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ADT ast-experimental enum pthread-emulation qualifiedEnum

Last change on this file since 778315e was c9c1c1cb, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
Minor changes to kernel main loop and fixed stats.
Property mode set to `100644`
File size: 28.7 KB

Rev	Line
[8118303]	1	//
	2	// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
	3	//
	4	// The contents of this file are covered under the licence agreement in the
	5	// file "LICENCE" distributed with Cforall.
	6	//
	7	// kernel.c --
	8	//
	9	// Author : Thierry Delisle
[75f3522]	10	// Created On : Tue Jan 17 12:27:26 2017
[6b0b624]	11	// Last Modified By : Peter A. Buhr
[0190480]	12	// Last Modified On : Mon Aug 31 07:08:20 2020
	13	// Update Count : 71
[8118303]	14	//
	15
[2026bb6]	16	#define __cforall_thread__
[43784ac]	17	#define _GNU_SOURCE
	18
[4069faad]	19	// #define __CFA_DEBUG_PRINT_RUNTIME_CORE__
[2026bb6]	20
[8118303]	21	//C Includes
[214e8da]	22	#include <errno.h>
[9d944b2]	23	#include <stdio.h>
[445f984]	24	#include <string.h>
[58b6d1b]	25	#include <signal.h>
[9d944b2]	26	#include <unistd.h>
[dddb3dd0]	27	extern "C" {
	28	#include <sys/eventfd.h>
[d3605f8]	29	#include <sys/uio.h>
[dddb3dd0]	30	}
[8118303]	31
	32	//CFA Includes
[73abe95]	33	#include "kernel_private.hfa"
	34	#include "preemption.hfa"
[445f984]	35	#include "strstream.hfa"
	36	#include "device/cpu.hfa"
[7ef162b2]	37	#include "io/types.hfa"
[8118303]	38
	39	//Private includes
	40	#define __CFA_INVOKE_PRIVATE__
	41	#include "invoke.h"
	42
[89eff25]	43	#if !defined(__CFA_NO_STATISTICS__)
[c9c1c1cb]	44	#define __STATS_DEF( ...) __VA_ARGS__
[89eff25]	45	#else
[c9c1c1cb]	46	#define __STATS_DEF( ...)
[89eff25]	47	#endif
[4069faad]	48
[deca0f5]	49	//-----------------------------------------------------------------------------
	50	// Some assembly required
[1805b1b]	51	#if defined( __i386 )
[deca0f5]	52	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	53	// fcw : X87 FPU control word (preserved across function calls)
	54	#define __x87_store \
	55	uint32_t __mxcr; \
	56	uint16_t __fcw; \
	57	__asm__ volatile ( \
	58	"stmxcsr %0\n" \
	59	"fnstcw %1\n" \
	60	: "=m" (__mxcr),\
	61	"=m" (__fcw) \
	62	)
	63
	64	#define __x87_load \
	65	__asm__ volatile ( \
	66	"fldcw %1\n" \
	67	"ldmxcsr %0\n" \
	68	::"m" (__mxcr),\
	69	"m" (__fcw) \
	70	)
	71
	72	#elif defined( __x86_64 )
	73	#define __x87_store \
	74	uint32_t __mxcr; \
	75	uint16_t __fcw; \
	76	__asm__ volatile ( \
	77	"stmxcsr %0\n" \
	78	"fnstcw %1\n" \
	79	: "=m" (__mxcr),\
	80	"=m" (__fcw) \
	81	)
	82
	83	#define __x87_load \
	84	__asm__ volatile ( \
	85	"fldcw %1\n" \
	86	"ldmxcsr %0\n" \
	87	:: "m" (__mxcr),\
	88	"m" (__fcw) \
	89	)
	90
[0190480]	91	#elif defined( __arm__ )
	92	#define __x87_store
	93	#define __x87_load
	94
	95	#elif defined( __aarch64__ )
[74f5c83]	96	#define __x87_store \
	97	uint32_t __fpcntl[2]; \
	98	__asm__ volatile ( \
	99	"mrs x9, FPCR\n" \
	100	"mrs x10, FPSR\n" \
	101	"stp x9, x10, %0\n" \
	102	: "=m" (__fpcntl) : : "x9", "x10" \
	103	)
	104
	105	#define __x87_load \
	106	__asm__ volatile ( \
	107	"ldp x9, x10, %0\n" \
	108	"msr FPSR, x10\n" \
	109	"msr FPCR, x9\n" \
