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kernel.cfa@ c426b03

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

Last change on this file since c426b03 was a5e7233, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
C interface now runs worker init routine in dedicated thread. Also added test for this case.
Property mode set to `100644`
File size: 24.1 KB

Rev	Line
[8118303]	1	//
	2	// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
	3	//
	4	// The contents of this file are covered under the licence agreement in the
	5	// file "LICENCE" distributed with Cforall.
	6	//
	7	// kernel.c --
	8	//
	9	// Author : Thierry Delisle
[75f3522]	10	// Created On : Tue Jan 17 12:27:26 2017
[6b0b624]	11	// Last Modified By : Peter A. Buhr
[0190480]	12	// Last Modified On : Mon Aug 31 07:08:20 2020
	13	// Update Count : 71
[8118303]	14	//
	15
[2026bb6]	16	#define __cforall_thread__
[4069faad]	17	// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
[2026bb6]	18
[8118303]	19	//C Includes
[214e8da]	20	#include <errno.h>
[9d944b2]	21	#include <stdio.h>
[58b6d1b]	22	#include <signal.h>
[9d944b2]	23	#include <unistd.h>
[dddb3dd0]	24	extern "C" {
	25	#include <sys/eventfd.h>
	26	}
[8118303]	27
	28	//CFA Includes
[73abe95]	29	#include "kernel_private.hfa"
	30	#include "preemption.hfa"
[8118303]	31
	32	//Private includes
	33	#define __CFA_INVOKE_PRIVATE__
	34	#include "invoke.h"
	35
[4069faad]	36
[deca0f5]	37	//-----------------------------------------------------------------------------
	38	// Some assembly required
[1805b1b]	39	#if defined( __i386 )
[deca0f5]	40	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	41	// fcw : X87 FPU control word (preserved across function calls)
	42	#define __x87_store \
	43	uint32_t __mxcr; \
	44	uint16_t __fcw; \
	45	__asm__ volatile ( \
	46	"stmxcsr %0\n" \
	47	"fnstcw %1\n" \
	48	: "=m" (__mxcr),\
	49	"=m" (__fcw) \
	50	)
	51
	52	#define __x87_load \
	53	__asm__ volatile ( \
	54	"fldcw %1\n" \
	55	"ldmxcsr %0\n" \
	56	::"m" (__mxcr),\
	57	"m" (__fcw) \
	58	)
	59
	60	#elif defined( __x86_64 )
	61	#define __x87_store \
	62	uint32_t __mxcr; \
	63	uint16_t __fcw; \
	64	__asm__ volatile ( \
	65	"stmxcsr %0\n" \
	66	"fnstcw %1\n" \
	67	: "=m" (__mxcr),\
	68	"=m" (__fcw) \
	69	)
	70
	71	#define __x87_load \
	72	__asm__ volatile ( \
	73	"fldcw %1\n" \
	74	"ldmxcsr %0\n" \
	75	:: "m" (__mxcr),\
	76	"m" (__fcw) \
	77	)
	78
[0190480]	79	#elif defined( __arm__ )
	80	#define __x87_store
	81	#define __x87_load
	82
	83	#elif defined( __aarch64__ )
[74f5c83]	84	#define __x87_store \
	85	uint32_t __fpcntl[2]; \
	86	__asm__ volatile ( \
	87	"mrs x9, FPCR\n" \
	88	"mrs x10, FPSR\n" \
	89	"stp x9, x10, %0\n" \
	90	: "=m" (__fpcntl) : : "x9", "x10" \
	91	)
	92
	93	#define __x87_load \
	94	__asm__ volatile ( \
	95	"ldp x9, x10, %0\n" \
	96	"msr FPSR, x10\n" \
	97	"msr FPCR, x9\n" \
	98	: "=m" (__fpcntl) : : "x9", "x10" \
	99	)
	100
[deca0f5]	101	#else
[0190480]	102	#error unsupported hardware architecture
[deca0f5]	103	#endif
	104
[e660761]	105	extern $thread * mainThread;
	106	extern processor * mainProcessor;
[2ac095d]	107
[92e7631]	108	//-----------------------------------------------------------------------------
	109	// Kernel Scheduling logic
	110	static $thread * __next_thread(cluster * this);
[1eb239e4]	111	static $thread * __next_thread_slow(cluster * this);
[92e7631]	112	static void __run_thread(processor * this, $thread * dst);
[e873838]	113	static void __wake_one(cluster * cltr);
[1eb239e4]	114
	115	static void push (__cluster_idles & idles, processor & proc);
	116	static void remove(__cluster_idles & idles, processor & proc);
	117	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles );
	118
[dddb3dd0]	119	extern void __cfa_io_start( processor * );
	120	extern void __cfa_io_drain( processor * );
	121	extern void __cfa_io_flush( processor * );
