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kernel.cfa@ 9cc3a18

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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 9cc3a18 was fc59b580, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Clusters now keep track of the active processors as well
Property mode set to `100644`
File size: 25.1 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
[6a9b12b]	115	static void mark_idle (__cluster_proc_list & idles, processor & proc);
	116	static void mark_awake(__cluster_proc_list & idles, processor & proc);
	117	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list idles );
[1eb239e4]	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
[6a9b12b]	191	mark_idle(this->cltr->procs, * 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
[6a9b12b]	197	mark_awake(this->cltr->procs, * this);
[1eb239e4]	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
[6a9b12b]	227	mark_awake(this->cltr->procs, * this);
[1eb239e4]	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:
[ec43cf9]	359	#if !defined(__CFA_NO_STATISTICS__)
	360	__tls_stats()->ready.threads.threads++;
[73f4d08]	361	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	362	#endif
[3381ed7]	363	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	364	// In this case, just run it again.
	365	continue RUNNING;
	366	default:
	367	// This makes no sense, something is wrong abort
[ff79d5e]	368	abort();
[3381ed7]	369	}
[9f575ea]	370	}
[e8e457e]	371
[9f575ea]	372	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	373	proc_cor->state = Active;
[1eb239e4]	374
[dddb3dd0]	375	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	376
[ec43cf9]	377	#if !defined(__CFA_NO_STATISTICS__)
	378	__tls_stats()->ready.threads.threads--;
[73f4d08]	379	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", this );
[ec43cf9]	380	#endif
	381
[8fc652e0]	382	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	383	}
	384
[14a61b5]	385	// KERNEL_ONLY
[b0c7419]	386	void returnToKernel() {
[8fc652e0]	387	/* paranoid */ verify( ! __preemption_enabled() );
	388	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	389	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	390
[29cb302]	391	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	392	struct processor * last_proc = kernelTLS().this_processor;
[29cb302]	393	#endif
	394
[9f575ea]	395	// Run the thread on this processor
	396	{
	397	int local_errno = *__volatile_errno();
	398	#if defined( __i386 ) \|\| defined( __x86_64 )
	399	__x87_store;
	400	#endif
[b4b63e8]	401	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	402	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	403	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	404	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	405	#if defined( __i386 ) \|\| defined( __x86_64 )
	406	__x87_load;
	407	#endif
	408	*__volatile_errno() = local_errno;
[8fcbb4c]	409	}
[deca0f5]	410
[29cb302]	411	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	412	if(last_proc != kernelTLS().this_processor) {
[29cb302]	413	__tls_stats()->ready.threads.migration++;
	414	}
	415	#endif
	416
[8fc652e0]	417	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	418	/* 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 );
	419	/* 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]	420	}
	421
[8def349]	422	//-----------------------------------------------------------------------------
	423	// Scheduler routines
[14a61b5]	424	// KERNEL ONLY
[e873838]	425	void __schedule_thread( $thread * thrd ) {
[8fc652e0]	426	/* paranoid */ verify( ! __preemption_enabled() );
[9d6e1b8a]	427	/* paranoid */ verify( kernelTLS().this_proc_id );
[6a490b2]	428	/* paranoid */ verify( thrd );
	429	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	430	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	431	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	432	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	433	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	434	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	435	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	436	/* paranoid */ #endif
[6a490b2]	437	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	438	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	439
[9f575ea]	440
[ae7be7a]	441	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	442
[ec43cf9]	443	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	444	struct cluster * cl = thrd->curr_cluster;
[32a8b61]	445
[ec43cf9]	446	ready_schedule_lock();
[32a8b61]	447	// push the thread to the cluster ready-queue
	448	push( cl, thrd );
	449
	450	// variable thrd is no longer safe to use
	451
	452	// wake the cluster using the save variable.
