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ADT ast-experimental enum forall-pointer-decay pthread-emulation qualifiedEnum

Last change on this file since cd4c605 was 1757f98, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
Refactoring idle sleep to try and help the change from idle on read to idle on io_uring_enter.
Property mode set to `100644`
File size: 30.0 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__
[43784ac]	17	#define _GNU_SOURCE
	18
[4069faad]	19	// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
[2026bb6]	20
[8118303]	21	//C Includes
[214e8da]	22	#include <errno.h>
[9d944b2]	23	#include <stdio.h>
[445f984]	24	#include <string.h>
[58b6d1b]	25	#include <signal.h>
[9d944b2]	26	#include <unistd.h>
[dddb3dd0]	27	extern "C" {
	28	#include <sys/eventfd.h>
	29	}
[8118303]	30
	31	//CFA Includes
[73abe95]	32	#include "kernel_private.hfa"
	33	#include "preemption.hfa"
[445f984]	34	#include "strstream.hfa"
	35	#include "device/cpu.hfa"
[8118303]	36
	37	//Private includes
	38	#define __CFA_INVOKE_PRIVATE__
	39	#include "invoke.h"
	40
[89eff25]	41	#if !defined(__CFA_NO_STATISTICS__)
	42	#define __STATS( ...) __VA_ARGS__
	43	#else
	44	#define __STATS( ...)
	45	#endif
[4069faad]	46
[deca0f5]	47	//-----------------------------------------------------------------------------
	48	// Some assembly required
[1805b1b]	49	#if defined( __i386 )
[deca0f5]	50	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	51	// fcw : X87 FPU control word (preserved across function calls)
	52	#define __x87_store \
	53	uint32_t __mxcr; \
	54	uint16_t __fcw; \
	55	__asm__ volatile ( \
	56	"stmxcsr %0\n" \
	57	"fnstcw %1\n" \
	58	: "=m" (__mxcr),\
	59	"=m" (__fcw) \
	60	)
	61
	62	#define __x87_load \
	63	__asm__ volatile ( \
	64	"fldcw %1\n" \
	65	"ldmxcsr %0\n" \
	66	::"m" (__mxcr),\
	67	"m" (__fcw) \
	68	)
	69
	70	#elif defined( __x86_64 )
	71	#define __x87_store \
	72	uint32_t __mxcr; \
	73	uint16_t __fcw; \
	74	__asm__ volatile ( \
	75	"stmxcsr %0\n" \
	76	"fnstcw %1\n" \
	77	: "=m" (__mxcr),\
	78	"=m" (__fcw) \
	79	)
	80
	81	#define __x87_load \
	82	__asm__ volatile ( \
	83	"fldcw %1\n" \
	84	"ldmxcsr %0\n" \
	85	:: "m" (__mxcr),\
	86	"m" (__fcw) \
	87	)
	88
[0190480]	89	#elif defined( __arm__ )
	90	#define __x87_store
	91	#define __x87_load
	92
	93	#elif defined( __aarch64__ )
[74f5c83]	94	#define __x87_store \
	95	uint32_t __fpcntl[2]; \
	96	__asm__ volatile ( \
	97	"mrs x9, FPCR\n" \
	98	"mrs x10, FPSR\n" \
	99	"stp x9, x10, %0\n" \
	100	: "=m" (__fpcntl) : : "x9", "x10" \
	101	)
	102
	103	#define __x87_load \
	104	__asm__ volatile ( \
	105	"ldp x9, x10, %0\n" \
	106	"msr FPSR, x10\n" \
	107	"msr FPCR, x9\n" \
	108	: "=m" (__fpcntl) : : "x9", "x10" \
	109	)
	110
[deca0f5]	111	#else
[0190480]	112	#error unsupported hardware architecture
[deca0f5]	113	#endif
	114
