source: libcfa/src/concurrency/kernel.cfa@ 8e9d567

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum stuck-waitfor-destruct
Last change on this file since 8e9d567 was f2384c9a, checked in by Thierry Delisle <tdelisle@…>, 6 years ago

Added forward/reverse rng for later use in the ready queue
  • Property mode set to 100644
File size: 22.2 KB
RevLine 
[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]82extern $thread * mainThread;
83extern processor * mainProcessor;
[2ac095d]84
[92e7631]85//-----------------------------------------------------------------------------
86// Kernel Scheduling logic
87static $thread * __next_thread(cluster * this);
[1eb239e4]88static $thread * __next_thread_slow(cluster * this);
[92e7631]89static void __run_thread(processor * this, $thread * dst);
[1eb239e4]90static void __wake_one(struct __processor_id_t * id, cluster * cltr);
91
92static void push (__cluster_idles & idles, processor & proc);
93static void remove(__cluster_idles & idles, processor & proc);
94static [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]101void 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();
[f2384c9a]105 kernelTLS.ready_rng.fwd_seed = 25214903917_l64u * (rdtscl() ^ (uintptr_t)&runner);
106 __tls_rand_advance_bck();
[21184e3]107
[83a071f9]108 processor * this = runner.proc;
[094476d]109 verify(this);
[c81ebf9]110
[4069faad]111 __cfadbg_print_safe(runtime_core, "Kernel : core %p starting\n", this);
[28d73c1]112 #if !defined(__CFA_NO_STATISTICS__)
113 if( this->print_halts ) {
114 __cfaabi_bits_print_safe( STDOUT_FILENO, "Processor : %d - %s (%p)\n", this->id, this->name, (void*)this);
115 }
116 #endif
[b798713]117
[75f3522]118 {
[c81ebf9]119 // Setup preemption data
120 preemption_scope scope = { this };
121
[4069faad]122 __cfadbg_print_safe(runtime_core, "Kernel : core %p started\n", this);
[8118303]123
[ac2b598]124 $thread * readyThread = 0p;
[1eb239e4]125 MAIN_LOOP:
126 for() {
[92e7631]127 // Try to get the next thread
[8c50aed]128 readyThread = __next_thread( this->cltr );
[75f3522]129
[1eb239e4]130 if( !readyThread ) {
131 readyThread = __next_thread_slow( this->cltr );
132 }
[4e6fb8e]133
[1eb239e4]134 HALT:
135 if( !readyThread ) {
136 // Don't block if we are done
137 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]138
[1eb239e4]139 #if !defined(__CFA_NO_STATISTICS__)
140 __tls_stats()->ready.sleep.halts++;
141 #endif
[398e8e9]142
[1eb239e4]143 // Push self to idle stack
144 push(this->cltr->idles, * this);
[398e8e9]145
[1eb239e4]146 // Confirm the ready-queue is empty
147 readyThread = __next_thread_slow( this->cltr );
148 if( readyThread ) {
149 // A thread was found, cancel the halt
150 remove(this->cltr->idles, * this);
151
152 #if !defined(__CFA_NO_STATISTICS__)
153 __tls_stats()->ready.sleep.cancels++;
154 #endif
155
156 // continue the mai loop
157 break HALT;
158 }
159
160 #if !defined(__CFA_NO_STATISTICS__)
161 if(this->print_halts) {
162 __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 0\n", this->id, rdtscl());
163 }
164 #endif
165
166 wait( this->idle );
167
168 #if !defined(__CFA_NO_STATISTICS__)
169 if(this->print_halts) {
170 __cfaabi_bits_print_safe( STDOUT_FILENO, "PH:%d - %lld 1\n", this->id, rdtscl());
171 }
172 #endif
173
174 // We were woken up, remove self from idle
175 remove(this->cltr->idles, * this);
176
177 // DON'T just proceed, start looking again
178 continue MAIN_LOOP;
[64a7146]179 }
[1eb239e4]180
181 /* paranoid */ verify( readyThread );
182
183 // We found a thread run it
184 __run_thread(this, readyThread);
185
186 // Are we done?
