source: src/libcfa/concurrency/monitor.c @ 59a0bde

aaron-thesisarm-ehcleanup-dtorsdeferred_resndemanglerjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerresolv-newwith_gc
Last change on this file since 59a0bde was 59a0bde, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

Converted more shorts to int_fast16_T

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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 : Mon Jul 31 14:59:05 2017
13// Update Count     : 3
14//
15
16#include "monitor"
17
18#include <stdlib>
19
20#include "libhdr.h"
21#include "kernel_private.h"
22
23#include "bits/algorithms.h"
24
25//-----------------------------------------------------------------------------
26// Forward declarations
27static inline void set_owner ( monitor_desc * this, thread_desc * owner );
28static inline void set_owner ( monitor_desc * storage [], __lock_size_t count, thread_desc * owner );
29static inline void set_mask  ( monitor_desc * storage [], __lock_size_t count, const __waitfor_mask_t & mask );
30static inline void reset_mask( monitor_desc * this );
31
32static inline thread_desc * next_thread( monitor_desc * this );
33static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & monitors );
34
35static inline void lock_all  ( spinlock * locks [], __lock_size_t count );
36static inline void lock_all  ( monitor_desc * source [], spinlock * /*out*/ locks [], __lock_size_t count );
37static inline void unlock_all( spinlock * locks [], __lock_size_t count );
38static inline void unlock_all( monitor_desc * locks [], __lock_size_t count );
39
40static inline void save   ( monitor_desc * ctx [], __lock_size_t count, spinlock * locks [], unsigned int /*out*/ recursions [], __waitfor_mask_t /*out*/ masks [] );
41static inline void restore( monitor_desc * ctx [], __lock_size_t count, spinlock * locks [], unsigned int /*in */ recursions [], __waitfor_mask_t /*in */ masks [] );
42
43static inline void init     ( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
44static inline void init_push( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
45
46static inline thread_desc *        check_condition   ( __condition_criterion_t * );
47static inline void                 brand_condition   ( condition & );
48static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t &, monitor_desc * monitors [], __lock_size_t count );
49
50forall(dtype T | sized( T ))
51static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val );
52static inline __lock_size_t count_max    ( const __waitfor_mask_t & mask );
53static inline __lock_size_t aggregate    ( monitor_desc * storage [], const __waitfor_mask_t & mask );
54
55//-----------------------------------------------------------------------------
56// Useful defines
57#define wait_ctx(thrd, user_info)                               /* Create the necessary information to use the signaller stack                         */ \
58        __condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
59        __condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
60        init( count, monitors, waiter, criteria );                /* Link everything together                                                            */ \
61
62#define wait_ctx_primed(thrd, user_info)                        /* Create the necessary information to use the signaller stack                         */ \
63        __condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
64        __condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
65        init_push( count, monitors, waiter, criteria );           /* Link everything together and push it to the AS-Stack                                */ \
66
67#define monitor_ctx( mons, cnt )                                /* Define that create the necessary struct for internal/external scheduling operations */ \
68        monitor_desc ** monitors = mons;                          /* Save the targeted monitors                                                          */ \
69        __lock_size_t count = cnt;                                /* Save the count to a local variable                                                  */ \
70        unsigned int recursions[ count ];                         /* Save the current recursion levels to restore them later                             */ \
71        __waitfor_mask_t masks [ count ];                         /* Save the current waitfor masks to restore them later                                */ \
72        spinlock *   locks     [ count ];                         /* We need to pass-in an array of locks to BlockInternal                               */ \
73
74#define monitor_save    save   ( monitors, count, locks, recursions, masks )
75#define monitor_restore restore( monitors, count, locks, recursions, masks )
76
77
78//-----------------------------------------------------------------------------
79// Enter/Leave routines
80
81
82extern "C" {
83        // Enter single monitor
84        static void __enter_monitor_desc( monitor_desc * this, const __monitor_group_t & group ) {
85                // Lock the monitor spinlock, lock_yield to reduce contention
86                lock_yield( &this->lock DEBUG_CTX2 );
87                thread_desc * thrd = this_thread;
88
89                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
90
91                if( !this->owner ) {
92                        // No one has the monitor, just take it
93                        set_owner( this, thrd );
94
95                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon is free \n");
96                }
97                else if( this->owner == thrd) {
98                        // We already have the monitor, just note how many times we took it
99                        this->recursion += 1;
100
101                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon already owned \n");
102                }
103                else if( is_accepted( this, group) ) {
