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

Last change on this file since 471ff17 was 96bfdde7, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
Forgot to add symmetric change to last verify change
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Rev	Line
[8118303]	1	//
	2	// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
	3	//
	4	// The contents of this file are covered under the licence agreement in the
	5	// file "LICENCE" distributed with Cforall.
	6	//
	7	// kernel.c --
	8	//
	9	// Author : Thierry Delisle
[75f3522]	10	// Created On : Tue Jan 17 12:27:26 2017
[6b0b624]	11	// Last Modified By : Peter A. Buhr
[0190480]	12	// Last Modified On : Mon Aug 31 07:08:20 2020
	13	// Update Count : 71
[8118303]	14	//
	15
[2026bb6]	16	#define __cforall_thread__
[4069faad]	17	// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
[2026bb6]	18
[8118303]	19	//C Includes
[214e8da]	20	#include <errno.h>
[9d944b2]	21	#include <stdio.h>
[58b6d1b]	22	#include <signal.h>
[9d944b2]	23	#include <unistd.h>
[dddb3dd0]	24	extern "C" {
	25	#include <sys/eventfd.h>
	26	}
[8118303]	27
	28	//CFA Includes
[73abe95]	29	#include "kernel_private.hfa"
	30	#include "preemption.hfa"
[8118303]	31
	32	//Private includes
	33	#define __CFA_INVOKE_PRIVATE__
	34	#include "invoke.h"
	35
[89eff25]	36	#if !defined(__CFA_NO_STATISTICS__)
	37	#define __STATS( ...) __VA_ARGS__
	38	#else
	39	#define __STATS( ...)
	40	#endif
[4069faad]	41
[deca0f5]	42	//-----------------------------------------------------------------------------
	43	// Some assembly required
[1805b1b]	44	#if defined( __i386 )
[deca0f5]	45	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	46	// fcw : X87 FPU control word (preserved across function calls)
	47	#define __x87_store \
	48	uint32_t __mxcr; \
	49	uint16_t __fcw; \
	50	__asm__ volatile ( \
	51	"stmxcsr %0\n" \
	52	"fnstcw %1\n" \
	53	: "=m" (__mxcr),\
	54	"=m" (__fcw) \
	55	)
	56
	57	#define __x87_load \
	58	__asm__ volatile ( \
	59	"fldcw %1\n" \
	60	"ldmxcsr %0\n" \
	61	::"m" (__mxcr),\
	62	"m" (__fcw) \
	63	)
	64
	65	#elif defined( __x86_64 )
	66	#define __x87_store \
	67	uint32_t __mxcr; \
	68	uint16_t __fcw; \
	69	__asm__ volatile ( \
	70	"stmxcsr %0\n" \
	71	"fnstcw %1\n" \
	72	: "=m" (__mxcr),\
	73	"=m" (__fcw) \
	74	)
	75
	76	#define __x87_load \
	77	__asm__ volatile ( \
	78	"fldcw %1\n" \
	79	"ldmxcsr %0\n" \
	80	:: "m" (__mxcr),\
	81	"m" (__fcw) \
	82	)
	83
[0190480]	84	#elif defined( __arm__ )
	85	#define __x87_store
	86	#define __x87_load
	87
	88	#elif defined( __aarch64__ )
[74f5c83]	89	#define __x87_store \
	90	uint32_t __fpcntl[2]; \
	91	__asm__ volatile ( \
	92	"mrs x9, FPCR\n" \
	93	"mrs x10, FPSR\n" \
	94	"stp x9, x10, %0\n" \
	95	: "=m" (__fpcntl) : : "x9", "x10" \
	96	)
	97
	98	#define __x87_load \
	99	__asm__ volatile ( \
	100	"ldp x9, x10, %0\n" \
	101	"msr FPSR, x10\n" \
	102	"msr FPCR, x9\n" \
	103	: "=m" (__fpcntl) : : "x9", "x10" \
	104	)
	105
[deca0f5]	106	#else
[0190480]	107	#error unsupported hardware architecture
[deca0f5]	108	#endif
	109
[e660761]	110	extern $thread * mainThread;
	111	extern processor * mainProcessor;
[2ac095d]	112
[92e7631]	113	//-----------------------------------------------------------------------------
	114	// Kernel Scheduling logic
	115	static $thread * __next_thread(cluster * this);
[1eb239e4]	116	static $thread * __next_thread_slow(cluster * this);
[c6c7e6c]	117	static inline bool __must_unpark( $thread * thrd ) __attribute((nonnull(1)));
[92e7631]	118	static void __run_thread(processor * this, $thread * dst);
[e873838]	119	static void __wake_one(cluster * cltr);
[1eb239e4]	120
[6a9b12b]	121	static void mark_idle (__cluster_proc_list & idles, processor & proc);
	122	static void mark_awake(__cluster_proc_list & idles, processor & proc);
