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ADT ast-experimental enum forall-pointer-decay jacob/cs343-translation pthread-emulation qualifiedEnum

Last change on this file since 181ef73 was c86ee4c, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc
Property mode set to `100644`
File size: 29.6 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>
[58b6d1b]	24	#include <signal.h>
[9d944b2]	25	#include <unistd.h>
[dddb3dd0]	26	extern "C" {
	27	#include <sys/eventfd.h>
	28	}
[8118303]	29
	30	//CFA Includes
[73abe95]	31	#include "kernel_private.hfa"
	32	#include "preemption.hfa"
[8118303]	33
	34	//Private includes
	35	#define __CFA_INVOKE_PRIVATE__
	36	#include "invoke.h"
	37
[89eff25]	38	#if !defined(__CFA_NO_STATISTICS__)
	39	#define __STATS( ...) __VA_ARGS__
	40	#else
	41	#define __STATS( ...)
	42	#endif
[4069faad]	43
[deca0f5]	44	//-----------------------------------------------------------------------------
	45	// Some assembly required
[1805b1b]	46	#if defined( __i386 )
[deca0f5]	47	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	48	// fcw : X87 FPU control word (preserved across function calls)
	49	#define __x87_store \
	50	uint32_t __mxcr; \
	51	uint16_t __fcw; \
	52	__asm__ volatile ( \
	53	"stmxcsr %0\n" \
	54	"fnstcw %1\n" \
	55	: "=m" (__mxcr),\
	56	"=m" (__fcw) \
	57	)
	58
	59	#define __x87_load \
	60	__asm__ volatile ( \
	61	"fldcw %1\n" \
	62	"ldmxcsr %0\n" \
	63	::"m" (__mxcr),\
	64	"m" (__fcw) \
	65	)
	66
	67	#elif defined( __x86_64 )
	68	#define __x87_store \
	69	uint32_t __mxcr; \
	70	uint16_t __fcw; \
	71	__asm__ volatile ( \
	72	"stmxcsr %0\n" \
	73	"fnstcw %1\n" \
	74	: "=m" (__mxcr),\
	75	"=m" (__fcw) \
	76	)
	77
	78	#define __x87_load \
	79	__asm__ volatile ( \
	80	"fldcw %1\n" \
	81	"ldmxcsr %0\n" \
	82	:: "m" (__mxcr),\
	83	"m" (__fcw) \
	84	)
	85
[0190480]	86	#elif defined( __arm__ )
	87	#define __x87_store
	88	#define __x87_load
	89
	90	#elif defined( __aarch64__ )
[74f5c83]	91	#define __x87_store \
	92	uint32_t __fpcntl[2]; \
	93	__asm__ volatile ( \
	94	"mrs x9, FPCR\n" \
	95	"mrs x10, FPSR\n" \
	96	"stp x9, x10, %0\n" \
	97	: "=m" (__fpcntl) : : "x9", "x10" \
	98	)
	99
	100	#define __x87_load \
	101	__asm__ volatile ( \
	102	"ldp x9, x10, %0\n" \
	103	"msr FPSR, x10\n" \
	104	"msr FPCR, x9\n" \
	105	: "=m" (__fpcntl) : : "x9", "x10" \
	106	)
	107
[deca0f5]	108	#else
[0190480]	109	#error unsupported hardware architecture
[deca0f5]	110	#endif
	111
[e84ab3d]	112	extern thread$ * mainThread;
[e660761]	113	extern processor * mainProcessor;
[2ac095d]	114
[92e7631]	115	//-----------------------------------------------------------------------------
	116	// Kernel Scheduling logic
[e84ab3d]	117	static thread$ * __next_thread(cluster * this);
	118	static thread$ * __next_thread_slow(cluster * this);
	119	static inline bool __must_unpark( thread$ * thrd ) __attribute((nonnull(1)));
	120	static void __run_thread(processor * this, thread$ * dst);
[e873838]	121	static void __wake_one(cluster * cltr);
[1eb239e4]	122
[6a9b12b]	123	static void mark_idle (__cluster_proc_list & idles, processor & proc);
	124	static void mark_awake(__cluster_proc_list & idles, processor & proc);
	125	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list idles );
[1eb239e4]	126
[dddb3dd0]	127	extern void __cfa_io_start( processor * );
[c1c95b1]	128	extern bool __cfa_io_drain( processor * );
[dddb3dd0]	129	extern void __cfa_io_flush( processor * );
	130	extern void __cfa_io_stop ( processor * );
[c1c95b1]	131	static inline bool __maybe_io_drain( processor * );
[dddb3dd0]	132
	133	extern void __disable_interrupts_hard();
	134	extern void __enable_interrupts_hard();
[c84e80a]	135
[a3821fa]	136	static inline void __disable_interrupts_checked() {
	137	/* paranoid */ verify( __preemption_enabled() );
