source: libcfa/src/concurrency/monitor.cfa @ 9f575ea

arm-ehjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-expr
Last change on this file since 9f575ea was 9f575ea, checked in by Thierry Delisle <tdelisle@…>, 22 months ago

First attempt at park/unpark

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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// monitor_desc.c --
8//
9// Author           : Thierry Delisle
10// Created On       : Thd Feb 23 12:27:26 2017
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Wed Dec  4 07:55:14 2019
13// Update Count     : 10
14//
15
16#define __cforall_thread__
17
18#include "monitor.hfa"
19
20#include <stdlib.hfa>
21#include <inttypes.h>
22
23#include "kernel_private.hfa"
24
25#include "bits/algorithm.hfa"
26
27//-----------------------------------------------------------------------------
28// Forward declarations
29static inline void set_owner ( monitor_desc * this, thread_desc * owner );
30static inline void set_owner ( monitor_desc * storage [], __lock_size_t count, thread_desc * owner );
31static inline void set_mask  ( monitor_desc * storage [], __lock_size_t count, const __waitfor_mask_t & mask );
32static inline void reset_mask( monitor_desc * this );
33
34static inline thread_desc * next_thread( monitor_desc * this );
35static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & monitors );
36
37static inline void lock_all  ( __spinlock_t * locks [], __lock_size_t count );
38static inline void lock_all  ( monitor_desc * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count );
39static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count );
40static inline void unlock_all( monitor_desc * locks [], __lock_size_t count );
41
42static inline void save   ( monitor_desc * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*out*/ recursions [], __waitfor_mask_t /*out*/ masks [] );
43static inline void restore( monitor_desc * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*in */ recursions [], __waitfor_mask_t /*in */ masks [] );
44
45static inline void init     ( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
46static inline void init_push( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
47
48static inline thread_desc *        check_condition   ( __condition_criterion_t * );
49static inline void                 brand_condition   ( condition & );
50static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t &, monitor_desc * monitors [], __lock_size_t count );
51
52forall(dtype T | sized( T ))
53static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val );
54static inline __lock_size_t count_max    ( const __waitfor_mask_t & mask );
55static inline __lock_size_t aggregate    ( monitor_desc * storage [], const __waitfor_mask_t & mask );
56
57//-----------------------------------------------------------------------------
58// Useful defines
59#define wait_ctx(thrd, user_info)                               /* Create the necessary information to use the signaller stack                         */ \
60        __condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
61        __condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
62        init( count, monitors, waiter, criteria );                /* Link everything together                                                            */ \
63
64#define wait_ctx_primed(thrd, user_info)                        /* Create the necessary information to use the signaller stack                         */ \
65        __condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
66        __condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
67        init_push( count, monitors, waiter, criteria );           /* Link everything together and push it to the AS-Stack                                */ \
68
69#define monitor_ctx( mons, cnt )                                /* Define that create the necessary struct for internal/external scheduling operations */ \
70        monitor_desc ** monitors = mons;                          /* Save the targeted monitors                                                          */ \
71        __lock_size_t count = cnt;                                /* Save the count to a local variable                                                  */ \
72        unsigned int recursions[ count ];                         /* Save the current recursion levels to restore them later                             */ \
73        __waitfor_mask_t masks [ count ];                         /* Save the current waitfor masks to restore them later                                */ \
74        __spinlock_t *   locks [ count ];                         /* We need to pass-in an array of locks to BlockInternal                               */ \
75
76#define monitor_save    save   ( monitors, count, locks, recursions, masks )
77#define monitor_restore restore( monitors, count, locks, recursions, masks )
78
79
80//-----------------------------------------------------------------------------
81// Enter/Leave routines
82
83
84extern "C" {
85        // Enter single monitor
86        static void __enter_monitor_desc( monitor_desc * this, const __monitor_group_t & group ) {
87                // Lock the monitor spinlock
88                lock( this->lock __cfaabi_dbg_ctx2 );
89                // Interrupts disable inside critical section
90                thread_desc * thrd = kernelTLS.this_thread;
91
92                __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
93
94                if( !this->owner ) {
95                        // No one has the monitor, just take it
96                        set_owner( this, thrd );
97
98                        __cfaabi_dbg_print_safe( "Kernel :  mon is free \n" );
99                }
100                else if( this->owner == thrd) {
101                        // We already have the monitor, just note how many times we took it
102                        this->recursion += 1;
103
104                        __cfaabi_dbg_print_safe( "Kernel :  mon already owned \n" );