	123	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list idles );
[1eb239e4]	124
[dddb3dd0]	125	extern void __cfa_io_start( processor * );
[c1c95b1]	126	extern bool __cfa_io_drain( processor * );
[dddb3dd0]	127	extern void __cfa_io_flush( processor * );
	128	extern void __cfa_io_stop ( processor * );
[c1c95b1]	129	static inline bool __maybe_io_drain( processor * );
[dddb3dd0]	130
	131	extern void __disable_interrupts_hard();
	132	extern void __enable_interrupts_hard();
[c84e80a]	133
[a3821fa]	134	static inline void __disable_interrupts_checked() {
	135	/* paranoid */ verify( __preemption_enabled() );
	136	disable_interrupts();
	137	/* paranoid */ verify( ! __preemption_enabled() );
	138	}
	139
	140	static inline void __enable_interrupts_checked( bool poll = true ) {
	141	/* paranoid */ verify( ! __preemption_enabled() );
	142	enable_interrupts( poll );
	143	/* paranoid */ verify( __preemption_enabled() );
	144	}
	145
[75f3522]	146	//=============================================================================================
	147	// Kernel Scheduling logic
	148	//=============================================================================================
[8fcbb4c]	149	//Main of the processor contexts
[83a071f9]	150	void main(processorCtx_t & runner) {
[21184e3]	151	// Because of a bug, we couldn't initialized the seed on construction
	152	// Do it here
[8fc652e0]	153	__cfaabi_tls.rand_seed ^= rdtscl();
	154	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	155	__tls_rand_advance_bck();
[21184e3]	156
[83a071f9]	157	processor * this = runner.proc;
[094476d]	158	verify(this);
[c81ebf9]	159
[dddb3dd0]	160	__cfa_io_start( this );
	161
[4069faad]	162	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	163	#if !defined(__CFA_NO_STATISTICS__)
	164	if( this->print_halts ) {
[c993b15]	165	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->unique_id, this->name, (void*)this);
[28d73c1]	166	}
	167	#endif
[b798713]	168
[75f3522]	169	{
[c81ebf9]	170	// Setup preemption data
	171	preemption_scope scope = { this };
	172
[a5e7233]	173	// if we need to run some special setup, now is the time to do it.
	174	if(this->init.thrd) {
	175	this->init.thrd->curr_cluster = this->cltr;
	176	__run_thread(this, this->init.thrd);
	177	}
[325e6ea]	178
[4069faad]	179	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	180
[ac2b598]	181	$thread * readyThread = 0p;
[1eb239e4]	182	MAIN_LOOP:
	183	for() {
[57f70ab]	184	#define OLD_MAIN 1
	185	#if OLD_MAIN
[dddb3dd0]	186	// Check if there is pending io
	187	__maybe_io_drain( this );
	188
[92e7631]	189	// Try to get the next thread
[8c50aed]	190	readyThread = __next_thread( this->cltr );
[75f3522]	191
[1eb239e4]	192	if( !readyThread ) {
[dddb3dd0]	193	__cfa_io_flush( this );
[1eb239e4]	194	readyThread = __next_thread_slow( this->cltr );
	195	}
[4e6fb8e]	196
[1eb239e4]	197	HALT:
	198	if( !readyThread ) {
	199	// Don't block if we are done
	200	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	201
[1eb239e4]	202	#if !defined(__CFA_NO_STATISTICS__)
	203	__tls_stats()->ready.sleep.halts++;
	204	#endif
[398e8e9]	205
[1eb239e4]	206	// Push self to idle stack
[6a9b12b]	207	mark_idle(this->cltr->procs, * this);
[398e8e9]	208
[1eb239e4]	209	// Confirm the ready-queue is empty
	210	readyThread = __next_thread_slow( this->cltr );
	211	if( readyThread ) {
	212	// A thread was found, cancel the halt
[6a9b12b]	213	mark_awake(this->cltr->procs, * this);
[1eb239e4]	214
	215	#if !defined(__CFA_NO_STATISTICS__)
	216	__tls_stats()->ready.sleep.cancels++;
	217	#endif
	218
	219	// continue the mai loop
	220	break HALT;
	221	}
	222
	223	#if !defined(__CFA_NO_STATISTICS__)
	224	if(this->print_halts) {
[c993b15]	225	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
[1eb239e4]	226	}