	453	__wake_one( cl );
[e873838]	454	ready_schedule_unlock();
[1c273d0]	455
[ec43cf9]	456	#if !defined(__CFA_NO_STATISTICS__)
	457	if( kernelTLS().this_stats ) {
	458	__tls_stats()->ready.threads.threads++;
[73f4d08]	459	__push_stat( __tls_stats(), __tls_stats()->ready.threads.threads, false, "Processor", kernelTLS().this_processor );
[ec43cf9]	460	}
	461	else {
	462	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[73f4d08]	463	__push_stat( cl->stats, cl->stats->ready.threads.threads, true, "Cluster", cl );
[ec43cf9]	464	}
	465	#endif
	466
[8fc652e0]	467	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	468	}
	469
[14a61b5]	470	// KERNEL ONLY
[1eb239e4]	471	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	472	/* paranoid */ verify( ! __preemption_enabled() );
	473	/* paranoid */ verify( kernelTLS().this_proc_id );
[7768b8d]	474
[e873838]	475	ready_schedule_lock();
[1eb239e4]	476	$thread * thrd = pop( this );
[e873838]	477	ready_schedule_unlock();
[7768b8d]	478
[8fc652e0]	479	/* paranoid */ verify( kernelTLS().this_proc_id );
	480	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	481	return thrd;
[eb2e723]	482	}
	483
[64a7146]	484	// KERNEL ONLY
[1eb239e4]	485	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	486	/* paranoid */ verify( ! __preemption_enabled() );
	487	/* paranoid */ verify( kernelTLS().this_proc_id );
[64a7146]	488
[e873838]	489	ready_schedule_lock();
[1eb239e4]	490	$thread * thrd = pop_slow( this );
[e873838]	491	ready_schedule_unlock();
[64a7146]	492
[8fc652e0]	493	/* paranoid */ verify( kernelTLS().this_proc_id );
	494	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	495	return thrd;
[64a7146]	496	}
	497
[e873838]	498	void unpark( $thread * thrd ) {
	499	if( !thrd ) return;
	500
[ff79d5e]	501	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	502	switch(old_ticket) {
[6a77224]	503	case TICKET_RUNNING:
[3381ed7]	504	// Wake won the race, the thread will reschedule/rerun itself
	505	break;
[6a77224]	506	case TICKET_BLOCKED:
[3381ed7]	507	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	508	/* paranoid */ verify( thrd->state == Blocked );
[0b33412]	509
[8fc652e0]	510	{
	511	/* paranoid */ verify( publicTLS_get(this_proc_id) );
[5cb51502]	512	disable_interrupts();
[8fc652e0]	513
	514	/* paranoid */ verify( ! __preemption_enabled() );
	515
	516	// Wake lost the race,
	517	__schedule_thread( thrd );
	518
	519	/* paranoid */ verify( ! __preemption_enabled() );
	520
[5cb51502]	521	enable_interrupts_noPoll();
[8fc652e0]	522	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	523	}
	524
[3381ed7]	525	break;
	526	default:
	527	// This makes no sense, something is wrong abort
[7ee8153]	528	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	529	}
[eb2e723]	530	}
	531
[e235429]	532	void park( void ) {
[8fc652e0]	533	/* paranoid */ verify( __preemption_enabled() );
[82ff5845]	534	disable_interrupts();
[8fc652e0]	535	/* paranoid */ verify( ! __preemption_enabled() );
	536	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
[0b33412]	537
[82c948c]	538	returnToKernel();
[0b33412]	539
[8fc652e0]	540	/* paranoid */ verify( ! __preemption_enabled() );
[36982fc]	541	enable_interrupts( __cfaabi_dbg_ctx );
[8fc652e0]	542	/* paranoid */ verify( __preemption_enabled() );
[0c78741]	543
	544	}
[09800e9]	545
[5afb49a]	546	extern "C" {
	547	// Leave the thread monitor
	548	// last routine called by a thread.