	138	disable_interrupts();
	139	/* paranoid */ verify( ! __preemption_enabled() );
	140	}
	141
	142	static inline void __enable_interrupts_checked( bool poll = true ) {
	143	/* paranoid */ verify( ! __preemption_enabled() );
	144	enable_interrupts( poll );
	145	/* paranoid */ verify( __preemption_enabled() );
	146	}
	147
[75f3522]	148	//=============================================================================================
	149	// Kernel Scheduling logic
	150	//=============================================================================================
[8fcbb4c]	151	//Main of the processor contexts
[83a071f9]	152	void main(processorCtx_t & runner) {
[21184e3]	153	// Because of a bug, we couldn't initialized the seed on construction
	154	// Do it here
[8fc652e0]	155	__cfaabi_tls.rand_seed ^= rdtscl();
	156	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	157	__tls_rand_advance_bck();
[21184e3]	158
[83a071f9]	159	processor * this = runner.proc;
[094476d]	160	verify(this);
[c81ebf9]	161
[dddb3dd0]	162	__cfa_io_start( this );
	163
[4069faad]	164	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	165	#if !defined(__CFA_NO_STATISTICS__)
	166	if( this->print_halts ) {
[c993b15]	167	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->unique_id, this->name, (void*)this);
[28d73c1]	168	}
	169	#endif
[b798713]	170
[75f3522]	171	{
[c81ebf9]	172	// Setup preemption data
	173	preemption_scope scope = { this };
	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
[e84ab3d]	183	thread$ * readyThread = 0p;
[1eb239e4]	184	MAIN_LOOP:
	185	for() {
[57f70ab]	186	#define OLD_MAIN 1
	187	#if OLD_MAIN
[dddb3dd0]	188	// Check if there is pending io
	189	__maybe_io_drain( this );
	190
[92e7631]	191	// Try to get the next thread
[8c50aed]	192	readyThread = __next_thread( this->cltr );
[75f3522]	193
[1eb239e4]	194	if( !readyThread ) {
[dddb3dd0]	195	__cfa_io_flush( this );
[1eb239e4]	196	readyThread = __next_thread_slow( this->cltr );
	197	}
[4e6fb8e]	198
[1eb239e4]	199	HALT:
	200	if( !readyThread ) {
	201	// Don't block if we are done
	202	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	203
[1eb239e4]	204	#if !defined(__CFA_NO_STATISTICS__)
	205	__tls_stats()->ready.sleep.halts++;
	206	#endif
[398e8e9]	207
[1eb239e4]	208	// Push self to idle stack
[6a9b12b]	209	mark_idle(this->cltr->procs, * this);
[398e8e9]	210
[1eb239e4]	211	// Confirm the ready-queue is empty
	212	readyThread = __next_thread_slow( this->cltr );
	213	if( readyThread ) {
	214	// A thread was found, cancel the halt
[6a9b12b]	215	mark_awake(this->cltr->procs, * this);
[1eb239e4]	216
	217	#if !defined(__CFA_NO_STATISTICS__)
	218	__tls_stats()->ready.sleep.cancels++;
	219	#endif
	220
	221	// continue the mai loop
	222	break HALT;
	223	}
	224
	225	#if !defined(__CFA_NO_STATISTICS__)
	226	if(this->print_halts) {
[c993b15]	227	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
[1eb239e4]	228	}
	229	#endif
	230
[dddb3dd0]	231	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	232
	233	__disable_interrupts_hard();
	234	eventfd_t val;
	235	eventfd_read( this->idle, &val );
	236	__enable_interrupts_hard();
[1eb239e4]	237
	238	#if !defined(__CFA_NO_STATISTICS__)
	239	if(this->print_halts) {
[c993b15]	240	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
[1eb239e4]	241	}
	242	#endif
	243
	244	// We were woken up, remove self from idle
[6a9b12b]	245	mark_awake(this->cltr->procs, * this);
[1eb239e4]	246
	247	// DON'T just proceed, start looking again
	248	continue MAIN_LOOP;
[64a7146]	249	}
[1eb239e4]	250
	251	/* paranoid */ verify( readyThread );
	252
[dddb3dd0]	253	// Reset io dirty bit
	254	this->io.dirty = false;
	255
[1eb239e4]	256	// We found a thread run it
	257	__run_thread(this, readyThread);
	258
	259	// Are we done?