	110	: "=m" (__fpcntl) : : "x9", "x10" \
	111	)
	112
[deca0f5]	113	#else
[0190480]	114	#error unsupported hardware architecture
[deca0f5]	115	#endif
	116
[e84ab3d]	117	extern thread$ * mainThread;
[e660761]	118	extern processor * mainProcessor;
[2ac095d]	119
[92e7631]	120	//-----------------------------------------------------------------------------
	121	// Kernel Scheduling logic
[e84ab3d]	122	static thread$ * __next_thread(cluster * this);
	123	static thread$ * __next_thread_slow(cluster * this);
[c9c1c1cb]	124	static thread$ * __next_thread_search(cluster * this);
[e84ab3d]	125	static inline bool __must_unpark( thread$ * thrd ) __attribute((nonnull(1)));
	126	static void __run_thread(processor * this, thread$ * dst);
[e873838]	127	static void __wake_one(cluster * cltr);
[1eb239e4]	128
[d3605f8]	129	static void idle_sleep(processor * proc, io_future_t & future, iovec & iov);
[5f5a729]	130	static bool mark_idle (__cluster_proc_list & idles, processor & proc);
[6a9b12b]	131	static void mark_awake(__cluster_proc_list & idles, processor & proc);
[1eb239e4]	132
[dddb3dd0]	133	extern void __cfa_io_start( processor * );
[c1c95b1]	134	extern bool __cfa_io_drain( processor * );
[c7b2215]	135	extern bool __cfa_io_flush( processor *, int min_comp );
[dddb3dd0]	136	extern void __cfa_io_stop ( processor * );
[c1c95b1]	137	static inline bool __maybe_io_drain( processor * );
[dddb3dd0]	138
[d3605f8]	139	#if defined(CFA_WITH_IO_URING_IDLE)
	140	extern bool __kernel_read(processor * proc, io_future_t & future, iovec &, int fd);
[6ddef36]	141	#endif
[7ef162b2]	142
[dddb3dd0]	143	extern void __disable_interrupts_hard();
	144	extern void __enable_interrupts_hard();
[c84e80a]	145
[7ef162b2]	146
[75f3522]	147	//=============================================================================================
	148	// Kernel Scheduling logic
	149	//=============================================================================================
[8fcbb4c]	150	//Main of the processor contexts
[83a071f9]	151	void main(processorCtx_t & runner) {
[21184e3]	152	// Because of a bug, we couldn't initialized the seed on construction
	153	// Do it here
[8fc652e0]	154	__cfaabi_tls.rand_seed ^= rdtscl();
	155	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	156	__tls_rand_advance_bck();
[21184e3]	157
[83a071f9]	158	processor * this = runner.proc;
[094476d]	159	verify(this);
[c81ebf9]	160
[7ef162b2]	161	io_future_t future; // used for idle sleep when io_uring is present
	162	future.self.ptr = 1p; // mark it as already fulfilled so we know if there is a pending request or not
[c7b2215]	163	eventfd_t idle_val;
[d3605f8]	164	iovec idle_iovec = { &idle_val, sizeof(idle_val) };
[7ef162b2]	165
[dddb3dd0]	166	__cfa_io_start( this );
	167
[4069faad]	168	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	169	#if !defined(__CFA_NO_STATISTICS__)
	170	if( this->print_halts ) {
[c993b15]	171	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->unique_id, this->name, (void*)this);
[28d73c1]	172	}
	173	#endif
[b798713]	174
[75f3522]	175	{
[c81ebf9]	176	// Setup preemption data
	177	preemption_scope scope = { this };
	178
[a5e7233]	179	// if we need to run some special setup, now is the time to do it.