104                        // Some one was waiting for us, enter
105                        set_owner( this, thrd );
106
107                        // Reset mask
108                        reset_mask( this );
109
110                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon accepts \n");
111                }
112                else {
113                        LIB_DEBUG_PRINT_SAFE("Kernel :  blocking \n");
114
115                        // Some one else has the monitor, wait in line for it
116                        append( this->entry_queue, thrd );
117                        BlockInternal( &this->lock );
118
119                        LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered  mon %p\n", thrd, this);
120
121                        // BlockInternal will unlock spinlock, no need to unlock ourselves
122                        return;
123                }
124
125                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered  mon %p\n", thrd, this);
126
127                // Release the lock and leave
128                unlock( &this->lock );
129                return;
130        }
131
132        static void __enter_monitor_dtor( monitor_desc * this, fptr_t func ) {
133                // Lock the monitor spinlock, lock_yield to reduce contention
134                lock_yield( &this->lock DEBUG_CTX2 );
135                thread_desc * thrd = this_thread;
136
137                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
138
139
140                if( !this->owner ) {
141                        LIB_DEBUG_PRINT_SAFE("Kernel : Destroying free mon %p\n", this);
142
143                        // No one has the monitor, just take it
144                        set_owner( this, thrd );
145
146                        unlock( &this->lock );
147                        return;
148                }
149                else if( this->owner == thrd) {
150                        // We already have the monitor... but where about to destroy it so the nesting will fail
151                        // Abort!
152                        abortf("Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.");
153                }
154
155                __lock_size_t count = 1;
156                monitor_desc ** monitors = &this;
157                __monitor_group_t group = { &this, 1, func };
158                if( is_accepted( this, group) ) {
159                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon accepts dtor, block and signal it \n");
160
161                        // Wake the thread that is waiting for this
162                        __condition_criterion_t * urgent = pop( this->signal_stack );
163                        verify( urgent );
164
165                        // Reset mask
166                        reset_mask( this );
167
168                        // Create the node specific to this wait operation
169                        wait_ctx_primed( this_thread, 0 )
170
171                        // Some one else has the monitor, wait for him to finish and then run
172                        BlockInternal( &this->lock, urgent->owner->waiting_thread );
173
174                        // Some one was waiting for us, enter
175                        set_owner( this, thrd );
176                }
177                else {
178                        LIB_DEBUG_PRINT_SAFE("Kernel :  blocking \n");
179
180                        wait_ctx( this_thread, 0 )
181                        this->dtor_node = &waiter;
182
183                        // Some one else has the monitor, wait in line for it
184                        append( this->entry_queue, thrd );
185                        BlockInternal( &this->lock );
186
187                        // BlockInternal will unlock spinlock, no need to unlock ourselves
188                        return;
189                }
190
191                LIB_DEBUG_PRINT_SAFE("Kernel : Destroying %p\n", this);
192
193        }
194
195        // Leave single monitor
196        void __leave_monitor_desc( monitor_desc * this ) {
197                // Lock the monitor spinlock, lock_yield to reduce contention
198                lock_yield( &this->lock DEBUG_CTX2 );
199
200                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Leaving mon %p (%p)\n", this_thread, this, this->owner);
201
202                verifyf( this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", this_thread, this->owner, this->recursion, this );
203
204                // Leaving a recursion level, decrement the counter
205                this->recursion -= 1;
206
207                // If we haven't left the last level of recursion
208                // it means we don't need to do anything
209                if( this->recursion != 0) {
210                        LIB_DEBUG_PRINT_SAFE("Kernel :  recursion still %d\n", this->recursion);
211                        unlock( &this->lock );
212                        return;
213                }
214
215                // Get the next thread, will be null on low contention monitor
216                thread_desc * new_owner = next_thread( this );
217
218                // We can now let other threads in safely
219                unlock( &this->lock );
220
221                //We need to wake-up the thread
222                WakeThread( new_owner );
223        }
224
225        // Leave single monitor for the last time
226        void __leave_dtor_monitor_desc( monitor_desc * this ) {
227                LIB_DEBUG_DO(
228                        if( this_thread != this->owner ) {
229                                abortf("Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, this_thread, this->owner);
230                        }
231                        if( this->recursion != 1 ) {
232                                abortf("Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
233                        }
234                )
235        }
236
237        // Leave the thread monitor
238        // last routine called by a thread.
