source: src/libcfa/concurrency/monitor.c @ b8116cd

aaron-thesisarm-ehcleanup-dtorsdeferred_resndemanglerjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerresolv-newwith_gc
Last change on this file since b8116cd was b8116cd, checked in by Thierry Delisle <tdelisle@…>, 4 years ago

Tested and fixed out-of-order waitfor of dtors

  • Property mode set to 100644
File size: 27.6 KB
Line 
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//-----------------------------------------------------------------------------
24// Forward declarations
25static inline void set_owner ( monitor_desc * this, thread_desc * owner );
26static inline void set_owner ( monitor_desc ** storage, short count, thread_desc * owner );
27static inline void set_mask  ( monitor_desc ** storage, short count, const __waitfor_mask_t & mask );
28static inline void reset_mask( monitor_desc * this );
29
30static inline thread_desc * next_thread( monitor_desc * this );
31static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & monitors );
32
33static inline void lock_all( spinlock ** locks, unsigned short count );
34static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count );
35static inline void unlock_all( spinlock ** locks, unsigned short count );
36static inline void unlock_all( monitor_desc ** locks, unsigned short count );
37
38static inline void save   ( monitor_desc ** ctx, short count, spinlock ** locks, unsigned int * /*out*/ recursions, __waitfor_mask_t * /*out*/ masks );
39static inline void restore( monitor_desc ** ctx, short count, spinlock ** locks, unsigned int * /*in */ recursions, __waitfor_mask_t * /*in */ masks );
40
41static inline void init     ( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria );
42static inline void init_push( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria );
43
44static inline thread_desc *        check_condition   ( __condition_criterion_t * );
45static inline void                 brand_condition   ( condition * );
46static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t &, monitor_desc ** monitors, int count );
47
48forall(dtype T | sized( T ))
49static inline short insert_unique( T ** array, short & size, T * val );
50static inline short count_max    ( const __waitfor_mask_t & mask );
51static inline short aggregate    ( monitor_desc ** storage, const __waitfor_mask_t & mask );
52
53//-----------------------------------------------------------------------------
54// Useful defines
55#define wait_ctx(thrd, user_info)                               /* Create the necessary information to use the signaller stack                         */ \
56        __condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
57        __condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
58        init( count, monitors, &waiter, criteria );               /* Link everything together                                                            */ \
59
60#define wait_ctx_primed(thrd, user_info)                        /* Create the necessary information to use the signaller stack                         */ \
61        __condition_node_t waiter = { thrd, count, user_info };   /* Create the node specific to this wait operation                                     */ \
62        __condition_criterion_t criteria[count];                  /* Create the creteria this wait operation needs to wake up                            */ \
63        init_push( count, monitors, &waiter, criteria );          /* Link everything together and push it to the AS-Stack                                */ \
64
65#define monitor_ctx( mons, cnt )                                /* Define that create the necessary struct for internal/external scheduling operations */ \
66        monitor_desc ** monitors = mons;                          /* Save the targeted monitors                                                          */ \
67        unsigned short count = cnt;                               /* Save the count to a local variable                                                  */ \
68        unsigned int recursions[ count ];                         /* Save the current recursion levels to restore them later                             */ \
69        __waitfor_mask_t masks[ count ];                          /* Save the current waitfor masks to restore them later                                */ \
70        spinlock *   locks     [ count ];                         /* We need to pass-in an array of locks to BlockInternal                               */ \
71
72#define monitor_save    save   ( monitors, count, locks, recursions, masks )
73#define monitor_restore restore( monitors, count, locks, recursions, masks )
74
75
76//-----------------------------------------------------------------------------
77// Enter/Leave routines
78
79
80extern "C" {
81        // Enter single monitor
82        static void __enter_monitor_desc( monitor_desc * this, const __monitor_group_t & group ) {
83                // Lock the monitor spinlock, lock_yield to reduce contention
84                lock_yield( &this->lock DEBUG_CTX2 );
85                thread_desc * thrd = this_thread;
86
87                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
88
89                if( !this->owner ) {
90                        // No one has the monitor, just take it
91                        set_owner( this, thrd );
92
93                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon is free \n");
94                }
95                else if( this->owner == thrd) {
96                        // We already have the monitor, just note how many times we took it
97                        verify( this->recursion > 0 );
98                        this->recursion += 1;
99
100                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon already owned \n");
101                }
102                else if( is_accepted( this, group) ) {