	260	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	261
[dddb3dd0]	262	if(this->io.pending && !this->io.dirty) {
	263	__cfa_io_flush( this );
	264	}
[89eff25]	265
[34b2796]	266	#else
[57f70ab]	267	#warning new kernel loop
[34b2796]	268	SEARCH: {
	269	/* paranoid */ verify( ! __preemption_enabled() );
	270
	271	// First, lock the scheduler since we are searching for a thread
	272	ready_schedule_lock();
	273
	274	// Try to get the next thread
	275	readyThread = pop_fast( this->cltr );
	276	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	277
	278	// If we can't find a thread, might as well flush any outstanding I/O
	279	if(this->io.pending) { __cfa_io_flush( this ); }
	280
	281	// Spin a little on I/O, just in case
[12daa43]	282	for(5) {
[34b2796]	283	__maybe_io_drain( this );
	284	readyThread = pop_fast( this->cltr );
	285	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	286	}
	287
	288	// no luck, try stealing a few times
[12daa43]	289	for(5) {
[34b2796]	290	if( __maybe_io_drain( this ) ) {
	291	readyThread = pop_fast( this->cltr );
	292	} else {
	293	readyThread = pop_slow( this->cltr );
	294	}
	295	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	296	}
	297
	298	// still no luck, search for a thread
	299	readyThread = pop_search( this->cltr );
	300	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	301
	302	// Don't block if we are done
	303	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	304
	305	__STATS( __tls_stats()->ready.sleep.halts++; )
	306
	307	// Push self to idle stack
	308	ready_schedule_unlock();
	309	mark_idle(this->cltr->procs, * this);
	310	ready_schedule_lock();
	311
	312	// Confirm the ready-queue is empty
	313	__maybe_io_drain( this );
	314	readyThread = pop_search( this->cltr );
	315	ready_schedule_unlock();
	316
	317	if( readyThread ) {
	318	// A thread was found, cancel the halt
	319	mark_awake(this->cltr->procs, * this);
	320
	321	__STATS( __tls_stats()->ready.sleep.cancels++; )
	322
	323	// continue the main loop
	324	break SEARCH;
	325	}
	326
[fb4ccdf]	327	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl()); )
[34b2796]	328	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	329
	330	// __disable_interrupts_hard();
	331	eventfd_t val;
	332	eventfd_read( this->idle, &val );
	333	// __enable_interrupts_hard();
	334
[fb4ccdf]	335	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl()); )
[34b2796]	336
	337	// We were woken up, remove self from idle
	338	mark_awake(this->cltr->procs, * this);
	339
	340	// DON'T just proceed, start looking again
	341	continue MAIN_LOOP;
	342	}
	343
	344	RUN_THREAD:
	345	/* paranoid */ verify( ! __preemption_enabled() );
	346	/* paranoid */ verify( readyThread );
	347
	348	// Reset io dirty bit
	349	this->io.dirty = false;
	350
	351	// We found a thread run it
	352	__run_thread(this, readyThread);
	353
	354	// Are we done?