	122	extern void __cfa_io_stop ( processor * );
	123	static inline void __maybe_io_drain( processor * );
	124
	125	extern void __disable_interrupts_hard();
	126	extern void __enable_interrupts_hard();
[c84e80a]	127
[75f3522]	128	//=============================================================================================
	129	// Kernel Scheduling logic
	130	//=============================================================================================
[8fcbb4c]	131	//Main of the processor contexts
[83a071f9]	132	void main(processorCtx_t & runner) {
[21184e3]	133	// Because of a bug, we couldn't initialized the seed on construction
	134	// Do it here
[8fc652e0]	135	__cfaabi_tls.rand_seed ^= rdtscl();
	136	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	137	__tls_rand_advance_bck();
[21184e3]	138
[83a071f9]	139	processor * this = runner.proc;
[094476d]	140	verify(this);
[c81ebf9]	141
[dddb3dd0]	142	__cfa_io_start( this );
	143
[4069faad]	144	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	145	#if !defined(__CFA_NO_STATISTICS__)
	146	if( this->print_halts ) {
	147	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
	148	}
	149	#endif
[b798713]	150
[75f3522]	151	{
[c81ebf9]	152	// Setup preemption data
	153	preemption_scope scope = { this };
	154
[325e6ea]	155	#if !defined(__CFA_NO_STATISTICS__)
	156	unsigned long long last_tally = rdtscl();
	157	#endif
	158
[a5e7233]	159	// if we need to run some special setup, now is the time to do it.
	160	if(this->init.thrd) {
	161	this->init.thrd->curr_cluster = this->cltr;
	162	__run_thread(this, this->init.thrd);
	163	}
[325e6ea]	164
[4069faad]	165	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	166
[ac2b598]	167	$thread * readyThread = 0p;
[1eb239e4]	168	MAIN_LOOP:
	169	for() {
[dddb3dd0]	170	// Check if there is pending io
	171	__maybe_io_drain( this );
	172
[92e7631]	173	// Try to get the next thread
[8c50aed]	174	readyThread = __next_thread( this->cltr );
[75f3522]	175
[1eb239e4]	176	if( !readyThread ) {
[dddb3dd0]	177	__cfa_io_flush( this );
[1eb239e4]	178	readyThread = __next_thread_slow( this->cltr );
	179	}
[4e6fb8e]	180
[1eb239e4]	181	HALT:
	182	if( !readyThread ) {
	183	// Don't block if we are done
	184	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	185
[1eb239e4]	186	#if !defined(__CFA_NO_STATISTICS__)
	187	__tls_stats()->ready.sleep.halts++;
	188	#endif
[398e8e9]	189
[1eb239e4]	190	// Push self to idle stack
	191	push(this->cltr->idles, * this);
[398e8e9]	192
[1eb239e4]	193	// Confirm the ready-queue is empty
	194	readyThread = __next_thread_slow( this->cltr );
	195	if( readyThread ) {
	196	// A thread was found, cancel the halt
	197	remove(this->cltr->idles, * this);
	198
	199	#if !defined(__CFA_NO_STATISTICS__)
	200	__tls_stats()->ready.sleep.cancels++;
	201	#endif
	202
	203	// continue the mai loop
	204	break HALT;
	205	}
	206
	207	#if !defined(__CFA_NO_STATISTICS__)
	208	if(this->print_halts) {
	209	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
	210	}
	211	#endif
	212
[dddb3dd0]	213	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle);
	214
	215	__disable_interrupts_hard();
	216	eventfd_t val;
	217	eventfd_read( this->idle, &val );
	218	__enable_interrupts_hard();
[1eb239e4]	219
	220	#if !defined(__CFA_NO_STATISTICS__)
	221	if(this->print_halts) {
	222	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
	223	}
	224	#endif
	225
	226	// We were woken up, remove self from idle
	227	remove(this->cltr->idles, * this);
	228
	229	// DON'T just proceed, start looking again
	230	continue MAIN_LOOP;
[64a7146]	231	}
[1eb239e4]	232
	233	/* paranoid */ verify( readyThread );
	234
[dddb3dd0]	235	// Reset io dirty bit
	236	this->io.dirty = false;
	237
[1eb239e4]	238	// We found a thread run it
	239	__run_thread(this, readyThread);
	240
	241	// Are we done?
	242	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	243
