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kernel.cfa@ 78de1e5

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ADT ast-experimental

Last change on this file since 78de1e5 was a757ba1, checked in by Thierry Delisle <tdelisle@…>, 3 years ago
Removed wait-with-io_uring feature which was slow, broken and ifdefed out.
Property mode set to `100644`
File size: 28.6 KB

Rev	Line
[8118303]	1	//
	2	// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
	3	//
	4	// The contents of this file are covered under the licence agreement in the
	5	// file "LICENCE" distributed with Cforall.
	6	//
	7	// kernel.c --
	8	//
	9	// Author : Thierry Delisle
[75f3522]	10	// Created On : Tue Jan 17 12:27:26 2017
[6b0b624]	11	// Last Modified By : Peter A. Buhr
[0190480]	12	// Last Modified On : Mon Aug 31 07:08:20 2020
	13	// Update Count : 71
[8118303]	14	//
	15
[2026bb6]	16	#define __cforall_thread__
[43784ac]	17	#define _GNU_SOURCE
	18
[4069faad]	19	// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
[2026bb6]	20
[bfb9bf5]	21	#pragma GCC diagnostic push
	22	#pragma GCC diagnostic ignored "-Waddress-of-packed-member"
	23
[8118303]	24	//C Includes
[214e8da]	25	#include <errno.h>
[9d944b2]	26	#include <stdio.h>
[445f984]	27	#include <string.h>
[58b6d1b]	28	#include <signal.h>
[9d944b2]	29	#include <unistd.h>
[bfb9bf5]	30
[dddb3dd0]	31	extern "C" {
	32	#include <sys/eventfd.h>
[d3605f8]	33	#include <sys/uio.h>
[dddb3dd0]	34	}
[8118303]	35
	36	//CFA Includes
[708ae38]	37	#include "kernel/private.hfa"
[73abe95]	38	#include "preemption.hfa"
[445f984]	39	#include "strstream.hfa"
	40	#include "device/cpu.hfa"
[7ef162b2]	41	#include "io/types.hfa"
[8118303]	42
	43	//Private includes
	44	#define __CFA_INVOKE_PRIVATE__
	45	#include "invoke.h"
[bfb9bf5]	46	#pragma GCC diagnostic pop
[8118303]	47
[89eff25]	48	#if !defined(__CFA_NO_STATISTICS__)
[c9c1c1cb]	49	#define __STATS_DEF( ...) __VA_ARGS__
[89eff25]	50	#else
[c9c1c1cb]	51	#define __STATS_DEF( ...)
[89eff25]	52	#endif
[4069faad]	53
[deca0f5]	54	//-----------------------------------------------------------------------------
	55	// Some assembly required
[1805b1b]	56	#if defined( __i386 )
[deca0f5]	57	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	58	// fcw : X87 FPU control word (preserved across function calls)
	59	#define __x87_store \
	60	uint32_t __mxcr; \
	61	uint16_t __fcw; \
	62	__asm__ volatile ( \
	63	"stmxcsr %0\n" \
	64	"fnstcw %1\n" \
	65	: "=m" (__mxcr),\
	66	"=m" (__fcw) \
	67	)
	68
	69	#define __x87_load \
	70	__asm__ volatile ( \
	71	"fldcw %1\n" \
	72	"ldmxcsr %0\n" \
	73	::"m" (__mxcr),\
	74	"m" (__fcw) \
	75	)
	76
	77	#elif defined( __x86_64 )
	78	#define __x87_store \
	79	uint32_t __mxcr; \
	80	uint16_t __fcw; \
	81	__asm__ volatile ( \
	82	"stmxcsr %0\n" \
	83	"fnstcw %1\n" \
	84	: "=m" (__mxcr),\
	85	"=m" (__fcw) \
	86	)
	87
	88	#define __x87_load \
	89	__asm__ volatile ( \
	90	"fldcw %1\n" \
	91	"ldmxcsr %0\n" \
	92	:: "m" (__mxcr),\
	93	"m" (__fcw) \
	94	)
	95
[0190480]	96	#elif defined( __arm__ )
	97	#define __x87_store
	98	#define __x87_load
	99
	100	#elif defined( __aarch64__ )
[74f5c83]	101	#define __x87_store \
	102	uint32_t __fpcntl[2]; \
	103	__asm__ volatile ( \
	104	"mrs x9, FPCR\n" \
	105	"mrs x10, FPSR\n" \
	106	"stp x9, x10, %0\n" \
	107	: "=m" (__fpcntl) : : "x9", "x10" \
	108	)
	109
	110	#define __x87_load \
	111	__asm__ volatile ( \
	112	"ldp x9, x10, %0\n" \
	113	"msr FPSR, x10\n" \
	114	"msr FPCR, x9\n" \
	115	: "=m" (__fpcntl) : : "x9", "x10" \
	116	)
	117
[deca0f5]	118	#else
[0190480]	119	#error unsupported hardware architecture
[deca0f5]	120	#endif
	121
[e84ab3d]	122	extern thread$ * mainThread;
[e660761]	123	extern processor * mainProcessor;
[2ac095d]	124
[92e7631]	125	//-----------------------------------------------------------------------------
	126	// Kernel Scheduling logic
[e84ab3d]	127	static thread$ * __next_thread(cluster * this);