105                }
106                else if( is_accepted( this, group) ) {
107                        // Some one was waiting for us, enter
108                        set_owner( this, thrd );
109
110                        // Reset mask
111                        reset_mask( this );
112
113                        __cfaabi_dbg_print_safe( "Kernel :  mon accepts \n" );
114                }
115                else {
116                        __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
117
118                        // Some one else has the monitor, wait in line for it
119                        append( this->entry_queue, thrd );
120
121                        BlockInternal( &this->lock );
122
123                        __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
124
125                        // BlockInternal will unlock spinlock, no need to unlock ourselves
126                        return;
127                }
128
129                __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
130
131                // Release the lock and leave
132                unlock( this->lock );
133                return;
134        }
135
136        static void __enter_monitor_dtor( monitor_desc * this, fptr_t func ) {
137                // Lock the monitor spinlock
138                lock( this->lock __cfaabi_dbg_ctx2 );
139                // Interrupts disable inside critical section
140                thread_desc * thrd = kernelTLS.this_thread;
141
142                __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
143
144
145                if( !this->owner ) {
146                        __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
147
148                        // No one has the monitor, just take it
149                        set_owner( this, thrd );
150
151                        unlock( this->lock );
152                        return;
153                }
154                else if( this->owner == thrd) {
155                        // We already have the monitor... but where about to destroy it so the nesting will fail
156                        // Abort!
157                        abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
158                }
159
160                __lock_size_t count = 1;
161                monitor_desc ** monitors = &this;
162                __monitor_group_t group = { &this, 1, func };
163                if( is_accepted( this, group) ) {
164                        __cfaabi_dbg_print_safe( "Kernel :  mon accepts dtor, block and signal it \n" );
165
166                        // Wake the thread that is waiting for this
167                        __condition_criterion_t * urgent = pop( this->signal_stack );
168                        verify( urgent );
169
170                        // Reset mask
171                        reset_mask( this );
172
173                        // Create the node specific to this wait operation
174                        wait_ctx_primed( thrd, 0 )
175
176                        // Some one else has the monitor, wait for him to finish and then run
177                        BlockInternal( &this->lock, urgent->owner->waiting_thread );
178
179                        // Some one was waiting for us, enter
180                        set_owner( this, thrd );
181                }
182                else {
183                        __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
184
185                        wait_ctx( thrd, 0 )
186                        this->dtor_node = &waiter;
187
188                        // Some one else has the monitor, wait in line for it
189                        append( this->entry_queue, thrd );
190                        BlockInternal( &this->lock );
191
192                        // BlockInternal will unlock spinlock, no need to unlock ourselves
193                        return;
194                }
195
196                __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
197
198        }
199
200        // Leave single monitor
201        void __leave_monitor_desc( monitor_desc * this ) {
202                // Lock the monitor spinlock
203                lock( this->lock __cfaabi_dbg_ctx2 );
204
205                __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", kernelTLS.this_thread, this, this->owner);
206
207                verifyf( kernelTLS.this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, this->owner, this->recursion, this );
208
209                // Leaving a recursion level, decrement the counter
210                this->recursion -= 1;
211
212                // If we haven't left the last level of recursion
213                // it means we don't need to do anything
214                if( this->recursion != 0) {
215                        __cfaabi_dbg_print_safe( "Kernel :  recursion still %d\n", this->recursion);
216                        unlock( this->lock );
217                        return;
218                }
219
220                // Get the next thread, will be null on low contention monitor
221                thread_desc * new_owner = next_thread( this );
222
223                // We can now let other threads in safely
224                unlock( this->lock );
225
226                //We need to wake-up the thread
227                WakeThread( new_owner, false );
228        }
229
230        // Leave single monitor for the last time
231        void __leave_dtor_monitor_desc( monitor_desc * this ) {
232                __cfaabi_dbg_debug_do(
233                        if( TL_GET( this_thread ) != this->owner ) {
234                                abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, TL_GET( this_thread ), this->owner);
235                        }
236                        if( this->recursion != 1 ) {
237                                abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
238                        }
239                )
240        }
241
242        // Leave the thread monitor
243        // last routine called by a thread.
