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kernel.cfa@ 29c9b23

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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 29c9b23 was 454f478, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Re-arranged and commented low-level headers. Main goal was for better support of weakso locks that are comming.
Property mode set to `100644`
File size: 22.3 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>
[8118303]	24
	25	//CFA Includes
[73abe95]	26	#include "kernel_private.hfa"
	27	#include "preemption.hfa"
[8118303]	28
	29	//Private includes
	30	#define __CFA_INVOKE_PRIVATE__
	31	#include "invoke.h"
	32
[4069faad]	33
[deca0f5]	34	//-----------------------------------------------------------------------------
	35	// Some assembly required
[1805b1b]	36	#if defined( __i386 )
[deca0f5]	37	// mxcr : SSE Status and Control bits (control bits are preserved across function calls)
	38	// fcw : X87 FPU control word (preserved across function calls)
	39	#define __x87_store \
	40	uint32_t __mxcr; \
	41	uint16_t __fcw; \
	42	__asm__ volatile ( \
	43	"stmxcsr %0\n" \
	44	"fnstcw %1\n" \
	45	: "=m" (__mxcr),\
	46	"=m" (__fcw) \
	47	)
	48
	49	#define __x87_load \
	50	__asm__ volatile ( \
	51	"fldcw %1\n" \
	52	"ldmxcsr %0\n" \
	53	::"m" (__mxcr),\
	54	"m" (__fcw) \
	55	)
	56
	57	#elif defined( __x86_64 )
	58	#define __x87_store \
	59	uint32_t __mxcr; \
	60	uint16_t __fcw; \
	61	__asm__ volatile ( \
	62	"stmxcsr %0\n" \
	63	"fnstcw %1\n" \
	64	: "=m" (__mxcr),\
	65	"=m" (__fcw) \
	66	)
	67
	68	#define __x87_load \
	69	__asm__ volatile ( \
	70	"fldcw %1\n" \
	71	"ldmxcsr %0\n" \
	72	:: "m" (__mxcr),\
	73	"m" (__fcw) \
	74	)
	75
[0190480]	76	#elif defined( __arm__ )
	77	#define __x87_store
	78	#define __x87_load
	79
	80	#elif defined( __aarch64__ )
[74f5c83]	81	#define __x87_store \
	82	uint32_t __fpcntl[2]; \
	83	__asm__ volatile ( \
	84	"mrs x9, FPCR\n" \
	85	"mrs x10, FPSR\n" \
	86	"stp x9, x10, %0\n" \
	87	: "=m" (__fpcntl) : : "x9", "x10" \
	88	)
	89
	90	#define __x87_load \
	91	__asm__ volatile ( \
	92	"ldp x9, x10, %0\n" \
	93	"msr FPSR, x10\n" \
	94	"msr FPCR, x9\n" \
	95	: "=m" (__fpcntl) : : "x9", "x10" \
	96	)
	97
[deca0f5]	98	#else
[0190480]	99	#error unsupported hardware architecture
[deca0f5]	100	#endif
	101
[e660761]	102	extern $thread * mainThread;
	103	extern processor * mainProcessor;
[2ac095d]	104
[92e7631]	105	//-----------------------------------------------------------------------------
	106	// Kernel Scheduling logic
	107	static $thread * __next_thread(cluster * this);
[1eb239e4]	108	static $thread * __next_thread_slow(cluster * this);
[92e7631]	109	static void __run_thread(processor * this, $thread * dst);
[e873838]	110	static void __wake_one(cluster * cltr);
[1eb239e4]	111
	112	static void push (__cluster_idles & idles, processor & proc);
	113	static void remove(__cluster_idles & idles, processor & proc);
	114	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles );
	115
[c84e80a]	116
[75f3522]	117	//=============================================================================================
	118	// Kernel Scheduling logic
	119	//=============================================================================================
[8fcbb4c]	120	//Main of the processor contexts
[83a071f9]	121	void main(processorCtx_t & runner) {
[21184e3]	122	// Because of a bug, we couldn't initialized the seed on construction
	123	// Do it here
[8fc652e0]	124	__cfaabi_tls.rand_seed ^= rdtscl();
	125	__cfaabi_tls.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
[f2384c9a]	126	__tls_rand_advance_bck();
[21184e3]	127
[83a071f9]	128	processor * this = runner.proc;
[094476d]	129	verify(this);
[c81ebf9]	130
[4069faad]	131	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	132	#if !defined(__CFA_NO_STATISTICS__)
	133	if( this->print_halts ) {
	134	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
	135	}
	136	#endif
[b798713]	137
[75f3522]	138	{
[c81ebf9]	139	// Setup preemption data
	140	preemption_scope scope = { this };
	141
[325e6ea]	142	#if !defined(__CFA_NO_STATISTICS__)
	143	unsigned long long last_tally = rdtscl();
	144	#endif
	145
	146
[4069faad]	147	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	148
[ac2b598]	149	$thread * readyThread = 0p;
[1eb239e4]	150	MAIN_LOOP:
	151	for() {
[92e7631]	152	// Try to get the next thread
[8c50aed]	153	readyThread = __next_thread( this->cltr );
[75f3522]	154
[1eb239e4]	155	if( !readyThread ) {
	156	readyThread = __next_thread_slow( this->cltr );
	157	}
[4e6fb8e]	158
[1eb239e4]	159	HALT:
	160	if( !readyThread ) {
	161	// Don't block if we are done
	162	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	163
[1eb239e4]	164	#if !defined(__CFA_NO_STATISTICS__)
	165	__tls_stats()->ready.sleep.halts++;
	166	#endif
[398e8e9]	167
[1eb239e4]	168	// Push self to idle stack
	169	push(this->cltr->idles, * this);
[398e8e9]	170
[1eb239e4]	171	// Confirm the ready-queue is empty
	172	readyThread = __next_thread_slow( this->cltr );
	173	if( readyThread ) {
	174	// A thread was found, cancel the halt
	175	remove(this->cltr->idles, * this);
	176
	177	#if !defined(__CFA_NO_STATISTICS__)
	178	__tls_stats()->ready.sleep.cancels++;
	179	#endif
	180
	181	// continue the mai loop
	182	break HALT;
	183	}
	184
	185	#if !defined(__CFA_NO_STATISTICS__)
	186	if(this->print_halts) {
	187	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
	188	}
	189	#endif
	190
	191	wait( this->idle );
	192
	193	#if !defined(__CFA_NO_STATISTICS__)
	194	if(this->print_halts) {
	195	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
	196	}
	197	#endif
	198
	199	// We were woken up, remove self from idle
	200	remove(this->cltr->idles, * this);
	201
	202	// DON'T just proceed, start looking again
	203	continue MAIN_LOOP;
[64a7146]	204	}
[1eb239e4]	205
	206	/* paranoid */ verify( readyThread );
	207
	208	// We found a thread run it
	209	__run_thread(this, readyThread);
	210
	211	// Are we done?