103                        // Some one was waiting for us, enter
104                        set_owner( this, thrd );
105
106                        // Reset mask
107                        reset_mask( this );
108
109                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon accepts \n");
110                }
111                else {
112                        LIB_DEBUG_PRINT_SAFE("Kernel :  blocking \n");
113
114                        // Some one else has the monitor, wait in line for it
115                        append( &this->entry_queue, thrd );
116                        BlockInternal( &this->lock );
117
118                        LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered  mon %p\n", thrd, this);
119
120                        // BlockInternal will unlock spinlock, no need to unlock ourselves
121                        return;
122                }
123
124                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entered  mon %p\n", thrd, this);
125
126                // Release the lock and leave
127                unlock( &this->lock );
128                return;
129        }
130
131        static void __enter_monitor_dtor( monitor_desc * this, fptr_t func ) {
132                // Lock the monitor spinlock, lock_yield to reduce contention
133                lock_yield( &this->lock DEBUG_CTX2 );
134                thread_desc * thrd = this_thread;
135
136                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
137
138
139                if( !this->owner ) {
140                        LIB_DEBUG_PRINT_SAFE("Kernel : Destroying free mon %p\n", this);
141
142                        // No one has the monitor, just take it
143                        set_owner( this, thrd );
144
145                        unlock( &this->lock );
146                        return;
147                }
148                else if( this->owner == thrd) {
149                        // We already have the monitor... but where about to destroy it so the nesting will fail
150                        // Abort!
151                        abortf("Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.");
152                }
153
154                int count = 1;
155                monitor_desc ** monitors = &this;
156                __monitor_group_t group = { &this, 1, func };
157                if( is_accepted( this, group) ) {
158                        LIB_DEBUG_PRINT_SAFE("Kernel :  mon accepts dtor, block and signal it \n");
159
160                        // Wake the thread that is waiting for this
161                        __condition_criterion_t * urgent = pop( &this->signal_stack );
162                        verify( urgent );
163
164                        // Reset mask
165                        reset_mask( this );
166
167                        // Create the node specific to this wait operation
168                        wait_ctx_primed( this_thread, 0 )
169
170                        // Some one else has the monitor, wait for him to finish and then run
171                        BlockInternal( &this->lock, urgent->owner->waiting_thread );
172
173                        // Some one was waiting for us, enter
174                        set_owner( this, thrd );
175                }
176                else {
177                        LIB_DEBUG_PRINT_SAFE("Kernel :  blocking \n");
178
179                        wait_ctx( this_thread, 0 )
180                        this->dtor_node = &waiter;
181
182                        // Some one else has the monitor, wait in line for it
183                        append( &this->entry_queue, thrd );
184                        BlockInternal( &this->lock );
185
186                        // BlockInternal will unlock spinlock, no need to unlock ourselves
187                        return;
188                }
189
190                LIB_DEBUG_PRINT_SAFE("Kernel : Destroying %p\n", this);
191
192        }
193
194        // Leave single monitor
195        void __leave_monitor_desc( monitor_desc * this ) {
196                // Lock the monitor spinlock, lock_yield to reduce contention
197                lock_yield( &this->lock DEBUG_CTX2 );
198
199                LIB_DEBUG_PRINT_SAFE("Kernel : %10p Leaving mon %p (%p)\n", this_thread, this, this->owner);
200
201                verifyf( this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", this_thread, this->owner, this->recursion, this );
202
203                // Leaving a recursion level, decrement the counter
204                this->recursion -= 1;
205
206                // If we haven't left the last level of recursion
207                // it means we don't need to do anything
208                if( this->recursion != 0) {
209                        unlock( &this->lock );
210                        return;
211                }
212
213                // Get the next thread, will be null on low contention monitor
214                thread_desc * new_owner = next_thread( this );
215
216                // We can now let other threads in safely
217                unlock( &this->lock );
218
219                //We need to wake-up the thread
220                WakeThread( new_owner );
221        }
222
223        // Leave single monitor for the last time
224        void __leave_dtor_monitor_desc( monitor_desc * this ) {
225                LIB_DEBUG_DO(
226                        if( this_thread != this->owner ) {
227                                abortf("Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, this_thread, this->owner);
228                        }
229                        if( this->recursion != 1 ) {
230                                abortf("Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
231                        }
232                )
233        }
234
235        // Leave the thread monitor
236        // last routine called by a thread.