	355	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	356
	357	if(this->io.pending && !this->io.dirty) {
	358	__cfa_io_flush( this );
	359	}
	360
	361	ready_schedule_lock();
	362	__maybe_io_drain( this );
	363	ready_schedule_unlock();
	364	#endif
[c81ebf9]	365	}
	366
[4069faad]	367	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	368	}
[8118303]	369
[dddb3dd0]	370	__cfa_io_stop( this );
	371
[454f478]	372	post( this->terminated );
[bdeba0b]	373
[28d73c1]	374	if(this == mainProcessor) {
[6a490b2]	375	// HACK : the coroutine context switch expects this_thread to be set
	376	// and it make sense for it to be set in all other cases except here
	377	// fake it
[8fc652e0]	378	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	379	}
[7768b8d]	380
[4069faad]	381	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	382	}
	383
[5c1a531]	384	static int * __volatile_errno() __attribute__((noinline));
	385	static int * __volatile_errno() { asm(""); return &errno; }
	386
[14a61b5]	387	// KERNEL ONLY
[1c273d0]	388	// runThread runs a thread by context switching
	389	// from the processor coroutine to the target thread
[e84ab3d]	390	static void __run_thread(processor * this, thread$ * thrd_dst) {
[8fc652e0]	391	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	392	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	393	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	394	__builtin_prefetch( thrd_dst->context.SP );
	395
[1f45c7d]	396	int curr = __kernel_getcpu();
	397	if(thrd_dst->last_cpu != curr) {
	398	int64_t l = thrd_dst->last_cpu;
	399	int64_t c = curr;
	400	int64_t v = (l << 32) \| c;
	401	__push_stat( __tls_stats(), v, false, "Processor", this );
	402	}
	403
	404	thrd_dst->last_cpu = curr;
	405
[dddb3dd0]	406	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	407
[e84ab3d]	408	coroutine$ * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	409
[9f575ea]	410	// set state of processor coroutine to inactive
	411	verify(proc_cor->state == Active);
[ae7be7a]	412	proc_cor->state = Blocked;
[e8e457e]	413
[9f575ea]	414	// Actually run the thread
[3381ed7]	415	RUNNING: while(true) {
[ff79d5e]	416	thrd_dst->preempted = __NO_PREEMPTION;
	417	thrd_dst->state = Active;
[e8e457e]	418
[58d64a4]	419	// Update global state
[8fc652e0]	420	kernelTLS().this_thread = thrd_dst;
[75f3522]	421
[8fc652e0]	422	/* paranoid */ verify( ! __preemption_enabled() );
	423	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	424	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	425	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	426	/* paranoid */ verify( thrd_dst->state != Halted );
[e84ab3d]	427	/* 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
	428	/* 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]	429	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	430
[3381ed7]	431
[58d64a4]	432
[9f575ea]	433	// set context switch to the thread that the processor is executing
[c7a900a]	434	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	435	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	436
[50871b4]	437
	438
[ac12f1f]	439	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[e84ab3d]	440	/* 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 );
	441	/* 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]	442	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	443	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	444	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	445	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	446
[58d64a4]	447	// Reset global state
[8fc652e0]	448	kernelTLS().this_thread = 0p;
[3381ed7]	449
	450	// We just finished running a thread, there are a few things that could have happened.
	451	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	452	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	453	// 4 - Preempted
	454	// In case 1, we may have won a race so we can't write to the state again.
	455	// In case 2, we lost the race so we now own the thread.
	456
	457	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	458	// The thread was preempted, reschedule it and reset the flag
[254ad1b]	459	schedule_thread$( thrd_dst );
[3381ed7]	460	break RUNNING;
	461	}
[75f3522]	462
[3ea8ad1]	463	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	464	// The thread has halted, it should never be scheduled/run again
[5afb49a]	465	// finish the thread
	466	__thread_finish( thrd_dst );
[ff79d5e]	467	break RUNNING;
	468	}
	469
	470	/* paranoid */ verify( thrd_dst->state == Active );
	471	thrd_dst->state = Blocked;
	472
[3381ed7]	473	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	474	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	475	switch(old_ticket) {
[6a77224]	476	case TICKET_RUNNING:
[3381ed7]	477	// This is case 1, the regular case, nothing more is needed
	478	break RUNNING;
[6a77224]	479	case TICKET_UNBLOCK:
[ec43cf9]	480	#if !defined(__CFA_NO_STATISTICS__)
	481	__tls_stats()->ready.threads.threads++;
	482	#endif
[3381ed7]	483	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	484	// In this case, just run it again.