	180	if(this->init.thrd) {
	181	this->init.thrd->curr_cluster = this->cltr;
	182	__run_thread(this, this->init.thrd);
	183	}
[325e6ea]	184
[4069faad]	185	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	186
[e84ab3d]	187	thread$ * readyThread = 0p;
[1eb239e4]	188	MAIN_LOOP:
	189	for() {
[dddb3dd0]	190	// Check if there is pending io
	191	__maybe_io_drain( this );
	192
[92e7631]	193	// Try to get the next thread
[8c50aed]	194	readyThread = __next_thread( this->cltr );
[75f3522]	195
[1eb239e4]	196	if( !readyThread ) {
[c9c1c1cb]	197	__IO_STATS__(true, io.flush.idle++; )
[c7b2215]	198	__cfa_io_flush( this, 0 );
[c33c2af]	199
[c9c1c1cb]	200	readyThread = __next_thread( this->cltr );
	201	}
	202
	203	if( !readyThread ) for(5) {
	204	__IO_STATS__(true, io.flush.idle++; )
	205
[1eb239e4]	206	readyThread = __next_thread_slow( this->cltr );
[c9c1c1cb]	207
	208	if( readyThread ) break;
	209
	210	__cfa_io_flush( this, 0 );
[1eb239e4]	211	}
[4e6fb8e]	212
[1eb239e4]	213	HALT:
	214	if( !readyThread ) {
	215	// Don't block if we are done
	216	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	217
[1eb239e4]	218	// Push self to idle stack
[5f5a729]	219	if(!mark_idle(this->cltr->procs, * this)) continue MAIN_LOOP;
[398e8e9]	220
[1eb239e4]	221	// Confirm the ready-queue is empty
[c9c1c1cb]	222	readyThread = __next_thread_search( this->cltr );
[1eb239e4]	223	if( readyThread ) {
	224	// A thread was found, cancel the halt
[6a9b12b]	225	mark_awake(this->cltr->procs, * this);
[1eb239e4]	226
[c9c1c1cb]	227	__STATS__(true, ready.sleep.cancels++; )
[1eb239e4]	228
	229	// continue the mai loop
	230	break HALT;
	231	}
	232
[d3605f8]	233	idle_sleep( this, future, idle_iovec );
[1eb239e4]	234
	235	// We were woken up, remove self from idle
[6a9b12b]	236	mark_awake(this->cltr->procs, * this);
[1eb239e4]	237
	238	// DON'T just proceed, start looking again
	239	continue MAIN_LOOP;
[64a7146]	240	}
[1eb239e4]	241
	242	/* paranoid */ verify( readyThread );
	243
[dddb3dd0]	244	// Reset io dirty bit
	245	this->io.dirty = false;
	246
[1eb239e4]	247	// We found a thread run it
	248	__run_thread(this, readyThread);
	249
	250	// Are we done?
	251	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	252
[dddb3dd0]	253	if(this->io.pending && !this->io.dirty) {
[c9c1c1cb]	254	__IO_STATS__(true, io.flush.dirty++; )
[c7b2215]	255	__cfa_io_flush( this, 0 );
[dddb3dd0]	256	}
[c81ebf9]	257	}
	258
[4069faad]	259	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	260	}
[8118303]	261
[3bb4f85]	262	for(int i = 0; !available(future); i++) {
	263	if(i > 1000) __cfaabi_dbg_write( "ERROR: kernel has bin spinning on a flush after exit loop.\n", 60);
	264	__cfa_io_flush( this, 1 );
	265	}
	266
[dddb3dd0]	267	__cfa_io_stop( this );
	268
[454f478]	269	post( this->terminated );
[bdeba0b]	270
[28d73c1]	271	if(this == mainProcessor) {
[6a490b2]	272	// HACK : the coroutine context switch expects this_thread to be set
	273	// and it make sense for it to be set in all other cases except here
	274	// fake it
[8fc652e0]	275	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	276	}
[7768b8d]	277
[4069faad]	278	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	279	}
	280
[5c1a531]	281	static int * __volatile_errno() __attribute__((noinline));
	282	static int * __volatile_errno() { asm(""); return &errno; }
	283
[14a61b5]	284	// KERNEL ONLY
[1c273d0]	285	// runThread runs a thread by context switching
	286	// from the processor coroutine to the target thread
[e84ab3d]	287	static void __run_thread(processor * this, thread$ * thrd_dst) {
[8fc652e0]	288	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	289	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	290	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	291	__builtin_prefetch( thrd_dst->context.SP );
	292
[dddb3dd0]	293	__cfadbg_print_safe(runtime_core, "Kernel : core %p running thread %p (%s)\n", this, thrd_dst, thrd_dst->self_cor.name);
	294
[e84ab3d]	295	coroutine$ * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	296
[9f575ea]	297	// set state of processor coroutine to inactive
	298	verify(proc_cor->state == Active);
[ae7be7a]	299	proc_cor->state = Blocked;
[e8e457e]	300
[9f575ea]	301	// Actually run the thread
[3381ed7]	302	RUNNING: while(true) {
[ff79d5e]	303	thrd_dst->preempted = __NO_PREEMPTION;
	304	thrd_dst->state = Active;
[e8e457e]	305
[58d64a4]	306	// Update global state
[8fc652e0]	307	kernelTLS().this_thread = thrd_dst;
[75f3522]	308
[8fc652e0]	309	/* paranoid */ verify( ! __preemption_enabled() );
	310	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	311	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	312	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	313	/* paranoid */ verify( thrd_dst->state != Halted );
[e84ab3d]	314	/* 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
	315	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) > ((uintptr_t)__get_stack(thrd_dst->curr_cor)->limit) \|\| thrd_dst->curr_cor == proc_cor \|\| thrd_dst->corctx_flag, "ERROR : Destination thread$ %p has been corrupted.\n StackPointer too large.\n", thrd_dst ); // add escape condition if we are setting up the processor
[ac12f1f]	316	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	317
[3381ed7]	318
[58d64a4]	319
[9f575ea]	320	// set context switch to the thread that the processor is executing
[c7a900a]	321	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	322	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	323
[50871b4]	324
	325
[ac12f1f]	326	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[e84ab3d]	327	/* 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 );
	328	/* paranoid */ verifyf( ((uintptr_t)thrd_dst->context.SP) < ((uintptr_t)__get_stack(thrd_dst->curr_cor)->base ) \|\| thrd_dst->corctx_flag, "ERROR : Destination thread$ %p has been corrupted.\n StackPointer too small.\n", thrd_dst );
[b4b63e8]	329	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	330	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	331	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	332	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	333
[58d64a4]	334	// Reset global state
[8fc652e0]	335	kernelTLS().this_thread = 0p;
[3381ed7]	336
	337	// We just finished running a thread, there are a few things that could have happened.