187 if( __atomic_load_n(&this->do_terminate, __ATOMIC_SEQ_CST) ) break MAIN_LOOP;
[c81ebf9]188 }
189
[4069faad]190 __cfadbg_print_safe(runtime_core, "Kernel : core %p stopping\n", this);
[c84e80a]191 }
[8118303]192
[4cedd9f]193 V( this->terminated );
[bdeba0b]194
[28d73c1]195 if(this == mainProcessor) {
[6a490b2]196 // HACK : the coroutine context switch expects this_thread to be set
197 // and it make sense for it to be set in all other cases except here
198 // fake it
199 kernelTLS.this_thread = mainThread;
200 }
[7768b8d]201
[4069faad]202 __cfadbg_print_safe(runtime_core, "Kernel : core %p terminated\n", this);
[c84e80a]203}
204
[5c1a531]205static int * __volatile_errno() __attribute__((noinline));
206static int * __volatile_errno() { asm(""); return &errno; }
207
[14a61b5]208// KERNEL ONLY
[1c273d0]209// runThread runs a thread by context switching
210// from the processor coroutine to the target thread
[ac2b598]211static void __run_thread(processor * this, $thread * thrd_dst) {
[1eb239e4]212 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
213 /* paranoid */ verifyf( thrd_dst->state == Ready || thrd_dst->preempted != __NO_PREEMPTION, "state : %d, preempted %d\n", thrd_dst->state, thrd_dst->preempted);
214 /* paranoid */ verifyf( thrd_dst->link.next == 0p, "Expected null got %p", thrd_dst->link.next );
215 __builtin_prefetch( thrd_dst->context.SP );
216
[ac2b598]217 $coroutine * proc_cor = get_coroutine(this->runner);
[8fcbb4c]218
[14a61b5]219 // Update global state
[e8e457e]220 kernelTLS.this_thread = thrd_dst;
221
[9f575ea]222 // set state of processor coroutine to inactive
223 verify(proc_cor->state == Active);
[ae7be7a]224 proc_cor->state = Blocked;
[e8e457e]225
[9f575ea]226 // Actually run the thread
[3381ed7]227 RUNNING: while(true) {
[ff79d5e]228 thrd_dst->preempted = __NO_PREEMPTION;
229 thrd_dst->state = Active;
[e8e457e]230
[ae66348]231 __cfaabi_dbg_debug_do(
[276ae57e]232 thrd_dst->park_stale = true;
233 thrd_dst->unpark_stale = true;
[ae66348]234 )
[75f3522]235
[3381ed7]236 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[a7b486b]237 /* paranoid */ verify( kernelTLS.this_thread == thrd_dst );
[210b8b3]238 /* 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
239 /* 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]240
[9f575ea]241 // set context switch to the thread that the processor is executing
242 verify( thrd_dst->context.SP );
[c7a900a]243 __cfactx_switch( &proc_cor->context, &thrd_dst->context );
244 // when __cfactx_switch returns we are back in the processor coroutine
[9f575ea]245
[210b8b3]246 /* 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 );
247 /* 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]248 /* paranoid */ verify( kernelTLS.this_thread == thrd_dst );
[3381ed7]249 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[75f3522]250
[3381ed7]251
252 // We just finished running a thread, there are a few things that could have happened.
253 // 1 - Regular case : the thread has blocked and now one has scheduled it yet.
254 // 2 - Racy case : the thread has blocked but someone has already tried to schedule it.
255 // 4 - Preempted
256 // In case 1, we may have won a race so we can't write to the state again.
257 // In case 2, we lost the race so we now own the thread.