[e84ab3d]	115	extern thread$ * mainThread;
[e660761]	116	extern processor * mainProcessor;
[2ac095d]	117
[92e7631]	118	//-----------------------------------------------------------------------------
	119	// Kernel Scheduling logic
[e84ab3d]	120	static thread$ * __next_thread(cluster * this);
	121	static thread$ * __next_thread_slow(cluster * this);
	122	static inline bool __must_unpark( thread$ * thrd ) __attribute((nonnull(1)));
	123	static void __run_thread(processor * this, thread$ * dst);
[e873838]	124	static void __wake_one(cluster * cltr);
[1eb239e4]	125
[1757f98]	126	static void idle_sleep(processor * proc);
[5f5a729]	127	static bool mark_idle (__cluster_proc_list & idles, processor & proc);
[6a9b12b]	128	static void mark_awake(__cluster_proc_list & idles, processor & proc);
[1eb239e4]	129
[dddb3dd0]	130	extern void __cfa_io_start( processor * );
[c1c95b1]	131	extern bool __cfa_io_drain( processor * );
[dddb3dd0]	132	extern void __cfa_io_flush( processor * );
	133	extern void __cfa_io_stop ( processor * );
[c1c95b1]	134	static inline bool __maybe_io_drain( processor * );
[dddb3dd0]	135
	136	extern void __disable_interrupts_hard();
	137	extern void __enable_interrupts_hard();
[c84e80a]	138
[a3821fa]	139	static inline void __disable_interrupts_checked() {
	140	/* paranoid */ verify( __preemption_enabled() );
	141	disable_interrupts();
	142	/* paranoid */ verify( ! __preemption_enabled() );
	143	}
	144
	145	static inline void __enable_interrupts_checked( bool poll = true ) {
	146	/* paranoid */ verify( ! __preemption_enabled() );
	147	enable_interrupts( poll );
	148	/* paranoid */ verify( __preemption_enabled() );
	149	}
	150
[75f3522]	151	//=============================================================================================
	152	// Kernel Scheduling logic
	153	//=============================================================================================
[8fcbb4c]	154	//Main of the processor contexts
[83a071f9]	155	void main(processorCtx_t & runner) {
[21184e3]	156	// Because of a bug, we couldn't initialized the seed on construction
	157	// Do it here
[8fc652e0]	158	__cfaabi_tls.rand_seed ^= rdtscl();
	159	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	160	__tls_rand_advance_bck();
[21184e3]	161
[83a071f9]	162	processor * this = runner.proc;
[094476d]	163	verify(this);
[c81ebf9]	164
[dddb3dd0]	165	__cfa_io_start( this );
	166
[4069faad]	167	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	168	#if !defined(__CFA_NO_STATISTICS__)
	169	if( this->print_halts ) {
[c993b15]	170	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->unique_id, this->name, (void*)this);
[28d73c1]	171	}
	172	#endif
[b798713]	173
[75f3522]	174	{
[c81ebf9]	175	// Setup preemption data
	176	preemption_scope scope = { this };
	177
[a5e7233]	178	// if we need to run some special setup, now is the time to do it.