	338	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	339	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	340	// 4 - Preempted
	341	// In case 1, we may have won a race so we can't write to the state again.
	342	// In case 2, we lost the race so we now own the thread.
	343
	344	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	345	// The thread was preempted, reschedule it and reset the flag
[24e321c]	346	schedule_thread$( thrd_dst, UNPARK_LOCAL );
[3381ed7]	347	break RUNNING;
	348	}
[75f3522]	349
[3ea8ad1]	350	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	351	// The thread has halted, it should never be scheduled/run again
[5afb49a]	352	// finish the thread
	353	__thread_finish( thrd_dst );
[ff79d5e]	354	break RUNNING;
	355	}
	356
	357	/* paranoid */ verify( thrd_dst->state == Active );
	358	thrd_dst->state = Blocked;
	359
[3381ed7]	360	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	361	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	362	switch(old_ticket) {
[6a77224]	363	case TICKET_RUNNING:
[3381ed7]	364	// This is case 1, the regular case, nothing more is needed
	365	break RUNNING;
[6a77224]	366	case TICKET_UNBLOCK:
[c9c1c1cb]	367	__STATS__(true, ready.threads.threads++; )
[3381ed7]	368	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	369	// In this case, just run it again.
	370	continue RUNNING;
	371	default:
	372	// This makes no sense, something is wrong abort
[ff79d5e]	373	abort();
[3381ed7]	374	}
[9f575ea]	375	}
[e8e457e]	376
[9f575ea]	377	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	378	proc_cor->state = Active;
[1eb239e4]	379
[dddb3dd0]	380	__cfadbg_print_safe(runtime_core, "Kernel : core %p finished running thread %p\n", this, thrd_dst);
	381
[c9c1c1cb]	382	__STATS__(true, ready.threads.threads--; )
[ec43cf9]	383
[8fc652e0]	384	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	385	}
	386
[14a61b5]	387	// KERNEL_ONLY
[b0c7419]	388	void returnToKernel() {
[8fc652e0]	389	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	390	coroutine$ * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	391	thread$ * thrd_src = kernelTLS().this_thread;
[e8e457e]	392
[c9c1c1cb]	393	__STATS_DEF( thrd_src->last_proc = kernelTLS().this_processor; )
[29cb302]	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__)
[89eff25]	412	/* paranoid */ verify( thrd_src->last_proc != 0p );
	413	if(thrd_src->last_proc != kernelTLS().this_processor) {
[29cb302]	414	__tls_stats()->ready.threads.migration++;
	415	}
	416	#endif
	417
[8fc652e0]	418	/* paranoid */ verify( ! __preemption_enabled() );
[e84ab3d]	419	/* 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 );
	420	/* 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]	421	}
	422
[8def349]	423	//-----------------------------------------------------------------------------
	424	// Scheduler routines
[14a61b5]	425	// KERNEL ONLY
[24e321c]	426	static void __schedule_thread( thread$ * thrd, unpark_hint hint ) {
[8fc652e0]	427	/* paranoid */ verify( ! __preemption_enabled() );
[254ad1b]	428	/* paranoid */ verify( ready_schedule_islocked());
[6a490b2]	429	/* paranoid */ verify( thrd );
	430	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	431	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	432	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	433	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	434	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	435	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	436	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	437	/* paranoid */ #endif
[6a490b2]	438	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	439	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	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;
[c9c1c1cb]	445	__STATS_DEF(bool outside = hint == UNPARK_LOCAL && thrd->last_proc && thrd->last_proc != kernelTLS().this_processor; )
[32a8b61]	446
[254ad1b]	447	// push the thread to the cluster ready-queue
[24e321c]	448	push( cl, thrd, hint );
[32a8b61]	449
[254ad1b]	450	// variable thrd is no longer safe to use
[734908c]	451	thrd = 0xdeaddeaddeaddeadp;
[32a8b61]	452
[254ad1b]	453	// wake the cluster using the save variable.