237        // Should never return
238        void __leave_thread_monitor( thread_desc * thrd ) {
239                monitor_desc * this = &thrd->self_mon;
240
241                // Lock the monitor now
242                lock_yield( &this->lock DEBUG_CTX2 );
243
244                disable_interrupts();
245
246                thrd->self_cor.state = Halted;
247
248                verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
249
250                // Leaving a recursion level, decrement the counter
251                this->recursion -= 1;
252
253                // If we haven't left the last level of recursion
254                // it must mean there is an error
255                if( this->recursion != 0) { abortf("Thread internal monitor has unbalanced recursion"); }
256
257                // Fetch the next thread, can be null
258                thread_desc * new_owner = next_thread( this );
259
260                // Leave the thread, this will unlock the spinlock
261                // Use leave thread instead of BlockInternal which is
262                // specialized for this case and supports null new_owner
263                LeaveThread( &this->lock, new_owner );
264
265                // Control flow should never reach here!
266        }
267}
268
269// Enter multiple monitor
270// relies on the monitor array being sorted
271static inline void enter( __monitor_group_t monitors ) {
272        for(int i = 0; i < monitors.size; i++) {
273                __enter_monitor_desc( monitors.list[i], monitors );
274        }
275}
276
277// Leave multiple monitor
278// relies on the monitor array being sorted
279static inline void leave(monitor_desc ** monitors, int count) {
280        for(int i = count - 1; i >= 0; i--) {
281                __leave_monitor_desc( monitors[i] );
282        }
283}
284
285// Ctor for monitor guard
286// Sorts monitors before entering
287void ?{}( monitor_guard_t & this, monitor_desc ** m, int count, fptr_t func ) {
288        // Store current array
289        this.m = m;
290        this.count = count;
291
292        // Sort monitors based on address -> TODO use a sort specialized for small numbers
293        qsort(this.m, count);
294
295        // Save previous thread context
296        this.prev_mntrs = this_thread->monitors.list;
297        this.prev_count = this_thread->monitors.size;
298        this.prev_func  = this_thread->monitors.func;
299
300        // Update thread context (needed for conditions)
301        this_thread->monitors.list = m;
302        this_thread->monitors.size = count;
303        this_thread->monitors.func = func;
304
305        // LIB_DEBUG_PRINT_SAFE("MGUARD : enter %d\n", count);
306
307        // Enter the monitors in order
308        __monitor_group_t group = {this.m, this.count, func};
309        enter( group );
310
311        // LIB_DEBUG_PRINT_SAFE("MGUARD : entered\n");
312}
313
314
315// Dtor for monitor guard
316void ^?{}( monitor_guard_t & this ) {
317        // LIB_DEBUG_PRINT_SAFE("MGUARD : leaving %d\n", this.count);
318
319        // Leave the monitors in order
320        leave( this.m, this.count );
321
322        // LIB_DEBUG_PRINT_SAFE("MGUARD : left\n");
323
324        // Restore thread context
325        this_thread->monitors.list = this.prev_mntrs;
326        this_thread->monitors.size = this.prev_count;
327        this_thread->monitors.func = this.prev_func;
328}
329
330
331// Ctor for monitor guard
332// Sorts monitors before entering
333void ?{}( monitor_dtor_guard_t & this, monitor_desc ** m, fptr_t func ) {
334        // Store current array
335        this.m = *m;
336
337        // Save previous thread context
338        this.prev_mntrs = this_thread->monitors.list;
339        this.prev_count = this_thread->monitors.size;
340        this.prev_func  = this_thread->monitors.func;
341
342        // Update thread context (needed for conditions)
343        this_thread->monitors.list = m;
344        this_thread->monitors.size = 1;
345        this_thread->monitors.func = func;
346
347        __enter_monitor_dtor( this.m, func );
348}
349
350
351// Dtor for monitor guard
352void ^?{}( monitor_dtor_guard_t & this ) {
353        // Leave the monitors in order
354        __leave_dtor_monitor_desc( this.m );
355
356        // Restore thread context
357        this_thread->monitors.list = this.prev_mntrs;
358        this_thread->monitors.size = this.prev_count;
359        this_thread->monitors.func = this.prev_func;
360}
361
362//-----------------------------------------------------------------------------
363// Internal scheduling types
364void ?{}(__condition_node_t & this, thread_desc * waiting_thread, unsigned short count, uintptr_t user_info ) {
365        this.waiting_thread = waiting_thread;
366        this.count = count;
367        this.next = NULL;
368        this.user_info = user_info;
369}
370
371void ?{}(__condition_criterion_t & this ) {
372        this.ready  = false;
373        this.target = NULL;
374        this.owner  = NULL;
375        this.next   = NULL;
376}
377
378void ?{}(__condition_criterion_t & this, monitor_desc * target, __condition_node_t * owner ) {