	227	#endif
	228
[dddb3dd0]	229	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	230
	231	__disable_interrupts_hard();
	232	eventfd_t val;
	233	eventfd_read( this->idle, &val );
	234	__enable_interrupts_hard();
[1eb239e4]	235
	236	#if !defined(__CFA_NO_STATISTICS__)
	237	if(this->print_halts) {
[c993b15]	238	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
[1eb239e4]	239	}
	240	#endif
	241
	242	// We were woken up, remove self from idle
[6a9b12b]	243	mark_awake(this->cltr->procs, * this);
[1eb239e4]	244
	245	// DON'T just proceed, start looking again
	246	continue MAIN_LOOP;
[64a7146]	247	}
[1eb239e4]	248
	249	/* paranoid */ verify( readyThread );
	250
[dddb3dd0]	251	// Reset io dirty bit
	252	this->io.dirty = false;
	253
[1eb239e4]	254	// We found a thread run it
	255	__run_thread(this, readyThread);
	256
	257	// Are we done?
	258	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	259
[dddb3dd0]	260	if(this->io.pending && !this->io.dirty) {
	261	__cfa_io_flush( this );
	262	}
[89eff25]	263
[34b2796]	264	#else
[57f70ab]	265	#warning new kernel loop
[34b2796]	266	SEARCH: {
	267	/* paranoid */ verify( ! __preemption_enabled() );
	268
	269	// First, lock the scheduler since we are searching for a thread
	270	ready_schedule_lock();
	271
	272	// Try to get the next thread
	273	readyThread = pop_fast( this->cltr );
	274	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	275
	276	// If we can't find a thread, might as well flush any outstanding I/O
	277	if(this->io.pending) { __cfa_io_flush( this ); }
	278
	279	// Spin a little on I/O, just in case
[57f70ab]	280	for(5) {
[34b2796]	281	__maybe_io_drain( this );
	282	readyThread = pop_fast( this->cltr );
	283	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	284	}
	285
	286	// no luck, try stealing a few times
[57f70ab]	287	for(5) {
[34b2796]	288	if( __maybe_io_drain( this ) ) {
	289	readyThread = pop_fast( this->cltr );
	290	} else {
	291	readyThread = pop_slow( this->cltr );
	292	}
	293	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	294	}
	295
	296	// still no luck, search for a thread
	297	readyThread = pop_search( this->cltr );
	298	if(readyThread) { ready_schedule_unlock(); break SEARCH; }
	299
	300	// Don't block if we are done
	301	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	302
	303	__STATS( __tls_stats()->ready.sleep.halts++; )
	304
	305	// Push self to idle stack
	306	ready_schedule_unlock();
	307	mark_idle(this->cltr->procs, * this);
	308	ready_schedule_lock();
	309
	310	// Confirm the ready-queue is empty
	311	__maybe_io_drain( this );
	312	readyThread = pop_search( this->cltr );
	313	ready_schedule_unlock();
	314
	315	if( readyThread ) {
	316	// A thread was found, cancel the halt
	317	mark_awake(this->cltr->procs, * this);
	318
	319	__STATS( __tls_stats()->ready.sleep.cancels++; )
	320
	321	// continue the main loop
	322	break SEARCH;
	323	}
	324
[fb4ccdf]	325	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl()); )
[34b2796]	326	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	327
	328	// __disable_interrupts_hard();
	329	eventfd_t val;
	330	eventfd_read( this->idle, &val );
	331	// __enable_interrupts_hard();
	332
[fb4ccdf]	333	__STATS( if(this->print_halts) __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl()); )
[34b2796]	334
	335	// We were woken up, remove self from idle
	336	mark_awake(this->cltr->procs, * this);
	337
	338	// DON'T just proceed, start looking again
	339	continue MAIN_LOOP;
	340	}
	341
	342	RUN_THREAD:
	343	/* paranoid */ verify( ! __preemption_enabled() );
	344	/* paranoid */ verify( readyThread );
	345
	346	// Reset io dirty bit
	347	this->io.dirty = false;
	348
	349	// We found a thread run it
	350	__run_thread(this, readyThread);
	351
	352	// Are we done?
