
[e8e457e]	497
[9f575ea]	498	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	499	proc_cor->state = Active;
[1eb239e4]	500
[dddb3dd0]	501	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	502
[ec43cf9]	503	#if !defined(__CFA_NO_STATISTICS__)
	504	__tls_stats()->ready.threads.threads--;
[73f4d08]	505	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	506	#endif
	507
[8fc652e0]	508	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	509	}
	510
[14a61b5]	511	// KERNEL_ONLY
[b0c7419]	512	void returnToKernel() {
[8fc652e0]	513	/* paranoid */ verify( ! __preemption_enabled() );
	514	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	515	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	516
[89eff25]	517	__STATS( thrd_src->last_proc = kernelTLS().this_processor; )
[29cb302]	518
[9f575ea]	519	// Run the thread on this processor
	520	{
	521	int local_errno = *__volatile_errno();
	522	#if defined( __i386 ) \|\| defined( __x86_64 )
	523	__x87_store;
	524	#endif
[b4b63e8]	525	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	526	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	527	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	528	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	529	#if defined( __i386 ) \|\| defined( __x86_64 )
	530	__x87_load;
	531	#endif
	532	*__volatile_errno() = local_errno;
[8fcbb4c]	533	}
[deca0f5]	534
[29cb302]	535	#if !defined(__CFA_NO_STATISTICS__)
[89eff25]	536	/* paranoid */ verify( thrd_src->last_proc != 0p );
	537	if(thrd_src->last_proc != kernelTLS().this_processor) {
[29cb302]	538	__tls_stats()->ready.threads.migration++;
	539	}
	540	#endif
	541
[8fc652e0]	542	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	543	/* 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 );
	544	/* 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]	545	}
	546
[8def349]	547	//-----------------------------------------------------------------------------
	548	// Scheduler routines
[14a61b5]	549	// KERNEL ONLY
[e9c0b4c]	550	static void __schedule_thread( $thread * thrd ) {
[8fc652e0]	551	/* paranoid */ verify( ! __preemption_enabled() );
[254ad1b]	552	/* paranoid */ verify( ready_schedule_islocked());
[6a490b2]	553	/* paranoid */ verify( thrd );
	554	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	555	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	556	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	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 );
[ff79d5e]	559	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	560	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	561	/* paranoid */ #endif
[6a490b2]	562	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	563	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	564
[9f575ea]	565
[ae7be7a]	566	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	567
[ec43cf9]	568	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	569	struct cluster * cl = thrd->curr_cluster;
[89eff25]	570	__STATS(bool outside = thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	571
[254ad1b]	572	// push the thread to the cluster ready-queue
	573	push( cl, thrd );
[32a8b61]	574
[254ad1b]	575	// variable thrd is no longer safe to use
[734908c]	576	thrd = 0xdeaddeaddeaddeadp;
[32a8b61]	577
[254ad1b]	578	// wake the cluster using the save variable.
	579	__wake_one( cl );
[1c273d0]	580
[ec43cf9]	581	#if !defined(__CFA_NO_STATISTICS__)
	582	if( kernelTLS().this_stats ) {
	583	__tls_stats()->ready.threads.threads++;
[89eff25]	584	if(outside) {
	585	__tls_stats()->ready.threads.extunpark++;
	586	}
[73f4d08]	587	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", kernelTLS().this_processor );
[ec43cf9]	588	}
	589	else {
	590	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	591	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[73f4d08]	592	__push_stat( cl->stats, cl->stats->ready.threads.threads, true, "Cluster", cl );
[ec43cf9]	593	}
	594	#endif
	595
[254ad1b]	596	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	597	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	598	}
	599
[254ad1b]	600	void schedule_thread$( $thread * thrd ) {
	601	ready_schedule_lock();
	602	__schedule_thread( thrd );
	603	ready_schedule_unlock();
	604	}
	605
[14a61b5]	606	// KERNEL ONLY
[1eb239e4]	607	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	608	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	609
[e873838]	610	ready_schedule_lock();
[431cd4f]	611	$thread * thrd = pop_fast( this );
[e873838]	612	ready_schedule_unlock();
[7768b8d]	613
[8fc652e0]	614	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	615	return thrd;
[eb2e723]	616	}
	617
[64a7146]	618	// KERNEL ONLY
[1eb239e4]	619	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	620	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	621
[e873838]	622	ready_schedule_lock();
[fc59df78]	623	$thread * thrd;
	624	for(25) {
	625	thrd = pop_slow( this );
	626	if(thrd) goto RET;
	627	}
	628	thrd = pop_search( this );
	629
	630	RET:
[e873838]	631	ready_schedule_unlock();
[64a7146]	632
[8fc652e0]	633	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	634	return thrd;
[64a7146]	635	}
	636
[c6c7e6c]	637	static inline bool __must_unpark( $thread * thrd ) {