	549	// Should never return
	550	void __cfactx_thrd_leave() {
[8fc652e0]	551	$thread * thrd = active_thread();
[5afb49a]	552	$monitor * this = &thrd->self_mon;
	553
	554	// Lock the monitor now
	555	lock( this->lock __cfaabi_dbg_ctx2 );
	556
	557	disable_interrupts();
	558
[9d6e1b8a]	559	/* paranoid */ verify( ! __preemption_enabled() );
	560	/* paranoid */ verify( thrd->state == Active );
	561	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	562	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	563	/* paranoid */ verify( thrd->context.SP );
	564	/* 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 );
	565	/* 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 );
	566
[3ea8ad1]	567	thrd->state = Halting;
[58688bf]	568	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	569	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	570	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	571
	572	// Leave the thread
	573	returnToKernel();
	574
	575	// Control flow should never reach here!
[9d6e1b8a]	576	abort();
[5afb49a]	577	}
[09800e9]	578	}
	579
[14a61b5]	580	// KERNEL ONLY
[3381ed7]	581	bool force_yield( __Preemption_Reason reason ) {
[8fc652e0]	582	/* paranoid */ verify( __preemption_enabled() );
[09800e9]	583	disable_interrupts();
[8fc652e0]	584	/* paranoid */ verify( ! __preemption_enabled() );
[09800e9]	585
[8fc652e0]	586	$thread * thrd = kernelTLS().this_thread;
[ff79d5e]	587	/* paranoid */ verify(thrd->state == Active);
[3381ed7]	588
	589	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	590	// it was going to park itself. If that is the case and it is already using the
	591	// intrusive fields then we can't use them to preempt the thread
	592	// If that is the case, abandon the preemption.
	593	bool preempted = false;
[504a7dc]	594	if(thrd->link.next == 0p) {
[3381ed7]	595	preempted = true;
	596	thrd->preempted = reason;
	597	returnToKernel();
[de6319f]	598	}
[f2b12406]	599
[8fc652e0]	600	/* paranoid */ verify( ! __preemption_enabled() );
[3381ed7]	601	enable_interrupts_noPoll();
[8fc652e0]	602	/* paranoid */ verify( __preemption_enabled() );
[f2b12406]	603
[3381ed7]	604	return preempted;
[f2b12406]	605	}
	606
[14a61b5]	607	//=============================================================================================
[92e7631]	608	// Kernel Idle Sleep
[14a61b5]	609	//=============================================================================================
[64a7146]	610	// Wake a thread from the front if there are any
[e873838]	611	static void __wake_one(cluster * this) {
[8fc652e0]	612	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	613	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	614
[64a7146]	615	// Check if there is a sleeping processor
[1eb239e4]	616	processor * p;
	617	unsigned idle;
	618	unsigned total;
[6a9b12b]	619	[idle, total, p] = query_idles(this->procs);
[14a61b5]	620
[64a7146]	621	// If no one is sleeping, we are done
[1eb239e4]	622	if( idle == 0 ) return;
[14a61b5]	623
[64a7146]	624	// We found a processor, wake it up
[dddb3dd0]	625	eventfd_t val;
	626	val = 1;
	627	eventfd_write( p->idle, val );
[14a61b5]	628
[1eb239e4]	629	#if !defined(__CFA_NO_STATISTICS__)
[5cb51502]	630	if( kernelTLS().this_stats ) {
	631	__tls_stats()->ready.sleep.wakes++;
	632	}
	633	else {
	634	__atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED);
	635	}
[1eb239e4]	636	#endif
	637
[e873838]	638	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	639	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	640
	641	return;
[64a7146]	642	}
[14a61b5]	643
[64a7146]	644	// Unconditionnaly wake a thread
[1eb239e4]	645	void __wake_proc(processor * this) {
[64a7146]	646	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	647
[64a7146]	648	disable_interrupts();
[8fc652e0]	649	/* paranoid */ verify( ! __preemption_enabled() );
[dddb3dd0]	650	eventfd_t val;
	651	val = 1;
[55d6affb]	652	eventfd_write( this->idle, val );
[64a7146]	653	enable_interrupts( __cfaabi_dbg_ctx );
[92e7631]	654	}
	655
[6a9b12b]	656	static void mark_idle(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	657	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	658	lock( this );
	659	this.idle++;
	660	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	661	remove(proc);
[6a9b12b]	662	insert_first(this.idles, proc);
[1eb239e4]	663	unlock( this );
[8fc652e0]	664	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	665	}
[8e16177]	666