239        // Should never return
240        void __leave_thread_monitor( thread_desc * thrd ) {
241                monitor_desc * this = &thrd->self_mon;
242
243                // Lock the monitor now
244                lock_yield( &this->lock DEBUG_CTX2 );
245
246                disable_interrupts();
247
248                thrd->self_cor.state = Halted;
249
250                verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
251
252                // Leaving a recursion level, decrement the counter
253                this->recursion -= 1;
254
255                // If we haven't left the last level of recursion
256                // it must mean there is an error
257                if( this->recursion != 0) { abortf("Thread internal monitor has unbalanced recursion"); }
258
259                // Fetch the next thread, can be null
260                thread_desc * new_owner = next_thread( this );
261
262                // Leave the thread, this will unlock the spinlock
263                // Use leave thread instead of BlockInternal which is
264                // specialized for this case and supports null new_owner
265                LeaveThread( &this->lock, new_owner );
266
267                // Control flow should never reach here!
268        }
269}
270
271// Enter multiple monitor
272// relies on the monitor array being sorted
273static inline void enter( __monitor_group_t monitors ) {
274        for( __lock_size_t i = 0; i < monitors.size; i++) {
275                __enter_monitor_desc( monitors.list[i], monitors );
276        }
277}
278
279// Leave multiple monitor
280// relies on the monitor array being sorted
281static inline void leave(monitor_desc * monitors [], __lock_size_t count) {
282        for( __lock_size_t i = count - 1; i >= 0; i--) {
283                __leave_monitor_desc( monitors[i] );
284        }
285}
286
287// Ctor for monitor guard
288// Sorts monitors before entering
289void ?{}( monitor_guard_t & this, monitor_desc * m [], __lock_size_t count, fptr_t func ) {
290        // Store current array
291        this.m = m;
292        this.count = count;
293
294        // Sort monitors based on address -> TODO use a sort specialized for small numbers
295        __libcfa_small_sort(this.m, count);
296
297        // Save previous thread context
298        this.[prev_mntrs, prev_count, prev_func] = this_thread->monitors.[list, size, func];
299
300        // Update thread context (needed for conditions)
301        this_thread->monitors.[list, size, func] = [m, count, func];
302
303        // LIB_DEBUG_PRINT_SAFE("MGUARD : enter %d\n", count);
304
305        // Enter the monitors in order
306        __monitor_group_t group = {this.m, this.count, func};
307        enter( group );
308
309        // LIB_DEBUG_PRINT_SAFE("MGUARD : entered\n");
310}
311
312
313// Dtor for monitor guard
314void ^?{}( monitor_guard_t & this ) {
315        // LIB_DEBUG_PRINT_SAFE("MGUARD : leaving %d\n", this.count);
316
317        // Leave the monitors in order
318        leave( this.m, this.count );
319
320        // LIB_DEBUG_PRINT_SAFE("MGUARD : left\n");
321
322        // Restore thread context
323        this_thread->monitors.[list, size, func] = this.[prev_mntrs, prev_count, prev_func];
324}
325
326// Ctor for monitor guard
327// Sorts monitors before entering
328void ?{}( monitor_dtor_guard_t & this, monitor_desc * m [], fptr_t func ) {
329        // Store current array
330        this.m = *m;
331
332        // Save previous thread context
333        this.[prev_mntrs, prev_count, prev_func] = this_thread->monitors.[list, size, func];
334
335        // Update thread context (needed for conditions)
336        this_thread->monitors.[list, size, func] = [m, 1, func];
337
338        __enter_monitor_dtor( this.m, func );
339}
340
341// Dtor for monitor guard
342void ^?{}( monitor_dtor_guard_t & this ) {
343        // Leave the monitors in order
344        __leave_dtor_monitor_desc( this.m );
345
346        // Restore thread context
347        this_thread->monitors.[list, size, func] = this.[prev_mntrs, prev_count, prev_func];
348}
349
350//-----------------------------------------------------------------------------
351// Internal scheduling types
352void ?{}(__condition_node_t & this, thread_desc * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
353        this.waiting_thread = waiting_thread;
354        this.count = count;
355        this.next = NULL;
356        this.user_info = user_info;
357}
358
359void ?{}(__condition_criterion_t & this ) {
360        this.ready  = false;