	244	#if !defined(__CFA_NO_STATISTICS__)
	245	unsigned long long curr = rdtscl();
	246	if(curr > (last_tally + 500000000)) {
	247	__tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
	248	last_tally = curr;
	249	}
	250	#endif
[dddb3dd0]	251
	252	if(this->io.pending && !this->io.dirty) {
	253	__cfa_io_flush( this );
	254	}
[c81ebf9]	255	}
	256
[4069faad]	257	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	258	}
[8118303]	259
[dddb3dd0]	260	__cfa_io_stop( this );
	261
[454f478]	262	post( this->terminated );
[bdeba0b]	263
[dddb3dd0]	264
[28d73c1]	265	if(this == mainProcessor) {
[6a490b2]	266	// HACK : the coroutine context switch expects this_thread to be set
	267	// and it make sense for it to be set in all other cases except here
	268	// fake it
[8fc652e0]	269	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	270	}
[7768b8d]	271
[4069faad]	272	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	273	}
	274
[5c1a531]	275	static int * __volatile_errno() __attribute__((noinline));
	276	static int * __volatile_errno() { asm(""); return &errno; }
	277
[14a61b5]	278	// KERNEL ONLY
[1c273d0]	279	// runThread runs a thread by context switching
	280	// from the processor coroutine to the target thread
[ac2b598]	281	static void __run_thread(processor * this, $thread * thrd_dst) {
[8fc652e0]	282	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	283	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	284	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	285	__builtin_prefetch( thrd_dst->context.SP );
	286
[dddb3dd0]	287	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	288
[ac2b598]	289	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	290
[9f575ea]	291	// set state of processor coroutine to inactive
	292	verify(proc_cor->state == Active);
[ae7be7a]	293	proc_cor->state = Blocked;
[e8e457e]	294
[9f575ea]	295	// Actually run the thread
[3381ed7]	296	RUNNING: while(true) {
[ff79d5e]	297	thrd_dst->preempted = __NO_PREEMPTION;
	298	thrd_dst->state = Active;
[e8e457e]	299
[58d64a4]	300	// Update global state
[8fc652e0]	301	kernelTLS().this_thread = thrd_dst;
[75f3522]	302
[8fc652e0]	303	/* paranoid */ verify( ! __preemption_enabled() );
	304	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	305	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	306	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	307	/* paranoid */ verify( thrd_dst->state != Halted );
[210b8b3]	308	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) \|\| thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst ); // add escape condition if we are setting up the processor
	309	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) \|\| thrd_dst->curr_cor == proc_cor, "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor
[ac12f1f]	310	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	311
[3381ed7]	312
[58d64a4]	313
[9f575ea]	314	// set context switch to the thread that the processor is executing
[c7a900a]	315	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	316	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	317
[ac12f1f]	318	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[210b8b3]	319	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too large.\n", thrd_dst );
	320	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ), "ERROR : Destination $thread %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
[b4b63e8]	321	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	322	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	323	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	324	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	325
[58d64a4]	326	// Reset global state
[8fc652e0]	327	kernelTLS().this_thread = 0p;
[3381ed7]	328
	329	// We just finished running a thread, there are a few things that could have happened.
