Context Navigation

kernel.cfa@ a77257be

Visit:

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

Last change on this file since a77257be was 1eb239e4, checked in by Thierry Delisle <tdelisle@…>, 5 years ago
Removed snzi and replaced it with a fast/slow path
Property mode set to `100644`
File size: 22.0 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
[bb83b47]	12	// Last Modified On : Thu Jul 9 06:22:54 2020
	13	// Update Count : 66
[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
	76
	77	#elif defined( __ARM_ARCH )
	78	#else
	79	#error unknown hardware architecture
	80	#endif
	81
[e660761]	82	extern $thread * mainThread;
	83	extern processor * mainProcessor;
[2ac095d]	84
[92e7631]	85	//-----------------------------------------------------------------------------
	86	// Kernel Scheduling logic
	87	static $thread * __next_thread(cluster * this);
[1eb239e4]	88	static $thread * __next_thread_slow(cluster * this);
[92e7631]	89	static void __run_thread(processor * this, $thread * dst);
[1eb239e4]	90	static void __wake_one(struct __processor_id_t * id, cluster * cltr);
	91
	92	static void push (__cluster_idles & idles, processor & proc);
	93	static void remove(__cluster_idles & idles, processor & proc);
	94	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles idles );
	95
[c84e80a]	96
[75f3522]	97	//=============================================================================================
	98	// Kernel Scheduling logic
	99	//=============================================================================================
[8fcbb4c]	100	//Main of the processor contexts
[83a071f9]	101	void main(processorCtx_t & runner) {
[21184e3]	102	// Because of a bug, we couldn't initialized the seed on construction
	103	// Do it here
[7768b8d]	104	kernelTLS.rand_seed ^= rdtscl();
[21184e3]	105
[83a071f9]	106	processor * this = runner.proc;
[094476d]	107	verify(this);
[c81ebf9]	108
[4069faad]	109	__cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]	110	#if !defined(__CFA_NO_STATISTICS__)
	111	if( this->print_halts ) {
	112	__cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
	113	}
	114	#endif
[b798713]	115
[75f3522]	116	{
[c81ebf9]	117	// Setup preemption data
	118	preemption_scope scope = { this };
	119
[4069faad]	120	__cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]	121
[ac2b598]	122	$thread * readyThread = 0p;
[1eb239e4]	123	MAIN_LOOP:
	124	for() {
[92e7631]	125	// Try to get the next thread
[8c50aed]	126	readyThread = __next_thread( this->cltr );
[75f3522]	127
[1eb239e4]	128	if( !readyThread ) {
	129	readyThread = __next_thread_slow( this->cltr );
	130	}
[4e6fb8e]	131
[1eb239e4]	132	HALT:
	133	if( !readyThread ) {
	134	// Don't block if we are done
	135	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	136
[1eb239e4]	137	#if !defined(__CFA_NO_STATISTICS__)
	138	__tls_stats()->ready.sleep.halts++;
	139	#endif
[398e8e9]	140
[1eb239e4]	141	// Push self to idle stack
	142	push(this->cltr->idles, * this);
[398e8e9]	143
[1eb239e4]	144	// Confirm the ready-queue is empty
	145	readyThread = __next_thread_slow( this->cltr );
	146	if( readyThread ) {
	147	// A thread was found, cancel the halt
	148	remove(this->cltr->idles, * this);
	149
	150	#if !defined(__CFA_NO_STATISTICS__)
	151	__tls_stats()->ready.sleep.cancels++;
	152	#endif
	153
	154	// continue the mai loop
	155	break HALT;
	156	}
	157
	158	#if !defined(__CFA_NO_STATISTICS__)
	159	if(this->print_halts) {
	160	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
	161	}
	162	#endif
	163
	164	wait( this->idle );
	165
	166	#if !defined(__CFA_NO_STATISTICS__)
	167	if(this->print_halts) {
	168	__cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
	169	}
	170	#endif
	171
	172	// We were woken up, remove self from idle
	173	remove(this->cltr->idles, * this);
	174
	175	// DON'T just proceed, start looking again
	176	continue MAIN_LOOP;
[64a7146]	177	}
[1eb239e4]	178
	179	/* paranoid */ verify( readyThread );
	180
	181	// We found a thread run it
	182	__run_thread(this, readyThread);
	183
	184	// Are we done?