[ff79d5e]	638	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	639	switch(old_ticket) {
[6a77224]	640	case TICKET_RUNNING:
[3381ed7]	641	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	642	return false;
[6a77224]	643	case TICKET_BLOCKED:
[3381ed7]	644	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	645	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	646	return true;
[3381ed7]	647	default:
	648	// This makes no sense, something is wrong abort
[7ee8153]	649	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	650	}
[eb2e723]	651	}
	652
[e9c0b4c]	653	void __kernel_unpark( $thread * thrd ) {
	654	/* paranoid */ verify( ! __preemption_enabled() );
	655	/* paranoid */ verify( ready_schedule_islocked());
	656
	657	if( !thrd ) return;
	658
	659	if(__must_unpark(thrd)) {
	660	// Wake lost the race,
	661	__schedule_thread( thrd );
	662	}
	663
	664	/* paranoid */ verify( ready_schedule_islocked());
	665	/* paranoid */ verify( ! __preemption_enabled() );
	666	}
	667
[c6c7e6c]	668	void unpark( $thread * thrd ) {
	669	if( !thrd ) return;
[0b33412]	670
[c6c7e6c]	671	if(__must_unpark(thrd)) {
	672	disable_interrupts();
[a3821fa]	673	// Wake lost the race,
[254ad1b]	674	schedule_thread$( thrd );
[a3821fa]	675	enable_interrupts(false);
[de6319f]	676	}
[eb2e723]	677	}
[0b33412]	678
[e235429]	679	void park( void ) {
[a3821fa]	680	__disable_interrupts_checked();
	681	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	682	returnToKernel();
	683	__enable_interrupts_checked();
[0c78741]	684
	685	}
[09800e9]	686
[5afb49a]	687	extern "C" {
	688	// Leave the thread monitor
	689	// last routine called by a thread.
	690	// Should never return
	691	void __cfactx_thrd_leave() {
[8fc652e0]	692	$thread * thrd = active_thread();
[5afb49a]	693	$monitor * this = &thrd->self_mon;
	694
	695	// Lock the monitor now
	696	lock( this->lock __cfaabi_dbg_ctx2 );
	697
	698	disable_interrupts();
	699
[9d6e1b8a]	700	/* paranoid */ verify( ! __preemption_enabled() );
	701	/* paranoid */ verify( thrd->state == Active );
	702	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	703	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	704	/* paranoid */ verify( thrd->context.SP );
	705	/* 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 );
	706	/* 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 );
	707
[3ea8ad1]	708	thrd->state = Halting;
[58688bf]	709	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	710	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	711	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	712
	713	// Leave the thread
	714	returnToKernel();
	715
	716	// Control flow should never reach here!
[9d6e1b8a]	717	abort();
[5afb49a]	718	}
[09800e9]	719	}
	720
[14a61b5]	721	// KERNEL ONLY
[3381ed7]	722	bool force_yield( __Preemption_Reason reason ) {
[a3821fa]	723	__disable_interrupts_checked();
	724	$thread * thrd = kernelTLS().this_thread;
	725	/* paranoid */ verify(thrd->state == Active);
	726
	727	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	728	// it was going to park itself. If that is the case and it is already using the
	729	// intrusive fields then we can't use them to preempt the thread
	730	// If that is the case, abandon the preemption.
	731	bool preempted = false;
	732	if(thrd->link.next == 0p) {
	733	preempted = true;
	734	thrd->preempted = reason;
	735	returnToKernel();
	736	}
	737	__enable_interrupts_checked( false );
[3381ed7]	738	return preempted;
[f2b12406]	739	}
	740
[14a61b5]	741	//=============================================================================================
[92e7631]	742	// Kernel Idle Sleep
[14a61b5]	743	//=============================================================================================
[64a7146]	744	// Wake a thread from the front if there are any
[e873838]	745	static void __wake_one(cluster * this) {
[8fc652e0]	746	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	747	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	748
[64a7146]	749	// Check if there is a sleeping processor
[1eb239e4]	750	processor * p;
	751	unsigned idle;
	752	unsigned total;
[6a9b12b]	753	[idle, total, p] = query_idles(this->procs);
[14a61b5]	754
[64a7146]	755	// If no one is sleeping, we are done
[1eb239e4]	756	if( idle == 0 ) return;
[14a61b5]	757
[64a7146]	758	// We found a processor, wake it up
[dddb3dd0]	759	eventfd_t val;
	760	val = 1;
	761	eventfd_write( p->idle, val );
[14a61b5]	762
[1eb239e4]	763	#if !defined(__CFA_NO_STATISTICS__)
[5cb51502]	764	if( kernelTLS().this_stats ) {
	765	__tls_stats()->ready.sleep.wakes++;
	766	}
	767	else {
	768	__atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
	769	}
[1eb239e4]	770	#endif
	771
[e873838]	772	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	773	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	774
	775	return;
[64a7146]	776	}
[14a61b5]	777
[64a7146]	778	// Unconditionnaly wake a thread
[1eb239e4]	779	void __wake_proc(processor * this) {
[64a7146]	780	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	781
[a3821fa]	782	__disable_interrupts_checked();
[8fc652e0]	783	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	784	eventfd_t val;
	785	val = 1;
[55d6affb]	786	eventfd_write( this->idle, val );