244        // Should never return
245        void __leave_thread_monitor() {
246                thread_desc * thrd = TL_GET( this_thread );
247                monitor_desc * this = &thrd->self_mon;
248
249                // Lock the monitor now
250                lock( this->lock __cfaabi_dbg_ctx2 );
251
252                disable_interrupts();
253
254                thrd->self_cor.state = Halted;
255
256                verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
257
258                // Leaving a recursion level, decrement the counter
259                this->recursion -= 1;
260
261                // If we haven't left the last level of recursion
262                // it must mean there is an error
263                if( this->recursion != 0) { abort( "Thread internal monitor has unbalanced recursion" ); }
264
265                // Fetch the next thread, can be null
266                thread_desc * new_owner = next_thread( this );
267
268                // Leave the thread, this will unlock the spinlock
269                // Use leave thread instead of BlockInternal which is
270                // specialized for this case and supports null new_owner
271                LeaveThread( &this->lock, new_owner );
272
273                // Control flow should never reach here!
274        }
275}
276
277// Enter multiple monitor
278// relies on the monitor array being sorted
279static inline void enter( __monitor_group_t monitors ) {
280        for( __lock_size_t i = 0; i < monitors.size; i++) {
281                __enter_monitor_desc( monitors[i], monitors );
282        }
283}
284
285// Leave multiple monitor
286// relies on the monitor array being sorted
287static inline void leave(monitor_desc * monitors [], __lock_size_t count) {
288        for( __lock_size_t i = count - 1; i >= 0; i--) {
289                __leave_monitor_desc( monitors[i] );
290        }
291}
292
293// Ctor for monitor guard
294// Sorts monitors before entering
295void ?{}( monitor_guard_t & this, monitor_desc * m [], __lock_size_t count, fptr_t func ) {
296        thread_desc * thrd = TL_GET( this_thread );
297
298        // Store current array
299        this.m = m;
300        this.count = count;
301
302        // Sort monitors based on address
303        __libcfa_small_sort(this.m, count);
304
305        // Save previous thread context
306        this.prev = thrd->monitors;
307
308        // Update thread context (needed for conditions)
309        (thrd->monitors){m, count, func};
310
311        // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
312
313        // Enter the monitors in order
314        __monitor_group_t group = {this.m, this.count, func};
315        enter( group );
316
317        // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
318}
319
320
321// Dtor for monitor guard
322void ^?{}( monitor_guard_t & this ) {
323        // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
324
325        // Leave the monitors in order
326        leave( this.m, this.count );
327
328        // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
329
330        // Restore thread context
331        TL_GET( this_thread )->monitors = this.prev;
332}
333
334// Ctor for monitor guard
335// Sorts monitors before entering
336void ?{}( monitor_dtor_guard_t & this, monitor_desc * m [], fptr_t func ) {
337        // optimization
338        thread_desc * thrd = TL_GET( this_thread );
339
340        // Store current array
341        this.m = *m;
342
343        // Save previous thread context
344        this.prev = thrd->monitors;
345
346        // Update thread context (needed for conditions)
347        (thrd->monitors){m, 1, func};
348
349        __enter_monitor_dtor( this.m, func );
350}
351
352// Dtor for monitor guard
353void ^?{}( monitor_dtor_guard_t & this ) {
354        // Leave the monitors in order
355        __leave_dtor_monitor_desc( this.m );
356
357        // Restore thread context
358        TL_GET( this_thread )->monitors = this.prev;
359}
360
361//-----------------------------------------------------------------------------
362// Internal scheduling types
363void ?{}(__condition_node_t & this, thread_desc * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
364        this.waiting_thread = waiting_thread;
365        this.count = count;
366        this.next = 0p;
367        this.user_info = user_info;
368}
369
370void ?{}(__condition_criterion_t & this ) with( this ) {
371        ready  = false;
372        target = 0p;
373        owner  = 0p;
374        next   = 0p;
375}
376
377void ?{}(__condition_criterion_t & this, monitor_desc * target, __condition_node_t & owner ) {
378        this.ready  = false;
379        this.target = target;
380        this.owner  = &owner;
381        this.next   = 0p;
382}
383
384//-----------------------------------------------------------------------------