	179	if(this->init.thrd) {
	180	this->init.thrd->curr_cluster = this->cltr;
	181	__run_thread(this, this->init.thrd);
	182	}
[325e6ea]	183
[4069faad]	184	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	185
[e84ab3d]	186	thread$ * readyThread = 0p;
[1eb239e4]	187	MAIN_LOOP:
	188	for() {
[57f70ab]	189	#define OLD_MAIN 1
	190	#if OLD_MAIN
[dddb3dd0]	191	// Check if there is pending io
	192	__maybe_io_drain( this );
	193
[92e7631]	194	// Try to get the next thread
[8c50aed]	195	readyThread = __next_thread( this->cltr );
[75f3522]	196
[1eb239e4]	197	if( !readyThread ) {
[c33c2af]	198	ready_schedule_lock();
[dddb3dd0]	199	__cfa_io_flush( this );
[c33c2af]	200	ready_schedule_unlock();
	201
[1eb239e4]	202	readyThread = __next_thread_slow( this->cltr );
	203	}
[4e6fb8e]	204
[1eb239e4]	205	HALT:
	206	if( !readyThread ) {
	207	// Don't block if we are done
	208	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	209
[1eb239e4]	210	#if !defined(__CFA_NO_STATISTICS__)
	211	__tls_stats()->ready.sleep.halts++;
	212	#endif
[398e8e9]	213
[1eb239e4]	214	// Push self to idle stack
[5f5a729]	215	if(!mark_idle(this->cltr->procs, * this)) continue MAIN_LOOP;
[398e8e9]	216
[1eb239e4]	217	// Confirm the ready-queue is empty
	218	readyThread = __next_thread_slow( this->cltr );
	219	if( readyThread ) {
	220	// A thread was found, cancel the halt
[6a9b12b]	221	mark_awake(this->cltr->procs, * this);
[1eb239e4]	222
	223	#if !defined(__CFA_NO_STATISTICS__)
	224	__tls_stats()->ready.sleep.cancels++;
	225	#endif
	226
	227	// continue the mai loop
	228	break HALT;
	229	}
	230
[1757f98]	231	idle_sleep( this );
[1eb239e4]	232
	233	// We were woken up, remove self from idle
[6a9b12b]	234	mark_awake(this->cltr->procs, * this);
[1eb239e4]	235
	236	// DON'T just proceed, start looking again
	237	continue MAIN_LOOP;
[64a7146]	238	}
[1eb239e4]	239
	240	/* paranoid */ verify( readyThread );
	241
[dddb3dd0]	242	// Reset io dirty bit
	243	this->io.dirty = false;
	244
[1eb239e4]	245	// We found a thread run it
	246	__run_thread(this, readyThread);
	247
	248	// Are we done?
	249	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	250
[dddb3dd0]	251	if(this->io.pending && !this->io.dirty) {
[c33c2af]	252	ready_schedule_lock();
[dddb3dd0]	253	__cfa_io_flush( this );
[c33c2af]	254	ready_schedule_unlock();
[dddb3dd0]	255	}
[89eff25]	256
[34b2796]	257	#else
[57f70ab]	258	#warning new kernel loop
[34b2796]	259	SEARCH: {
	260	/* paranoid */ verify( ! __preemption_enabled() );
	261
	262	// First, lock the scheduler since we are searching for a thread
	263	ready_schedule_lock();
	264
	265	// Try to get the next thread
	266	readyThread = pop_fast( this->cltr );
	267	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	268
	269	// If we can't find a thread, might as well flush any outstanding I/O
	270	if(this->io.pending) { __cfa_io_flush( this ); }
	271
	272	// Spin a little on I/O, just in case
[12daa43]	273	for(5) {
[34b2796]	274	__maybe_io_drain( this );
	275	readyThread = pop_fast( this->cltr );
	276	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	277	}
	278
	279	// no luck, try stealing a few times
[12daa43]	280	for(5) {
[34b2796]	281	if( __maybe_io_drain( this ) ) {
	282	readyThread = pop_fast( this->cltr );
	283	} else {
	284	readyThread = pop_slow( this->cltr );
	285	}
	286	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	287	}
	288
	289	// still no luck, search for a thread
	290	readyThread = pop_search( this->cltr );
	291	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	292
	293	// Don't block if we are done
[c33c2af]	294	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) {
	295	ready_schedule_unlock();
	296	break MAIN_LOOP;
	297	}
[34b2796]	298
	299	__STATS( __tls_stats()->ready.sleep.halts++; )
	300
	301	// Push self to idle stack
	302	ready_schedule_unlock();
[5f5a729]	303	if(!mark_idle(this->cltr->procs, * this)) goto SEARCH;
[34b2796]	304	ready_schedule_lock();
	305
	306	// Confirm the ready-queue is empty
	307	__maybe_io_drain( this );
	308	readyThread = pop_search( this->cltr );
	309	ready_schedule_unlock();
	310
	311	if( readyThread ) {
	312	// A thread was found, cancel the halt
	313	mark_awake(this->cltr->procs, * this);