258
259 if(unlikely(thrd_dst->preempted != __NO_PREEMPTION)) {
260 // The thread was preempted, reschedule it and reset the flag
[9b1dcc2]261 __schedule_thread( (__processor_id_t*)this, thrd_dst );
[3381ed7]262 break RUNNING;
263 }
[75f3522]264
[ff79d5e]265 if(unlikely(thrd_dst->state == Halted)) {
266 // The thread has halted, it should never be scheduled/run again
267 // We may need to wake someone up here since
268 unpark( this->destroyer __cfaabi_dbg_ctx2 );
269 this->destroyer = 0p;
270 break RUNNING;
271 }
272
273 /* paranoid */ verify( thrd_dst->state == Active );
274 thrd_dst->state = Blocked;
275
[3381ed7]276 // set state of processor coroutine to active and the thread to inactive
[ff79d5e]277 int old_ticket = __atomic_fetch_sub(&thrd_dst->ticket, 1, __ATOMIC_SEQ_CST);
278 __cfaabi_dbg_debug_do( thrd_dst->park_result = old_ticket; )
279 switch(old_ticket) {
280 case 1:
[3381ed7]281 // This is case 1, the regular case, nothing more is needed
282 break RUNNING;
[ff79d5e]283 case 2:
[3381ed7]284 // This is case 2, the racy case, someone tried to run this thread before it finished blocking
285 // In this case, just run it again.
286 continue RUNNING;
287 default:
288 // This makes no sense, something is wrong abort
[ff79d5e]289 abort();
[3381ed7]290 }
[9f575ea]291 }
[e8e457e]292
[9f575ea]293 // Just before returning to the processor, set the processor coroutine to active
[e8e457e]294 proc_cor->state = Active;
[ae7be7a]295 kernelTLS.this_thread = 0p;
[1eb239e4]296
297 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[82c948c]298}
299
[14a61b5]300// KERNEL_ONLY
[b0c7419]301void returnToKernel() {
[3381ed7]302 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[ac2b598]303 $coroutine * proc_cor = get_coroutine(kernelTLS.this_processor->runner);
304 $thread * thrd_src = kernelTLS.this_thread;
[e8e457e]305
[29cb302]306 #if !defined(__CFA_NO_STATISTICS__)
307 struct processor * last_proc = kernelTLS.this_processor;
308 #endif
309
[9f575ea]310 // Run the thread on this processor
311 {
312 int local_errno = *__volatile_errno();
313 #if defined( __i386 ) || defined( __x86_64 )
314 __x87_store;
315 #endif
316 verify( proc_cor->context.SP );
[c7a900a]317 __cfactx_switch( &thrd_src->context, &proc_cor->context );
[9f575ea]318 #if defined( __i386 ) || defined( __x86_64 )
319 __x87_load;
320 #endif
321 *__volatile_errno() = local_errno;
[8fcbb4c]322 }
[deca0f5]323
[29cb302]324 #if !defined(__CFA_NO_STATISTICS__)
325 if(last_proc != kernelTLS.this_processor) {
326 __tls_stats()->ready.threads.migration++;
327 }
328 #endif
329
[3381ed7]330 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[210b8b3]331 /* 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 );
332 /* 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]333}
334
[8def349]335//-----------------------------------------------------------------------------
336// Scheduler routines
[14a61b5]337// KERNEL ONLY
[9b1dcc2]338void __schedule_thread( struct __processor_id_t * id, $thread * thrd ) {
[6a490b2]339 /* paranoid */ verify( thrd );
340 /* paranoid */ verify( thrd->state != Halted );
[9f575ea]341 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[3381ed7]342 /* paranoid */ #if defined( __CFA_WITH_VERIFY__ )
[504a7dc]343 /* paranoid */ if( thrd->state == Blocked || thrd->state == Start ) assertf( thrd->preempted == __NO_PREEMPTION,
344 "Error inactive thread marked as preempted, state %d, preemption %d\n", thrd->state, thrd->preempted );