	212	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[325e6ea]	213
	214	#if !defined(__CFA_NO_STATISTICS__)
	215	unsigned long long curr = rdtscl();
	216	if(curr > (last_tally + 500000000)) {
	217	__tally_stats(this->cltr->stats, __cfaabi_tls.this_stats);
	218	last_tally = curr;
	219	}
	220	#endif
[c81ebf9]	221	}
	222
[4069faad]	223	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	224	}
[8118303]	225
[454f478]	226	post( this->terminated );
[bdeba0b]	227
[28d73c1]	228	if(this == mainProcessor) {
[6a490b2]	229	// HACK : the coroutine context switch expects this_thread to be set
	230	// and it make sense for it to be set in all other cases except here
	231	// fake it
[8fc652e0]	232	__cfaabi_tls.this_thread = mainThread;
[6a490b2]	233	}
[7768b8d]	234
[4069faad]	235	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	236	}
	237
[5c1a531]	238	static int * __volatile_errno() __attribute__((noinline));
	239	static int * __volatile_errno() { asm(""); return &errno; }
	240
[14a61b5]	241	// KERNEL ONLY
[1c273d0]	242	// runThread runs a thread by context switching
	243	// from the processor coroutine to the target thread
[ac2b598]	244	static void __run_thread(processor * this, $thread * thrd_dst) {
[8fc652e0]	245	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	246	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	247	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	248	__builtin_prefetch( thrd_dst->context.SP );
	249
[ac2b598]	250	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	251
[9f575ea]	252	// set state of processor coroutine to inactive
	253	verify(proc_cor->state == Active);
[ae7be7a]	254	proc_cor->state = Blocked;
[e8e457e]	255
[9f575ea]	256	// Actually run the thread
[3381ed7]	257	RUNNING: while(true) {
[ff79d5e]	258	thrd_dst->preempted = __NO_PREEMPTION;
	259	thrd_dst->state = Active;
[e8e457e]	260
[58d64a4]	261	// Update global state
[8fc652e0]	262	kernelTLS().this_thread = thrd_dst;
[75f3522]	263
[8fc652e0]	264	/* paranoid */ verify( ! __preemption_enabled() );
	265	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
[9d6e1b8a]	266	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[b4b63e8]	267	/* paranoid */ verify( thrd_dst->context.SP );
[5afb49a]	268	/* paranoid */ verify( thrd_dst->state != Halted );
[210b8b3]	269	/* 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
	270	/* 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]	271	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[b4b63e8]	272
[3381ed7]	273
[58d64a4]	274
[9f575ea]	275	// set context switch to the thread that the processor is executing
[c7a900a]	276	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	277	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	278
[ac12f1f]	279	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_dst->canary );
[210b8b3]	280	/* 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 );
	281	/* 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]	282	/* paranoid */ verify( thrd_dst->context.SP );
[9d6e1b8a]	283	/* paranoid */ verify( thrd_dst->curr_cluster == this->cltr );
[8fc652e0]	284	/* paranoid */ verify( kernelTLS().this_thread == thrd_dst );
	285	/* paranoid */ verify( ! __preemption_enabled() );
[75f3522]	286
[58d64a4]	287	// Reset global state
[8fc652e0]	288	kernelTLS().this_thread = 0p;
[3381ed7]	289
	290	// We just finished running a thread, there are a few things that could have happened.
	291	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	292	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	293	// 4 - Preempted
	294	// In case 1, we may have won a race so we can't write to the state again.
	295	// In case 2, we lost the race so we now own the thread.
	296
	297	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	298	// The thread was preempted, reschedule it and reset the flag
[e873838]	299	__schedule_thread( thrd_dst );
[3381ed7]	300	break RUNNING;
	301	}
[75f3522]	302
[3ea8ad1]	303	if(unlikely(thrd_dst->state == Halting)) {
[ff79d5e]	304	// The thread has halted, it should never be scheduled/run again
[5afb49a]	305	// finish the thread
	306	__thread_finish( thrd_dst );
[ff79d5e]	307	break RUNNING;
	308	}
	309
	310	/* paranoid */ verify( thrd_dst->state == Active );
	311	thrd_dst->state = Blocked;
	312
[3381ed7]	313	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	314	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	315	switch(old_ticket) {
[6a77224]	316	case TICKET_RUNNING:
[3381ed7]	317	// This is case 1, the regular case, nothing more is needed
	318	break RUNNING;
[6a77224]	319	case TICKET_UNBLOCK:
[3381ed7]	320	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	321	// In this case, just run it again.