	330	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	331	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	332	// 4 - Preempted
	333	// In case 1, we may have won a race so we can't write to the state again.
	334	// In case 2, we lost the race so we now own the thread.
	335
	336	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	337	// The thread was preempted, reschedule it and reset the flag
[e873838]	338	__schedule_thread( thrd_dst );
[3381ed7]	339	break RUNNING;
	340	}
[75f3522]	341
[3ea8ad1]	342	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	343	// The thread has halted, it should never be scheduled/run again
[5afb49a]	344	// finish the thread
	345	__thread_finish( thrd_dst );
[ff79d5e]	346	break RUNNING;
	347	}
	348
	349	/* paranoid */ verify( thrd_dst->state == Active );
	350	thrd_dst->state = Blocked;
	351
[3381ed7]	352	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	353	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	354	switch(old_ticket) {
[6a77224]	355	case TICKET_RUNNING:
[3381ed7]	356	// This is case 1, the regular case, nothing more is needed
	357	break RUNNING;
[6a77224]	358	case TICKET_UNBLOCK:
[3381ed7]	359	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	360	// In this case, just run it again.
	361	continue RUNNING;
	362	default:
	363	// This makes no sense, something is wrong abort
[ff79d5e]	364	abort();
[3381ed7]	365	}
[9f575ea]	366	}
[e8e457e]	367
[9f575ea]	368	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	369	proc_cor->state = Active;
[1eb239e4]	370
[dddb3dd0]	371	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	372
[8fc652e0]	373	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	374	}
	375
[14a61b5]	376	// KERNEL_ONLY
[b0c7419]	377	void returnToKernel() {
[8fc652e0]	378	/* paranoid */ verify( ! __preemption_enabled() );
	379	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	380	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	381
[29cb302]	382	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	383	struct processor * last_proc = kernelTLS().this_processor;
[29cb302]	384	#endif
	385
[9f575ea]	386	// Run the thread on this processor
	387	{
	388	int local_errno = *__volatile_errno();
	389	#if defined( __i386 ) \|\| defined( __x86_64 )
	390	__x87_store;
	391	#endif
[b4b63e8]	392	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	393	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	394	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	395	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	396	#if defined( __i386 ) \|\| defined( __x86_64 )
	397	__x87_load;
	398	#endif
	399	*__volatile_errno() = local_errno;
[8fcbb4c]	400	}
[deca0f5]	401
[29cb302]	402	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	403	if(last_proc != kernelTLS().this_processor) {
[29cb302]	404	__tls_stats()->ready.threads.migration++;
	405	}
	406	#endif
	407
[8fc652e0]	408	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	409	/* 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 );
	410	/* 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]	411	}
	412
[8def349]	413	//-----------------------------------------------------------------------------
	414	// Scheduler routines
[14a61b5]	415	// KERNEL ONLY
[e873838]	416	void __schedule_thread( $thread * thrd ) {
[8fc652e0]	417	/* paranoid */ verify( ! __preemption_enabled() );
[9d6e1b8a]	418	/* paranoid */ verify( kernelTLS().this_proc_id );
[6a490b2]	419	/* paranoid */ verify( thrd );
	420	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	421	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	422	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	423	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	424	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	425	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	426	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	427	/* paranoid */ #endif
[6a490b2]	428	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	429	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	430
[9f575ea]	431
[ae7be7a]	432	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	433
[e873838]	434	ready_schedule_lock();
[32a8b61]	435	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	436	struct cluster * cl = thrd->curr_cluster;
	437
	438	// push the thread to the cluster ready-queue
	439	push( cl, thrd );
	440
	441	// variable thrd is no longer safe to use
	442
	443	// wake the cluster using the save variable.