	314
	315	__STATS( __tls_stats()->ready.sleep.cancels++; )
	316
	317	// continue the main loop
	318	break SEARCH;
	319	}
	320
[abcae55]	321	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl()); )
[1757f98]	322	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle_fd);
[34b2796]	323
[ec421636]	324	{
	325	eventfd_t val;
[1757f98]	326	ssize_t ret = read( this->idle_fd, &val, sizeof(val) );
[ec421636]	327	if(ret < 0) {
	328	switch((int)errno) {
	329	case EAGAIN:
	330	#if EAGAIN != EWOULDBLOCK
	331	case EWOULDBLOCK:
	332	#endif
	333	case EINTR:
	334	// No need to do anything special here, just assume it's a legitimate wake-up
	335	break;
	336	default:
	337	abort( "KERNEL : internal error, read failure on idle eventfd, error(%d) %s.", (int)errno, strerror( (int)errno ) );
	338	}
	339	}
	340	}
[34b2796]	341
[fb4ccdf]	342	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl()); )
[34b2796]	343
	344	// We were woken up, remove self from idle
	345	mark_awake(this->cltr->procs, * this);
	346
	347	// DON'T just proceed, start looking again
	348	continue MAIN_LOOP;
	349	}
	350
	351	RUN_THREAD:
	352	/* paranoid */ verify( ! __preemption_enabled() );
	353	/* paranoid */ verify( readyThread );
	354
	355	// Reset io dirty bit
	356	this->io.dirty = false;
	357
	358	// We found a thread run it
	359	__run_thread(this, readyThread);
	360
	361	// Are we done?
	362	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	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
[e84ab3d]	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
[e84ab3d]	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 );
[e84ab3d]	424	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) \|\| thrd_dst->curr_cor == proc_cor \|\| thrd_dst->corctx_flag, "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 \|\| thrd_dst->corctx_flag, "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
[50871b4]	434
	435
[ac12f1f]	436	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[e84ab3d]	437	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) \|\| thrd_dst->corctx_flag, "ERROR : Destination thread$ %p has been corrupted.\n StackPointer too large.\n", thrd_dst );
	438	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) \|\| thrd_dst->corctx_flag, "ERROR : Destination thread$ %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
[b4b63e8]	439	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	440	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	441	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	442	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	443
[58d64a4]	444	// Reset global state
[8fc652e0]	445	kernelTLS().this_thread = 0p;
[3381ed7]	446
	447	// We just finished running a thread, there are a few things that could have happened.
	448	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	449	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	450	// 4 - Preempted
	451	// In case 1, we may have won a race so we can't write to the state again.
	452	// In case 2, we lost the race so we now own the thread.
	453
	454	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	455	// The thread was preempted, reschedule it and reset the flag
[24e321c]	456	schedule_thread$( thrd_dst, UNPARK_LOCAL );
[3381ed7]	457	break RUNNING;
	458	}
[75f3522]	459
[3ea8ad1]	460	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	461	// The thread has halted, it should never be scheduled/run again
[5afb49a]	462	// finish the thread
	463	__thread_finish( thrd_dst );
[ff79d5e]	464	break RUNNING;
	465	}
	466
	467	/* paranoid */ verify( thrd_dst->state == Active );
	468	thrd_dst->state = Blocked;
	469
[3381ed7]	470	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	471	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	472	switch(old_ticket) {
[6a77224]	473	case TICKET_RUNNING:
[3381ed7]	474	// This is case 1, the regular case, nothing more is needed
	475	break RUNNING;
[6a77224]	476	case TICKET_UNBLOCK:
[ec43cf9]	477	#if !defined(__CFA_NO_STATISTICS__)
	478	__tls_stats()->ready.threads.threads++;
	479	#endif
[3381ed7]	480	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	481	// In this case, just run it again.