	322	continue RUNNING;
	323	default:
	324	// This makes no sense, something is wrong abort
[ff79d5e]	325	abort();
[3381ed7]	326	}
[9f575ea]	327	}
[e8e457e]	328
[9f575ea]	329	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	330	proc_cor->state = Active;
[1eb239e4]	331
[8fc652e0]	332	/* paranoid */ verify( ! __preemption_enabled() );
[82c948c]	333	}
	334
[14a61b5]	335	// KERNEL_ONLY
[b0c7419]	336	void returnToKernel() {
[8fc652e0]	337	/* paranoid */ verify( ! __preemption_enabled() );
	338	$coroutine * proc_cor = get_coroutine(kernelTLS().this_processor->runner);
	339	$thread * thrd_src = kernelTLS().this_thread;
[e8e457e]	340
[29cb302]	341	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	342	struct processor * last_proc = kernelTLS().this_processor;
[29cb302]	343	#endif
	344
[9f575ea]	345	// Run the thread on this processor
	346	{
	347	int local_errno = *__volatile_errno();
	348	#if defined( __i386 ) \|\| defined( __x86_64 )
	349	__x87_store;
	350	#endif
[b4b63e8]	351	/* paranoid */ verify( proc_cor->context.SP );
[ac12f1f]	352	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[c7a900a]	353	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[ac12f1f]	354	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd_src->canary );
[9f575ea]	355	#if defined( __i386 ) \|\| defined( __x86_64 )
	356	__x87_load;
	357	#endif
	358	*__volatile_errno() = local_errno;
[8fcbb4c]	359	}
[deca0f5]	360
[29cb302]	361	#if !defined(__CFA_NO_STATISTICS__)
[8fc652e0]	362	if(last_proc != kernelTLS().this_processor) {
[29cb302]	363	__tls_stats()->ready.threads.migration++;
	364	}
	365	#endif
	366
[8fc652e0]	367	/* paranoid */ verify( ! __preemption_enabled() );
[210b8b3]	368	/* 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 );
	369	/* 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]	370	}
	371
[8def349]	372	//-----------------------------------------------------------------------------
	373	// Scheduler routines
[14a61b5]	374	// KERNEL ONLY
[e873838]	375	void __schedule_thread( $thread * thrd ) {
[8fc652e0]	376	/* paranoid */ verify( ! __preemption_enabled() );
[9d6e1b8a]	377	/* paranoid */ verify( kernelTLS().this_proc_id );
[6a490b2]	378	/* paranoid */ verify( thrd );
	379	/* paranoid */ verify( thrd->state != Halted );
[9d6e1b8a]	380	/* paranoid */ verify( thrd->curr_cluster );
[3381ed7]	381	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	382	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	383	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	384	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	385	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	386	/* paranoid */ #endif
[6a490b2]	387	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[ac12f1f]	388	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
[b4b63e8]	389
[9f575ea]	390
[ae7be7a]	391	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	392
[e873838]	393	ready_schedule_lock();
[32a8b61]	394	// Dereference the thread now because once we push it, there is not guaranteed it's still valid.
	395	struct cluster * cl = thrd->curr_cluster;
	396
	397	// push the thread to the cluster ready-queue
	398	push( cl, thrd );
	399
	400	// variable thrd is no longer safe to use
	401
	402	// wake the cluster using the save variable.