[ff79d5e]345 /* paranoid */ if( thrd->preempted != __NO_PREEMPTION ) assertf(thrd->state == Active,
[504a7dc]346 "Error preempted thread marked as not currently running, state %d, preemption %d\n", thrd->state, thrd->preempted );
[3381ed7]347 /* paranoid */ #endif
[6a490b2]348 /* paranoid */ verifyf( thrd->link.next == 0p, "Expected null got %p", thrd->link.next );
[9f575ea]349
[ae7be7a]350 if (thrd->preempted == __NO_PREEMPTION) thrd->state = Ready;
[6b4cdd3]351
[9b1dcc2]352 ready_schedule_lock ( id );
[504a7dc]353 push( thrd->curr_cluster, thrd );
[1eb239e4]354 __wake_one(id, thrd->curr_cluster);
[9b1dcc2]355 ready_schedule_unlock( id );
[1c273d0]356
[9f575ea]357 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[db6f06a]358}
359
[14a61b5]360// KERNEL ONLY
[1eb239e4]361static inline $thread * __next_thread(cluster * this) with( *this ) {
[3381ed7]362 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[7768b8d]363
[9b1dcc2]364 ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor );
[1eb239e4]365 $thread * thrd = pop( this );
[9b1dcc2]366 ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor );
[7768b8d]367
[3381ed7]368 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[1eb239e4]369 return thrd;
[eb2e723]370}
371
[64a7146]372// KERNEL ONLY
[1eb239e4]373static inline $thread * __next_thread_slow(cluster * this) with( *this ) {
[64a7146]374 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
375
376 ready_schedule_lock ( (__processor_id_t*)kernelTLS.this_processor );
[1eb239e4]377 $thread * thrd = pop_slow( this );
[64a7146]378 ready_schedule_unlock( (__processor_id_t*)kernelTLS.this_processor );
379
380 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[1eb239e4]381 return thrd;
[64a7146]382}
383
[2d8f7b0]384// KERNEL ONLY unpark with out disabling interrupts
[9b1dcc2]385void __unpark( struct __processor_id_t * id, $thread * thrd __cfaabi_dbg_ctx_param2 ) {
[ae66348]386 // record activity
387 __cfaabi_dbg_record_thrd( *thrd, false, caller );
388
[ff79d5e]389 int old_ticket = __atomic_fetch_add(&thrd->ticket, 1, __ATOMIC_SEQ_CST);
390 __cfaabi_dbg_debug_do( thrd->unpark_result = old_ticket; thrd->unpark_state = thrd->state; )
391 switch(old_ticket) {
392 case 1:
[3381ed7]393 // Wake won the race, the thread will reschedule/rerun itself
394 break;
[ff79d5e]395 case 0:
[3381ed7]396 /* paranoid */ verify( ! thrd->preempted != __NO_PREEMPTION );
[ff79d5e]397 /* paranoid */ verify( thrd->state == Blocked );
[0b33412]398
[3381ed7]399 // Wake lost the race,
[9b1dcc2]400 __schedule_thread( id, thrd );
[3381ed7]401 break;
402 default:
403 // This makes no sense, something is wrong abort
404 abort();
[de6319f]405 }
[db6f06a]406}
407
[2d8f7b0]408void unpark( $thread * thrd __cfaabi_dbg_ctx_param2 ) {
409 if( !thrd ) return;
[db6f06a]410
[82ff5845]411 disable_interrupts();
[9b1dcc2]412 __unpark( (__processor_id_t*)kernelTLS.this_processor, thrd __cfaabi_dbg_ctx_fwd2 );
[36982fc]413 enable_interrupts( __cfaabi_dbg_ctx );
[eb2e723]414}
415
[ae66348]416void park( __cfaabi_dbg_ctx_param ) {
[3381ed7]417 /* paranoid */ verify( kernelTLS.preemption_state.enabled );
[82ff5845]418 disable_interrupts();
[3381ed7]419 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
420 /* paranoid */ verify( kernelTLS.this_thread->preempted == __NO_PREEMPTION );
[0b33412]421
[ae66348]422 // record activity
423 __cfaabi_dbg_record_thrd( *kernelTLS.this_thread, true, caller );
[0b33412]424
[82c948c]425 returnToKernel();