	454	__wake_one( cl );
[1c273d0]	455
[ec43cf9]	456	#if !defined(__CFA_NO_STATISTICS__)
	457	if( kernelTLS().this_stats ) {
	458	__tls_stats()->ready.threads.threads++;
[89eff25]	459	if(outside) {
	460	__tls_stats()->ready.threads.extunpark++;
	461	}
[ec43cf9]	462	}
	463	else {
	464	__atomic_fetch_add(&cl->stats->ready.threads.threads, 1, __ATOMIC_RELAXED);
[89eff25]	465	__atomic_fetch_add(&cl->stats->ready.threads.extunpark, 1, __ATOMIC_RELAXED);
[ec43cf9]	466	}
	467	#endif
	468
[254ad1b]	469	/* paranoid */ verify( ready_schedule_islocked());
[8fc652e0]	470	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	471	}
	472
[24e321c]	473	void schedule_thread$( thread$ * thrd, unpark_hint hint ) {
[254ad1b]	474	ready_schedule_lock();
[24e321c]	475	__schedule_thread( thrd, hint );
[254ad1b]	476	ready_schedule_unlock();
	477	}
	478
[14a61b5]	479	// KERNEL ONLY
[e84ab3d]	480	static inline thread$ * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	481	/* paranoid */ verify( ! __preemption_enabled() );
[7768b8d]	482
[e873838]	483	ready_schedule_lock();
[e84ab3d]	484	thread$ * thrd = pop_fast( this );
[e873838]	485	ready_schedule_unlock();
[7768b8d]	486
[8fc652e0]	487	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	488	return thrd;
[eb2e723]	489	}
	490
[64a7146]	491	// KERNEL ONLY
[e84ab3d]	492	static inline thread$ * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	493	/* paranoid */ verify( ! __preemption_enabled() );
[64a7146]	494
[e873838]	495	ready_schedule_lock();
[c9c1c1cb]	496	thread$ * thrd = pop_slow( this );
	497	ready_schedule_unlock();
	498
	499	/* paranoid */ verify( ! __preemption_enabled() );
	500	return thrd;
	501	}
[fc59df78]	502
[c9c1c1cb]	503	// KERNEL ONLY
	504	static inline thread$ * __next_thread_search(cluster * this) with( *this ) {
	505	/* paranoid */ verify( ! __preemption_enabled() );
	506
	507	ready_schedule_lock();
	508	thread$ * thrd = pop_search( this );
[e873838]	509	ready_schedule_unlock();
[64a7146]	510
[8fc652e0]	511	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	512	return thrd;
[64a7146]	513	}
	514
[e84ab3d]	515	static inline bool __must_unpark( thread$ * thrd ) {
[ff79d5e]	516	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	517	switch(old_ticket) {
[6a77224]	518	case TICKET_RUNNING:
[3381ed7]	519	// Wake won the race, the thread will reschedule/rerun itself
[c6c7e6c]	520	return false;
[6a77224]	521	case TICKET_BLOCKED:
[3381ed7]	522	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	523	/* paranoid */ verify( thrd->state == Blocked );
[c6c7e6c]	524	return true;
[3381ed7]	525	default:
	526	// This makes no sense, something is wrong abort
[7ee8153]	527	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	528	}
[eb2e723]	529	}
	530
[24e321c]	531	void __kernel_unpark( thread$ * thrd, unpark_hint hint ) {
[e9c0b4c]	532	/* paranoid */ verify( ! __preemption_enabled() );
	533	/* paranoid */ verify( ready_schedule_islocked());
	534
	535	if( !thrd ) return;
	536
	537	if(__must_unpark(thrd)) {
	538	// Wake lost the race,
[24e321c]	539	__schedule_thread( thrd, hint );
[e9c0b4c]	540	}
	541
	542	/* paranoid */ verify( ready_schedule_islocked());
	543	/* paranoid */ verify( ! __preemption_enabled() );
	544	}
	545
[24e321c]	546	void unpark( thread$ * thrd, unpark_hint hint ) {
[c6c7e6c]	547	if( !thrd ) return;
[0b33412]	548
[c6c7e6c]	549	if(__must_unpark(thrd)) {
	550	disable_interrupts();
[a3821fa]	551	// Wake lost the race,
[24e321c]	552	schedule_thread$( thrd, hint );
[a3821fa]	553	enable_interrupts(false);
[de6319f]	554	}
[eb2e723]	555	}
[0b33412]	556
[e235429]	557	void park( void ) {
[a3821fa]	558	__disable_interrupts_checked();
	559	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
	560	returnToKernel();
	561	__enable_interrupts_checked();
[0c78741]	562
	563	}
[09800e9]	564
[5afb49a]	565	extern "C" {
	566	// Leave the thread monitor
	567	// last routine called by a thread.