	482	continue RUNNING;
	483	default:
	484	// This makes no sense, something is wrong abort
[ff79d5e]	485	abort();
[3381ed7]	486	}
[9f575ea]	487	}
[e8e457e]	488
[9f575ea]	489	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	490	proc_cor->state = Active;
[1eb239e4]	491
[dddb3dd0]	492	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	493
[ec43cf9]	494	#if !defined(__CFA_NO_STATISTICS__)
	495	__tls_stats()->ready.threads.threads--;
	496	#endif
	497
[8fc652e0]	498	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	499	}
	500
[14a61b5]	501	// KERNEL_ONLY
[b0c7419]	502	void returnToKernel() {
[8fc652e0]	503	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	504	coroutine$ * 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() );
[e84ab3d]	533	/* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) < ((uintptr_t)__get_stack(thrd_src->curr_cor)->base ) \|\| thrd_src->corctx_flag, "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) \|\| thrd_src->corctx_flag, "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
[24e321c]	540	static void __schedule_thread( thread$ * thrd, unpark_hint hint ) {
[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
[b808625]	555	const bool local = thrd->state != Start;
[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;
[24e321c]	560	__STATS(bool outside = hint == UNPARK_LOCAL && thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	561
[254ad1b]	562	// push the thread to the cluster ready-queue
[24e321c]	563	push( cl, thrd, hint );
[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	}
[ec43cf9]	577	}
	578	else {
	579	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	580	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[ec43cf9]	581	}
	582	#endif
	583
[254ad1b]	584	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	585	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	586	}
	587
[24e321c]	588	void schedule_thread$( thread$ * thrd, unpark_hint hint ) {
[254ad1b]	589	ready_schedule_lock();
[24e321c]	590	__schedule_thread( thrd, hint );
[254ad1b]	591	ready_schedule_unlock();
	592	}
	593
[14a61b5]	594	// KERNEL ONLY
[e84ab3d]	595	static inline thread$ * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	596	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	597
[e873838]	598	ready_schedule_lock();
[e84ab3d]	599	thread$ * thrd = pop_fast( this );
[e873838]	600	ready_schedule_unlock();
[7768b8d]	601
[8fc652e0]	602	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	603	return thrd;
[eb2e723]	604	}
	605
[64a7146]	606	// KERNEL ONLY
[e84ab3d]	607	static inline thread$ * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	608	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	609
[e873838]	610	ready_schedule_lock();
[e84ab3d]	611	thread$ * thrd;
[fc59df78]	612	for(25) {
	613	thrd = pop_slow( this );
	614	if(thrd) goto RET;
	615	}
	616	thrd = pop_search( this );
	617
	618	RET:
[e873838]	619	ready_schedule_unlock();
[64a7146]	620
[8fc652e0]	621	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	622	return thrd;
[64a7146]	623	}
	624
[e84ab3d]	625	static inline bool __must_unpark( thread$ * thrd ) {
[ff79d5e]	626	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	627	switch(old_ticket) {
[6a77224]	628	case TICKET_RUNNING:
[3381ed7]	629	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	630	return false;
[6a77224]	631	case TICKET_BLOCKED:
[3381ed7]	632	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	633	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	634	return true;
[3381ed7]	635	default:
	636	// This makes no sense, something is wrong abort
[7ee8153]	637	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	638	}
[eb2e723]	639	}
	640
[24e321c]	641	void __kernel_unpark( thread$ * thrd, unpark_hint hint ) {
[e9c0b4c]	642	/* paranoid */ verify( ! __preemption_enabled() );
	643	/* paranoid */ verify( ready_schedule_islocked());
	644
	645	if( !thrd ) return;
	646
	647	if(__must_unpark(thrd)) {
	648	// Wake lost the race,
[24e321c]	649	__schedule_thread( thrd, hint );
[e9c0b4c]	650	}
	651
	652	/* paranoid */ verify( ready_schedule_islocked());
	653	/* paranoid */ verify( ! __preemption_enabled() );
	654	}
	655
[24e321c]	656	void unpark( thread$ * thrd, unpark_hint hint ) {
[c6c7e6c]	657	if( !thrd ) return;
[0b33412]	658
[c6c7e6c]	659	if(__must_unpark(thrd)) {
	660	disable_interrupts();
[a3821fa]	661	// Wake lost the race,
[24e321c]	662	schedule_thread$( thrd, hint );
[a3821fa]	663	enable_interrupts(false);
[de6319f]	664	}
[eb2e723]	665	}
[0b33412]	666
[e235429]	667	void park( void ) {
[a3821fa]	668	__disable_interrupts_checked();
	669	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	670	returnToKernel();
	671	__enable_interrupts_checked();
[0c78741]	672
	673	}
[09800e9]	674
[5afb49a]	675	extern "C" {
	676	// Leave the thread monitor
	677	// last routine called by a thread.