	128	static thread$ * __next_thread_slow(cluster * this);
[c9c1c1cb]	129	static thread$ * __next_thread_search(cluster * this);
[e84ab3d]	130	static inline bool __must_unpark( thread$ * thrd ) __attribute((nonnull(1)));
	131	static void __run_thread(processor * this, thread$ * dst);
[e873838]	132	static void __wake_one(cluster * cltr);
[1eb239e4]	133
[18f7858]	134	static void idle_sleep(processor * proc);
[5f5a729]	135	static bool mark_idle (__cluster_proc_list & idles, processor & proc);
[6a9b12b]	136	static void mark_awake(__cluster_proc_list & idles, processor & proc);
[1eb239e4]	137
[4479890]	138	extern bool __cfa_io_drain( processor * proc ) __attribute__((nonnull (1)));
[18f7858]	139	extern bool __cfa_io_flush( processor * ) __attribute__((nonnull (1)));
[dddb3dd0]	140
[7ef162b2]	141
[dddb3dd0]	142	extern void __disable_interrupts_hard();
	143	extern void __enable_interrupts_hard();
[c84e80a]	144
[7ef162b2]	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
[4069faad]	160	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	161	#if !defined(__CFA_NO_STATISTICS__)
	162	if( this->print_halts ) {
[c993b15]	163	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->unique_id, this->name, (void*)this);
[28d73c1]	164	}
	165	#endif
[b798713]	166
[75f3522]	167	{
[c81ebf9]	168	// Setup preemption data
	169	preemption_scope scope = { this };
	170
[a5e7233]	171	// if we need to run some special setup, now is the time to do it.
	172	if(this->init.thrd) {
	173	this->init.thrd->curr_cluster = this->cltr;
	174	__run_thread(this, this->init.thrd);
	175	}
[325e6ea]	176
[4069faad]	177	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	178
[e84ab3d]	179	thread$ * readyThread = 0p;
[1eb239e4]	180	MAIN_LOOP:
	181	for() {
[dddb3dd0]	182	// Check if there is pending io
[18f7858]	183	__cfa_io_drain( this );
[dddb3dd0]	184
[92e7631]	185	// Try to get the next thread
[8c50aed]	186	readyThread = __next_thread( this->cltr );
[75f3522]	187
[1eb239e4]	188	if( !readyThread ) {
[18f7858]	189	// there is no point in holding submissions if we are idle
[c9c1c1cb]	190	__IO_STATS__(true, io.flush.idle++; )
[18f7858]	191	__cfa_io_flush( this );
	192
	193	// drain again in case something showed up
	194	__cfa_io_drain( this );
[c33c2af]	195
[c9c1c1cb]	196	readyThread = __next_thread( this->cltr );
	197	}
	198
	199	if( !readyThread ) for(5) {
[1eb239e4]	200	readyThread = __next_thread_slow( this->cltr );
[c9c1c1cb]	201
	202	if( readyThread ) break;
	203
[18f7858]	204	// It's unlikely we still I/O to submit, but the arbiter could
	205	__IO_STATS__(true, io.flush.idle++; )
	206	__cfa_io_flush( this );
	207
	208	// drain again in case something showed up
	209	__cfa_io_drain( this );
[1eb239e4]	210	}
[4e6fb8e]	211
[1eb239e4]	212	HALT:
	213	if( !readyThread ) {
	214	// Don't block if we are done
	215	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	216
[1eb239e4]	217	// Push self to idle stack
[5f5a729]	218	if(!mark_idle(this->cltr->procs, * this)) continue MAIN_LOOP;
[398e8e9]	219
[1eb239e4]	220	// Confirm the ready-queue is empty
[c9c1c1cb]	221	readyThread = __next_thread_search( this->cltr );
[1eb239e4]	222	if( readyThread ) {
	223	// A thread was found, cancel the halt
[6a9b12b]	224	mark_awake(this->cltr->procs, * this);
[1eb239e4]	225
[c9c1c1cb]	226	__STATS__(true, ready.sleep.cancels++; )
[1eb239e4]	227
	228	// continue the mai loop
	229	break HALT;
	230	}
	231
[18f7858]	232	idle_sleep( this );
[1eb239e4]	233
	234	// We were woken up, remove self from idle
[6a9b12b]	235	mark_awake(this->cltr->procs, * this);
[1eb239e4]	236
	237	// DON'T just proceed, start looking again
	238	continue MAIN_LOOP;
[64a7146]	239	}
[1eb239e4]	240
	241	/* paranoid */ verify( readyThread );
	242
[dddb3dd0]	243	// Reset io dirty bit
	244	this->io.dirty = false;
	245
[1eb239e4]	246	// We found a thread run it
	247	__run_thread(this, readyThread);
	248
	249	// Are we done?