	353	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
	354
	355	if(this->io.pending && !this->io.dirty) {
	356	__cfa_io_flush( this );
	357	}
	358
	359	ready_schedule_lock();
	360	__maybe_io_drain( this );
	361	ready_schedule_unlock();
	362	#endif
[c81ebf9]	363	}
	364
[4069faad]	365	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	366	}
[8118303]	367
[dddb3dd0]	368	__cfa_io_stop( this );
	369
[454f478]	370	post( this->terminated );
[bdeba0b]	371
[28d73c1]	372	if(this == mainProcessor) {
[6a490b2]	373	// HACK : the coroutine context switch expects this_thread to be set
	374	// and it make sense for it to be set in all other cases except here
	375	// fake it
[8fc652e0]	376	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	377	}
[7768b8d]	378
[4069faad]	379	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	380	}
	381
[5c1a531]	382	static int * __volatile_errno() __attribute__((noinline));
	383	static int * __volatile_errno() { asm(""); return &errno; }
	384
[14a61b5]	385	// KERNEL ONLY
[1c273d0]	386	// runThread runs a thread by context switching
	387	// from the processor coroutine to the target thread
[ac2b598]	388	static void __run_thread(processor * this, $thread * thrd_dst) {
[8fc652e0]	389	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	390	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	391	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	392	__builtin_prefetch( thrd_dst->context.SP );
	393
[dddb3dd0]	394	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	395
[ac2b598]	396	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	397
[9f575ea]	398	// set state of processor coroutine to inactive
	399	verify(proc_cor->state == Active);
[ae7be7a]	400	proc_cor->state = Blocked;
[e8e457e]	401
[9f575ea]	402	// Actually run the thread
[3381ed7]	403	RUNNING: while(true) {
[ff79d5e]	404	thrd_dst->preempted = __NO_PREEMPTION;
	405	thrd_dst->state = Active;
[e8e457e]	406
[58d64a4]	407	// Update global state
[8fc652e0]	408	kernelTLS().this_thread = thrd_dst;
[75f3522]	409
[8fc652e0]	410	/* paranoid */ verify( ! __preemption_enabled() );
	411	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	412	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	413	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	414	/* paranoid */ verify( thrd_dst->state != Halted );
[96bfdde7]	415	/* 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
	416	/* 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]	417	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	418
[3381ed7]	419
[58d64a4]	420
[9f575ea]	421	// set context switch to the thread that the processor is executing
[c7a900a]	422	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	423	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	424
[ac12f1f]	425	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[ab5baab]	426	/* 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 );
	427	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) \|\| thrd_dst->corctx_flag, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
[b4b63e8]	428	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	429	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	430	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	431	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	432
[58d64a4]	433	// Reset global state
[8fc652e0]	434	kernelTLS().this_thread = 0p;
[3381ed7]	435
	436	// We just finished running a thread, there are a few things that could have happened.
	437	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	438	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	439	// 4 - Preempted
	440	// In case 1, we may have won a race so we can't write to the state again.
	441	// In case 2, we lost the race so we now own the thread.