	678	// Should never return
	679	void __cfactx_thrd_leave() {
[e84ab3d]	680	thread$ * thrd = active_thread();
	681	monitor$ * this = &thrd->self_mon;
[5afb49a]	682
	683	// Lock the monitor now
	684	lock( this->lock __cfaabi_dbg_ctx2 );
	685
	686	disable_interrupts();
	687
[9d6e1b8a]	688	/* paranoid */ verify( ! __preemption_enabled() );
	689	/* paranoid */ verify( thrd->state == Active );
	690	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	691	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	692	/* paranoid */ verify( thrd->context.SP );
[e84ab3d]	693	/* 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 );
	694	/* 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 );
[9d6e1b8a]	695
[3ea8ad1]	696	thrd->state = Halting;
[58688bf]	697	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	698	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	699	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	700
	701	// Leave the thread
	702	returnToKernel();
	703
	704	// Control flow should never reach here!
[9d6e1b8a]	705	abort();
[5afb49a]	706	}
[09800e9]	707	}
	708
[14a61b5]	709	// KERNEL ONLY
[3381ed7]	710	bool force_yield( __Preemption_Reason reason ) {
[a3821fa]	711	__disable_interrupts_checked();
[e84ab3d]	712	thread$ * thrd = kernelTLS().this_thread;
[a3821fa]	713	/* paranoid */ verify(thrd->state == Active);
	714
	715	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	716	// it was going to park itself. If that is the case and it is already using the
	717	// intrusive fields then we can't use them to preempt the thread
	718	// If that is the case, abandon the preemption.
	719	bool preempted = false;
	720	if(thrd->link.next == 0p) {
	721	preempted = true;
	722	thrd->preempted = reason;
	723	returnToKernel();
	724	}
	725	__enable_interrupts_checked( false );
[3381ed7]	726	return preempted;
[f2b12406]	727	}
	728
[14a61b5]	729	//=============================================================================================
[92e7631]	730	// Kernel Idle Sleep
[14a61b5]	731	//=============================================================================================
[64a7146]	732	// Wake a thread from the front if there are any
[e873838]	733	static void __wake_one(cluster * this) {
[8fc652e0]	734	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	735	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	736
[64a7146]	737	// Check if there is a sleeping processor
[34b8cb7]	738	int fd = __atomic_load_n(&this->procs.fd, __ATOMIC_SEQ_CST);
[14a61b5]	739
[64a7146]	740	// If no one is sleeping, we are done
[34b8cb7]	741	if( fd == 0 ) return;
[14a61b5]	742
[64a7146]	743	// We found a processor, wake it up
[dddb3dd0]	744	eventfd_t val;
	745	val = 1;
[34b8cb7]	746	eventfd_write( fd, val );
[14a61b5]	747
[1eb239e4]	748	#if !defined(__CFA_NO_STATISTICS__)
[5cb51502]	749	if( kernelTLS().this_stats ) {
	750	__tls_stats()->ready.sleep.wakes++;
	751	}
	752	else {
	753	__atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
	754	}
[1eb239e4]	755	#endif
	756
[e873838]	757	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	758	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	759
	760	return;
[64a7146]	761	}
[14a61b5]	762
[64a7146]	763	// Unconditionnaly wake a thread
[1eb239e4]	764	void __wake_proc(processor * this) {
[64a7146]	765	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	766
[a3821fa]	767	__disable_interrupts_checked();
[8fc652e0]	768	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	769	eventfd_t val;
	770	val = 1;