385// Internal scheduling
386void wait( condition & this, uintptr_t user_info = 0 ) {
387        brand_condition( this );
388
389        // Check that everything is as expected
390        assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
391        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
392        verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
393
394        // Create storage for monitor context
395        monitor_ctx( this.monitors, this.monitor_count );
396
397        // Create the node specific to this wait operation
398        wait_ctx( TL_GET( this_thread ), user_info );
399
400        // Append the current wait operation to the ones already queued on the condition
401        // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
402        append( this.blocked, &waiter );
403
404        // Lock all monitors (aggregates the locks as well)
405        lock_all( monitors, locks, count );
406
407        // Find the next thread(s) to run
408        __lock_size_t thread_count = 0;
409        thread_desc * threads[ count ];
410        __builtin_memset( threads, 0, sizeof( threads ) );
411
412        // Save monitor states
413        monitor_save;
414
415        // Remove any duplicate threads
416        for( __lock_size_t i = 0; i < count; i++) {
417                thread_desc * new_owner = next_thread( monitors[i] );
418                insert_unique( threads, thread_count, new_owner );
419        }
420
421        // Everything is ready to go to sleep
422        BlockInternal( locks, count, threads, thread_count );
423
424        // We are back, restore the owners and recursions
425        monitor_restore;
426}
427
428bool signal( condition & this ) {
429        if( is_empty( this ) ) { return false; }
430
431        //Check that everything is as expected
432        verify( this.monitors );
433        verify( this.monitor_count != 0 );
434
435        //Some more checking in debug
436        __cfaabi_dbg_debug_do(
437                thread_desc * this_thrd = TL_GET( this_thread );
438                if ( this.monitor_count != this_thrd->monitors.size ) {
439                        abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
440                }
441
442                for(int i = 0; i < this.monitor_count; i++) {
443                        if ( this.monitors[i] != this_thrd->monitors[i] ) {
444                                abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
445                        }
446                }
447        );
448
449        __lock_size_t count = this.monitor_count;
450
451        // Lock all monitors
452        lock_all( this.monitors, 0p, count );
453
454        //Pop the head of the waiting queue
455        __condition_node_t * node = pop_head( this.blocked );
456
457        //Add the thread to the proper AS stack
458        for(int i = 0; i < count; i++) {
459                __condition_criterion_t * crit = &node->criteria[i];
460                assert( !crit->ready );
461                push( crit->target->signal_stack, crit );
462        }
463
464        //Release
465        unlock_all( this.monitors, count );
466
467        return true;
468}
469
470bool signal_block( condition & this ) {
471        if( !this.blocked.head ) { return false; }
472
473        //Check that everything is as expected
474        verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
475        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
476
477        // Create storage for monitor context
478        monitor_ctx( this.monitors, this.monitor_count );
479
480        // Lock all monitors (aggregates the locks them as well)
481        lock_all( monitors, locks, count );
482
483
484        // Create the node specific to this wait operation
485        wait_ctx_primed( kernelTLS.this_thread, 0 )
486
487        //save contexts
488        monitor_save;
489
490        //Find the thread to run
491        thread_desc * signallee = pop_head( this.blocked )->waiting_thread;
492        set_owner( monitors, count, signallee );
493
494        __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
495
496        //Everything is ready to go to sleep
497        BlockInternal( locks, count, &signallee, 1 );
498
499
500        // WE WOKE UP
501
502
503        __cfaabi_dbg_print_buffer_local( "Kernel :   signal_block returned\n" );
504
505        //We are back, restore the masks and recursions
506        monitor_restore;
507
508        return true;
509}
510
511// Access the user_info of the thread waiting at the front of the queue
512uintptr_t front( condition & this ) {
513        verifyf( !is_empty(this),
514                "Attempt to access user data on an empty condition.\n"
515                "Possible cause is not checking if the condition is empty before reading stored data."