	185	if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]	186	}
	187
[4069faad]	188	__cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]	189	}
[8118303]	190
[4cedd9f]	191	V( this->terminated );
[bdeba0b]	192
[28d73c1]	193	if(this == mainProcessor) {
[6a490b2]	194	// HACK : the coroutine context switch expects this_thread to be set
	195	// and it make sense for it to be set in all other cases except here
	196	// fake it
	197	kernelTLS.this_thread = mainThread;
	198	}
[7768b8d]	199
[4069faad]	200	__cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]	201	}
	202
[5c1a531]	203	static int * __volatile_errno() __attribute__((noinline));
	204	static int * __volatile_errno() { asm(""); return &errno; }
	205
[14a61b5]	206	// KERNEL ONLY
[1c273d0]	207	// runThread runs a thread by context switching
	208	// from the processor coroutine to the target thread
[ac2b598]	209	static void __run_thread(processor * this, $thread * thrd_dst) {
[1eb239e4]	210	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	211	/* paranoid */ verifyf( thrd_dst->state == Ready \|\| thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
	212	/* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
	213	__builtin_prefetch( thrd_dst->context.SP );
	214
[ac2b598]	215	$coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]	216
[14a61b5]	217	// Update global state
[e8e457e]	218	kernelTLS.this_thread = thrd_dst;
	219
[9f575ea]	220	// set state of processor coroutine to inactive
	221	verify(proc_cor->state == Active);
[ae7be7a]	222	proc_cor->state = Blocked;
[e8e457e]	223
[9f575ea]	224	// Actually run the thread
[3381ed7]	225	RUNNING: while(true) {
[ff79d5e]	226	thrd_dst->preempted = __NO_PREEMPTION;
	227	thrd_dst->state = Active;
[e8e457e]	228
[ae66348]	229	__cfaabi_dbg_debug_do(
[276ae57e]	230	thrd_dst->park_stale = true;
	231	thrd_dst->unpark_stale = true;
[ae66348]	232	)
[75f3522]	233
[3381ed7]	234	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[a7b486b]	235	/* paranoid */ verify( kernelTLS.this_thread == thrd_dst );
[210b8b3]	236	/* 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
	237	/* 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
[3381ed7]	238
[9f575ea]	239	// set context switch to the thread that the processor is executing
	240	verify( thrd_dst->context.SP );
[c7a900a]	241	__cfactx_switch( &proc_cor->context, &thrd_dst->context );
	242	// when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]	243
[210b8b3]	244	/* 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 );
	245	/* 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 );
[a7b486b]	246	/* paranoid */ verify( kernelTLS.this_thread == thrd_dst );
[3381ed7]	247	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[75f3522]	248
[3381ed7]	249
	250	// We just finished running a thread, there are a few things that could have happened.
	251	// 1 - Regular case : the thread has blocked and now one has scheduled it yet.
	252	// 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
	253	// 4 - Preempted
	254	// In case 1, we may have won a race so we can't write to the state again.
	255	// In case 2, we lost the race so we now own the thread.
	256
	257	if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
	258	// The thread was preempted, reschedule it and reset the flag
[9b1dcc2]	259	__schedule_thread( (__processor_id_t*)this, thrd_dst );
[3381ed7]	260	break RUNNING;
	261	}
[75f3522]	262
[ff79d5e]	263	if(unlikely(thrd_dst->state == Halted)) {
	264	// The thread has halted, it should never be scheduled/run again
	265	// We may need to wake someone up here since
	266	unpark( this->destroyer __cfaabi_dbg_ctx2 );
	267	this->destroyer = 0p;
	268	break RUNNING;
	269	}
	270
	271	/* paranoid */ verify( thrd_dst->state == Active );
	272	thrd_dst->state = Blocked;
	273
[3381ed7]	274	// set state of processor coroutine to active and the thread to inactive
[ff79d5e]	275	int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
	276	__cfaabi_dbg_debug_do( thrd_dst->park_result = old_ticket; )
	277	switch(old_ticket) {
	278	case 1:
[3381ed7]	279	// This is case 1, the regular case, nothing more is needed
	280	break RUNNING;
[ff79d5e]	281	case 2:
[3381ed7]	282	// This is case 2, the racy case, someone tried to run this thread before it finished blocking
	283	// In this case, just run it again.