[0b33412]426
[3381ed7]427 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[36982fc]428 enable_interrupts( __cfaabi_dbg_ctx );
[3381ed7]429 /* paranoid */ verify( kernelTLS.preemption_state.enabled );
[0c78741]430
431}
[09800e9]432
[3381ed7]433// KERNEL ONLY
[b0c7419]434void __leave_thread() {
[3381ed7]435 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[09800e9]436 returnToKernel();
[b0c7419]437 abort();
[09800e9]438}
439
[14a61b5]440// KERNEL ONLY
[3381ed7]441bool force_yield( __Preemption_Reason reason ) {
442 /* paranoid */ verify( kernelTLS.preemption_state.enabled );
[09800e9]443 disable_interrupts();
[3381ed7]444 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[09800e9]445
[ac2b598]446 $thread * thrd = kernelTLS.this_thread;
[ff79d5e]447 /* paranoid */ verify(thrd->state == Active);
[3381ed7]448
449 // SKULLDUGGERY: It is possible that we are preempting this thread just before
450 // it was going to park itself. If that is the case and it is already using the
451 // intrusive fields then we can't use them to preempt the thread
452 // If that is the case, abandon the preemption.
453 bool preempted = false;
[504a7dc]454 if(thrd->link.next == 0p) {
[3381ed7]455 preempted = true;
456 thrd->preempted = reason;
457 returnToKernel();
[de6319f]458 }
[f2b12406]459
[3381ed7]460 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
461 enable_interrupts_noPoll();
462 /* paranoid */ verify( kernelTLS.preemption_state.enabled );
[f2b12406]463
[3381ed7]464 return preempted;
[f2b12406]465}
466
[14a61b5]467//=============================================================================================
[92e7631]468// Kernel Idle Sleep
[14a61b5]469//=============================================================================================
[64a7146]470// Wake a thread from the front if there are any
[1eb239e4]471static void __wake_one(struct __processor_id_t * id, cluster * this) {
472 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
[64a7146]473 /* paranoid */ verify( ready_schedule_islocked( id ) );
[14a61b5]474
[64a7146]475 // Check if there is a sleeping processor
[1eb239e4]476 processor * p;
477 unsigned idle;
478 unsigned total;
479 [idle, total, p] = query(this->idles);
[14a61b5]480
[64a7146]481 // If no one is sleeping, we are done
[1eb239e4]482 if( idle == 0 ) return;
[14a61b5]483
[64a7146]484 // We found a processor, wake it up
485 post( p->idle );
[14a61b5]486
[1eb239e4]487 #if !defined(__CFA_NO_STATISTICS__)
488 __tls_stats()->ready.sleep.wakes++;
489 #endif
490
491 /* paranoid */ verify( ready_schedule_islocked( id ) );
492 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
493
494 return;
[64a7146]495}
[14a61b5]496
[64a7146]497// Unconditionnaly wake a thread
[1eb239e4]498void __wake_proc(processor * this) {
[64a7146]499 __cfadbg_print_safe(runtime_core, "Kernel : waking Processor %p\n", this);
[14a61b5]500
[64a7146]501 disable_interrupts();
502 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
503 bool ret = post( this->idle );
504 enable_interrupts( __cfaabi_dbg_ctx );
[92e7631]505}
506
[1eb239e4]507static void push (__cluster_idles & this, processor & proc) {
508 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
509 lock( this );
510 this.idle++;
511 /* paranoid */ verify( this.idle <= this.total );
[8e16177]512
[1eb239e4]513 insert_first(this.list, proc);
514 unlock( this );
515 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
516}