516        );
517        return ((typeof(this.blocked.head))this.blocked.head)->user_info;
518}
519
520//-----------------------------------------------------------------------------
521// External scheduling
522// cases to handle :
523//      - target already there :
524//              block and wake
525//      - dtor already there
526//              put thread on signaller stack
527//      - non-blocking
528//              return else
529//      - timeout
530//              return timeout
531//      - block
532//              setup mask
533//              block
534void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
535        // This statment doesn't have a contiguous list of monitors...
536        // Create one!
537        __lock_size_t max = count_max( mask );
538        monitor_desc * mon_storage[max];
539        __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
540        __lock_size_t actual_count = aggregate( mon_storage, mask );
541
542        __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
543
544        if(actual_count == 0) return;
545
546        __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
547
548        // Create storage for monitor context
549        monitor_ctx( mon_storage, actual_count );
550
551        // Lock all monitors (aggregates the locks as well)
552        lock_all( monitors, locks, count );
553
554        {
555                // Check if the entry queue
556                thread_desc * next; int index;
557                [next, index] = search_entry_queue( mask, monitors, count );
558
559                if( next ) {
560                        *mask.accepted = index;
561                        __acceptable_t& accepted = mask[index];
562                        if( accepted.is_dtor ) {
563                                __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
564                                verifyf( accepted.size == 1,  "ERROR: Accepted dtor has more than 1 mutex parameter." );
565
566                                monitor_desc * mon2dtor = accepted[0];
567                                verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
568
569                                __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
570                                push( mon2dtor->signal_stack, dtor_crit );
571
572                                unlock_all( locks, count );
573                        }
574                        else {
575                                __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
576
577                                // Create the node specific to this wait operation
578                                wait_ctx_primed( kernelTLS.this_thread, 0 );
579
580                                // Save monitor states
581                                monitor_save;
582
583                                __cfaabi_dbg_print_buffer_local( "Kernel :  baton of %"PRIdFAST16" monitors : ", count );
584                                #ifdef __CFA_DEBUG_PRINT__
585                                        for( int i = 0; i < count; i++) {
586                                                __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
587                                        }
588                                #endif
589                                __cfaabi_dbg_print_buffer_local( "\n" );
590
591                                // Set the owners to be the next thread
592                                set_owner( monitors, count, next );
593
594                                // Everything is ready to go to sleep
595                                BlockInternal( locks, count, &next, 1 );
596
597                                // We are back, restore the owners and recursions
598                                monitor_restore;
599
600                                __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
601                        }
602
603                        __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
604                        return;
605                }
606        }
607
608
609        if( duration == 0 ) {
610                __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
611
612                unlock_all( locks, count );
613
614                __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
615                return;
616        }
617
618
619        verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
620
621        __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
622
623        // Create the node specific to this wait operation
624        wait_ctx_primed( kernelTLS.this_thread, 0 );
625
626        monitor_save;
627        set_mask( monitors, count, mask );
628
629        for( __lock_size_t i = 0; i < count; i++) {
630                verify( monitors[i]->owner == kernelTLS.this_thread );
631        }
632
633        //Everything is ready to go to sleep
634        BlockInternal( locks, count );
635
636
637        // WE WOKE UP
638
639