	250	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	251
[d529ad0]	252	if(__atomic_load_n(&this->io.pending, __ATOMIC_RELAXED) && !__atomic_load_n(&this->io.dirty, __ATOMIC_RELAXED)) {
[c9c1c1cb]	253	__IO_STATS__(true, io.flush.dirty++; )
[18f7858]	254	__cfa_io_flush( this );
[dddb3dd0]	255	}
[c81ebf9]	256	}
	257
[4069faad]	258	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	259	}
[8118303]	260
[454f478]	261	post( this->terminated );
[bdeba0b]	262
[28d73c1]	263	if(this == mainProcessor) {
[6a490b2]	264	// HACK : the coroutine context switch expects this_thread to be set
	265	// and it make sense for it to be set in all other cases except here
	266	// fake it
[8fc652e0]	267	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	268	}
[7768b8d]	269
[4069faad]	270	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	271	}
	272
[5c1a531]	273	static int * __volatile_errno() __attribute__((noinline));
	274	static int * __volatile_errno() { asm(""); return &errno; }
	275
[14a61b5]	276	// KERNEL ONLY
[1c273d0]	277	// runThread runs a thread by context switching
	278	// from the processor coroutine to the target thread
[e84ab3d]	279	static void __run_thread(processor * this, thread$ * thrd_dst) {
[8fc652e0]	280	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	281	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
[15c93d8]	282	/* paranoid */ verifyf( thrd_dst->rdy_link.next == 0p, "Expected null got %p", thrd_dst->rdy_link.next );
[1eb239e4]	283	__builtin_prefetch( thrd_dst->context.SP );
	284
[dddb3dd0]	285	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	286
[e84ab3d]	287	coroutine$ * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	288
[9f575ea]	289	// set state of processor coroutine to inactive
	290	verify(proc_cor->state == Active);
[ae7be7a]	291	proc_cor->state = Blocked;
[e8e457e]	292
[9f575ea]	293	// Actually run the thread
[3381ed7]	294	RUNNING: while(true) {
[ff79d5e]	295	thrd_dst->preempted = __NO_PREEMPTION;
[e8e457e]	296
[58d64a4]	297	// Update global state
[8fc652e0]	298	kernelTLS().this_thread = thrd_dst;
[75f3522]	299
[8bee858]	300	// Update the state after setting this_thread
	301	// so that the debugger can find all active threads
	302	// in tls storage
	303	thrd_dst->state = Active;
	304
[8fc652e0]	305	/* paranoid */ verify( ! __preemption_enabled() );
	306	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	307	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	308	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	309	/* paranoid */ verify( thrd_dst->state != Halted );
[e84ab3d]	310	/* 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
	311	/* 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
[878cfcc]	312	/* paranoid */ verify( __atomic_exchange_n( &thrd_dst->executing, this, __ATOMIC_SEQ_CST) == 0p );
[ac12f1f]	313	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	314
[3381ed7]	315
[58d64a4]	316
[9f575ea]	317	// set context switch to the thread that the processor is executing
[c7a900a]	318	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	319	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	320
[50871b4]	321
	322
[ac12f1f]	323	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[878cfcc]	324	/* paranoid */ verify( __atomic_exchange_n( &thrd_dst->executing, 0p, __ATOMIC_SEQ_CST) == this );
[e84ab3d]	325	/* 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 );
	326	/* 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 );
[878cfcc]	327	/* paranoid */ verify( thrd_dst->state != Halted );
[b4b63e8]	328	/* paranoid */ verify( thrd_dst->context.SP );
[8fc652e0]	329	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	330	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	331
[3381ed7]	332	// We just finished running a thread, there are a few things that could have happened.
	333	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	334	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	335	// 4 - Preempted
	336	// In case 1, we may have won a race so we can't write to the state again.