[1757f98]	771	eventfd_write( this->idle_fd, val );
[a3821fa]	772	__enable_interrupts_checked();
[92e7631]	773	}
	774
[1757f98]	775	static void idle_sleep(processor * this) {
	776	#if !defined(__CFA_NO_STATISTICS__)
	777	if(this->print_halts) {
	778	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
	779	}
	780	#endif
	781
	782	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle_fd);
	783
	784	{
	785	eventfd_t val;
	786	ssize_t ret = read( this->idle_fd, &val, sizeof(val) );
	787	if(ret < 0) {
	788	switch((int)errno) {
	789	case EAGAIN:
	790	#if EAGAIN != EWOULDBLOCK
	791	case EWOULDBLOCK:
	792	#endif
	793	case EINTR:
	794	// No need to do anything special here, just assume it's a legitimate wake-up
	795	break;
	796	default:
	797	abort( "KERNEL : internal error, read failure on idle eventfd, error(%d) %s.", (int)errno, strerror( (int)errno ) );
	798	}
	799	}
	800	}
	801
	802	#if !defined(__CFA_NO_STATISTICS__)
	803	if(this->print_halts) {
	804	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
	805	}
	806	#endif
	807	}
	808
[5f5a729]	809	static bool mark_idle(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	810	/* paranoid */ verify( ! __preemption_enabled() );
[5f5a729]	811	if(!try_lock( this )) return false;
[1eb239e4]	812	this.idle++;
	813	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	814	remove(proc);
[6a9b12b]	815	insert_first(this.idles, proc);
[34b8cb7]	816
[1757f98]	817	__atomic_store_n(&this.fd, proc.idle_fd, __ATOMIC_SEQ_CST);
[1eb239e4]	818	unlock( this );
[8fc652e0]	819	/* paranoid */ verify( ! __preemption_enabled() );
[5f5a729]	820
	821	return true;
[1eb239e4]	822	}
[8e16177]	823
[6a9b12b]	824	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	825	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	826	lock( this );
	827	this.idle--;
	828	/* paranoid */ verify( this.idle >= 0 );
	829	remove(proc);
[fc59b580]	830	insert_last(this.actives, proc);
[6a9b12b]	831
[a633f6f]	832	{
	833	int fd = 0;
[1757f98]	834	if(!this.idles`isEmpty) fd = this.idles`first.idle_fd;
[a633f6f]	835	__atomic_store_n(&this.fd, fd, __ATOMIC_SEQ_CST);
	836	}
	837
[34b8cb7]	838	unlock( this );
[6a9b12b]	839	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	840	}
	841
[dbe9b08]	842	//=============================================================================================
	843	// Unexpected Terminating logic
	844	//=============================================================================================
[92bfda0]	845	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
[e84ab3d]	846	thread$ * thrd = __cfaabi_tls.this_thread;
[9d944b2]	847
[de94a60]	848	if(thrd) {
	849	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	850	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	851
[212c2187]	852	if ( &thrd->self_cor != thrd->curr_cor ) {
	853	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	854	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	855	}
	856	else {
[1c40091]	857	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	858	}
[1c273d0]	859	}
[9d944b2]	860	else {
[de94a60]	861	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	862	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	863	}
	864	}
	865
[92bfda0]	866	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	867	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	868	}
	869
[de94a60]	870	static __spinlock_t kernel_debug_lock;
	871
[9d944b2]	872	extern "C" {
[1c40091]	873	void __cfaabi_bits_acquire() {
[36982fc]	874	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	875	}
	876