	485	continue RUNNING;
	486	default:
	487	// This makes no sense, something is wrong abort
[ff79d5e]	488	abort();
[3381ed7]	489	}
[9f575ea]	490	}
[e8e457e]	491
[9f575ea]	492	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	493	proc_cor->state = Active;
[1eb239e4]	494
[dddb3dd0]	495	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	496
[ec43cf9]	497	#if !defined(__CFA_NO_STATISTICS__)
	498	__tls_stats()->ready.threads.threads--;
	499	#endif
	500
[8fc652e0]	501	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	502	}
	503
[14a61b5]	504	// KERNEL_ONLY
[b0c7419]	505	void returnToKernel() {
[8fc652e0]	506	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	507	coroutine$ * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	508	thread$ * thrd_src = kernelTLS().this_thread;
[e8e457e]	509
[89eff25]	510	__STATS( thrd_src->last_proc = kernelTLS().this_processor; )
[29cb302]	511
[9f575ea]	512	// Run the thread on this processor
	513	{
	514	int local_errno = *__volatile_errno();
	515	#if defined( __i386 ) \|\| defined( __x86_64 )
	516	__x87_store;
	517	#endif
[b4b63e8]	518	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	519	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	520	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	521	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	522	#if defined( __i386 ) \|\| defined( __x86_64 )
	523	__x87_load;
	524	#endif
	525	*__volatile_errno() = local_errno;
[8fcbb4c]	526	}
[deca0f5]	527
[29cb302]	528	#if !defined(__CFA_NO_STATISTICS__)
[89eff25]	529	/* paranoid */ verify( thrd_src->last_proc != 0p );
	530	if(thrd_src->last_proc != kernelTLS().this_processor) {
[29cb302]	531	__tls_stats()->ready.threads.migration++;
	532	}
	533	#endif
	534
[8fc652e0]	535	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	536	/* 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 );
	537	/* 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]	538	}
	539
[8def349]	540	//-----------------------------------------------------------------------------
	541	// Scheduler routines
[14a61b5]	542	// KERNEL ONLY
[e84ab3d]	543	static void __schedule_thread( thread$ * thrd ) {
[8fc652e0]	544	/* paranoid */ verify( ! __preemption_enabled() );
[254ad1b]	545	/* paranoid */ verify( ready_schedule_islocked());
[6a490b2]	546	/* paranoid */ verify( thrd );
	547	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	548	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	549	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	550	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	551	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	552	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	553	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	554	/* paranoid */ #endif
[6a490b2]	555	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	556	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	557
[b808625]	558	const bool local = thrd->state != Start;
[ae7be7a]	559	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	560
[ec43cf9]	561	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	562	struct cluster * cl = thrd->curr_cluster;
[89eff25]	563	__STATS(bool outside = thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	564
[254ad1b]	565	// push the thread to the cluster ready-queue
[b808625]	566	push( cl, thrd, local );
[32a8b61]	567
[254ad1b]	568	// variable thrd is no longer safe to use
[734908c]	569	thrd = 0xdeaddeaddeaddeadp;
[32a8b61]	570
[254ad1b]	571	// wake the cluster using the save variable.