	337	// In case 2, we lost the race so we now own the thread.
	338
	339	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
[8bee858]	340	// Reset the this_thread now that we know
	341	// the state isn't active anymore
	342	kernelTLS().this_thread = 0p;
	343
[3381ed7]	344	// The thread was preempted, reschedule it and reset the flag
[24e321c]	345	schedule_thread$( thrd_dst, UNPARK_LOCAL );
[3381ed7]	346	break RUNNING;
	347	}
[75f3522]	348
[3ea8ad1]	349	if(unlikely(thrd_dst->state == Halting)) {
[8bee858]	350	// Reset the this_thread now that we know
	351	// the state isn't active anymore
	352	kernelTLS().this_thread = 0p;
	353
[ff79d5e]	354	// The thread has halted, it should never be scheduled/run again
[5afb49a]	355	// finish the thread
	356	__thread_finish( thrd_dst );
[ff79d5e]	357	break RUNNING;
	358	}
	359
	360	/* paranoid */ verify( thrd_dst->state == Active );
	361	thrd_dst->state = Blocked;
	362
[8bee858]	363	// Reset the this_thread now that we know
	364	// the state isn't active anymore
	365	kernelTLS().this_thread = 0p;
	366
[3381ed7]	367	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	368	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	369	switch(old_ticket) {
[6a77224]	370	case TICKET_RUNNING:
[3381ed7]	371	// This is case 1, the regular case, nothing more is needed
	372	break RUNNING;
[6a77224]	373	case TICKET_UNBLOCK:
[c9c1c1cb]	374	__STATS__(true, ready.threads.threads++; )
[3381ed7]	375	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	376	// In this case, just run it again.
	377	continue RUNNING;
	378	default:
	379	// This makes no sense, something is wrong abort
[ff79d5e]	380	abort();
[3381ed7]	381	}
[9f575ea]	382	}
[e8e457e]	383
[9f575ea]	384	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	385	proc_cor->state = Active;
[1eb239e4]	386
[dddb3dd0]	387	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	388
[c9c1c1cb]	389	__STATS__(true, ready.threads.threads--; )
[ec43cf9]	390
[8fc652e0]	391	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	392	}
	393
[14a61b5]	394	// KERNEL_ONLY
[c18bf9e]	395	static void returnToKernel() {
[8fc652e0]	396	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	397	coroutine$ * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	398	thread$ * thrd_src = kernelTLS().this_thread;
[e8e457e]	399
[c9c1c1cb]	400	__STATS_DEF( thrd_src->last_proc = kernelTLS().this_processor; )
[29cb302]	401
[9f575ea]	402	// Run the thread on this processor
	403	{
	404	int local_errno = *__volatile_errno();
	405	#if defined( __i386 ) \|\| defined( __x86_64 )
	406	__x87_store;
	407	#endif
[b4b63e8]	408	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	409	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	410	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	411	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	412	#if defined( __i386 ) \|\| defined( __x86_64 )
	413	__x87_load;
	414	#endif
	415	*__volatile_errno() = local_errno;
[8fcbb4c]	416	}
[deca0f5]	417
[29cb302]	418	#if !defined(__CFA_NO_STATISTICS__)
[89eff25]	419	/* paranoid */ verify( thrd_src->last_proc != 0p );
	420	if(thrd_src->last_proc != kernelTLS().this_processor) {
[29cb302]	421	__tls_stats()->ready.threads.migration++;
	422	}
	423	#endif
	424
[8fc652e0]	425	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	426	/* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) < ((uintptr_t)__get_stack(thrd_src->curr_cor)->base ) \|\| thrd_src->corctx_flag, "ERROR : Returning thread$ %p has been corrupted.\n StackPointer too small.\n", thrd_src );
	427	/* paranoid */ verifyf( ((uintptr_t)thrd_src->context.SP) > ((uintptr_t)__get_stack(thrd_src->curr_cor)->limit) \|\| thrd_src->corctx_flag, "ERROR : Returning thread$ %p has been corrupted.\n StackPointer too large.\n", thrd_src );
[c84e80a]	428	}
	429
[8def349]	430	//-----------------------------------------------------------------------------
	431	// Scheduler routines
[14a61b5]	432	// KERNEL ONLY
[24e321c]	433	static void __schedule_thread( thread$ * thrd, unpark_hint hint ) {
[8fc652e0]	434	/* paranoid */ verify( ! __preemption_enabled() );
[254ad1b]	435	/* paranoid */ verify( ready_schedule_islocked());
[6a490b2]	436	/* paranoid */ verify( thrd );
	437	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	438	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	439	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	440	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	441	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	442	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	443	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	444	/* paranoid */ #endif
[15c93d8]	445	/* paranoid */ verifyf( thrd->rdy_link.next == 0p, "Expected null got %p", thrd->rdy_link.next );
[ac12f1f]	446	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	447
[ae7be7a]	448	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	449
[ec43cf9]	450	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	451	struct cluster * cl = thrd->curr_cluster;
[c9c1c1cb]	452	__STATS_DEF(bool outside = hint == UNPARK_LOCAL && thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	453
[254ad1b]	454	// push the thread to the cluster ready-queue
[24e321c]	455	push( cl, thrd, hint );
[32a8b61]	456
[254ad1b]	457	// variable thrd is no longer safe to use
[734908c]	458	thrd = 0xdeaddeaddeaddeadp;
[32a8b61]	459
[254ad1b]	460	// wake the cluster using the save variable.