	444	__wake_one( cl );
[e873838]	445	ready_schedule_unlock();
[1c273d0]	446
[8fc652e0]	447	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	448	}
	449
[14a61b5]	450	// KERNEL ONLY
[1eb239e4]	451	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	452	/* paranoid */ verify( ! __preemption_enabled() );
	453	/* paranoid */ verify( kernelTLS().this_proc_id );
[7768b8d]	454
[e873838]	455	ready_schedule_lock();
[1eb239e4]	456	$thread * thrd = pop( this );
[e873838]	457	ready_schedule_unlock();
[7768b8d]	458
[8fc652e0]	459	/* paranoid */ verify( kernelTLS().this_proc_id );
	460	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	461	return thrd;
[eb2e723]	462	}
	463
[64a7146]	464	// KERNEL ONLY
[1eb239e4]	465	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	466	/* paranoid */ verify( ! __preemption_enabled() );
	467	/* paranoid */ verify( kernelTLS().this_proc_id );
[64a7146]	468
[e873838]	469	ready_schedule_lock();
[1eb239e4]	470	$thread * thrd = pop_slow( this );
[e873838]	471	ready_schedule_unlock();
[64a7146]	472
[8fc652e0]	473	/* paranoid */ verify( kernelTLS().this_proc_id );
	474	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	475	return thrd;
[64a7146]	476	}
	477
[e873838]	478	void unpark( $thread * thrd ) {
	479	if( !thrd ) return;
	480
[ff79d5e]	481	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	482	switch(old_ticket) {
[6a77224]	483	case TICKET_RUNNING:
[3381ed7]	484	// Wake won the race, the thread will reschedule/rerun itself
	485	break;
[6a77224]	486	case TICKET_BLOCKED:
[3381ed7]	487	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	488	/* paranoid */ verify( thrd->state == Blocked );
[0b33412]	489
[8fc652e0]	490	{
	491	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	492	bool full = publicTLS_get(this_proc_id)->full_proc;
	493	if(full) disable_interrupts();
	494
	495	/* paranoid */ verify( ! __preemption_enabled() );
	496
	497	// Wake lost the race,
	498	__schedule_thread( thrd );
	499
	500	/* paranoid */ verify( ! __preemption_enabled() );
	501
	502	if(full) enable_interrupts( __cfaabi_dbg_ctx );
	503	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	504	}
	505
[3381ed7]	506	break;
	507	default:
	508	// This makes no sense, something is wrong abort
[7ee8153]	509	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	510	}
[eb2e723]	511	}
	512
[e235429]	513	void park( void ) {
[8fc652e0]	514	/* paranoid */ verify( __preemption_enabled() );
[82ff5845]	515	disable_interrupts();
[8fc652e0]	516	/* paranoid */ verify( ! __preemption_enabled() );
	517	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
[0b33412]	518
[82c948c]	519	returnToKernel();
[0b33412]	520
[8fc652e0]	521	/* paranoid */ verify( ! __preemption_enabled() );
[36982fc]	522	enable_interrupts( __cfaabi_dbg_ctx );
[8fc652e0]	523	/* paranoid */ verify( __preemption_enabled() );
[0c78741]	524
	525	}
[09800e9]	526
[5afb49a]	527	extern "C" {
	528	// Leave the thread monitor
	529	// last routine called by a thread.