	403	__wake_one( cl );
[e873838]	404	ready_schedule_unlock();
[1c273d0]	405
[8fc652e0]	406	/* paranoid */ verify( ! __preemption_enabled() );
[db6f06a]	407	}
	408
[14a61b5]	409	// KERNEL ONLY
[1eb239e4]	410	static inline $thread * __next_thread(cluster * this) with( *this ) {
[8fc652e0]	411	/* paranoid */ verify( ! __preemption_enabled() );
	412	/* paranoid */ verify( kernelTLS().this_proc_id );
[7768b8d]	413
[e873838]	414	ready_schedule_lock();
[1eb239e4]	415	$thread * thrd = pop( this );
[e873838]	416	ready_schedule_unlock();
[7768b8d]	417
[8fc652e0]	418	/* paranoid */ verify( kernelTLS().this_proc_id );
	419	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	420	return thrd;
[eb2e723]	421	}
	422
[64a7146]	423	// KERNEL ONLY
[1eb239e4]	424	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[8fc652e0]	425	/* paranoid */ verify( ! __preemption_enabled() );
	426	/* paranoid */ verify( kernelTLS().this_proc_id );
[64a7146]	427
[e873838]	428	ready_schedule_lock();
[1eb239e4]	429	$thread * thrd = pop_slow( this );
[e873838]	430	ready_schedule_unlock();
[64a7146]	431
[8fc652e0]	432	/* paranoid */ verify( kernelTLS().this_proc_id );
	433	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	434	return thrd;
[64a7146]	435	}
	436
[e873838]	437	void unpark( $thread * thrd ) {
	438	if( !thrd ) return;
	439
[ff79d5e]	440	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	441	switch(old_ticket) {
[6a77224]	442	case TICKET_RUNNING:
[3381ed7]	443	// Wake won the race, the thread will reschedule/rerun itself
	444	break;
[6a77224]	445	case TICKET_BLOCKED:
[3381ed7]	446	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	447	/* paranoid */ verify( thrd->state == Blocked );
[0b33412]	448
[8fc652e0]	449	{
	450	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	451	bool full = publicTLS_get(this_proc_id)->full_proc;
	452	if(full) disable_interrupts();
	453
	454	/* paranoid */ verify( ! __preemption_enabled() );
	455
	456	// Wake lost the race,
	457	__schedule_thread( thrd );
	458
	459	/* paranoid */ verify( ! __preemption_enabled() );
	460
	461	if(full) enable_interrupts( __cfaabi_dbg_ctx );
	462	/* paranoid */ verify( publicTLS_get(this_proc_id) );
	463	}
	464
[3381ed7]	465	break;
	466	default:
	467	// This makes no sense, something is wrong abort
[7ee8153]	468	abort("Thread %p (%s) has mismatch park/unpark\n", thrd, thrd->self_cor.name);
[de6319f]	469	}
[eb2e723]	470	}
	471
[e235429]	472	void park( void ) {
[8fc652e0]	473	/* paranoid */ verify( __preemption_enabled() );
[82ff5845]	474	disable_interrupts();
[8fc652e0]	475	/* paranoid */ verify( ! __preemption_enabled() );
	476	/* paranoid */ verify( kernelTLS().this_thread->preempted == __NO_PREEMPTION );
[0b33412]	477
[82c948c]	478	returnToKernel();
[0b33412]	479
[8fc652e0]	480	/* paranoid */ verify( ! __preemption_enabled() );
[36982fc]	481	enable_interrupts( __cfaabi_dbg_ctx );
[8fc652e0]	482	/* paranoid */ verify( __preemption_enabled() );
[0c78741]	483
	484	}
[09800e9]	485
[5afb49a]	486	extern "C" {
	487	// Leave the thread monitor
	488	// last routine called by a thread.
	489	// Should never return
	490	void __cfactx_thrd_leave() {
[8fc652e0]	491	$thread * thrd = active_thread();
[5afb49a]	492	$monitor * this = &thrd->self_mon;
	493
	494	// Lock the monitor now
	495	lock( this->lock __cfaabi_dbg_ctx2 );
	496
	497	disable_interrupts();
	498
[9d6e1b8a]	499	/* paranoid */ verify( ! __preemption_enabled() );
	500	/* paranoid */ verify( thrd->state == Active );
	501	/* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
	502	/* paranoid */ verify( kernelTLS().this_thread == thrd );
	503	/* paranoid */ verify( thrd->context.SP );
	504	/* 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 );
	505	/* 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 );
	506
[3ea8ad1]	507	thrd->state = Halting;
[58688bf]	508	if( TICKET_RUNNING != thrd->ticket ) { abort( "Thread terminated with pending unpark" ); }
[9d6e1b8a]	509	if( thrd != this->owner ) { abort( "Thread internal monitor has incorrect owner" ); }
	510	if( this->recursion != 1) { abort( "Thread internal monitor has unbalanced recursion" ); }
[5afb49a]	511
	512	// Leave the thread
	513	returnToKernel();
	514
	515	// Control flow should never reach here!