	461	__wake_one( cl );
[1c273d0]	462
[ec43cf9]	463	#if !defined(__CFA_NO_STATISTICS__)
	464	if( kernelTLS().this_stats ) {
	465	__tls_stats()->ready.threads.threads++;
[89eff25]	466	if(outside) {
	467	__tls_stats()->ready.threads.extunpark++;
	468	}
[ec43cf9]	469	}
	470	else {
	471	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	472	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[ec43cf9]	473	}
	474	#endif
	475
[254ad1b]	476	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	477	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	478	}
	479
[24e321c]	480	void schedule_thread$( thread$ * thrd, unpark_hint hint ) {
[254ad1b]	481	ready_schedule_lock();
[24e321c]	482	__schedule_thread( thrd, hint );
[254ad1b]	483	ready_schedule_unlock();
	484	}
	485
[14a61b5]	486	// KERNEL ONLY
[e84ab3d]	487	static inline thread$ * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	488	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	489
[e873838]	490	ready_schedule_lock();
[e84ab3d]	491	thread$ * thrd = pop_fast( this );
[e873838]	492	ready_schedule_unlock();
[7768b8d]	493
[8fc652e0]	494	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	495	return thrd;
[eb2e723]	496	}
	497
[64a7146]	498	// KERNEL ONLY
[e84ab3d]	499	static inline thread$ * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	500	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	501
[e873838]	502	ready_schedule_lock();
[c9c1c1cb]	503	thread$ * thrd = pop_slow( this );
	504	ready_schedule_unlock();
	505
	506	/* paranoid */ verify( ! __preemption_enabled() );
	507	return thrd;
	508	}
[fc59df78]	509
[c9c1c1cb]	510	// KERNEL ONLY
	511	static inline thread$ * __next_thread_search(cluster * this) with( *this ) {
	512	/* paranoid */ verify( ! __preemption_enabled() );
	513
	514	ready_schedule_lock();
	515	thread$ * thrd = pop_search( this );
[e873838]	516	ready_schedule_unlock();
[64a7146]	517
[8fc652e0]	518	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	519	return thrd;
[64a7146]	520	}
	521
[e84ab3d]	522	static inline bool __must_unpark( thread$ * thrd ) {
[ff79d5e]	523	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	524	switch(old_ticket) {
[6a77224]	525	case TICKET_RUNNING:
[3381ed7]	526	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	527	return false;
[6a77224]	528	case TICKET_BLOCKED:
[3381ed7]	529	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	530	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	531	return true;
[3381ed7]	532	default:
	533	// This makes no sense, something is wrong abort
[7ee8153]	534	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	535	}
[eb2e723]	536	}
	537
[24e321c]	538	void __kernel_unpark( thread$ * thrd, unpark_hint hint ) {
[e9c0b4c]	539	/* paranoid */ verify( ! __preemption_enabled() );
	540	/* paranoid */ verify( ready_schedule_islocked());
	541
	542	if( !thrd ) return;
	543
	544	if(__must_unpark(thrd)) {
	545	// Wake lost the race,
[24e321c]	546	__schedule_thread( thrd, hint );
[e9c0b4c]	547	}
	548
	549	/* paranoid */ verify( ready_schedule_islocked());
	550	/* paranoid */ verify( ! __preemption_enabled() );
	551	}
	552
[c18bf9e]	553	void unpark( thread$ * thrd, unpark_hint hint ) libcfa_public {
[c6c7e6c]	554	if( !thrd ) return;
[0b33412]	555
[c6c7e6c]	556	if(__must_unpark(thrd)) {
	557	disable_interrupts();
[a3821fa]	558	// Wake lost the race,
[24e321c]	559	schedule_thread$( thrd, hint );
[a3821fa]	560	enable_interrupts(false);
[de6319f]	561	}
[eb2e723]	562	}
[0b33412]	563
[c18bf9e]	564	void park( void ) libcfa_public {
[a3821fa]	565	__disable_interrupts_checked();
	566	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	567	returnToKernel();
	568	__enable_interrupts_checked();
[0c78741]	569
	570	}
[09800e9]	571
[5afb49a]	572	extern "C" {
	573	// Leave the thread monitor
	574	// last routine called by a thread.