361        this.target = NULL;
362        this.owner  = NULL;
363        this.next   = NULL;
364}
365
366void ?{}(__condition_criterion_t & this, monitor_desc * target, __condition_node_t & owner ) {
367        this.ready  = false;
368        this.target = target;
369        this.owner  = &owner;
370        this.next   = NULL;
371}
372
373//-----------------------------------------------------------------------------
374// Internal scheduling
375void wait( condition & this, uintptr_t user_info = 0 ) {
376        brand_condition( this );
377
378        // Check that everything is as expected
379        assertf( this.monitors != NULL, "Waiting with no monitors (%p)", this.monitors );
380        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%i)", this.monitor_count );
381        verifyf( this.monitor_count < 32u, "Excessive monitor count (%i)", this.monitor_count );
382
383        // Create storage for monitor context
384        monitor_ctx( this.monitors, this.monitor_count );
385
386        // Create the node specific to this wait operation
387        wait_ctx( this_thread, user_info );
388
389        // Append the current wait operation to the ones already queued on the condition
390        // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
391        append( this.blocked, &waiter );
392
393        // Lock all monitors (aggregates the locks as well)
394        lock_all( monitors, locks, count );
395
396        // Find the next thread(s) to run
397        __lock_size_t thread_count = 0;
398        thread_desc * threads[ count ];
399        __builtin_memset( threads, 0, sizeof( threads ) );
400
401        // Save monitor states
402        monitor_save;
403
404        // Remove any duplicate threads
405        for( __lock_size_t i = 0; i < count; i++) {
406                thread_desc * new_owner = next_thread( monitors[i] );
407                insert_unique( threads, thread_count, new_owner );
408        }
409
410        // Everything is ready to go to sleep
411        BlockInternal( locks, count, threads, thread_count );
412
413        // We are back, restore the owners and recursions
414        monitor_restore;
415}
416
417bool signal( condition & this ) {
418        if( is_empty( this ) ) { return false; }
419
420        //Check that everything is as expected
421        verify( this.monitors );
422        verify( this.monitor_count != 0 );
423
424        //Some more checking in debug
425        LIB_DEBUG_DO(
426                thread_desc * this_thrd = this_thread;
427                if ( this.monitor_count != this_thrd->monitors.size ) {
428                        abortf( "Signal on condition %p made with different number of monitor(s), expected %i got %i", &this, this.monitor_count, this_thrd->monitors.size );
429                }
430
431                for(int i = 0; i < this.monitor_count; i++) {
432                        if ( this.monitors[i] != this_thrd->monitors.list[i] ) {
433                                abortf( "Signal on condition %p made with different monitor, expected %p got %i", &this, this.monitors[i], this_thrd->monitors.list[i] );
434                        }
435                }
436        );
437
438        __lock_size_t count = this.monitor_count;
439
440        // Lock all monitors
441        lock_all( this.monitors, NULL, count );
442
443        //Pop the head of the waiting queue
444        __condition_node_t * node = pop_head( this.blocked );
445
446        //Add the thread to the proper AS stack
447        for(int i = 0; i < count; i++) {
448                __condition_criterion_t * crit = &node->criteria[i];
449                assert( !crit->ready );
450                push( crit->target->signal_stack, crit );
451        }
452
453        //Release
454        unlock_all( this.monitors, count );
455
456        return true;
457}
458
459bool signal_block( condition & this ) {
460        if( !this.blocked.head ) { return false; }
461
462        //Check that everything is as expected
463        verifyf( this.monitors != NULL, "Waiting with no monitors (%p)", this.monitors );
464        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%i)", this.monitor_count );
465
466        // Create storage for monitor context
467        monitor_ctx( this.monitors, this.monitor_count );
468
469        // Lock all monitors (aggregates the locks them as well)
470        lock_all( monitors, locks, count );
471
472        // Create the node specific to this wait operation
473        wait_ctx_primed( this_thread, 0 )
474