640        //We are back, restore the masks and recursions
641        monitor_restore;
642
643        __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
644
645        __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
646}
647
648//-----------------------------------------------------------------------------
649// Utilities
650
651static inline void set_owner( monitor_desc * this, thread_desc * owner ) {
652        // __cfaabi_dbg_print_safe( "Kernal :   Setting owner of %p to %p ( was %p)\n", this, owner, this->owner );
653
654        //Pass the monitor appropriately
655        this->owner = owner;
656
657        //We are passing the monitor to someone else, which means recursion level is not 0
658        this->recursion = owner ? 1 : 0;
659}
660
661static inline void set_owner( monitor_desc * monitors [], __lock_size_t count, thread_desc * owner ) {
662        monitors[0]->owner     = owner;
663        monitors[0]->recursion = 1;
664        for( __lock_size_t i = 1; i < count; i++ ) {
665                monitors[i]->owner     = owner;
666                monitors[i]->recursion = 0;
667        }
668}
669
670static inline void set_mask( monitor_desc * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
671        for( __lock_size_t i = 0; i < count; i++) {
672                storage[i]->mask = mask;
673        }
674}
675
676static inline void reset_mask( monitor_desc * this ) {
677        this->mask.accepted = 0p;
678        this->mask.data = 0p;
679        this->mask.size = 0;
680}
681
682static inline thread_desc * next_thread( monitor_desc * this ) {
683        //Check the signaller stack
684        __cfaabi_dbg_print_safe( "Kernel :  mon %p AS-stack top %p\n", this, this->signal_stack.top);
685        __condition_criterion_t * urgent = pop( this->signal_stack );
686        if( urgent ) {
687                //The signaller stack is not empty,
688                //regardless of if we are ready to baton pass,
689                //we need to set the monitor as in use
690                set_owner( this,  urgent->owner->waiting_thread );
691
692                return check_condition( urgent );
693        }
694
695        // No signaller thread
696        // Get the next thread in the entry_queue
697        thread_desc * new_owner = pop_head( this->entry_queue );
698        set_owner( this, new_owner );
699
700        return new_owner;
701}
702
703static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & group ) {
704        __acceptable_t * it = this->mask.data; // Optim
705        __lock_size_t count = this->mask.size;
706
707        // Check if there are any acceptable functions
708        if( !it ) return false;
709
710        // If this isn't the first monitor to test this, there is no reason to repeat the test.
711        if( this != group[0] ) return group[0]->mask.accepted >= 0;
712
713        // For all acceptable functions check if this is the current function.
714        for( __lock_size_t i = 0; i < count; i++, it++ ) {
715                if( *it == group ) {
716                        *this->mask.accepted = i;
717                        return true;
718                }
719        }
720
721        // No function matched
722        return false;
723}
724
725static inline void init( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
726        for( __lock_size_t i = 0; i < count; i++) {
727                (criteria[i]){ monitors[i], waiter };
728        }
729
730        waiter.criteria = criteria;
731}
732
733static inline void init_push( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
734        for( __lock_size_t i = 0; i < count; i++) {
735                (criteria[i]){ monitors[i], waiter };
736                __cfaabi_dbg_print_safe( "Kernel :  target %p = %p\n", criteria[i].target, &criteria[i] );
737                push( criteria[i].target->signal_stack, &criteria[i] );
738        }
739
740        waiter.criteria = criteria;
741}
742
743static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
744        for( __lock_size_t i = 0; i < count; i++ ) {
745                lock( *locks[i] __cfaabi_dbg_ctx2 );
746        }
747}
748
749static inline void lock_all( monitor_desc * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
750        for( __lock_size_t i = 0; i < count; i++ ) {
751                __spinlock_t * l = &source[i]->lock;
752                lock( *l __cfaabi_dbg_ctx2 );
753                if(locks) locks[i] = l;
754        }
755}
756
757static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
758        for( __lock_size_t i = 0; i < count; i++ ) {
759                unlock( *locks[i] );
760        }
761}
762
763static inline void unlock_all( monitor_desc * locks [], __lock_size_t count ) {
764        for( __lock_size_t i = 0; i < count; i++ ) {
765                unlock( locks[i]->lock );
766        }
767}
768
769static inline void save(
770        monitor_desc * ctx [],
771        __lock_size_t count,
772        __attribute((unused)) __spinlock_t * locks [],