	568	// Should never return
	569	void __cfactx_thrd_leave() {
[e84ab3d]	570	thread$ * thrd = active_thread();
	571	monitor$ * this = &thrd->self_mon;
[5afb49a]	572
	573	// Lock the monitor now
	574	lock( this->lock __cfaabi_dbg_ctx2 );
	575
	576	disable_interrupts();
	577
[9d6e1b8a]	578	/* paranoid */ verify( ! __preemption_enabled() );
	579	/* paranoid */ verify( thrd->state == Active );
	580	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	581	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	582	/* paranoid */ verify( thrd->context.SP );
[e84ab3d]	583	/* 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 );
	584	/* 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]	585
[3ea8ad1]	586	thrd->state = Halting;
[58688bf]	587	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	588	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	589	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	590
	591	// Leave the thread
	592	returnToKernel();
	593
	594	// Control flow should never reach here!
[9d6e1b8a]	595	abort();
[5afb49a]	596	}
[09800e9]	597	}
	598
[14a61b5]	599	// KERNEL ONLY
[3381ed7]	600	bool force_yield( __Preemption_Reason reason ) {
[a3821fa]	601	__disable_interrupts_checked();
[e84ab3d]	602	thread$ * thrd = kernelTLS().this_thread;
[a3821fa]	603	/* paranoid */ verify(thrd->state == Active);
	604
	605	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	606	// it was going to park itself. If that is the case and it is already using the
	607	// intrusive fields then we can't use them to preempt the thread
	608	// If that is the case, abandon the preemption.
	609	bool preempted = false;
	610	if(thrd->link.next == 0p) {
	611	preempted = true;
	612	thrd->preempted = reason;
	613	returnToKernel();
	614	}
	615	__enable_interrupts_checked( false );
[3381ed7]	616	return preempted;
[f2b12406]	617	}
	618
[14a61b5]	619	//=============================================================================================
[92e7631]	620	// Kernel Idle Sleep
[14a61b5]	621	//=============================================================================================
[64a7146]	622	// Wake a thread from the front if there are any
[e873838]	623	static void __wake_one(cluster * this) {
[7cf3b1d]	624	eventfd_t val;
	625
[8fc652e0]	626	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	627	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	628
[64a7146]	629	// Check if there is a sleeping processor
[7cf3b1d]	630	struct __fd_waitctx * fdp = __atomic_load_n(&this->procs.fdw, __ATOMIC_SEQ_CST);
[14a61b5]	631
[7cf3b1d]	632	// If no one is sleeping: we are done
	633	if( fdp == 0p ) return;
[14a61b5]	634
[7cf3b1d]	635	int fd = 1;
	636	if( __atomic_load_n(&fdp->fd, __ATOMIC_SEQ_CST) != 1 ) {
	637	fd = __atomic_exchange_n(&fdp->fd, 1, __ATOMIC_RELAXED);
	638	}
[14a61b5]	639
[7cf3b1d]	640	switch(fd) {
	641	case 0:
	642	// If the processor isn't ready to sleep then the exchange will already wake it up
	643	#if !defined(__CFA_NO_STATISTICS__)
	644	if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.early++;
	645	} else { __atomic_fetch_add(&this->stats->ready.sleep.early, 1, __ATOMIC_RELAXED); }
	646	#endif
	647	break;
	648	case 1:
	649	// If someone else already said they will wake them: we are done
	650	#if !defined(__CFA_NO_STATISTICS__)
	651	if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.seen++;
	652	} else { __atomic_fetch_add(&this->stats->ready.sleep.seen, 1, __ATOMIC_RELAXED); }
	653	#endif
	654	break;
	655	default:
	656	// If the processor was ready to sleep, we need to wake it up with an actual write
	657	val = 1;
	658	eventfd_write( fd, val );
	659
	660	#if !defined(__CFA_NO_STATISTICS__)
	661	if( kernelTLS().this_stats ) { __tls_stats()->ready.sleep.wakes++;
	662	} else { __atomic_fetch_add(&this->stats->ready.sleep.wakes, 1, __ATOMIC_RELAXED); }
	663	#endif
	664	break;
	665	}
[1eb239e4]	666
[e873838]	667	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	668	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	669
	670	return;
[64a7146]	671	}
[14a61b5]	672
[64a7146]	673	// Unconditionnaly wake a thread
[1eb239e4]	674	void __wake_proc(processor * this) {
[7d0ebd0]	675	/* paranoid */ verify( ! __preemption_enabled() );
	676
[64a7146]	677	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	678
[7cf3b1d]	679	this->idle_wctx.fd = 1;
	680
[7d0ebd0]	681	eventfd_t val;
	682	val = 1;
	683	eventfd_write( this->idle_fd, val );
	684
	685	/* paranoid */ verify( ! __preemption_enabled() );
[92e7631]	686	}
	687
[d3605f8]	688	static void idle_sleep(processor * this, io_future_t & future, iovec & iov) {
[7cf3b1d]	689	// Tell everyone we are ready to go do sleep
	690	for() {
	691	int expected = this->idle_wctx.fd;
	692
	693	// Someone already told us to wake-up! No time for a nap.