475        //save contexts
476        monitor_save;
477
478        //Find the thread to run
479        thread_desc * signallee = pop_head( this.blocked )->waiting_thread;
480        set_owner( monitors, count, signallee );
481
482        LIB_DEBUG_PRINT_BUFFER_DECL( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
483
484        //Everything is ready to go to sleep
485        BlockInternal( locks, count, &signallee, 1 );
486
487
488        // WE WOKE UP
489
490
491        LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel :   signal_block returned\n" );
492
493        //We are back, restore the masks and recursions
494        monitor_restore;
495
496        return true;
497}
498
499// Access the user_info of the thread waiting at the front of the queue
500uintptr_t front( condition & this ) {
501        verifyf( !is_empty(this),
502                "Attempt to access user data on an empty condition.\n"
503                "Possible cause is not checking if the condition is empty before reading stored data."
504        );
505        return this.blocked.head->user_info;
506}
507
508//-----------------------------------------------------------------------------
509// External scheduling
510// cases to handle :
511//      - target already there :
512//              block and wake
513//      - dtor already there
514//              put thread on signaller stack
515//      - non-blocking
516//              return else
517//      - timeout
518//              return timeout
519//      - block
520//              setup mask
521//              block
522void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
523        // This statment doesn't have a contiguous list of monitors...
524        // Create one!
525        __lock_size_t max = count_max( mask );
526        monitor_desc * mon_storage[max];
527        __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
528        __lock_size_t actual_count = aggregate( mon_storage, mask );
529
530        LIB_DEBUG_PRINT_BUFFER_DECL( "Kernel : waitfor %d (s: %d, m: %d)\n", actual_count, mask.size, (__lock_size_t)max);
531
532        if(actual_count == 0) return;
533
534        LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : waitfor internal proceeding\n");
535
536        // Create storage for monitor context
537        monitor_ctx( mon_storage, actual_count );
538
539        // Lock all monitors (aggregates the locks as well)
540        lock_all( monitors, locks, count );
541
542        {
543                // Check if the entry queue
544                thread_desc * next; int index;
545                [next, index] = search_entry_queue( mask, monitors, count );
546
547                if( next ) {
548                        *mask.accepted = index;
549                        if( mask.clauses[index].is_dtor ) {
550                                LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : dtor already there\n");
551                                verifyf( mask.clauses[index].size == 1        , "ERROR: Accepted dtor has more than 1 mutex parameter." );
552
553                                monitor_desc * mon2dtor = mask.clauses[index].list[0];
554                                verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
555
556                                __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
557                                push( mon2dtor->signal_stack, dtor_crit );
558
559                                unlock_all( locks, count );
560                        }
561                        else {
562                                LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : thread present, baton-passing\n");
563
564                                // Create the node specific to this wait operation
565                                wait_ctx_primed( this_thread, 0 );
566
567                                // Save monitor states
568                                monitor_save;
569
570                                LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel :  baton of %d monitors : ", count );
571                                #ifdef __CFA_DEBUG_PRINT__
572                                        for( int i = 0; i < count; i++) {
573                                                LIB_DEBUG_PRINT_BUFFER_LOCAL( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
574                                        }
575                                #endif
576                                LIB_DEBUG_PRINT_BUFFER_LOCAL( "\n");
577