	284	continue RUNNING;
	285	default:
	286	// This makes no sense, something is wrong abort
[ff79d5e]	287	abort();
[3381ed7]	288	}
[9f575ea]	289	}
[e8e457e]	290
[9f575ea]	291	// Just before returning to the processor, set the processor coroutine to active
[e8e457e]	292	proc_cor->state = Active;
[ae7be7a]	293	kernelTLS.this_thread = 0p;
[1eb239e4]	294
	295	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[82c948c]	296	}
	297
[14a61b5]	298	// KERNEL_ONLY
[b0c7419]	299	void returnToKernel() {
[3381ed7]	300	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[ac2b598]	301	$coroutine * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
	302	$thread * thrd_src = kernelTLS.this_thread;
[e8e457e]	303
[29cb302]	304	#if !defined(__CFA_NO_STATISTICS__)
	305	struct processor * last_proc = kernelTLS.this_processor;
	306	#endif
	307
[9f575ea]	308	// Run the thread on this processor
	309	{
	310	int local_errno = *__volatile_errno();
	311	#if defined( __i386 ) \|\| defined( __x86_64 )
	312	__x87_store;
	313	#endif
	314	verify( proc_cor->context.SP );
[c7a900a]	315	__cfactx_switch( &thrd_src->context, &proc_cor->context );
[9f575ea]	316	#if defined( __i386 ) \|\| defined( __x86_64 )
	317	__x87_load;
	318	#endif
	319	*__volatile_errno() = local_errno;
[8fcbb4c]	320	}
[deca0f5]	321
[29cb302]	322	#if !defined(__CFA_NO_STATISTICS__)
	323	if(last_proc != kernelTLS.this_processor) {
	324	__tls_stats()->ready.threads.migration++;
	325	}
	326	#endif
	327
[3381ed7]	328	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[210b8b3]	329	/* 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 );
	330	/* 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]	331	}
	332
[8def349]	333	//-----------------------------------------------------------------------------
	334	// Scheduler routines
[14a61b5]	335	// KERNEL ONLY
[9b1dcc2]	336	void __schedule_thread( struct __processor_id_t * id, $thread * thrd ) {
[6a490b2]	337	/* paranoid */ verify( thrd );
	338	/* paranoid */ verify( thrd->state != Halted );
[9f575ea]	339	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[3381ed7]	340	/* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]	341	/* paranoid */ if( thrd->state == Blocked \|\| thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
	342	"Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]	343	/* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]	344	"Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]	345	/* paranoid */ #endif
[6a490b2]	346	/* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[9f575ea]	347
[ae7be7a]	348	if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]	349
[9b1dcc2]	350	ready_schedule_lock ( id );
[504a7dc]	351	push( thrd->curr_cluster, thrd );
[1eb239e4]	352	__wake_one(id, thrd->curr_cluster);
[9b1dcc2]	353	ready_schedule_unlock( id );
[1c273d0]	354
[9f575ea]	355	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[db6f06a]	356	}
	357
[14a61b5]	358	// KERNEL ONLY
[1eb239e4]	359	static inline $thread * __next_thread(cluster * this) with( *this ) {
[3381ed7]	360	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[7768b8d]	361
[9b1dcc2]	362	ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor );
[1eb239e4]	363	$thread * thrd = pop( this );
[9b1dcc2]	364	ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor );
[7768b8d]	365
[3381ed7]	366	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[1eb239e4]	367	return thrd;