[a3821fa]	787	__enable_interrupts_checked();
[92e7631]	788	}
	789
[6a9b12b]	790	static void mark_idle(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	791	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	792	lock( this );
	793	this.idle++;
	794	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	795	remove(proc);
[6a9b12b]	796	insert_first(this.idles, proc);
[1eb239e4]	797	unlock( this );
[8fc652e0]	798	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	799	}
[8e16177]	800
[6a9b12b]	801	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	802	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	803	lock( this );
	804	this.idle--;
	805	/* paranoid */ verify( this.idle >= 0 );
	806	remove(proc);
[fc59b580]	807	insert_last(this.actives, proc);
[1eb239e4]	808	unlock( this );
[8fc652e0]	809	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	810	}
[c34ebf2]	811
[6a9b12b]	812	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list this ) {
	813	/* paranoid */ verify( ! __preemption_enabled() );
	814	/* paranoid */ verify( ready_schedule_islocked() );
	815
[1eb239e4]	816	for() {
	817	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	818	if( 1 == (l % 2) ) { Pause(); continue; }
	819	unsigned idle = this.idle;
	820	unsigned total = this.total;
[6a9b12b]	821	processor * proc = &this.idles`first;
[7fdae38]	822	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	823	asm volatile("": : :"memory");
[1eb239e4]	824	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	825	return [idle, total, proc];
	826	}
[6a9b12b]	827
	828	/* paranoid */ verify( ready_schedule_islocked() );
	829	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	830	}
	831
[dbe9b08]	832	//=============================================================================================
	833	// Unexpected Terminating logic
	834	//=============================================================================================
[92bfda0]	835	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
	836	$thread * thrd = __cfaabi_tls.this_thread;
[9d944b2]	837
[de94a60]	838	if(thrd) {
	839	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	840	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	841
[212c2187]	842	if ( &thrd->self_cor != thrd->curr_cor ) {
	843	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	844	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	845	}
	846	else {
[1c40091]	847	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	848	}
[1c273d0]	849	}
[9d944b2]	850	else {
[de94a60]	851	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	852	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	853	}
	854	}
	855
[92bfda0]	856	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	857	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	858	}
	859
[de94a60]	860	static __spinlock_t kernel_debug_lock;
	861
[9d944b2]	862	extern "C" {
[1c40091]	863	void __cfaabi_bits_acquire() {
[36982fc]	864	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	865	}
	866
[1c40091]	867	void __cfaabi_bits_release() {
[ea7d2b0]	868	unlock( kernel_debug_lock );
[9d944b2]	869	}
[8118303]	870	}
	871
[fa21ac9]	872	//=============================================================================================
	873	// Kernel Utilities
	874	//=============================================================================================
[dddb3dd0]	875	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	876	#include "io/types.hfa"
	877	#endif
	878
[c1c95b1]	879	static inline bool __maybe_io_drain( processor * proc ) {
[e9c0b4c]	880	bool ret = false;
[dddb3dd0]	881	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	882	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	883
	884	// Check if we should drain the queue
	885	$io_context * ctx = proc->io.ctx;
	886	unsigned head = *ctx->cq.head;
	887	unsigned tail = *ctx->cq.tail;
[c1c95b1]	888	if(head == tail) return false;
[b7fd2db6]	889	ready_schedule_lock();
[e9c0b4c]	890	ret = __cfa_io_drain( proc );
[b7fd2db6]	891	ready_schedule_unlock();
[dddb3dd0]	892	#endif
[e9c0b4c]	893	return ret;
[dddb3dd0]	894	}
	895
[de94a60]	896	//-----------------------------------------------------------------------------
	897	// Debug
	898	__cfaabi_dbg_debug_do(
[1997b4e]	899	extern "C" {
[ae66348]	900	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	901	this.prev_name = prev_name;
[8fc652e0]	902	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	903	}
[9181f1d]	904	}
[f7d6bb0]	905	)
[2026bb6]	906
	907	//-----------------------------------------------------------------------------
	908	// Debug
[8c50aed]	909	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	910	return true;
	911	}
[c34ebf2]	912
	913	//-----------------------------------------------------------------------------
	914	// Statistics
	915	#if !defined(__CFA_NO_STATISTICS__)
	916	void print_halts( processor & this ) {
	917	this.print_halts = true;
	918	}
[58688bf]	919
	920	void print_stats_now( cluster & this, int flags ) {
[1b033b8]	921	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	922	}
[c34ebf2]	923	#endif
[8118303]	924	// Local Variables: //
	925	// mode: c //
	926	// tab-width: 4 //
	927	// End: //

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