	442
	443	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	444	// The thread was preempted, reschedule it and reset the flag
[254ad1b]	445	schedule_thread$( thrd_dst );
[3381ed7]	446	break RUNNING;
	447	}
[75f3522]	448
[3ea8ad1]	449	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	450	// The thread has halted, it should never be scheduled/run again
[5afb49a]	451	// finish the thread
	452	__thread_finish( thrd_dst );
[ff79d5e]	453	break RUNNING;
	454	}
	455
	456	/* paranoid */ verify( thrd_dst->state == Active );
	457	thrd_dst->state = Blocked;
	458
[3381ed7]	459	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	460	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	461	switch(old_ticket) {
[6a77224]	462	case TICKET_RUNNING:
[3381ed7]	463	// This is case 1, the regular case, nothing more is needed
	464	break RUNNING;
[6a77224]	465	case TICKET_UNBLOCK:
[ec43cf9]	466	#if !defined(__CFA_NO_STATISTICS__)
	467	__tls_stats()->ready.threads.threads++;
[73f4d08]	468	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	469	#endif
[3381ed7]	470	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	471	// In this case, just run it again.
	472	continue RUNNING;
	473	default:
	474	// This makes no sense, something is wrong abort
[ff79d5e]	475	abort();
[3381ed7]	476	}
[9f575ea]	477	}
[e8e457e]	478
[9f575ea]	479	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	480	proc_cor->state = Active;
[1eb239e4]	481
[dddb3dd0]	482	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	483
[ec43cf9]	484	#if !defined(__CFA_NO_STATISTICS__)
	485	__tls_stats()->ready.threads.threads--;
[73f4d08]	486	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	487	#endif
	488
[8fc652e0]	489	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	490	}
	491
[14a61b5]	492	// KERNEL_ONLY
[b0c7419]	493	void returnToKernel() {
[8fc652e0]	494	/* paranoid */ verify( ! __preemption_enabled() );
	495	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	496	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	497
[89eff25]	498	__STATS( thrd_src->last_proc = kernelTLS().this_processor; )
[29cb302]	499
[9f575ea]	500	// Run the thread on this processor
	501	{
	502	int local_errno = *__volatile_errno();
	503	#if defined( __i386 ) \|\| defined( __x86_64 )
	504	__x87_store;
	505	#endif
[b4b63e8]	506	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	507	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	508	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	509	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	510	#if defined( __i386 ) \|\| defined( __x86_64 )
	511	__x87_load;
	512	#endif
	513	*__volatile_errno() = local_errno;
[8fcbb4c]	514	}
[deca0f5]	515
[29cb302]	516	#if !defined(__CFA_NO_STATISTICS__)
[89eff25]	517	/* paranoid */ verify( thrd_src->last_proc != 0p );
	518	if(thrd_src->last_proc != kernelTLS().this_processor) {
[29cb302]	519	__tls_stats()->ready.threads.migration++;
	520	}
	521	#endif
	522
[8fc652e0]	523	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	524	/* 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 );
	525	/* 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]	526	}
	527
[8def349]	528	//-----------------------------------------------------------------------------
	529	// Scheduler routines
[14a61b5]	530	// KERNEL ONLY
[e9c0b4c]	531	static void __schedule_thread( $thread * thrd ) {
[8fc652e0]	532	/* paranoid */ verify( ! __preemption_enabled() );
[254ad1b]	533	/* paranoid */ verify( ready_schedule_islocked());
[6a490b2]	534	/* paranoid */ verify( thrd );
	535	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	536	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	537	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	538	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	539	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	540	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	541	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	542	/* paranoid */ #endif
[6a490b2]	543	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	544	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	545
[b808625]	546	const bool local = thrd->state != Start;
[ae7be7a]	547	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	548
[ec43cf9]	549	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	550	struct cluster * cl = thrd->curr_cluster;
[89eff25]	551	__STATS(bool outside = thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	552
[254ad1b]	553	// push the thread to the cluster ready-queue
[b808625]	554	push( cl, thrd, local );
[32a8b61]	555
[254ad1b]	556	// variable thrd is no longer safe to use
[734908c]	557	thrd = 0xdeaddeaddeaddeadp;
[32a8b61]	558
[254ad1b]	559	// wake the cluster using the save variable.