379        this.ready  = false;
380        this.target = target;
381        this.owner  = owner;
382        this.next   = NULL;
383}
384
385//-----------------------------------------------------------------------------
386// Internal scheduling
387void wait( condition * this, uintptr_t user_info = 0 ) {
388        brand_condition( this );
389
390        // Check that everything is as expected
391        assertf( this->monitors != NULL, "Waiting with no monitors (%p)", this->monitors );
392        verifyf( this->monitor_count != 0, "Waiting with 0 monitors (%i)", this->monitor_count );
393        verifyf( this->monitor_count < 32u, "Excessive monitor count (%i)", this->monitor_count );
394
395        // Create storage for monitor context
396        monitor_ctx( this->monitors, this->monitor_count );
397
398        // Create the node specific to this wait operation
399        wait_ctx( this_thread, user_info );
400
401        // Append the current wait operation to the ones already queued on the condition
402        // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
403        append( &this->blocked, &waiter );
404
405        // Lock all monitors (aggregates the locks as well)
406        lock_all( monitors, locks, count );
407
408        // Find the next thread(s) to run
409        short thread_count = 0;
410        thread_desc * threads[ count ];
411        for(int i = 0; i < count; i++) {
412                threads[i] = 0;
413        }
414
415        // Save monitor states
416        monitor_save;
417
418        // Remove any duplicate threads
419        for( int i = 0; i < count; i++) {
420                thread_desc * new_owner = next_thread( monitors[i] );
421                insert_unique( threads, thread_count, new_owner );
422        }
423
424        // Everything is ready to go to sleep
425        BlockInternal( locks, count, threads, thread_count );
426
427        // We are back, restore the owners and recursions
428        monitor_restore;
429}
430
431bool signal( condition * this ) {
432        if( is_empty( this ) ) { return false; }
433
434        //Check that everything is as expected
435        verify( this->monitors );
436        verify( this->monitor_count != 0 );
437
438        //Some more checking in debug
439        LIB_DEBUG_DO(
440                thread_desc * this_thrd = this_thread;
441                if ( this->monitor_count != this_thrd->monitors.size ) {
442                        abortf( "Signal on condition %p made with different number of monitor(s), expected %i got %i", this, this->monitor_count, this_thrd->monitors.size );
443                }
444
445                for(int i = 0; i < this->monitor_count; i++) {
446                        if ( this->monitors[i] != this_thrd->monitors.list[i] ) {
447                                abortf( "Signal on condition %p made with different monitor, expected %p got %i", this, this->monitors[i], this_thrd->monitors.list[i] );
448                        }
449                }
450        );
451
452        unsigned short count = this->monitor_count;
453
454        // Lock all monitors
455        lock_all( this->monitors, NULL, count );
456
457        //Pop the head of the waiting queue
458        __condition_node_t * node = pop_head( &this->blocked );
459
460        //Add the thread to the proper AS stack
461        for(int i = 0; i < count; i++) {
462                __condition_criterion_t * crit = &node->criteria[i];
463                assert( !crit->ready );
464                push( &crit->target->signal_stack, crit );
465        }
466
467        //Release
468        unlock_all( this->monitors, count );
469
470        return true;
471}
472
473bool signal_block( condition * this ) {
474        if( !this->blocked.head ) { return false; }
475
476        //Check that everything is as expected
477        verifyf( this->monitors != NULL, "Waiting with no monitors (%p)", this->monitors );
478        verifyf( this->monitor_count != 0, "Waiting with 0 monitors (%i)", this->monitor_count );
479
480        // Create storage for monitor context
481        monitor_ctx( this->monitors, this->monitor_count );
482
483        // Lock all monitors (aggregates the locks them as well)
484        lock_all( monitors, locks, count );
485
486        // Create the node specific to this wait operation
487        wait_ctx_primed( this_thread, 0 )
488
489        //save contexts
490        monitor_save;
491
492        //Find the thread to run
493        thread_desc * signallee = pop_head( &this->blocked )->waiting_thread;
494        set_owner( monitors, count, 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        //We are back, restore the masks and recursions
504        monitor_restore;
505
506        return true;
507}
508
509// Access the user_info of the thread waiting at the front of the queue
510uintptr_t front( condition * this ) {
511        verifyf( !is_empty(this),
512                "Attempt to access user data on an empty condition.\n"
513                "Possible cause is not checking if the condition is empty before reading stored data."