578                                // Set the owners to be the next thread
579                                set_owner( monitors, count, next );
580
581                                // Everything is ready to go to sleep
582                                BlockInternal( locks, count, &next, 1 );
583
584                                // We are back, restore the owners and recursions
585                                monitor_restore;
586
587                                LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : thread present, returned\n");
588                        }
589
590                        LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : accepted %d\n", *mask.accepted);
591
592                        return;
593                }
594        }
595
596
597        if( duration == 0 ) {
598                LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : non-blocking, exiting\n");
599
600                unlock_all( locks, count );
601
602                LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : accepted %d\n", *mask.accepted);
603                return;
604        }
605
606
607        verifyf( duration < 0, "Timeout on waitfor statments not supported yet.");
608
609        LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : blocking waitfor\n");
610
611        // Create the node specific to this wait operation
612        wait_ctx_primed( this_thread, 0 );
613
614        monitor_save;
615        set_mask( monitors, count, mask );
616
617        for( __lock_size_t i = 0; i < count; i++) {
618                verify( monitors[i]->owner == this_thread );
619        }
620
621        //Everything is ready to go to sleep
622        BlockInternal( locks, count );
623
624
625        // WE WOKE UP
626
627
628        //We are back, restore the masks and recursions
629        monitor_restore;
630
631        LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : exiting\n");
632
633        LIB_DEBUG_PRINT_BUFFER_LOCAL( "Kernel : accepted %d\n", *mask.accepted);
634}
635
636//-----------------------------------------------------------------------------
637// Utilities
638
639static inline void set_owner( monitor_desc * this, thread_desc * owner ) {
640        // LIB_DEBUG_PRINT_SAFE("Kernal :   Setting owner of %p to %p ( was %p)\n", this, owner, this->owner );
641
642        //Pass the monitor appropriately
643        this->owner = owner;
644
645        //We are passing the monitor to someone else, which means recursion level is not 0
646        this->recursion = owner ? 1 : 0;
647}
648
649static inline void set_owner( monitor_desc * monitors [], __lock_size_t count, thread_desc * owner ) {
650        monitors[0]->owner     = owner;
651        monitors[0]->recursion = 1;
652        for( __lock_size_t i = 1; i < count; i++ ) {
653                monitors[i]->owner     = owner;
654                monitors[i]->recursion = 0;
655        }
656}
657
658static inline void set_mask( monitor_desc * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
659        for( __lock_size_t i = 0; i < count; i++) {
660                storage[i]->mask = mask;
661        }
662}
663
664static inline void reset_mask( monitor_desc * this ) {
665        this->mask.accepted = NULL;
666        this->mask.clauses = NULL;
667        this->mask.size = 0;
668}
669
670static inline thread_desc * next_thread( monitor_desc * this ) {
671        //Check the signaller stack
672        LIB_DEBUG_PRINT_SAFE("Kernel :  mon %p AS-stack top %p\n", this, this->signal_stack.top);
673        __condition_criterion_t * urgent = pop( this->signal_stack );
674        if( urgent ) {
675                //The signaller stack is not empty,
676                //regardless of if we are ready to baton pass,
677                //we need to set the monitor as in use
678                set_owner( this,  urgent->owner->waiting_thread );
679
680                return check_condition( urgent );
681        }
682
683        // No signaller thread
684        // Get the next thread in the entry_queue
685        thread_desc * new_owner = pop_head( this->entry_queue );
686        set_owner( this, new_owner );
687
688        return new_owner;
689}
690
691static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & group ) {
692        __acceptable_t * it = this->mask.clauses; // Optim
693        __lock_size_t count = this->mask.size;
694
695        // Check if there are any acceptable functions
696        if( !it ) return false;
697
698        // If this isn't the first monitor to test this, there is no reason to repeat the test.