	572	__wake_one( cl );
[1c273d0]	573
[ec43cf9]	574	#if !defined(__CFA_NO_STATISTICS__)
	575	if( kernelTLS().this_stats ) {
	576	__tls_stats()->ready.threads.threads++;
[89eff25]	577	if(outside) {
	578	__tls_stats()->ready.threads.extunpark++;
	579	}
[ec43cf9]	580	}
	581	else {
	582	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	583	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[ec43cf9]	584	}
	585	#endif
	586
[254ad1b]	587	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	588	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	589	}
	590
[e84ab3d]	591	void schedule_thread$( thread$ * thrd ) {
[254ad1b]	592	ready_schedule_lock();
	593	__schedule_thread( thrd );
	594	ready_schedule_unlock();
	595	}
	596
[14a61b5]	597	// KERNEL ONLY
[e84ab3d]	598	static inline thread$ * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	599	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	600
[e873838]	601	ready_schedule_lock();
[e84ab3d]	602	thread$ * thrd = pop_fast( this );
[e873838]	603	ready_schedule_unlock();
[7768b8d]	604
[8fc652e0]	605	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	606	return thrd;
[eb2e723]	607	}
	608
[64a7146]	609	// KERNEL ONLY
[e84ab3d]	610	static inline thread$ * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	611	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	612
[e873838]	613	ready_schedule_lock();
[e84ab3d]	614	thread$ * thrd;
[fc59df78]	615	for(25) {
	616	thrd = pop_slow( this );
	617	if(thrd) goto RET;
	618	}
	619	thrd = pop_search( this );
	620
	621	RET:
[e873838]	622	ready_schedule_unlock();
[64a7146]	623
[8fc652e0]	624	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	625	return thrd;
[64a7146]	626	}
	627
[e84ab3d]	628	static inline bool __must_unpark( thread$ * thrd ) {
[ff79d5e]	629	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	630	switch(old_ticket) {
[6a77224]	631	case TICKET_RUNNING:
[3381ed7]	632	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	633	return false;
[6a77224]	634	case TICKET_BLOCKED:
[3381ed7]	635	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	636	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	637	return true;
[3381ed7]	638	default:
	639	// This makes no sense, something is wrong abort
[7ee8153]	640	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	641	}
[eb2e723]	642	}
	643
[e84ab3d]	644	void __kernel_unpark( thread$ * thrd ) {
[e9c0b4c]	645	/* paranoid */ verify( ! __preemption_enabled() );
	646	/* paranoid */ verify( ready_schedule_islocked());
	647
	648	if( !thrd ) return;
	649
	650	if(__must_unpark(thrd)) {
	651	// Wake lost the race,
	652	__schedule_thread( thrd );
	653	}
	654
	655	/* paranoid */ verify( ready_schedule_islocked());
	656	/* paranoid */ verify( ! __preemption_enabled() );
	657	}
	658
[e84ab3d]	659	void unpark( thread$ * thrd ) {
[c6c7e6c]	660	if( !thrd ) return;
[0b33412]	661
[c6c7e6c]	662	if(__must_unpark(thrd)) {
	663	disable_interrupts();
[a3821fa]	664	// Wake lost the race,
[254ad1b]	665	schedule_thread$( thrd );
[a3821fa]	666	enable_interrupts(false);
[de6319f]	667	}
[eb2e723]	668	}
[0b33412]	669
[e235429]	670	void park( void ) {
[a3821fa]	671	__disable_interrupts_checked();
	672	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	673	returnToKernel();
	674	__enable_interrupts_checked();
[0c78741]	675
	676	}
[09800e9]	677
[5afb49a]	678	extern "C" {
	679	// Leave the thread monitor
	680	// last routine called by a thread.
	681	// Should never return
	682	void __cfactx_thrd_leave() {
[e84ab3d]	683	thread$ * thrd = active_thread();
	684	monitor$ * this = &thrd->self_mon;
[5afb49a]	685
	686	// Lock the monitor now
	687	lock( this->lock __cfaabi_dbg_ctx2 );
	688
	689	disable_interrupts();
	690
[9d6e1b8a]	691	/* paranoid */ verify( ! __preemption_enabled() );
	692	/* paranoid */ verify( thrd->state == Active );
	693	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	694	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	695	/* paranoid */ verify( thrd->context.SP );
[e84ab3d]	696	/* 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 );
	697	/* 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]	698
[3ea8ad1]	699	thrd->state = Halting;
[58688bf]	700	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	701	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	702	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	703
	704	// Leave the thread
	705	returnToKernel();
	706
	707	// Control flow should never reach here!