	560	__wake_one( cl );
[1c273d0]	561
[ec43cf9]	562	#if !defined(__CFA_NO_STATISTICS__)
	563	if( kernelTLS().this_stats ) {
	564	__tls_stats()->ready.threads.threads++;
[89eff25]	565	if(outside) {
	566	__tls_stats()->ready.threads.extunpark++;
	567	}
[73f4d08]	568	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", kernelTLS().this_processor );
[ec43cf9]	569	}
	570	else {
	571	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	572	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[73f4d08]	573	__push_stat( cl->stats, cl->stats->ready.threads.threads, true, "Cluster", cl );
[ec43cf9]	574	}
	575	#endif
	576
[254ad1b]	577	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	578	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	579	}
	580
[254ad1b]	581	void schedule_thread$( $thread * thrd ) {
	582	ready_schedule_lock();
	583	__schedule_thread( thrd );
	584	ready_schedule_unlock();
	585	}
	586
[14a61b5]	587	// KERNEL ONLY
[1eb239e4]	588	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	589	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	590
[e873838]	591	ready_schedule_lock();
[431cd4f]	592	$thread * thrd = pop_fast( this );
[e873838]	593	ready_schedule_unlock();
[7768b8d]	594
[8fc652e0]	595	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	596	return thrd;
[eb2e723]	597	}
	598
[64a7146]	599	// KERNEL ONLY
[1eb239e4]	600	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	601	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	602
[e873838]	603	ready_schedule_lock();
[fc59df78]	604	$thread * thrd;
	605	for(25) {
	606	thrd = pop_slow( this );
	607	if(thrd) goto RET;
	608	}
	609	thrd = pop_search( this );
	610
	611	RET:
[e873838]	612	ready_schedule_unlock();
[64a7146]	613
[8fc652e0]	614	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	615	return thrd;
[64a7146]	616	}
	617
[c6c7e6c]	618	static inline bool __must_unpark( $thread * thrd ) {
[ff79d5e]	619	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	620	switch(old_ticket) {
[6a77224]	621	case TICKET_RUNNING:
[3381ed7]	622	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	623	return false;
[6a77224]	624	case TICKET_BLOCKED:
[3381ed7]	625	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	626	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	627	return true;
[3381ed7]	628	default:
	629	// This makes no sense, something is wrong abort
[7ee8153]	630	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	631	}
[eb2e723]	632	}
	633
[e9c0b4c]	634	void __kernel_unpark( $thread * thrd ) {
	635	/* paranoid */ verify( ! __preemption_enabled() );
	636	/* paranoid */ verify( ready_schedule_islocked());
	637
	638	if( !thrd ) return;
	639
	640	if(__must_unpark(thrd)) {
	641	// Wake lost the race,
	642	__schedule_thread( thrd );
	643	}
	644
	645	/* paranoid */ verify( ready_schedule_islocked());
	646	/* paranoid */ verify( ! __preemption_enabled() );
	647	}
	648
[c6c7e6c]	649	void unpark( $thread * thrd ) {
	650	if( !thrd ) return;
[0b33412]	651
[c6c7e6c]	652	if(__must_unpark(thrd)) {
	653	disable_interrupts();
[a3821fa]	654	// Wake lost the race,
[254ad1b]	655	schedule_thread$( thrd );
[a3821fa]	656	enable_interrupts(false);
[de6319f]	657	}
[eb2e723]	658	}
[0b33412]	659
[e235429]	660	void park( void ) {
[a3821fa]	661	__disable_interrupts_checked();
	662	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	663	returnToKernel();
	664	__enable_interrupts_checked();
[0c78741]	665
	666	}
[09800e9]	667
[5afb49a]	668	extern "C" {
	669	// Leave the thread monitor
	670	// last routine called by a thread.
	671	// Should never return
	672	void __cfactx_thrd_leave() {
[8fc652e0]	673	$thread * thrd = active_thread();
[5afb49a]	674	$monitor * this = &thrd->self_mon;
	675
	676	// Lock the monitor now
	677	lock( this->lock __cfaabi_dbg_ctx2 );
	678
	679	disable_interrupts();
	680
[9d6e1b8a]	681	/* paranoid */ verify( ! __preemption_enabled() );
	682	/* paranoid */ verify( thrd->state == Active );
	683	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	684	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	685	/* paranoid */ verify( thrd->context.SP );
	686	/* 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 );
	687	/* 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 );
	688
[3ea8ad1]	689	thrd->state = Halting;
[58688bf]	690	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	691	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	692	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	693
	694	// Leave the thread
	695	returnToKernel();
	696
	697	// Control flow should never reach here!