[6a9b12b]	667	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	668	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	669	lock( this );
	670	this.idle--;
	671	/* paranoid */ verify( this.idle >= 0 );
	672	remove(proc);
[fc59b580]	673	insert_last(this.actives, proc);
[1eb239e4]	674	unlock( this );
[8fc652e0]	675	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	676	}
[c34ebf2]	677
[6a9b12b]	678	static [unsigned idle, unsigned total, * processor] query_idles( & __cluster_proc_list this ) {
	679	/* paranoid */ verify( ! __preemption_enabled() );
	680	/* paranoid */ verify( ready_schedule_islocked() );
	681
[1eb239e4]	682	for() {
	683	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	684	if( 1 == (l % 2) ) { Pause(); continue; }
	685	unsigned idle = this.idle;
	686	unsigned total = this.total;
[6a9b12b]	687	processor * proc = &this.idles`first;
[7fdae38]	688	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	689	asm volatile("": : :"memory");
[1eb239e4]	690	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	691	return [idle, total, proc];
	692	}
[6a9b12b]	693
	694	/* paranoid */ verify( ready_schedule_islocked() );
	695	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	696	}
	697
[dbe9b08]	698	//=============================================================================================
	699	// Unexpected Terminating logic
	700	//=============================================================================================
[92bfda0]	701	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
	702	$thread * thrd = __cfaabi_tls.this_thread;
[9d944b2]	703
[de94a60]	704	if(thrd) {
	705	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	706	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	707
[212c2187]	708	if ( &thrd->self_cor != thrd->curr_cor ) {
	709	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	710	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	711	}
	712	else {
[1c40091]	713	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	714	}
[1c273d0]	715	}
[9d944b2]	716	else {
[de94a60]	717	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	718	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	719	}
	720	}
	721
[92bfda0]	722	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	723	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	724	}
	725
[de94a60]	726	static __spinlock_t kernel_debug_lock;
	727
[9d944b2]	728	extern "C" {
[1c40091]	729	void __cfaabi_bits_acquire() {
[36982fc]	730	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	731	}
	732
[1c40091]	733	void __cfaabi_bits_release() {
[ea7d2b0]	734	unlock( kernel_debug_lock );
[9d944b2]	735	}
[8118303]	736	}
	737
[fa21ac9]	738	//=============================================================================================
	739	// Kernel Utilities
	740	//=============================================================================================
[dddb3dd0]	741	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	742	#include "io/types.hfa"
	743	#endif
	744
	745	static inline void __maybe_io_drain( processor * proc ) {
	746	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	747	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	748
	749	// Check if we should drain the queue
	750	$io_context * ctx = proc->io.ctx;
	751	unsigned head = *ctx->cq.head;
	752	unsigned tail = *ctx->cq.tail;
	753	if(head != tail) __cfa_io_drain( proc );
	754	#endif
	755	}
	756
[de94a60]	757	//-----------------------------------------------------------------------------
	758	// Debug
	759	__cfaabi_dbg_debug_do(
[1997b4e]	760	extern "C" {
[ae66348]	761	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	762	this.prev_name = prev_name;
[8fc652e0]	763	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	764	}
[9181f1d]	765	}
[f7d6bb0]	766	)
[2026bb6]	767
	768	//-----------------------------------------------------------------------------
	769	// Debug
[8c50aed]	770	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	771	return true;
	772	}
[c34ebf2]	773
	774	//-----------------------------------------------------------------------------
	775	// Statistics
	776	#if !defined(__CFA_NO_STATISTICS__)
	777	void print_halts( processor & this ) {
	778	this.print_halts = true;
	779	}
[58688bf]	780
	781	void print_stats_now( cluster & this, int flags ) {
[1b033b8]	782	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	783	}
[c34ebf2]	784	#endif
[8118303]	785	// Local Variables: //
	786	// mode: c //
	787	// tab-width: 4 //
	788	// End: //

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