	530	// Should never return
	531	void __cfactx_thrd_leave() {
[8fc652e0]	532	$thread * thrd = active_thread();
[5afb49a]	533	$monitor * this = &thrd->self_mon;
	534
	535	// Lock the monitor now
	536	lock( this->lock __cfaabi_dbg_ctx2 );
	537
	538	disable_interrupts();
	539
[9d6e1b8a]	540	/* paranoid */ verify( ! __preemption_enabled() );
	541	/* paranoid */ verify( thrd->state == Active );
	542	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	543	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	544	/* paranoid */ verify( thrd->context.SP );
	545	/* 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 );
	546	/* 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 );
	547
[3ea8ad1]	548	thrd->state = Halting;
[58688bf]	549	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	550	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	551	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	552
	553	// Leave the thread
	554	returnToKernel();
	555
	556	// Control flow should never reach here!
[9d6e1b8a]	557	abort();
[5afb49a]	558	}
[09800e9]	559	}
	560
[14a61b5]	561	// KERNEL ONLY
[3381ed7]	562	bool force_yield( __Preemption_Reason reason ) {
[8fc652e0]	563	/* paranoid */ verify( __preemption_enabled() );
[09800e9]	564	disable_interrupts();
[8fc652e0]	565	/* paranoid */ verify( ! __preemption_enabled() );
[09800e9]	566
[8fc652e0]	567	$thread * thrd = kernelTLS().this_thread;
[ff79d5e]	568	/* paranoid */ verify(thrd->state == Active);
[3381ed7]	569
	570	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	571	// it was going to park itself. If that is the case and it is already using the
	572	// intrusive fields then we can't use them to preempt the thread
	573	// If that is the case, abandon the preemption.
	574	bool preempted = false;
[504a7dc]	575	if(thrd->link.next == 0p) {
[3381ed7]	576	preempted = true;
	577	thrd->preempted = reason;
	578	returnToKernel();
[de6319f]	579	}
[f2b12406]	580
[8fc652e0]	581	/* paranoid */ verify( ! __preemption_enabled() );
[3381ed7]	582	enable_interrupts_noPoll();
[8fc652e0]	583	/* paranoid */ verify( __preemption_enabled() );
[f2b12406]	584
[3381ed7]	585	return preempted;
[f2b12406]	586	}
	587
[14a61b5]	588	//=============================================================================================
[92e7631]	589	// Kernel Idle Sleep
[14a61b5]	590	//=============================================================================================
[64a7146]	591	// Wake a thread from the front if there are any
[e873838]	592	static void __wake_one(cluster * this) {
[8fc652e0]	593	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	594	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	595
[64a7146]	596	// Check if there is a sleeping processor
[1eb239e4]	597	processor * p;
	598	unsigned idle;
	599	unsigned total;
	600	[idle, total, p] = query(this->idles);
[14a61b5]	601
[64a7146]	602	// If no one is sleeping, we are done
[1eb239e4]	603	if( idle == 0 ) return;
[14a61b5]	604
[64a7146]	605	// We found a processor, wake it up
[dddb3dd0]	606	eventfd_t val;
	607	val = 1;
	608	eventfd_write( p->idle, val );
[14a61b5]	609
[1eb239e4]	610	#if !defined(__CFA_NO_STATISTICS__)
	611	__tls_stats()->ready.sleep.wakes++;
	612	#endif
	613
[e873838]	614	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	615	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	616
	617	return;
[64a7146]	618	}
[14a61b5]	619
[64a7146]	620	// Unconditionnaly wake a thread
[1eb239e4]	621	void __wake_proc(processor * this) {
[64a7146]	622	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	623
[64a7146]	624	disable_interrupts();
[8fc652e0]	625	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	626	eventfd_t val;
	627	val = 1;
[55d6affb]	628	eventfd_write( this->idle, val );
[64a7146]	629	enable_interrupts( __cfaabi_dbg_ctx );
[92e7631]	630	}
	631
[1eb239e4]	632	static void push (__cluster_idles & this, processor & proc) {
[8fc652e0]	633	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	634	lock( this );
	635	this.idle++;
	636	/* paranoid */ verify( this.idle <= this.total );
[8e16177]	637
[1eb239e4]	638	insert_first(this.list, proc);
	639	unlock( this );
[8fc652e0]	640	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	641	}
[8e16177]	642
[1eb239e4]	643	static void remove(__cluster_idles & this, processor & proc) {