699        if( this != group[0] ) return group[0]->mask.accepted >= 0;
700
701        // For all acceptable functions check if this is the current function.
702        for( __lock_size_t i = 0; i < count; i++, it++ ) {
703                if( *it == group ) {
704                        *this->mask.accepted = i;
705                        return true;
706                }
707        }
708
709        // No function matched
710        return false;
711}
712
713static inline void init( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
714        for( __lock_size_t i = 0; i < count; i++) {
715                (criteria[i]){ monitors[i], waiter };
716        }
717
718        waiter.criteria = criteria;
719}
720
721static inline void init_push( __lock_size_t count, monitor_desc * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
722        for( __lock_size_t i = 0; i < count; i++) {
723                (criteria[i]){ monitors[i], waiter };
724                LIB_DEBUG_PRINT_SAFE( "Kernel :  target %p = %p\n", criteria[i].target, &criteria[i] );
725                push( criteria[i].target->signal_stack, &criteria[i] );
726        }
727
728        waiter.criteria = criteria;
729}
730
731static inline void lock_all( spinlock * locks [], __lock_size_t count ) {
732        for( __lock_size_t i = 0; i < count; i++ ) {
733                lock_yield( locks[i] DEBUG_CTX2 );
734        }
735}
736
737static inline void lock_all( monitor_desc * source [], spinlock * /*out*/ locks [], __lock_size_t count ) {
738        for( __lock_size_t i = 0; i < count; i++ ) {
739                spinlock * l = &source[i]->lock;
740                lock_yield( l DEBUG_CTX2 );
741                if(locks) locks[i] = l;
742        }
743}
744
745static inline void unlock_all( spinlock * locks [], __lock_size_t count ) {
746        for( __lock_size_t i = 0; i < count; i++ ) {
747                unlock( locks[i] );
748        }
749}
750
751static inline void unlock_all( monitor_desc * locks [], __lock_size_t count ) {
752        for( __lock_size_t i = 0; i < count; i++ ) {
753                unlock( &locks[i]->lock );
754        }
755}
756
757static inline void save(
758        monitor_desc * ctx [],
759        __lock_size_t count,
760        __attribute((unused)) spinlock * locks [],
761        unsigned int /*out*/ recursions [],
762        __waitfor_mask_t /*out*/ masks []
763) {
764        for( __lock_size_t i = 0; i < count; i++ ) {
765                recursions[i] = ctx[i]->recursion;
766                masks[i]      = ctx[i]->mask;
767        }
768}
769
770static inline void restore(
771        monitor_desc * ctx [],
772        __lock_size_t count,
773        spinlock * locks [],
774        unsigned int /*out*/ recursions [],
775        __waitfor_mask_t /*out*/ masks []
776) {
777        lock_all( locks, count );
778        for( __lock_size_t i = 0; i < count; i++ ) {
779                ctx[i]->recursion = recursions[i];
780                ctx[i]->mask      = masks[i];
781        }
782        unlock_all( locks, count );
783}
784
785// Function has 2 different behavior
786// 1 - Marks a monitors as being ready to run
787// 2 - Checks if all the monitors are ready to run
788//     if so return the thread to run
789static inline thread_desc * check_condition( __condition_criterion_t * target ) {
790        __condition_node_t * node = target->owner;
791        unsigned short count = node->count;
792        __condition_criterion_t * criteria = node->criteria;
793
794        bool ready2run = true;
795
796        for(    int i = 0; i < count; i++ ) {
797
798                // LIB_DEBUG_PRINT_SAFE( "Checking %p for %p\n", &criteria[i], target );
799                if( &criteria[i] == target ) {
800                        criteria[i].ready = true;
801                        // LIB_DEBUG_PRINT_SAFE( "True\n" );
802                }
803
804                ready2run = criteria[i].ready && ready2run;
805        }
806