[9d6e1b8a]	708	abort();
[5afb49a]	709	}
[09800e9]	710	}
	711
[14a61b5]	712	// KERNEL ONLY
[3381ed7]	713	bool force_yield( __Preemption_Reason reason ) {
[a3821fa]	714	__disable_interrupts_checked();
[e84ab3d]	715	thread$ * thrd = kernelTLS().this_thread;
[a3821fa]	716	/* paranoid */ verify(thrd->state == Active);
	717
	718	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	719	// it was going to park itself. If that is the case and it is already using the
	720	// intrusive fields then we can't use them to preempt the thread
	721	// If that is the case, abandon the preemption.
	722	bool preempted = false;
	723	if(thrd->link.next == 0p) {
	724	preempted = true;
	725	thrd->preempted = reason;
	726	returnToKernel();
	727	}
	728	__enable_interrupts_checked( false );
[3381ed7]	729	return preempted;
[f2b12406]	730	}
	731
[14a61b5]	732	//=============================================================================================
[92e7631]	733	// Kernel Idle Sleep
[14a61b5]	734	//=============================================================================================
[64a7146]	735	// Wake a thread from the front if there are any
[e873838]	736	static void __wake_one(cluster * this) {
[8fc652e0]	737	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	738	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	739
[64a7146]	740	// Check if there is a sleeping processor
[1eb239e4]	741	processor * p;
	742	unsigned idle;
	743	unsigned total;
[6a9b12b]	744	[idle, total, p] = query_idles(this->procs);
[14a61b5]	745
[64a7146]	746	// If no one is sleeping, we are done
[1eb239e4]	747	if( idle == 0 ) return;
[14a61b5]	748
[64a7146]	749	// We found a processor, wake it up
[dddb3dd0]	750	eventfd_t val;
	751	val = 1;
	752	eventfd_write( p->idle, val );
[14a61b5]	753
[1eb239e4]	754	#if !defined(__CFA_NO_STATISTICS__)
[5cb51502]	755	if( kernelTLS().this_stats ) {
	756	__tls_stats()->ready.sleep.wakes++;
	757	}
	758	else {
	759	__atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
	760	}
[1eb239e4]	761	#endif
	762
[e873838]	763	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	764	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	765
	766	return;
[64a7146]	767	}
[14a61b5]	768
[64a7146]	769	// Unconditionnaly wake a thread
[1eb239e4]	770	void __wake_proc(processor * this) {
[64a7146]	771	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	772
[a3821fa]	773	__disable_interrupts_checked();
[8fc652e0]	774	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	775	eventfd_t val;
	776	val = 1;
[55d6affb]	777	eventfd_write( this->idle, val );
[a3821fa]	778	__enable_interrupts_checked();
[92e7631]	779	}
	780
[6a9b12b]	781	static void mark_idle(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	782	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	783	lock( this );
	784	this.idle++;
	785	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	786	remove(proc);
[6a9b12b]	787	insert_first(this.idles, proc);
[1eb239e4]	788	unlock( this );
[8fc652e0]	789	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	790	}
[8e16177]	791
[6a9b12b]	792	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	793	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	794	lock( this );
	795	this.idle--;
	796	/* paranoid */ verify( this.idle >= 0 );
	797	remove(proc);
[fc59b580]	798	insert_last(this.actives, proc);
[1eb239e4]	799	unlock( this );
[8fc652e0]	800	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	801	}
[c34ebf2]	802
[6a9b12b]	803	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list this ) {
	804	/* paranoid */ verify( ! __preemption_enabled() );
	805	/* paranoid */ verify( ready_schedule_islocked() );
	806
[1eb239e4]	807	for() {
	808	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	809	if( 1 == (l % 2) ) { Pause(); continue; }
	810	unsigned idle = this.idle;
	811	unsigned total = this.total;
[6a9b12b]	812	processor * proc = &this.idles`first;
[7fdae38]	813	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	814	asm volatile("": : :"memory");
[1eb239e4]	815	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	816	return [idle, total, proc];
	817	}
[6a9b12b]	818
	819	/* paranoid */ verify( ready_schedule_islocked() );
	820	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	821	}
	822
[dbe9b08]	823	//=============================================================================================
	824	// Unexpected Terminating logic
	825	//=============================================================================================