[eb2e723]	368	}
	369
[64a7146]	370	// KERNEL ONLY
[1eb239e4]	371	static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[64a7146]	372	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	373
	374	ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor );
[1eb239e4]	375	$thread * thrd = pop_slow( this );
[64a7146]	376	ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor );
	377
	378	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[1eb239e4]	379	return thrd;
[64a7146]	380	}
	381
[2d8f7b0]	382	// KERNEL ONLY unpark with out disabling interrupts
[9b1dcc2]	383	void __unpark( struct __processor_id_t * id, $thread * thrd __cfaabi_dbg_ctx_param2 ) {
[ae66348]	384	// record activity
	385	__cfaabi_dbg_record_thrd( *thrd, false, caller );
	386
[ff79d5e]	387	int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
	388	__cfaabi_dbg_debug_do( thrd->unpark_result = old_ticket; thrd->unpark_state = thrd->state; )
	389	switch(old_ticket) {
	390	case 1:
[3381ed7]	391	// Wake won the race, the thread will reschedule/rerun itself
	392	break;
[ff79d5e]	393	case 0:
[3381ed7]	394	/* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]	395	/* paranoid */ verify( thrd->state == Blocked );
[0b33412]	396
[3381ed7]	397	// Wake lost the race,
[9b1dcc2]	398	__schedule_thread( id, thrd );
[3381ed7]	399	break;
	400	default:
	401	// This makes no sense, something is wrong abort
	402	abort();
[de6319f]	403	}
[db6f06a]	404	}
	405
[2d8f7b0]	406	void unpark( $thread * thrd __cfaabi_dbg_ctx_param2 ) {
	407	if( !thrd ) return;
[db6f06a]	408
[82ff5845]	409	disable_interrupts();
[9b1dcc2]	410	__unpark( (__processor_id_t*)kernelTLS.this_processor, thrd __cfaabi_dbg_ctx_fwd2 );
[36982fc]	411	enable_interrupts( __cfaabi_dbg_ctx );
[eb2e723]	412	}
	413
[ae66348]	414	void park( __cfaabi_dbg_ctx_param ) {
[3381ed7]	415	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
[82ff5845]	416	disable_interrupts();
[3381ed7]	417	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	418	/* paranoid */ verify( kernelTLS.this_thread->preempted == __NO_PREEMPTION );
[0b33412]	419
[ae66348]	420	// record activity
	421	__cfaabi_dbg_record_thrd( *kernelTLS.this_thread, true, caller );
[0b33412]	422
[82c948c]	423	returnToKernel();
[0b33412]	424
[3381ed7]	425	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[36982fc]	426	enable_interrupts( __cfaabi_dbg_ctx );
[3381ed7]	427	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
[0c78741]	428
	429	}
[09800e9]	430
[3381ed7]	431	// KERNEL ONLY
[b0c7419]	432	void __leave_thread() {
[3381ed7]	433	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[09800e9]	434	returnToKernel();
[b0c7419]	435	abort();
[09800e9]	436	}
	437
[14a61b5]	438	// KERNEL ONLY
[3381ed7]	439	bool force_yield( __Preemption_Reason reason ) {
	440	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
[09800e9]	441	disable_interrupts();
[3381ed7]	442	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[09800e9]	443
[ac2b598]	444	$thread * thrd = kernelTLS.this_thread;
[ff79d5e]	445	/* paranoid */ verify(thrd->state == Active);
[3381ed7]	446
	447	// SKULLDUGGERY: It is possible that we are preempting this thread just before
	448	// it was going to park itself. If that is the case and it is already using the
	449	// intrusive fields then we can't use them to preempt the thread
	450	// If that is the case, abandon the preemption.