[9d6e1b8a]	516	abort();
[5afb49a]	517	}
[09800e9]	518	}
	519
[14a61b5]	520	// KERNEL ONLY
[3381ed7]	521	bool force_yield( __Preemption_Reason reason ) {
[8fc652e0]	522	/* paranoid */ verify( __preemption_enabled() );
[09800e9]	523	disable_interrupts();
[8fc652e0]	524	/* paranoid */ verify( ! __preemption_enabled() );
[09800e9]	525
[8fc652e0]	526	$thread * thrd = kernelTLS().this_thread;
[ff79d5e]	527	/* paranoid */ verify(thrd->state == Active);
[3381ed7]	528
	529	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	530	// it was going to park itself. If that is the case and it is already using the
	531	// intrusive fields then we can't use them to preempt the thread
	532	// If that is the case, abandon the preemption.
	533	bool preempted = false;
[504a7dc]	534	if(thrd->link.next == 0p) {
[3381ed7]	535	preempted = true;
	536	thrd->preempted = reason;
	537	returnToKernel();
[de6319f]	538	}
[f2b12406]	539
[8fc652e0]	540	/* paranoid */ verify( ! __preemption_enabled() );
[3381ed7]	541	enable_interrupts_noPoll();
[8fc652e0]	542	/* paranoid */ verify( __preemption_enabled() );
[f2b12406]	543
[3381ed7]	544	return preempted;
[f2b12406]	545	}
	546
[14a61b5]	547	//=============================================================================================
[92e7631]	548	// Kernel Idle Sleep
[14a61b5]	549	//=============================================================================================
[64a7146]	550	// Wake a thread from the front if there are any
[e873838]	551	static void __wake_one(cluster * this) {
[8fc652e0]	552	/* paranoid */ verify( ! __preemption_enabled() );
[e873838]	553	/* paranoid */ verify( ready_schedule_islocked() );
[14a61b5]	554
[64a7146]	555	// Check if there is a sleeping processor
[1eb239e4]	556	processor * p;
	557	unsigned idle;
	558	unsigned total;
	559	[idle, total, p] = query(this->idles);
[14a61b5]	560
[64a7146]	561	// If no one is sleeping, we are done
[1eb239e4]	562	if( idle == 0 ) return;
[14a61b5]	563
[64a7146]	564	// We found a processor, wake it up
	565	post( p->idle );
[14a61b5]	566
[1eb239e4]	567	#if !defined(__CFA_NO_STATISTICS__)
	568	__tls_stats()->ready.sleep.wakes++;
	569	#endif
	570
[e873838]	571	/* paranoid */ verify( ready_schedule_islocked() );
[8fc652e0]	572	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	573
	574	return;
[64a7146]	575	}
[14a61b5]	576
[64a7146]	577	// Unconditionnaly wake a thread
[1eb239e4]	578	void __wake_proc(processor * this) {
[64a7146]	579	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	580
[64a7146]	581	disable_interrupts();
[8fc652e0]	582	/* paranoid */ verify( ! __preemption_enabled() );
[58d64a4]	583	post( this->idle );
[64a7146]	584	enable_interrupts( __cfaabi_dbg_ctx );
[92e7631]	585	}
	586
[1eb239e4]	587	static void push (__cluster_idles & this, processor & proc) {
[8fc652e0]	588	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	589	lock( this );
	590	this.idle++;
	591	/* paranoid */ verify( this.idle <= this.total );
[8e16177]	592
[1eb239e4]	593	insert_first(this.list, proc);
	594	unlock( this );
[8fc652e0]	595	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	596	}
[8e16177]	597
[1eb239e4]	598	static void remove(__cluster_idles & this, processor & proc) {
[8fc652e0]	599	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	600	lock( this );
	601	this.idle--;
	602	/* paranoid */ verify( this.idle >= 0 );
[c34ebf2]	603
[1eb239e4]	604	remove(proc);
	605	unlock( this );
[8fc652e0]	606	/* paranoid */ verify( ! __preemption_enabled() );
[1eb239e4]	607	}
[c34ebf2]	608