[8fc652e0]	644	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	645	lock( this );
	646	this.idle--;
	647	/* paranoid */ verify( this.idle >= 0 );
[c34ebf2]	648
[1eb239e4]	649	remove(proc);
	650	unlock( this );
[8fc652e0]	651	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	652	}
[c34ebf2]	653
[1eb239e4]	654	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
	655	for() {
	656	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	657	if( 1 == (l % 2) ) { Pause(); continue; }
	658	unsigned idle = this.idle;
	659	unsigned total = this.total;
	660	processor * proc = &this.list`first;
[7fdae38]	661	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	662	asm volatile("": : :"memory");
[1eb239e4]	663	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	664	return [idle, total, proc];
	665	}
[6b4cdd3]	666	}
	667
[dbe9b08]	668	//=============================================================================================
	669	// Unexpected Terminating logic
	670	//=============================================================================================
[92bfda0]	671	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
	672	$thread * thrd = __cfaabi_tls.this_thread;
[9d944b2]	673
[de94a60]	674	if(thrd) {
	675	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	676	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	677
[212c2187]	678	if ( &thrd->self_cor != thrd->curr_cor ) {
	679	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	680	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	681	}
	682	else {
[1c40091]	683	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	684	}
[1c273d0]	685	}
[9d944b2]	686	else {
[de94a60]	687	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	688	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	689	}
	690	}
	691
[92bfda0]	692	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	693	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	694	}
	695
[de94a60]	696	static __spinlock_t kernel_debug_lock;
	697
[9d944b2]	698	extern "C" {
[1c40091]	699	void __cfaabi_bits_acquire() {
[36982fc]	700	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	701	}
	702
[1c40091]	703	void __cfaabi_bits_release() {
[ea7d2b0]	704	unlock( kernel_debug_lock );
[9d944b2]	705	}
[8118303]	706	}
	707
[fa21ac9]	708	//=============================================================================================
	709	// Kernel Utilities
	710	//=============================================================================================
[dddb3dd0]	711	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	712	#include "io/types.hfa"
	713	#endif
	714
	715	static inline void __maybe_io_drain( processor * proc ) {
	716	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	717	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	718
	719	// Check if we should drain the queue
	720	$io_context * ctx = proc->io.ctx;
	721	unsigned head = *ctx->cq.head;
	722	unsigned tail = *ctx->cq.tail;
	723	if(head != tail) __cfa_io_drain( proc );
	724	#endif
	725	}
	726
[de94a60]	727	//-----------------------------------------------------------------------------
	728	// Debug
	729	__cfaabi_dbg_debug_do(
[1997b4e]	730	extern "C" {
[ae66348]	731	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	732	this.prev_name = prev_name;
[8fc652e0]	733	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	734	}
[9181f1d]	735	}
[f7d6bb0]	736	)
[2026bb6]	737
	738	//-----------------------------------------------------------------------------
	739	// Debug
[8c50aed]	740	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	741	return true;
	742	}
[c34ebf2]	743
	744	//-----------------------------------------------------------------------------
	745	// Statistics
	746	#if !defined(__CFA_NO_STATISTICS__)
	747	void print_halts( processor & this ) {
	748	this.print_halts = true;
	749	}
[58688bf]	750
	751	void print_stats_now( cluster & this, int flags ) {
[1b033b8]	752	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	753	}
	754
	755	extern int __print_alarm_stats;
	756	void print_alarm_stats() {
	757	__print_alarm_stats = -1;
[58688bf]	758	}
[c34ebf2]	759	#endif
[8118303]	760	// Local Variables: //
	761	// mode: c //
	762	// tab-width: 4 //
	763	// End: //

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