	575	// Should never return
	576	void __cfactx_thrd_leave() {
[e84ab3d]	577	thread$ * thrd = active_thread();
	578	monitor$ * this = &thrd->self_mon;
[5afb49a]	579
	580	// Lock the monitor now
	581	lock( this->lock __cfaabi_dbg_ctx2 );
	582
	583	disable_interrupts();
	584
[9d6e1b8a]	585	/* paranoid */ verify( ! __preemption_enabled() );
	586	/* paranoid */ verify( thrd->state == Active );
	587	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	588	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	589	/* paranoid */ verify( thrd->context.SP );
[e84ab3d]	590	/* 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 );
	591	/* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) < ((uintptr_t)__get_stack(thrd->curr_cor)->base ), "ERROR : thread$ %p has been corrupted.\n StackPointer too small.\n", thrd );
[9d6e1b8a]	592
[58688bf]	593	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	594	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	595	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	596
[28372f7]	597	thrd->state = Halting;
	598	thrd->ticket = TICKET_DEAD;
	599
[5afb49a]	600	// Leave the thread
	601	returnToKernel();
	602
	603	// Control flow should never reach here!
[9d6e1b8a]	604	abort();
[5afb49a]	605	}
[09800e9]	606	}
	607
[14a61b5]	608	// KERNEL ONLY
[c18bf9e]	609	bool force_yield( __Preemption_Reason reason ) libcfa_public {
[a3821fa]	610	__disable_interrupts_checked();
[e84ab3d]	611	thread$ * thrd = kernelTLS().this_thread;
[a3821fa]	612	/* paranoid */ verify(thrd->state == Active);
	613
	614	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	615	// it was going to park itself. If that is the case and it is already using the
	616	// intrusive fields then we can't use them to preempt the thread
	617	// If that is the case, abandon the preemption.
	618	bool preempted = false;
[15c93d8]	619	if(thrd->rdy_link.next == 0p) {
[a3821fa]	620	preempted = true;
	621	thrd->preempted = reason;
	622	returnToKernel();
	623	}
	624	__enable_interrupts_checked( false );
[3381ed7]	625	return preempted;
[f2b12406]	626	}
	627
[14a61b5]	628	//=============================================================================================
[92e7631]	629	// Kernel Idle Sleep
[14a61b5]	630	//=============================================================================================
[64a7146]	631	// Wake a thread from the front if there are any
[e873838]	632	static void __wake_one(cluster * this) {
[7cf3b1d]	633	eventfd_t val;
	634
[8fc652e0]	635	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	636	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	637
[64a7146]	638	// Check if there is a sleeping processor
[7cf3b1d]	639	struct __fd_waitctx * fdp = __atomic_load_n(&this->procs.fdw, __ATOMIC_SEQ_CST);
[14a61b5]	640
[7cf3b1d]	641	// If no one is sleeping: we are done
	642	if( fdp == 0p ) return;
[14a61b5]	643
[7cf3b1d]	644	int fd = 1;
[22226e4]	645	if( __atomic_load_n(&fdp->sem, __ATOMIC_SEQ_CST) != 1 ) {
	646	fd = __atomic_exchange_n(&fdp->sem, 1, __ATOMIC_RELAXED);
[7cf3b1d]	647	}
[14a61b5]	648
[7cf3b1d]	649	switch(fd) {
[4ccc150]	650	__attribute__((unused)) int ret;
[7cf3b1d]	651	case 0:
	652	// If the processor isn't ready to sleep then the exchange will already wake it up
	653	#if !defined(__CFA_NO_STATISTICS__)
	654	if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.early++;
	655	} else { __atomic_fetch_add(&this->stats->ready.sleep.early, 1, __ATOMIC_RELAXED); }
	656	#endif
	657	break;
	658	case 1:
	659	// If someone else already said they will wake them: we are done
	660	#if !defined(__CFA_NO_STATISTICS__)
	661	if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.seen++;