[1eb239e4]	609	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
	610	for() {
	611	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	612	if( 1 == (l % 2) ) { Pause(); continue; }
	613	unsigned idle = this.idle;
	614	unsigned total = this.total;
	615	processor * proc = &this.list`first;
[7fdae38]	616	// Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
	617	asm volatile("": : :"memory");
[1eb239e4]	618	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	619	return [idle, total, proc];
	620	}
[6b4cdd3]	621	}
	622
[dbe9b08]	623	//=============================================================================================
	624	// Unexpected Terminating logic
	625	//=============================================================================================
[92bfda0]	626	void __kernel_abort_msg( char * abort_text, int abort_text_size ) {
	627	$thread * thrd = __cfaabi_tls.this_thread;
[9d944b2]	628
[de94a60]	629	if(thrd) {
	630	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	631	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	632
[212c2187]	633	if ( &thrd->self_cor != thrd->curr_cor ) {
	634	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	635	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	636	}
	637	else {
[1c40091]	638	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	639	}
[1c273d0]	640	}
[9d944b2]	641	else {
[de94a60]	642	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	643	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	644	}
	645	}
	646
[92bfda0]	647	int __kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
	648	return get_coroutine(__cfaabi_tls.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	649	}
	650
[de94a60]	651	static __spinlock_t kernel_debug_lock;
	652
[9d944b2]	653	extern "C" {
[1c40091]	654	void __cfaabi_bits_acquire() {
[36982fc]	655	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	656	}
	657
[1c40091]	658	void __cfaabi_bits_release() {
[ea7d2b0]	659	unlock( kernel_debug_lock );
[9d944b2]	660	}
[8118303]	661	}
	662
[fa21ac9]	663	//=============================================================================================
	664	// Kernel Utilities
	665	//=============================================================================================
[de94a60]	666	//-----------------------------------------------------------------------------
	667	// Debug
	668	__cfaabi_dbg_debug_do(
[1997b4e]	669	extern "C" {
[ae66348]	670	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	671	this.prev_name = prev_name;
[8fc652e0]	672	this.prev_thrd = kernelTLS().this_thread;
[1997b4e]	673	}
[9181f1d]	674	}
[f7d6bb0]	675	)
[2026bb6]	676
	677	//-----------------------------------------------------------------------------
	678	// Debug
[8c50aed]	679	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	680	return true;
	681	}
[c34ebf2]	682
	683	//-----------------------------------------------------------------------------
	684	// Statistics
	685	#if !defined(__CFA_NO_STATISTICS__)
	686	void print_halts( processor & this ) {
	687	this.print_halts = true;
	688	}
[58688bf]	689
	690	void print_stats_now( cluster & this, int flags ) {
[1b033b8]	691	__print_stats( this.stats, this.print_stats, "Cluster", this.name, (void*)&this );
	692	}
	693
	694	extern int __print_alarm_stats;
	695	void print_alarm_stats() {
	696	__print_alarm_stats = -1;
[58688bf]	697	}
[c34ebf2]	698	#endif
[8118303]	699	// Local Variables: //
	700	// mode: c //
	701	// tab-width: 4 //
	702	// End: //

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