	451	bool preempted = false;
[504a7dc]	452	if(thrd->link.next == 0p) {
[3381ed7]	453	preempted = true;
	454	thrd->preempted = reason;
	455	returnToKernel();
[de6319f]	456	}
[f2b12406]	457
[3381ed7]	458	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	459	enable_interrupts_noPoll();
	460	/* paranoid */ verify( kernelTLS.preemption_state.enabled );
[f2b12406]	461
[3381ed7]	462	return preempted;
[f2b12406]	463	}
	464
[14a61b5]	465	//=============================================================================================
[92e7631]	466	// Kernel Idle Sleep
[14a61b5]	467	//=============================================================================================
[64a7146]	468	// Wake a thread from the front if there are any
[1eb239e4]	469	static void __wake_one(struct __processor_id_t * id, cluster * this) {
	470	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[64a7146]	471	/* paranoid */ verify( ready_schedule_islocked( id ) );
[14a61b5]	472
[64a7146]	473	// Check if there is a sleeping processor
[1eb239e4]	474	processor * p;
	475	unsigned idle;
	476	unsigned total;
	477	[idle, total, p] = query(this->idles);
[14a61b5]	478
[64a7146]	479	// If no one is sleeping, we are done
[1eb239e4]	480	if( idle == 0 ) return;
[14a61b5]	481
[64a7146]	482	// We found a processor, wake it up
	483	post( p->idle );
[14a61b5]	484
[1eb239e4]	485	#if !defined(__CFA_NO_STATISTICS__)
	486	__tls_stats()->ready.sleep.wakes++;
	487	#endif
	488
	489	/* paranoid */ verify( ready_schedule_islocked( id ) );
	490	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	491
	492	return;
[64a7146]	493	}
[14a61b5]	494
[64a7146]	495	// Unconditionnaly wake a thread
[1eb239e4]	496	void __wake_proc(processor * this) {
[64a7146]	497	__cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]	498
[64a7146]	499	disable_interrupts();
	500	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	501	bool ret = post( this->idle );
	502	enable_interrupts( __cfaabi_dbg_ctx );
[92e7631]	503	}
	504
[1eb239e4]	505	static void push (__cluster_idles & this, processor & proc) {
	506	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	507	lock( this );
	508	this.idle++;
	509	/* paranoid */ verify( this.idle <= this.total );
[8e16177]	510
[1eb239e4]	511	insert_first(this.list, proc);
	512	unlock( this );
	513	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	514	}
[8e16177]	515
[1eb239e4]	516	static void remove(__cluster_idles & this, processor & proc) {
	517	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	518	lock( this );
	519	this.idle--;
	520	/* paranoid */ verify( this.idle >= 0 );
[c34ebf2]	521
[1eb239e4]	522	remove(proc);
	523	unlock( this );
	524	/* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
	525	}
[c34ebf2]	526
[1eb239e4]	527	static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
	528	for() {
	529	uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
	530	if( 1 == (l % 2) ) { Pause(); continue; }
	531	unsigned idle = this.idle;
	532	unsigned total = this.total;
	533	processor * proc = &this.list`first;
	534	if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
	535	return [idle, total, proc];
	536	}
[6b4cdd3]	537	}
	538
[dbe9b08]	539	//=============================================================================================
	540	// Unexpected Terminating logic
	541	//=============================================================================================
[ea7d2b0]	542	static __spinlock_t kernel_abort_lock;
[9d944b2]	543	static bool kernel_abort_called = false;
	544
[afd550c]	545	void * kernel_abort(void) __attribute__ ((__nothrow__)) {
[9d944b2]	546	// abort cannot be recursively entered by the same or different processors because all signal handlers return when
	547	// the globalAbort flag is true.
[36982fc]	548	lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
[9d944b2]	549
	550	// first task to abort ?
[de94a60]	551	if ( kernel_abort_called ) { // not first task to abort ?
[ea7d2b0]	552	unlock( kernel_abort_lock );
[1c273d0]	553
[9d944b2]	554	sigset_t mask;
	555	sigemptyset( &mask );
[de94a60]	556	sigaddset( &mask, SIGALRM ); // block SIGALRM signals
[8a13c47]	557	sigaddset( &mask, SIGUSR1 ); // block SIGALRM signals
	558	sigsuspend( &mask ); // block the processor to prevent further damage during abort
	559	_exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
[de94a60]	560	}
	561	else {
	562	kernel_abort_called = true;
	563	unlock( kernel_abort_lock );
[9d944b2]	564	}
	565
[14a61b5]	566	return kernelTLS.this_thread;