[9d6e1b8a]	698	abort();
[5afb49a]	699	}
[09800e9]	700	}
	701
[14a61b5]	702	// KERNEL ONLY
[3381ed7]	703	bool force_yield( __Preemption_Reason reason ) {
[a3821fa]	704	__disable_interrupts_checked();
	705	$thread * thrd = kernelTLS().this_thread;
	706	/* paranoid */ verify(thrd->state == Active);
	707
	708	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	709	// it was going to park itself. If that is the case and it is already using the
	710	// intrusive fields then we can't use them to preempt the thread
	711	// If that is the case, abandon the preemption.
	712	bool preempted = false;
	713	if(thrd->link.next == 0p) {
	714	preempted = true;
	715	thrd->preempted = reason;
	716	returnToKernel();
	717	}
	718	__enable_interrupts_checked( false );
[3381ed7]	719	return preempted;
[f2b12406]	720	}
	721
[14a61b5]	722	//=============================================================================================
[92e7631]	723	// Kernel Idle Sleep
[14a61b5]	724	//=============================================================================================
[64a7146]	725	// Wake a thread from the front if there are any
[e873838]	726	static void __wake_one(cluster * this) {
[8fc652e0]	727	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	728	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	729
[64a7146]	730	// Check if there is a sleeping processor
[1eb239e4]	731	processor * p;
	732	unsigned idle;
	733	unsigned total;
[6a9b12b]	734	[idle, total, p] = query_idles(this->procs);
[14a61b5]	735
[64a7146]	736	// If no one is sleeping, we are done
[1eb239e4]	737	if( idle == 0 ) return;
[14a61b5]	738
[64a7146]	739	// We found a processor, wake it up
[dddb3dd0]	740	eventfd_t val;
	741	val = 1;
	742	eventfd_write( p->idle, val );
[14a61b5]	743
[1eb239e4]	744	#if !defined(__CFA_NO_STATISTICS__)
[5cb51502]	745	if( kernelTLS().this_stats ) {
	746	__tls_stats()->ready.sleep.wakes++;
	747	}
	748	else {
	749	__atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
	750	}
[1eb239e4]	751	#endif
	752
[e873838]	753	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	754	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	755
	756	return;
[64a7146]	757	}
[14a61b5]	758
[64a7146]	759	// Unconditionnaly wake a thread
[1eb239e4]	760	void __wake_proc(processor * this) {
[64a7146]	761	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	762
[a3821fa]	763	__disable_interrupts_checked();
[8fc652e0]	764	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	765	eventfd_t val;
	766	val = 1;
[55d6affb]	767	eventfd_write( this->idle, val );
[a3821fa]	768	__enable_interrupts_checked();
[92e7631]	769	}
	770
[6a9b12b]	771	static void mark_idle(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	772	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	773	lock( this );
	774	this.idle++;
	775	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	776	remove(proc);
[6a9b12b]	777	insert_first(this.idles, proc);
[1eb239e4]	778	unlock( this );
[8fc652e0]	779	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	780	}
[8e16177]	781
[6a9b12b]	782	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	783	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	784	lock( this );
	785	this.idle--;
	786	/* paranoid */ verify( this.idle >= 0 );
	787	remove(proc);
[fc59b580]	788	insert_last(this.actives, proc);
[1eb239e4]	789	unlock( this );
[8fc652e0]	790	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	791	}
[c34ebf2]	792
[6a9b12b]	793	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list this ) {
	794	/* paranoid */ verify( ! __preemption_enabled() );
	795	/* paranoid */ verify( ready_schedule_islocked() );
	796
[1eb239e4]	797	for() {
	798	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	799	if( 1 == (l % 2) ) { Pause(); continue; }
	800	unsigned idle = this.idle;
	801	unsigned total = this.total;
[6a9b12b]	802	processor * proc = &this.idles`first;
[7fdae38]	803	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	804	asm volatile("": : :"memory");
[1eb239e4]	805	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	806	return [idle, total, proc];
	807	}
[6a9b12b]	808
	809	/* paranoid */ verify( ready_schedule_islocked() );
	810	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	811	}
	812
[dbe9b08]	813	//=============================================================================================
	814	// Unexpected Terminating logic
	815	//=============================================================================================