807        LIB_DEBUG_PRINT_SAFE( "Kernel :  Runing %i (%p)\n", ready2run, ready2run ? node->waiting_thread : NULL );
808        return ready2run ? node->waiting_thread : NULL;
809}
810
811static inline void brand_condition( condition & this ) {
812        thread_desc * thrd = this_thread;
813        if( !this.monitors ) {
814                // LIB_DEBUG_PRINT_SAFE("Branding\n");
815                assertf( thrd->monitors.list != NULL, "No current monitor to brand condition %p", thrd->monitors.list );
816                this.monitor_count = thrd->monitors.size;
817
818                this.monitors = malloc( this.monitor_count * sizeof( *this.monitors ) );
819                for( int i = 0; i < this.monitor_count; i++ ) {
820                        this.monitors[i] = thrd->monitors.list[i];
821                }
822        }
823}
824
825static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor_desc * monitors [], __lock_size_t count ) {
826
827        __thread_queue_t & entry_queue = monitors[0]->entry_queue;
828
829        // For each thread in the entry-queue
830        for(    thread_desc ** thrd_it = &entry_queue.head;
831                *thrd_it;
832                thrd_it = &(*thrd_it)->next
833        ) {
834                // For each acceptable check if it matches
835                int i = 0;
836                __acceptable_t * end = mask.clauses + mask.size;
837                for( __acceptable_t * it = mask.clauses; it != end; it++, i++ ) {
838                        // Check if we have a match
839                        if( *it == (*thrd_it)->monitors ) {
840
841                                // If we have a match return it
842                                // after removeing it from the entry queue
843                                return [remove( entry_queue, thrd_it ), i];
844                        }
845                }
846        }
847
848        return [0, -1];
849}
850
851forall(dtype T | sized( T ))
852static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
853        if( !val ) return size;
854
855        for( __lock_size_t i = 0; i <= size; i++) {
856                if( array[i] == val ) return size;
857        }
858
859        array[size] = val;
860        size = size + 1;
861        return size;
862}
863
864static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
865        __lock_size_t max = 0;
866        for( __lock_size_t i = 0; i < mask.size; i++ ) {
867                max += mask.clauses[i].size;
868        }
869        return max;
870}
871
872static inline __lock_size_t aggregate( monitor_desc * storage [], const __waitfor_mask_t & mask ) {
873        __lock_size_t size = 0;
874        for( __lock_size_t i = 0; i < mask.size; i++ ) {
875                __libcfa_small_sort( mask.clauses[i].list, mask.clauses[i].size );
876                for( __lock_size_t j = 0; j < mask.clauses[i].size; j++) {
877                        insert_unique( storage, size, mask.clauses[i].list[j] );
878                }
879        }
880        // TODO insertion sort instead of this
881        __libcfa_small_sort( storage, size );
882        return size;
883}
884
885void ?{}( __condition_blocked_queue_t & this ) {
886        this.head = NULL;
887        this.tail = &this.head;
888}
889
890void append( __condition_blocked_queue_t & this, __condition_node_t * c ) {
891        verify(this.tail != NULL);
892        *this.tail = c;
893        this.tail = &c->next;
894}
895
896__condition_node_t * pop_head( __condition_blocked_queue_t & this ) {
897        __condition_node_t * head = this.head;
898        if( head ) {
899                this.head = head->next;
900                if( !head->next ) {
901                        this.tail = &this.head;
902                }
903                head->next = NULL;
904        }
905        return head;
906}
907
908// Local Variables: //
909// mode: c //
910// tab-width: 4 //
911// End: //
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