514        );
515        return this->blocked.head->user_info;
516}
517
518//-----------------------------------------------------------------------------
519// External scheduling
520// cases to handle :
521//      - target already there :
522//              block and wake
523//      - dtor already there
524//              put thread on signaller stack
525//      - non-blocking
526//              return else
527//      - timeout
528//              return timeout
529//      - block
530//              setup mask
531//              block
532void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
533        // This statment doesn't have a contiguous list of monitors...
534        // Create one!
535        short max = count_max( mask );
536        monitor_desc * mon_storage[max];
537        short actual_count = aggregate( mon_storage, mask );
538
539        if(actual_count == 0) return;
540
541        LIB_DEBUG_PRINT_SAFE("Kernel : waitfor internal proceeding\n");
542
543        // Create storage for monitor context
544        monitor_ctx( mon_storage, actual_count );
545
546        // Lock all monitors (aggregates the locks as well)
547        lock_all( monitors, locks, count );
548
549        {
550                // Check if the entry queue
551                thread_desc * next; int index;
552                [next, index] = search_entry_queue( mask, monitors, count );
553
554                if( next ) {
555                        *mask.accepted = index;
556                        if( mask.clauses[index].is_dtor ) {
557                                LIB_DEBUG_PRINT_SAFE("Kernel : dtor already there\n");
558                                verifyf( mask.clauses[index].size == 1        , "ERROR: Accepted dtor has more than 1 mutex parameter." );
559
560                                monitor_desc * mon2dtor = mask.clauses[index].list[0];
561                                verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
562
563                                __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
564                                push( &mon2dtor->signal_stack, dtor_crit );
565
566                                unlock_all( locks, count );
567                        }
568                        else {
569                                LIB_DEBUG_PRINT_SAFE("Kernel : thread present, baton-passing\n");
570
571                                // Create the node specific to this wait operation
572                                wait_ctx_primed( this_thread, 0 );
573
574                                // Save monitor states
575                                monitor_save;
576
577                                // Set the owners to be the next thread
578                                set_owner( monitors, count, next );
579
580                                // Everything is ready to go to sleep
581                                BlockInternal( locks, count, &next, 1 );
582
583                                // We are back, restore the owners and recursions
584                                monitor_restore;
585
586                                LIB_DEBUG_PRINT_SAFE("Kernel : thread present, returned\n");
587                        }
588
589                        LIB_DEBUG_PRINT_SAFE("Kernel : accepted %d\n", *mask.accepted);
590
591                        return;
592                }
593        }
594
595
596        if( duration == 0 ) {
597                LIB_DEBUG_PRINT_SAFE("Kernel : non-blocking, exiting\n");
598
599                unlock_all( locks, count );
600
601                LIB_DEBUG_PRINT_SAFE("Kernel : accepted %d\n", *mask.accepted);
602                return;
603        }
604
605
606        verifyf( duration < 0, "Timeout on waitfor statments not supported yet.");
607
608        LIB_DEBUG_PRINT_SAFE("Kernel : blocking waitfor\n");
609
610        // Create the node specific to this wait operation
611        wait_ctx_primed( this_thread, 0 );
612
613        monitor_save;
614        set_mask( monitors, count, mask );
615
616        for(int i = 0; i < count; i++) {
617                verify( monitors[i]->owner == this_thread );
618        }
619
620        //Everything is ready to go to sleep
621        BlockInternal( locks, count );
622
623
624        // WE WOKE UP
625
626
627        //We are back, restore the masks and recursions
628        monitor_restore;
629
630        LIB_DEBUG_PRINT_SAFE("Kernel : exiting\n");
631
632        LIB_DEBUG_PRINT_SAFE("Kernel : accepted %d\n", *mask.accepted);
633}
634
635//-----------------------------------------------------------------------------
636// Utilities
637
638static inline void set_owner( monitor_desc * this, thread_desc * owner ) {