[92bfda0]	816	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
	817	$thread * thrd = __cfaabi_tls.this_thread;
[9d944b2]	818
[de94a60]	819	if(thrd) {
	820	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	821	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	822
[212c2187]	823	if ( &thrd->self_cor != thrd->curr_cor ) {
	824	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	825	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	826	}
	827	else {
[1c40091]	828	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	829	}
[1c273d0]	830	}
[9d944b2]	831	else {
[de94a60]	832	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	833	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	834	}
	835	}
	836
[92bfda0]	837	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	838	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	839	}
	840
[de94a60]	841	static __spinlock_t kernel_debug_lock;
	842
[9d944b2]	843	extern "C" {
[1c40091]	844	void __cfaabi_bits_acquire() {
[36982fc]	845	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	846	}
	847
[1c40091]	848	void __cfaabi_bits_release() {
[ea7d2b0]	849	unlock( kernel_debug_lock );
[9d944b2]	850	}
[8118303]	851	}
	852
[fa21ac9]	853	//=============================================================================================
	854	// Kernel Utilities
	855	//=============================================================================================
[dddb3dd0]	856	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	857	#include "io/types.hfa"
	858	#endif
	859
[c1c95b1]	860	static inline bool __maybe_io_drain( processor * proc ) {
[e9c0b4c]	861	bool ret = false;
[dddb3dd0]	862	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	863	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	864
	865	// Check if we should drain the queue
	866	$io_context * ctx = proc->io.ctx;
	867	unsigned head = *ctx->cq.head;
	868	unsigned tail = *ctx->cq.tail;
[c1c95b1]	869	if(head == tail) return false;
[57f70ab]	870	#if OLD_MAIN
[b7fd2db6]	871	ready_schedule_lock();
[e9c0b4c]	872	ret = __cfa_io_drain( proc );
[b7fd2db6]	873	ready_schedule_unlock();
[57f70ab]	874	#else
	875	ret = __cfa_io_drain( proc );
	876	#endif
[dddb3dd0]	877	#endif
[e9c0b4c]	878	return ret;
[dddb3dd0]	879	}
	880
[de94a60]	881	//-----------------------------------------------------------------------------
	882	// Debug
	883	__cfaabi_dbg_debug_do(
[1997b4e]	884	extern "C" {
[ae66348]	885	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	886	this.prev_name = prev_name;
[8fc652e0]	887	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	888	}
[9181f1d]	889	}
[f7d6bb0]	890	)
[2026bb6]	891
	892	//-----------------------------------------------------------------------------
	893	// Debug
[8c50aed]	894	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	895	return true;
	896	}
[c34ebf2]	897
	898	//-----------------------------------------------------------------------------
	899	// Statistics
	900	#if !defined(__CFA_NO_STATISTICS__)
	901	void print_halts( processor & this ) {
	902	this.print_halts = true;
	903	}
[58688bf]	904
[69914cbc]	905	static void crawl_list( cluster * cltr, dlist(processor) & list, unsigned count ) {
[8464edf]	906	/* paranoid */ verify( cltr->stats );
	907
	908	processor * it = &list`first;
	909	for(unsigned i = 0; i < count; i++) {
	910	/* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
	911	/* paranoid */ verify( it->local_data->this_stats );
	912	__tally_stats( cltr->stats, it->local_data->this_stats );
	913	it = &(*it)`next;
	914	}
	915	}
	916
	917	void crawl_cluster_stats( cluster & this ) {
	918	// Stop the world, otherwise stats could get really messed-up
	919	// this doesn't solve all problems but does solve many
	920	// so it's probably good enough
	921	uint_fast32_t last_size = ready_mutate_lock();
	922
	923	crawl_list(&this, this.procs.actives, this.procs.total - this.procs.idle);
	924	crawl_list(&this, this.procs.idles , this.procs.idle );
	925
	926	// Unlock the RWlock
	927	ready_mutate_unlock( last_size );
	928	}
	929
	930
[58688bf]	931	void print_stats_now( cluster & this, int flags ) {
[8464edf]	932	crawl_cluster_stats( this );
[1b033b8]	933	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	934	}
[c34ebf2]	935	#endif
[8118303]	936	// Local Variables: //
	937	// mode: c //
	938	// tab-width: 4 //
	939	// End: //

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