773        unsigned int /*out*/ recursions [],
774        __waitfor_mask_t /*out*/ masks []
775) {
776        for( __lock_size_t i = 0; i < count; i++ ) {
777                recursions[i] = ctx[i]->recursion;
778                masks[i]      = ctx[i]->mask;
779        }
780}
781
782static inline void restore(
783        monitor_desc * ctx [],
784        __lock_size_t count,
785        __spinlock_t * locks [],
786        unsigned int /*out*/ recursions [],
787        __waitfor_mask_t /*out*/ masks []
788) {
789        lock_all( locks, count );
790        for( __lock_size_t i = 0; i < count; i++ ) {
791                ctx[i]->recursion = recursions[i];
792                ctx[i]->mask      = masks[i];
793        }
794        unlock_all( locks, count );
795}
796
797// Function has 2 different behavior
798// 1 - Marks a monitors as being ready to run
799// 2 - Checks if all the monitors are ready to run
800//     if so return the thread to run
801static inline thread_desc * check_condition( __condition_criterion_t * target ) {
802        __condition_node_t * node = target->owner;
803        unsigned short count = node->count;
804        __condition_criterion_t * criteria = node->criteria;
805
806        bool ready2run = true;
807
808        for(    int i = 0; i < count; i++ ) {
809
810                // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
811                if( &criteria[i] == target ) {
812                        criteria[i].ready = true;
813                        // __cfaabi_dbg_print_safe( "True\n" );
814                }
815
816                ready2run = criteria[i].ready && ready2run;
817        }
818
819        __cfaabi_dbg_print_safe( "Kernel :  Runing %i (%p)\n", ready2run, ready2run ? node->waiting_thread : 0p );
820        return ready2run ? node->waiting_thread : 0p;
821}
822
823static inline void brand_condition( condition & this ) {
824        thread_desc * thrd = TL_GET( this_thread );
825        if( !this.monitors ) {
826                // __cfaabi_dbg_print_safe( "Branding\n" );
827                assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
828                this.monitor_count = thrd->monitors.size;
829
830                this.monitors = (monitor_desc **)malloc( this.monitor_count * sizeof( *this.monitors ) );
831                for( int i = 0; i < this.monitor_count; i++ ) {
832                        this.monitors[i] = thrd->monitors[i];
833                }
834        }
835}
836
837static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor_desc * monitors [], __lock_size_t count ) {
838
839        __queue_t(thread_desc) & entry_queue = monitors[0]->entry_queue;
840
841        // For each thread in the entry-queue
842        for(    thread_desc ** thrd_it = &entry_queue.head;
843                *thrd_it;
844                thrd_it = &(*thrd_it)->next
845        ) {
846                // For each acceptable check if it matches
847                int i = 0;
848                __acceptable_t * end   = end  (mask);
849                __acceptable_t * begin = begin(mask);
850                for( __acceptable_t * it = begin; it != end; it++, i++ ) {
851                        // Check if we have a match
852                        if( *it == (*thrd_it)->monitors ) {
853
854                                // If we have a match return it
855                                // after removeing it from the entry queue
856                                return [remove( entry_queue, thrd_it ), i];
857                        }
858                }
859        }
860
861        return [0, -1];
862}
863
864forall(dtype T | sized( T ))
865static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
866        if( !val ) return size;
867
868        for( __lock_size_t i = 0; i <= size; i++) {
869                if( array[i] == val ) return size;
870        }
871
872        array[size] = val;
873        size = size + 1;
874        return size;
875}
876
877static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
878        __lock_size_t max = 0;
879        for( __lock_size_t i = 0; i < mask.size; i++ ) {
880                __acceptable_t & accepted = mask[i];
881                max += accepted.size;
882        }
883        return max;
884}
885
886static inline __lock_size_t aggregate( monitor_desc * storage [], const __waitfor_mask_t & mask ) {
887        __lock_size_t size = 0;
888        for( __lock_size_t i = 0; i < mask.size; i++ ) {
889                __acceptable_t & accepted = mask[i];
890                __libcfa_small_sort( accepted.data, accepted.size );
891                for( __lock_size_t j = 0; j < accepted.size; j++) {
892                        insert_unique( storage, size, accepted[j] );
893                }
894        }
895        // TODO insertion sort instead of this
896        __libcfa_small_sort( storage, size );
897        return size;
898}
899
900// Local Variables: //
901// mode: c //
902// tab-width: 4 //
903// End: //
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