[8e16177]517
[1eb239e4]518static void remove(__cluster_idles & this, processor & proc) {
519 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
520 lock( this );
521 this.idle--;
522 /* paranoid */ verify( this.idle >= 0 );
[c34ebf2]523
[1eb239e4]524 remove(proc);
525 unlock( this );
526 /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
527}
[c34ebf2]528
[1eb239e4]529static [unsigned idle, unsigned total, * processor] query( & __cluster_idles this ) {
530 for() {
531 uint64_t l = __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST);
532 if( 1 == (l % 2) ) { Pause(); continue; }
533 unsigned idle = this.idle;
534 unsigned total = this.total;
535 processor * proc = &this.list`first;
[7fdae38]536 // Compiler fence is unnecessary, but gcc-8 and older incorrectly reorder code without it
537 asm volatile("": : :"memory");
[1eb239e4]538 if(l != __atomic_load_n(&this.lock, __ATOMIC_SEQ_CST)) { Pause(); continue; }
539 return [idle, total, proc];
540 }
[6b4cdd3]541}
542
[dbe9b08]543//=============================================================================================
544// Unexpected Terminating logic
545//=============================================================================================
[ea7d2b0]546static __spinlock_t kernel_abort_lock;
[9d944b2]547static bool kernel_abort_called = false;
548
[afd550c]549void * kernel_abort(void) __attribute__ ((__nothrow__)) {
[9d944b2]550 // abort cannot be recursively entered by the same or different processors because all signal handlers return when
551 // the globalAbort flag is true.
[36982fc]552 lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
[9d944b2]553
554 // first task to abort ?
[de94a60]555 if ( kernel_abort_called ) { // not first task to abort ?
[ea7d2b0]556 unlock( kernel_abort_lock );
[1c273d0]557
[9d944b2]558 sigset_t mask;
559 sigemptyset( &mask );
[de94a60]560 sigaddset( &mask, SIGALRM ); // block SIGALRM signals
[8a13c47]561 sigaddset( &mask, SIGUSR1 ); // block SIGALRM signals
562 sigsuspend( &mask ); // block the processor to prevent further damage during abort
563 _exit( EXIT_FAILURE ); // if processor unblocks before it is killed, terminate it
[de94a60]564 }
565 else {
566 kernel_abort_called = true;
567 unlock( kernel_abort_lock );
[9d944b2]568 }
569
[14a61b5]570 return kernelTLS.this_thread;
[9d944b2]571}
572
573void kernel_abort_msg( void * kernel_data, char * abort_text, int abort_text_size ) {
[b81fd95]574 $thread * thrd = ( $thread * ) kernel_data;
[9d944b2]575
[de94a60]576 if(thrd) {
577 int len = snprintf( abort_text, abort_text_size, "Error occurred while executing thread %.256s (%p)", thrd->self_cor.name, thrd );
[1c40091]578 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]579
[212c2187]580 if ( &thrd->self_cor != thrd->curr_cor ) {
581 len = snprintf( abort_text, abort_text_size, " in coroutine %.256s (%p).\n", thrd->curr_cor->name, thrd->curr_cor );
[1c40091]582 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[de94a60]583 }
584 else {
[1c40091]585 __cfaabi_bits_write( STDERR_FILENO, ".\n", 2 );
[de94a60]586 }
[1c273d0]587 }
[9d944b2]588 else {
[de94a60]589 int len = snprintf( abort_text, abort_text_size, "Error occurred outside of any thread.\n" );
[1c40091]590 __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
[9d944b2]591 }
592}
593
[2b8bc41]594int kernel_abort_lastframe( void ) __attribute__ ((__nothrow__)) {
[14a61b5]595 return get_coroutine(kernelTLS.this_thread) == get_coroutine(mainThread) ? 4 : 2;