639        // LIB_DEBUG_PRINT_SAFE("Kernal :   Setting owner of %p to %p ( was %p)\n", this, owner, this->owner );
640
641        //Pass the monitor appropriately
642        this->owner = owner;
643
644        //We are passing the monitor to someone else, which means recursion level is not 0
645        this->recursion = owner ? 1 : 0;
646}
647
648static inline void set_owner( monitor_desc ** monitors, short count, thread_desc * owner ) {
649        for( int i = 0; i < count; i++ ) {
650                set_owner( monitors[i], owner );
651        }
652}
653
654static inline void set_mask( monitor_desc ** storage, short count, const __waitfor_mask_t & mask ) {
655        for(int i = 0; i < count; i++) {
656                storage[i]->mask = mask;
657        }
658}
659
660static inline void reset_mask( monitor_desc * this ) {
661        this->mask.accepted = NULL;
662        this->mask.clauses = NULL;
663        this->mask.size = 0;
664}
665
666static inline thread_desc * next_thread( monitor_desc * this ) {
667        //Check the signaller stack
668        __condition_criterion_t * urgent = pop( &this->signal_stack );
669        if( urgent ) {
670                //The signaller stack is not empty,
671                //regardless of if we are ready to baton pass,
672                //we need to set the monitor as in use
673                set_owner( this,  urgent->owner->waiting_thread );
674
675                return check_condition( urgent );
676        }
677
678        // No signaller thread
679        // Get the next thread in the entry_queue
680        thread_desc * new_owner = pop_head( &this->entry_queue );
681        set_owner( this, new_owner );
682
683        return new_owner;
684}
685
686static inline bool is_accepted( monitor_desc * this, const __monitor_group_t & group ) {
687        __acceptable_t * it = this->mask.clauses; // Optim
688        int count = this->mask.size;
689
690        // Check if there are any acceptable functions
691        if( !it ) return false;
692
693        // If this isn't the first monitor to test this, there is no reason to repeat the test.
694        if( this != group[0] ) return group[0]->mask.accepted >= 0;
695
696        // For all acceptable functions check if this is the current function.
697        for( short i = 0; i < count; i++, it++ ) {
698                if( *it == group ) {
699                        *this->mask.accepted = i;
700                        return true;
701                }
702        }
703
704        // No function matched
705        return false;
706}
707
708static inline void init( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria ) {
709        for(int i = 0; i < count; i++) {
710                (criteria[i]){ monitors[i], waiter };
711        }
712
713        waiter->criteria = criteria;
714}
715
716static inline void init_push( int count, monitor_desc ** monitors, __condition_node_t * waiter, __condition_criterion_t * criteria ) {
717        for(int i = 0; i < count; i++) {
718                (criteria[i]){ monitors[i], waiter };
719                push( &criteria[i].target->signal_stack, &criteria[i] );
720        }
721
722        waiter->criteria = criteria;
723}
724
725static inline void lock_all( spinlock ** locks, unsigned short count ) {
726        for( int i = 0; i < count; i++ ) {
727                lock_yield( locks[i] DEBUG_CTX2 );
728        }
729}
730
731static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count ) {
732        for( int i = 0; i < count; i++ ) {
733                spinlock * l = &source[i]->lock;
734                lock_yield( l DEBUG_CTX2 );
735                if(locks) locks[i] = l;
736        }
737}
738
739static inline void unlock_all( spinlock ** locks, unsigned short count ) {
740        for( int i = 0; i < count; i++ ) {
741                unlock( locks[i] );
742        }
743}
744
745static inline void unlock_all( monitor_desc ** locks, unsigned short count ) {
746        for( int i = 0; i < count; i++ ) {
747                unlock( &locks[i]->lock );
748        }
749}
750
751static inline void save( monitor_desc ** ctx, short count, __attribute((unused)) spinlock ** locks, unsigned int * /*out*/ recursions, __waitfor_mask_t * /*out*/ masks ) {
752        for( int i = 0; i < count; i++ ) {
753                recursions[i] = ctx[i]->recursion;
754                masks[i]      = ctx[i]->mask;
755        }
756}
757
758static inline void restore( monitor_desc ** ctx, short count, spinlock ** locks, unsigned int * /*out*/ recursions, __waitfor_mask_t * /*out*/ masks ) {
759        lock_all( locks, count );
760        for( int i = 0; i < count; i++ ) {
761                ctx[i]->recursion = recursions[i];
762                ctx[i]->mask      = masks[i];