	662	} else { __atomic_fetch_add(&this->stats->ready.sleep.seen, 1, __ATOMIC_RELAXED); }
	663	#endif
	664	break;
	665	default:
	666	// If the processor was ready to sleep, we need to wake it up with an actual write
	667	val = 1;
[4ccc150]	668	ret = eventfd_write( fd, val );
[77adaee]	669	/* paranoid */ verifyf( ret == 0, "Expected return to be 0, was %d\n", ret );
[7cf3b1d]	670
	671	#if !defined(__CFA_NO_STATISTICS__)
	672	if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.wakes++;
	673	} else { __atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED); }
	674	#endif
	675	break;
	676	}
[1eb239e4]	677
[e873838]	678	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	679	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	680
	681	return;
[64a7146]	682	}
[14a61b5]	683
[64a7146]	684	// Unconditionnaly wake a thread
[1eb239e4]	685	void __wake_proc(processor * this) {
[7d0ebd0]	686	/* paranoid */ verify( ! __preemption_enabled() );
	687
[64a7146]	688	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	689
[22226e4]	690	this->idle_wctx.sem = 1;
[7cf3b1d]	691
[efa28d5]	692	this->idle_wctx.wake__time = rdtscl();
[262fafd9]	693
[7d0ebd0]	694	eventfd_t val;
	695	val = 1;
[d080549]	696	__attribute__((unused)) int ret = eventfd_write( this->idle_wctx.evfd, val );
[7d0ebd0]	697
[d080549]	698	/* paranoid */ verifyf( ret == 0, "Expected return to be 0, was %d\n", ret );
[7d0ebd0]	699	/* paranoid */ verify( ! __preemption_enabled() );
[92e7631]	700	}
	701
[18f7858]	702	static void idle_sleep(processor * this) {
[202c80b]	703	/* paranoid */ verify( this->idle_wctx.evfd != 1 );
	704	/* paranoid */ verify( this->idle_wctx.evfd != 2 );
	705
[7cf3b1d]	706	// Tell everyone we are ready to go do sleep
	707	for() {
[22226e4]	708	int expected = this->idle_wctx.sem;
[7cf3b1d]	709
	710	// Someone already told us to wake-up! No time for a nap.
	711	if(expected == 1) { return; }
	712
	713	// Try to mark that we are going to sleep
[22226e4]	714	if(__atomic_compare_exchange_n(&this->idle_wctx.sem, &expected, this->idle_wctx.evfd, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) {
[7cf3b1d]	715	// Every one agreed, taking a nap
	716	break;
	717	}
	718	}
	719
	720
[a757ba1]	721	#if !defined(__CFA_NO_STATISTICS__)
	722	if(this->print_halts) {
	723	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
	724	}
	725	#endif
[1757f98]	726
[a757ba1]	727	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle_fd);
[1757f98]	728
[a757ba1]	729	{
	730	eventfd_t val;
	731	ssize_t ret = read( this->idle_wctx.evfd, &val, sizeof(val) );
	732	if(ret < 0) {
	733	switch((int)errno) {
	734	case EAGAIN:
	735	#if EAGAIN != EWOULDBLOCK
	736	case EWOULDBLOCK:
	737	#endif
	738	case EINTR:
	739	// No need to do anything special here, just assume it's a legitimate wake-up
	740	break;
	741	default:
	742	abort( "KERNEL : internal error, read failure on idle eventfd, error(%d) %s.", (int)errno, strerror( (int)errno ) );
[1757f98]	743	}
	744	}
[a757ba1]	745	}
[1757f98]	746
[a757ba1]	747	#if !defined(__CFA_NO_STATISTICS__)
	748	if(this->print_halts) {
	749	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
	750	}
[1757f98]	751	#endif
	752	}
	753
[5f5a729]	754	static bool mark_idle(__cluster_proc_list & this, processor & proc) {
[c9c1c1cb]	755	__STATS__(true, ready.sleep.halts++; )
[7cf3b1d]	756
[22226e4]	757	proc.idle_wctx.sem = 0;
[7cf3b1d]	758
[8fc652e0]	759	/* paranoid */ verify( ! __preemption_enabled() );
[5f5a729]	760	if(!try_lock( this )) return false;
[1eb239e4]	761	this.idle++;
	762	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	763	remove(proc);
[6a9b12b]	764	insert_first(this.idles, proc);
[34b8cb7]	765
[a757ba1]	766	// update the pointer to the head wait context, which should now point to this proc.