[1c40091]	877	void __cfaabi_bits_release() {
[ea7d2b0]	878	unlock( kernel_debug_lock );
[9d944b2]	879	}
[8118303]	880	}
	881
[fa21ac9]	882	//=============================================================================================
	883	// Kernel Utilities
	884	//=============================================================================================
[dddb3dd0]	885	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	886	#include "io/types.hfa"
	887	#endif
	888
[c1c95b1]	889	static inline bool __maybe_io_drain( processor * proc ) {
[e9c0b4c]	890	bool ret = false;
[dddb3dd0]	891	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	892	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	893
	894	// Check if we should drain the queue
	895	$io_context * ctx = proc->io.ctx;
	896	unsigned head = *ctx->cq.head;
	897	unsigned tail = *ctx->cq.tail;
[c1c95b1]	898	if(head == tail) return false;
[57f70ab]	899	#if OLD_MAIN
[34b8cb7]	900	ready_schedule_lock();
	901	ret = __cfa_io_drain( proc );
	902	ready_schedule_unlock();
[57f70ab]	903	#else
	904	ret = __cfa_io_drain( proc );
[34b8cb7]	905	#endif
[dddb3dd0]	906	#endif
[e9c0b4c]	907	return ret;
[dddb3dd0]	908	}
	909
[de94a60]	910	//-----------------------------------------------------------------------------
	911	// Debug
	912	__cfaabi_dbg_debug_do(
[1997b4e]	913	extern "C" {
[ae66348]	914	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	915	this.prev_name = prev_name;
[8fc652e0]	916	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	917	}
[9181f1d]	918	}
[f7d6bb0]	919	)
[2026bb6]	920
	921	//-----------------------------------------------------------------------------
	922	// Debug
[8c50aed]	923	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	924	return true;
	925	}
[c34ebf2]	926
	927	//-----------------------------------------------------------------------------
	928	// Statistics
	929	#if !defined(__CFA_NO_STATISTICS__)
	930	void print_halts( processor & this ) {
	931	this.print_halts = true;
	932	}
[58688bf]	933
[69914cbc]	934	static void crawl_list( cluster * cltr, dlist(processor) & list, unsigned count ) {
[8464edf]	935	/* paranoid */ verify( cltr->stats );
	936
	937	processor * it = &list`first;
	938	for(unsigned i = 0; i < count; i++) {
	939	/* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
	940	/* paranoid */ verify( it->local_data->this_stats );
[c33c2af]	941	// __print_stats( it->local_data->this_stats, cltr->print_stats, "Processor", it->name, (void*)it );
[8464edf]	942	__tally_stats( cltr->stats, it->local_data->this_stats );
	943	it = &(*it)`next;
	944	}
	945	}
	946
	947	void crawl_cluster_stats( cluster & this ) {
	948	// Stop the world, otherwise stats could get really messed-up
	949	// this doesn't solve all problems but does solve many
	950	// so it's probably good enough
[c33c2af]	951	disable_interrupts();
[8464edf]	952	uint_fast32_t last_size = ready_mutate_lock();
	953
	954	crawl_list(&this, this.procs.actives, this.procs.total - this.procs.idle);
	955	crawl_list(&this, this.procs.idles , this.procs.idle );
	956
	957	// Unlock the RWlock
	958	ready_mutate_unlock( last_size );
[c33c2af]	959	enable_interrupts();
[8464edf]	960	}
	961
	962
[58688bf]	963	void print_stats_now( cluster & this, int flags ) {
[8464edf]	964	crawl_cluster_stats( this );
[1b033b8]	965	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	966	}
[c34ebf2]	967	#endif
[8118303]	968	// Local Variables: //
	969	// mode: c //
	970	// tab-width: 4 //
	971	// End: //

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