763        }
764        unlock_all( locks, count );
765}
766
767// Function has 2 different behavior
768// 1 - Marks a monitors as being ready to run
769// 2 - Checks if all the monitors are ready to run
770//     if so return the thread to run
771static inline thread_desc * check_condition( __condition_criterion_t * target ) {
772        __condition_node_t * node = target->owner;
773        unsigned short count = node->count;
774        __condition_criterion_t * criteria = node->criteria;
775
776        bool ready2run = true;
777
778        for(    int i = 0; i < count; i++ ) {
779
780                // LIB_DEBUG_PRINT_SAFE( "Checking %p for %p\n", &criteria[i], target );
781                if( &criteria[i] == target ) {
782                        criteria[i].ready = true;
783                        // LIB_DEBUG_PRINT_SAFE( "True\n" );
784                }
785
786                ready2run = criteria[i].ready && ready2run;
787        }
788
789        // LIB_DEBUG_PRINT_SAFE( "Runing %i\n", ready2run );
790        return ready2run ? node->waiting_thread : NULL;
791}
792
793static inline void brand_condition( condition * this ) {
794        thread_desc * thrd = this_thread;
795        if( !this->monitors ) {
796                // LIB_DEBUG_PRINT_SAFE("Branding\n");
797                assertf( thrd->monitors.list != NULL, "No current monitor to brand condition %p", thrd->monitors.list );
798                this->monitor_count = thrd->monitors.size;
799
800                this->monitors = malloc( this->monitor_count * sizeof( *this->monitors ) );
801                for( int i = 0; i < this->monitor_count; i++ ) {
802                        this->monitors[i] = thrd->monitors.list[i];
803                }
804        }
805}
806
807static inline [thread_desc *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor_desc ** monitors, int count ) {
808
809        __thread_queue_t * entry_queue = &monitors[0]->entry_queue;
810
811        // For each thread in the entry-queue
812        for(    thread_desc ** thrd_it = &entry_queue->head;
813                *thrd_it;
814                thrd_it = &(*thrd_it)->next
815        ) {
816                // For each acceptable check if it matches
817                int i = 0;
818                __acceptable_t * end = mask.clauses + mask.size;
819                for( __acceptable_t * it = mask.clauses; it != end; it++, i++ ) {
820                        // Check if we have a match
821                        if( *it == (*thrd_it)->monitors ) {
822
823                                // If we have a match return it
824                                // after removeing it from the entry queue
825                                return [remove( entry_queue, thrd_it ), i];
826                        }
827                }
828        }
829
830        return [0, -1];
831}
832
833forall(dtype T | sized( T ))
834static inline short insert_unique( T ** array, short & size, T * val ) {
835        if( !val ) return size;
836
837        for(int i = 0; i <= size; i++) {
838                if( array[i] == val ) return size;
839        }
840
841        array[size] = val;
842        size = size + 1;
843        return size;
844}
845
846static inline short count_max( const __waitfor_mask_t & mask ) {
847        short max = 0;
848        for( int i = 0; i < mask.size; i++ ) {
849                max += mask.clauses[i].size;
850        }
851        return max;
852}
853
854static inline short aggregate( monitor_desc ** storage, const __waitfor_mask_t & mask ) {
855        short size = 0;
856        for( int i = 0; i < mask.size; i++ ) {
857                for( int j = 0; j < mask.clauses[i].size; j++) {
858                        insert_unique( storage, size, mask.clauses[i].list[j] );
859                }
860        }
861        qsort( storage, size );
862        return size;
863}
864
865void ?{}( __condition_blocked_queue_t & this ) {
866        this.head = NULL;
867        this.tail = &this.head;
868}
869
870void append( __condition_blocked_queue_t * this, __condition_node_t * c ) {
871        verify(this->tail != NULL);
872        *this->tail = c;
873        this->tail = &c->next;
874}
875
876__condition_node_t * pop_head( __condition_blocked_queue_t * this ) {
877        __condition_node_t * head = this->head;
878        if( head ) {
879                this->head = head->next;
880                if( !head->next ) {
881                        this->tail = &this->head;
882                }
883                head->next = NULL;
884        }
885        return head;
886}
887
888// Local Variables: //
889// mode: c //
890// tab-width: 4 //
891// End: //
Note: See TracBrowser for help on using the repository browser.