[7cf3b1d]	767	__atomic_store_n(&this.fdw, &proc.idle_wctx, __ATOMIC_SEQ_CST);
[1eb239e4]	768	unlock( this );
[8fc652e0]	769	/* paranoid */ verify( ! __preemption_enabled() );
[5f5a729]	770
	771	return true;
[1eb239e4]	772	}
[8e16177]	773
[6a9b12b]	774	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	775	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	776	lock( this );
	777	this.idle--;
	778	/* paranoid */ verify( this.idle >= 0 );
	779	remove(proc);
[fc59b580]	780	insert_last(this.actives, proc);
[6a9b12b]	781
[a633f6f]	782	{
[a757ba1]	783	// update the pointer to the head wait context
[7cf3b1d]	784	struct __fd_waitctx * wctx = 0;
	785	if(!this.idles`isEmpty) wctx = &this.idles`first.idle_wctx;
	786	__atomic_store_n(&this.fdw, wctx, __ATOMIC_SEQ_CST);
[a633f6f]	787	}
	788
[34b8cb7]	789	unlock( this );
[6a9b12b]	790	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	791	}
	792
[dbe9b08]	793	//=============================================================================================
	794	// Unexpected Terminating logic
	795	//=============================================================================================
[92bfda0]	796	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
[e84ab3d]	797	thread$ * thrd = __cfaabi_tls.this_thread;
[9d944b2]	798
[de94a60]	799	if(thrd) {
	800	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	801	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	802
[212c2187]	803	if ( &thrd->self_cor != thrd->curr_cor ) {
	804	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	805	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	806	}
	807	else {
[1c40091]	808	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	809	}
[1c273d0]	810	}
[9d944b2]	811	else {
[de94a60]	812	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	813	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	814	}
	815	}
	816
[92bfda0]	817	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	818	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	819	}
	820
[de94a60]	821	static __spinlock_t kernel_debug_lock;
	822
[9d944b2]	823	extern "C" {
[1c40091]	824	void __cfaabi_bits_acquire() {
[36982fc]	825	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	826	}
	827
[1c40091]	828	void __cfaabi_bits_release() {
[ea7d2b0]	829	unlock( kernel_debug_lock );
[9d944b2]	830	}
[8118303]	831	}
	832
[fa21ac9]	833	//=============================================================================================
	834	// Kernel Utilities
	835	//=============================================================================================
[dddb3dd0]	836	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	837	#include "io/types.hfa"
	838	#endif
	839
[2026bb6]	840	//-----------------------------------------------------------------------------
	841	// Debug
[c18bf9e]	842	bool threading_enabled(void) __attribute__((const)) libcfa_public {
[2026bb6]	843	return true;
	844	}
[c34ebf2]	845
	846	//-----------------------------------------------------------------------------
	847	// Statistics
	848	#if !defined(__CFA_NO_STATISTICS__)
[c18bf9e]	849	void print_halts( processor & this ) libcfa_public {
[c34ebf2]	850	this.print_halts = true;
	851	}
[58688bf]	852
[69914cbc]	853	static void crawl_list( cluster * cltr, dlist(processor) & list, unsigned count ) {
[8464edf]	854	/* paranoid */ verify( cltr->stats );
	855
	856	processor * it = &list`first;
	857	for(unsigned i = 0; i < count; i++) {
	858	/* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
	859	/* paranoid */ verify( it->local_data->this_stats );
[c33c2af]	860	// __print_stats( it->local_data->this_stats, cltr->print_stats, "Processor", it->name, (void*)it );
[8464edf]	861	__tally_stats( cltr->stats, it->local_data->this_stats );
	862	it = &(*it)`next;
	863	}
	864	}
	865
[c18bf9e]	866	static void crawl_cluster_stats( cluster & this ) {
[8464edf]	867	// Stop the world, otherwise stats could get really messed-up
	868	// this doesn't solve all problems but does solve many
	869	// so it's probably good enough
[c33c2af]	870	disable_interrupts();
[8464edf]	871	uint_fast32_t last_size = ready_mutate_lock();
	872
	873	crawl_list(&this, this.procs.actives, this.procs.total - this.procs.idle);
	874	crawl_list(&this, this.procs.idles , this.procs.idle );
	875
	876	// Unlock the RWlock
	877	ready_mutate_unlock( last_size );
[c33c2af]	878	enable_interrupts();
[8464edf]	879	}
	880
	881
[c18bf9e]	882	void print_stats_now( cluster & this, int flags ) libcfa_public {
[8464edf]	883	crawl_cluster_stats( this );
[202c80b]	884	__print_stats( this.stats, flags, "Cluster", this.name, (void*)&this );
[1b033b8]	885	}
[c34ebf2]	886	#endif
[8118303]	887	// Local Variables: //
	888	// mode: c //
	889	// tab-width: 4 //
	890	// End: //

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