[92bfda0]	826	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
[e84ab3d]	827	thread$ * thrd = __cfaabi_tls.this_thread;
[9d944b2]	828
[de94a60]	829	if(thrd) {
	830	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	831	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	832
[212c2187]	833	if ( &thrd->self_cor != thrd->curr_cor ) {
	834	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	835	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	836	}
	837	else {
[1c40091]	838	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	839	}
[1c273d0]	840	}
[9d944b2]	841	else {
[de94a60]	842	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	843	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	844	}
	845	}
	846
[92bfda0]	847	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	848	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	849	}
	850
[de94a60]	851	static __spinlock_t kernel_debug_lock;
	852
[9d944b2]	853	extern "C" {
[1c40091]	854	void __cfaabi_bits_acquire() {
[36982fc]	855	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	856	}
	857
[1c40091]	858	void __cfaabi_bits_release() {
[ea7d2b0]	859	unlock( kernel_debug_lock );
[9d944b2]	860	}
[8118303]	861	}
	862
[fa21ac9]	863	//=============================================================================================
	864	// Kernel Utilities
	865	//=============================================================================================
[dddb3dd0]	866	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	867	#include "io/types.hfa"
	868	#endif
	869
[c1c95b1]	870	static inline bool __maybe_io_drain( processor * proc ) {
[e9c0b4c]	871	bool ret = false;
[dddb3dd0]	872	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	873	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	874
	875	// Check if we should drain the queue
	876	$io_context * ctx = proc->io.ctx;
	877	unsigned head = *ctx->cq.head;
	878	unsigned tail = *ctx->cq.tail;
[c1c95b1]	879	if(head == tail) return false;
[57f70ab]	880	#if OLD_MAIN
[b7fd2db6]	881	ready_schedule_lock();
[e9c0b4c]	882	ret = __cfa_io_drain( proc );
[b7fd2db6]	883	ready_schedule_unlock();
[57f70ab]	884	#else
	885	ret = __cfa_io_drain( proc );
	886	#endif
[dddb3dd0]	887	#endif
[e9c0b4c]	888	return ret;
[dddb3dd0]	889	}
	890
[de94a60]	891	//-----------------------------------------------------------------------------
	892	// Debug
	893	__cfaabi_dbg_debug_do(
[1997b4e]	894	extern "C" {
[ae66348]	895	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	896	this.prev_name = prev_name;
[8fc652e0]	897	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	898	}
[9181f1d]	899	}
[f7d6bb0]	900	)
[2026bb6]	901
	902	//-----------------------------------------------------------------------------
	903	// Debug
[8c50aed]	904	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	905	return true;
	906	}
[c34ebf2]	907
	908	//-----------------------------------------------------------------------------
	909	// Statistics
	910	#if !defined(__CFA_NO_STATISTICS__)
	911	void print_halts( processor & this ) {
	912	this.print_halts = true;
	913	}
[58688bf]	914
[69914cbc]	915	static void crawl_list( cluster * cltr, dlist(processor) & list, unsigned count ) {
[8464edf]	916	/* paranoid */ verify( cltr->stats );
	917
	918	processor * it = &list`first;
	919	for(unsigned i = 0; i < count; i++) {
	920	/* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
	921	/* paranoid */ verify( it->local_data->this_stats );
	922	__tally_stats( cltr->stats, it->local_data->this_stats );
	923	it = &(*it)`next;
	924	}
	925	}
	926
	927	void crawl_cluster_stats( cluster & this ) {
	928	// Stop the world, otherwise stats could get really messed-up
	929	// this doesn't solve all problems but does solve many
	930	// so it's probably good enough
	931	uint_fast32_t last_size = ready_mutate_lock();
	932
	933	crawl_list(&this, this.procs.actives, this.procs.total - this.procs.idle);
	934	crawl_list(&this, this.procs.idles , this.procs.idle );
	935
	936	// Unlock the RWlock
	937	ready_mutate_unlock( last_size );
	938	}
	939
	940
[58688bf]	941	void print_stats_now( cluster & this, int flags ) {
[8464edf]	942	crawl_cluster_stats( this );
[1b033b8]	943	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	944	}
[c34ebf2]	945	#endif
[8118303]	946	// Local Variables: //
	947	// mode: c //
	948	// tab-width: 4 //
	949	// End: //

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