	694	if(expected == 1) { return; }
	695
	696	// Try to mark that we are going to sleep
	697	if(__atomic_compare_exchange_n(&this->idle_wctx.fd, &expected, this->idle_fd, false, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST) ) {
	698	// Every one agreed, taking a nap
	699	break;
	700	}
	701	}
	702
	703
[d3605f8]	704	#if !defined(CFA_WITH_IO_URING_IDLE)
[7ef162b2]	705	#if !defined(__CFA_NO_STATISTICS__)
	706	if(this->print_halts) {
	707	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->unique_id, rdtscl());
	708	}
	709	#endif
[1757f98]	710
[7ef162b2]	711	__cfadbg_print_safe(runtime_core, "Kernel : core %p waiting on eventfd %d\n", this, this->idle_fd);
[1757f98]	712
[7ef162b2]	713	{
	714	eventfd_t val;
	715	ssize_t ret = read( this->idle_fd, &val, sizeof(val) );
	716	if(ret < 0) {
	717	switch((int)errno) {
	718	case EAGAIN:
	719	#if EAGAIN != EWOULDBLOCK
	720	case EWOULDBLOCK:
	721	#endif
	722	case EINTR:
	723	// No need to do anything special here, just assume it's a legitimate wake-up
	724	break;
	725	default:
	726	abort( "KERNEL : internal error, read failure on idle eventfd, error(%d) %s.", (int)errno, strerror( (int)errno ) );
	727	}
[1757f98]	728	}
	729	}
	730
[7ef162b2]	731	#if !defined(__CFA_NO_STATISTICS__)
	732	if(this->print_halts) {
	733	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->unique_id, rdtscl());
	734	}
	735	#endif
	736	#else
	737	// Do we already have a pending read
	738	if(available(future)) {
	739	// There is no pending read, we need to add one
	740	reset(future);
	741
[d3605f8]	742	__kernel_read(this, future, iov, this->idle_fd );
[1757f98]	743	}
[7ef162b2]	744
[c7b2215]	745	__cfa_io_flush( this, 1 );
[1757f98]	746	#endif
	747	}
	748
[5f5a729]	749	static bool mark_idle(__cluster_proc_list & this, processor & proc) {
[c9c1c1cb]	750	__STATS__(true, ready.sleep.halts++; )
[7cf3b1d]	751
	752	proc.idle_wctx.fd = 0;
	753
[8fc652e0]	754	/* paranoid */ verify( ! __preemption_enabled() );
[5f5a729]	755	if(!try_lock( this )) return false;
[1eb239e4]	756	this.idle++;
	757	/* paranoid */ verify( this.idle <= this.total );
[fc59b580]	758	remove(proc);
[6a9b12b]	759	insert_first(this.idles, proc);
[34b8cb7]	760
[7cf3b1d]	761	__atomic_store_n(&this.fdw, &proc.idle_wctx, __ATOMIC_SEQ_CST);
[1eb239e4]	762	unlock( this );
[8fc652e0]	763	/* paranoid */ verify( ! __preemption_enabled() );
[5f5a729]	764
	765	return true;
[1eb239e4]	766	}
[8e16177]	767
[6a9b12b]	768	static void mark_awake(__cluster_proc_list & this, processor & proc) {
[8fc652e0]	769	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	770	lock( this );
	771	this.idle--;
	772	/* paranoid */ verify( this.idle >= 0 );
	773	remove(proc);
[fc59b580]	774	insert_last(this.actives, proc);
[6a9b12b]	775
[a633f6f]	776	{
[7cf3b1d]	777	struct __fd_waitctx * wctx = 0;
	778	if(!this.idles`isEmpty) wctx = &this.idles`first.idle_wctx;
	779	__atomic_store_n(&this.fdw, wctx, __ATOMIC_SEQ_CST);
[a633f6f]	780	}
	781
[34b8cb7]	782	unlock( this );
[6a9b12b]	783	/* paranoid */ verify( ! __preemption_enabled() );
[6b4cdd3]	784	}
	785
[dbe9b08]	786	//=============================================================================================
	787	// Unexpected Terminating logic
	788	//=============================================================================================
[92bfda0]	789	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
[e84ab3d]	790	thread$ * thrd = __cfaabi_tls.this_thread;
[9d944b2]	791
[de94a60]	792	if(thrd) {
	793	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	794	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	795
[212c2187]	796	if ( &thrd->self_cor != thrd->curr_cor ) {
	797	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	798	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	799	}
	800	else {
[1c40091]	801	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	802	}
[1c273d0]	803	}
[9d944b2]	804	else {