[2b8bc41]596}
597
[de94a60]598static __spinlock_t kernel_debug_lock;
599
[9d944b2]600extern "C" {
[1c40091]601 void __cfaabi_bits_acquire() {
[36982fc]602 lock( kernel_debug_lock __cfaabi_dbg_ctx2 );
[9d944b2]603 }
604
[1c40091]605 void __cfaabi_bits_release() {
[ea7d2b0]606 unlock( kernel_debug_lock );
[9d944b2]607 }
[8118303]608}
609
[fa21ac9]610//=============================================================================================
611// Kernel Utilities
612//=============================================================================================
[bd98b58]613//-----------------------------------------------------------------------------
614// Locks
[242a902]615void ?{}( semaphore & this, int count = 1 ) {
616 (this.lock){};
617 this.count = count;
618 (this.waiting){};
[db6f06a]619}
[242a902]620void ^?{}(semaphore & this) {}
[db6f06a]621
[71c8b7e]622bool P(semaphore & this) with( this ){
[65deb18]623 lock( lock __cfaabi_dbg_ctx2 );
624 count -= 1;
625 if ( count < 0 ) {
[bdeba0b]626 // queue current task
[14a61b5]627 append( waiting, kernelTLS.this_thread );
[bdeba0b]628
629 // atomically release spin lock and block
[3381ed7]630 unlock( lock );
[ae66348]631 park( __cfaabi_dbg_ctx );
[71c8b7e]632 return true;
[8def349]633 }
[4e6fb8e]634 else {
[65deb18]635 unlock( lock );
[71c8b7e]636 return false;
[4e6fb8e]637 }
[bd98b58]638}
639
[f0ce5f4]640bool V(semaphore & this) with( this ) {
[ac2b598]641 $thread * thrd = 0p;
[65deb18]642 lock( lock __cfaabi_dbg_ctx2 );
643 count += 1;
644 if ( count <= 0 ) {
[bdeba0b]645 // remove task at head of waiting list
[65deb18]646 thrd = pop_head( waiting );
[bd98b58]647 }
[bdeba0b]648
[65deb18]649 unlock( lock );
[bdeba0b]650
651 // make new owner
[ae66348]652 unpark( thrd __cfaabi_dbg_ctx2 );
[f0ce5f4]653
[d384787]654 return thrd != 0p;
655}
656
657bool V(semaphore & this, unsigned diff) with( this ) {
658 $thread * thrd = 0p;
659 lock( lock __cfaabi_dbg_ctx2 );
660 int release = max(-count, (int)diff);
661 count += diff;
662 for(release) {
663 unpark( pop_head( waiting ) __cfaabi_dbg_ctx2 );
664 }
665
666 unlock( lock );
667
[f0ce5f4]668 return thrd != 0p;
[bd98b58]669}
670
[de94a60]671//-----------------------------------------------------------------------------
672// Debug
673__cfaabi_dbg_debug_do(
[1997b4e]674 extern "C" {
[ae66348]675 void __cfaabi_dbg_record_lock(__spinlock_t & this, const char prev_name[]) {
[1997b4e]676 this.prev_name = prev_name;
677 this.prev_thrd = kernelTLS.this_thread;
678 }
[ae66348]679
680 void __cfaabi_dbg_record_thrd($thread & this, bool park, const char prev_name[]) {
681 if(park) {
[f0ce5f4]682 this.park_caller = prev_name;
683 this.park_stale = false;
[ae66348]684 }
685 else {
[f0ce5f4]686 this.unpark_caller = prev_name;
687 this.unpark_stale = false;
[ae66348]688 }
689 }
[9181f1d]690 }
[f7d6bb0]691)
[2026bb6]692
693//-----------------------------------------------------------------------------
694// Debug
[8c50aed]695bool threading_enabled(void) __attribute__((const)) {
[2026bb6]696 return true;
697}
[c34ebf2]698
699//-----------------------------------------------------------------------------
700// Statistics
701#if !defined(__CFA_NO_STATISTICS__)
702 void print_halts( processor & this ) {
703 this.print_halts = true;
704 }
705#endif
[8118303]706// Local Variables: //
707// mode: c //
708// tab-width: 4 //
709// End: //
Note: See TracBrowser for help on using the repository browser.