[9d944b2]	567	}
	568
	569	void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
[b81fd95]	570	$thread * thrd = ( $thread * ) kernel_data;
[9d944b2]	571
[de94a60]	572	if(thrd) {
	573	int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]	574	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	575
[212c2187]	576	if ( &thrd->self_cor != thrd->curr_cor ) {
	577	len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]	578	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]	579	}
	580	else {
[1c40091]	581	__cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]	582	}
[1c273d0]	583	}
[9d944b2]	584	else {
[de94a60]	585	int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]	586	__cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]	587	}
	588	}
	589
[2b8bc41]	590	int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
[14a61b5]	591	return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]	592	}
	593
[de94a60]	594	static __spinlock_t kernel_debug_lock;
	595
[9d944b2]	596	extern "C" {
[1c40091]	597	void __cfaabi_bits_acquire() {
[36982fc]	598	lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]	599	}
	600
[1c40091]	601	void __cfaabi_bits_release() {
[ea7d2b0]	602	unlock( kernel_debug_lock );
[9d944b2]	603	}
[8118303]	604	}
	605
[fa21ac9]	606	//=============================================================================================
	607	// Kernel Utilities
	608	//=============================================================================================
[bd98b58]	609	//-----------------------------------------------------------------------------
	610	// Locks
[242a902]	611	void ?{}( semaphore & this, int count = 1 ) {
	612	(this.lock){};
	613	this.count = count;
	614	(this.waiting){};
[db6f06a]	615	}
[242a902]	616	void ^?{}(semaphore & this) {}
[db6f06a]	617
[71c8b7e]	618	bool P(semaphore & this) with( this ){
[65deb18]	619	lock( lock __cfaabi_dbg_ctx2 );
	620	count -= 1;
	621	if ( count < 0 ) {
[bdeba0b]	622	// queue current task
[14a61b5]	623	append( waiting, kernelTLS.this_thread );
[bdeba0b]	624
	625	// atomically release spin lock and block
[3381ed7]	626	unlock( lock );
[ae66348]	627	park( __cfaabi_dbg_ctx );
[71c8b7e]	628	return true;
[8def349]	629	}
[4e6fb8e]	630	else {
[65deb18]	631	unlock( lock );
[71c8b7e]	632	return false;
[4e6fb8e]	633	}
[bd98b58]	634	}
	635
[f0ce5f4]	636	bool V(semaphore & this) with( this ) {
[ac2b598]	637	$thread * thrd = 0p;
[65deb18]	638	lock( lock __cfaabi_dbg_ctx2 );
	639	count += 1;
	640	if ( count <= 0 ) {
[bdeba0b]	641	// remove task at head of waiting list
[65deb18]	642	thrd = pop_head( waiting );
[bd98b58]	643	}
[bdeba0b]	644
[65deb18]	645	unlock( lock );
[bdeba0b]	646
	647	// make new owner
[ae66348]	648	unpark( thrd __cfaabi_dbg_ctx2 );
[f0ce5f4]	649
[d384787]	650	return thrd != 0p;
	651	}
	652
	653	bool V(semaphore & this, unsigned diff) with( this ) {
	654	$thread * thrd = 0p;
	655	lock( lock __cfaabi_dbg_ctx2 );
	656	int release = max(-count, (int)diff);
	657	count += diff;
	658	for(release) {
	659	unpark( pop_head( waiting ) __cfaabi_dbg_ctx2 );
	660	}
	661
	662	unlock( lock );
	663
[f0ce5f4]	664	return thrd != 0p;
[bd98b58]	665	}
	666
[de94a60]	667	//-----------------------------------------------------------------------------
	668	// Debug
	669	__cfaabi_dbg_debug_do(
[1997b4e]	670	extern "C" {
[ae66348]	671	void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]	672	this.prev_name = prev_name;
	673	this.prev_thrd = kernelTLS.this_thread;
	674	}
[ae66348]	675
	676	void __cfaabi_dbg_record_thrd($thread & this, bool park, const char prev_name[]) {
	677	if(park) {
[f0ce5f4]	678	this.park_caller = prev_name;
	679	this.park_stale = false;
[ae66348]	680	}
	681	else {
[f0ce5f4]	682	this.unpark_caller = prev_name;
	683	this.unpark_stale = false;
[ae66348]	684	}
	685	}
[9181f1d]	686	}
[f7d6bb0]	687	)
[2026bb6]	688
	689	//-----------------------------------------------------------------------------
	690	// Debug
[8c50aed]	691	bool threading_enabled(void) __attribute__((const)) {
[2026bb6]	692	return true;
	693	}
[c34ebf2]	694
	695	//-----------------------------------------------------------------------------
	696	// Statistics
	697	#if !defined(__CFA_NO_STATISTICS__)
	698	void print_halts( processor & this ) {
	699	this.print_halts = true;
	700	}
	701	#endif
[8118303]	702	// Local Variables: //
	703	// mode: c //
	704	// tab-width: 4 //
	705	// End: //

Note: See TracBrowser for help on using the repository browser.

Download in other formats:

Original Format