[de94a60]	805	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	806	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	807	}
	808	}
	809
[92bfda0]	810	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	811	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	812	}
	813
[de94a60]	814	static __spinlock_t kernel_debug_lock;
	815
[9d944b2]	816	extern "C" {
[1c40091]	817	void __cfaabi_bits_acquire() {
[36982fc]	818	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	819	}
	820
[1c40091]	821	void __cfaabi_bits_release() {
[ea7d2b0]	822	unlock( kernel_debug_lock );
[9d944b2]	823	}
[8118303]	824	}
	825
[fa21ac9]	826	//=============================================================================================
	827	// Kernel Utilities
	828	//=============================================================================================
[dddb3dd0]	829	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	830	#include "io/types.hfa"
	831	#endif
	832
[c1c95b1]	833	static inline bool __maybe_io_drain( processor * proc ) {
[e9c0b4c]	834	bool ret = false;
[dddb3dd0]	835	#if defined(CFA_HAVE_LINUX_IO_URING_H)
	836	__cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
	837
	838	// Check if we should drain the queue
	839	$io_context * ctx = proc->io.ctx;
	840	unsigned head = *ctx->cq.head;
	841	unsigned tail = *ctx->cq.tail;
[c1c95b1]	842	if(head == tail) return false;
[040334e]	843	ready_schedule_lock();
	844	ret = __cfa_io_drain( proc );
	845	ready_schedule_unlock();
[dddb3dd0]	846	#endif
[e9c0b4c]	847	return ret;
[dddb3dd0]	848	}
	849
[de94a60]	850	//-----------------------------------------------------------------------------
	851	// Debug
	852	__cfaabi_dbg_debug_do(
[1997b4e]	853	extern "C" {
[ae66348]	854	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	855	this.prev_name = prev_name;
[8fc652e0]	856	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	857	}
[9181f1d]	858	}
[f7d6bb0]	859	)
[2026bb6]	860
	861	//-----------------------------------------------------------------------------
	862	// Debug
[8c50aed]	863	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	864	return true;
	865	}
[c34ebf2]	866
	867	//-----------------------------------------------------------------------------
	868	// Statistics
	869	#if !defined(__CFA_NO_STATISTICS__)
	870	void print_halts( processor & this ) {
	871	this.print_halts = true;
	872	}
[58688bf]	873
[69914cbc]	874	static void crawl_list( cluster * cltr, dlist(processor) & list, unsigned count ) {
[8464edf]	875	/* paranoid */ verify( cltr->stats );
	876
	877	processor * it = &list`first;
	878	for(unsigned i = 0; i < count; i++) {
	879	/* paranoid */ verifyf( it, "Unexpected null iterator, at index %u of %u\n", i, count);
	880	/* paranoid */ verify( it->local_data->this_stats );
[c33c2af]	881	// __print_stats( it->local_data->this_stats, cltr->print_stats, "Processor", it->name, (void*)it );
[8464edf]	882	__tally_stats( cltr->stats, it->local_data->this_stats );
	883	it = &(*it)`next;
	884	}
	885	}
	886
	887	void crawl_cluster_stats( cluster & this ) {
	888	// Stop the world, otherwise stats could get really messed-up
	889	// this doesn't solve all problems but does solve many
	890	// so it's probably good enough
[c33c2af]	891	disable_interrupts();
[8464edf]	892	uint_fast32_t last_size = ready_mutate_lock();
	893
	894	crawl_list(&this, this.procs.actives, this.procs.total - this.procs.idle);
	895	crawl_list(&this, this.procs.idles , this.procs.idle );
	896
	897	// Unlock the RWlock
	898	ready_mutate_unlock( last_size );
[c33c2af]	899	enable_interrupts();
[8464edf]	900	}
	901
	902
[58688bf]	903	void print_stats_now( cluster & this, int flags ) {
[8464edf]	904	crawl_cluster_stats( this );
[1b033b8]	905	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	906	}
[c34ebf2]	907	#endif
[8118303]	908	// Local Variables: //
	909	// mode: c //
	910	// tab-width: 4 //
	911	// End: //

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