source: libcfa/src/concurrency/monitor.cfa @ ac2b598

arm-ehjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-expr
Last change on this file since ac2b598 was ac2b598, checked in by Thierry Delisle <tdelisle@…>, 20 months ago

Changed descriptors for concurrency to use $ prefix instead of trailing _desc

  • Property mode set to 100644
File size: 31.8 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.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 * this, $thread * owner );
30static inline void __set_owner ( $monitor * storage [], __lock_size_t count, $thread * owner );
31static inline void set_mask  ( $monitor * storage [], __lock_size_t count, const __waitfor_mask_t & mask );
32static inline void reset_mask( $monitor * this );
33
34static inline $thread * next_thread( $monitor * this );
35static inline bool is_accepted( $monitor * 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 * 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 * locks [], __lock_size_t count );
41
42static inline void save   ( $monitor * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*out*/ recursions [], __waitfor_mask_t /*out*/ masks [] );
43static inline void restore( $monitor * 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 * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
46static inline void init_push( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
47
48static inline $thread *        check_condition   ( __condition_criterion_t * );
49static inline void                 brand_condition   ( condition & );
50static inline [$thread *, int] search_entry_queue( const __waitfor_mask_t &, $monitor * 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 * 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 ** 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// Enter single monitor
83static void __enter( $monitor * this, const __monitor_group_t & group ) {
84        // Lock the monitor spinlock
85        lock( this->lock __cfaabi_dbg_ctx2 );
86        // Interrupts disable inside critical section
87        $thread * thrd = kernelTLS.this_thread;
88
89        __cfaabi_dbg_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                __cfaabi_dbg_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                __cfaabi_dbg_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                __cfaabi_dbg_print_safe( "Kernel :  mon accepts \n" );
111        }
112        else {
113                __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
114
115                // Some one else has the monitor, wait in line for it
116                /* paranoid */ verify( thrd->next == 0p );
117                append( this->entry_queue, thrd );
118                /* paranoid */ verify( thrd->next == 1p );
119
120                unlock( this->lock );
121                park();
122
123                __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
124
125                /* paranoid */ 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 );
126                return;
127        }
128
129        __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
130
131        /* paranoid */ 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 );
132        /* paranoid */ verify( this->lock.lock );
133
134        // Release the lock and leave
135        unlock( this->lock );
136        return;
137}
138
139static void __dtor_enter( $monitor * this, fptr_t func ) {
140        // Lock the monitor spinlock
141        lock( this->lock __cfaabi_dbg_ctx2 );
142        // Interrupts disable inside critical section
143        $thread * thrd = kernelTLS.this_thread;
144
145        __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
146
147
148        if( !this->owner ) {
149                __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
150
151                // No one has the monitor, just take it
152                __set_owner( this, thrd );
153
154                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 );
155
156                unlock( this->lock );
157                return;
158        }
159        else if( this->owner == thrd) {
160                // We already have the monitor... but where about to destroy it so the nesting will fail
161                // Abort!
162                abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
163        }
164
165        __lock_size_t count = 1;
166        $monitor ** monitors = &this;
167        __monitor_group_t group = { &this, 1, func };
168        if( is_accepted( this, group) ) {
169                __cfaabi_dbg_print_safe( "Kernel :  mon accepts dtor, block and signal it \n" );
170
171                // Wake the thread that is waiting for this
172                __condition_criterion_t * urgent = pop( this->signal_stack );
173                /* paranoid */ verify( urgent );
174
175                // Reset mask
176                reset_mask( this );
177
178                // Create the node specific to this wait operation
179                wait_ctx_primed( thrd, 0 )
180
181                // Some one else has the monitor, wait for him to finish and then run
182                unlock( this->lock );
183
184                // Release the next thread
185                /* paranoid */ verifyf( urgent->owner->waiting_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, this->owner, this->recursion, this );
186                unpark( urgent->owner->waiting_thread );
187
188                // Park current thread waiting
189                park();
190
191                // Some one was waiting for us, enter
192                /* paranoid */ 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 );
193        }
194        else {
195                __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
196
197                wait_ctx( thrd, 0 )
198                this->dtor_node = &waiter;
199
200                // Some one else has the monitor, wait in line for it
201                /* paranoid */ verify( thrd->next == 0p );
202                append( this->entry_queue, thrd );
203                /* paranoid */ verify( thrd->next == 1p );
204                unlock( this->lock );
205
206                // Park current thread waiting
207                park();
208
209                /* paranoid */ 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 );
210                return;
211        }
212
213        __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
214
215}
216
217// Leave single monitor
218void __leave( $monitor * this ) {
219        // Lock the monitor spinlock
220        lock( this->lock __cfaabi_dbg_ctx2 );
221
222        __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", kernelTLS.this_thread, this, this->owner);
223
224        /* paranoid */ 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 );
225
226        // Leaving a recursion level, decrement the counter
227        this->recursion -= 1;
228
229        // If we haven't left the last level of recursion
230        // it means we don't need to do anything
231        if( this->recursion != 0) {
232                __cfaabi_dbg_print_safe( "Kernel :  recursion still %d\n", this->recursion);
233                unlock( this->lock );
234                return;
235        }
236
237        // Get the next thread, will be null on low contention monitor
238        $thread * new_owner = next_thread( this );
239
240        // Check the new owner is consistent with who we wake-up
241        // new_owner might be null even if someone owns the monitor when the owner is still waiting for another monitor
242        /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
243
244        // We can now let other threads in safely
245        unlock( this->lock );
246
247        //We need to wake-up the thread
248        /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
249        unpark( new_owner );
250}
251
252// Leave single monitor for the last time
253void __dtor_leave( $monitor * this ) {
254        __cfaabi_dbg_debug_do(
255                if( TL_GET( this_thread ) != this->owner ) {
256                        abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, TL_GET( this_thread ), this->owner);
257                }
258                if( this->recursion != 1 ) {
259                        abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
260                }
261        )
262}
263
264extern "C" {
265        // Leave the thread monitor
266        // last routine called by a thread.
267        // Should never return
268        void __cfactx_thrd_leave() {
269                $thread * thrd = TL_GET( this_thread );
270                $monitor * this = &thrd->self_mon;
271
272                // Lock the monitor now
273                lock( this->lock __cfaabi_dbg_ctx2 );
274
275                disable_interrupts();
276
277                thrd->state = Halted;
278
279                /* paranoid */ verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
280
281                // Leaving a recursion level, decrement the counter
282                this->recursion -= 1;
283
284                // If we haven't left the last level of recursion
285                // it must mean there is an error
286                if( this->recursion != 0) { abort( "Thread internal monitor has unbalanced recursion" ); }
287
288                // Fetch the next thread, can be null
289                $thread * new_owner = next_thread( this );
290
291                // Release the monitor lock
292                unlock( this->lock );
293
294                // Unpark the next owner if needed
295                /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
296                /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
297                /* paranoid */ verify( ! kernelTLS.this_processor->destroyer );
298                /* paranoid */ verify( thrd->state == Halted );
299
300                kernelTLS.this_processor->destroyer = new_owner;
301
302                // Leave the thread
303                __leave_thread();
304
305                // Control flow should never reach here!
306        }
307}
308
309// Enter multiple monitor
310// relies on the monitor array being sorted
311static inline void enter( __monitor_group_t monitors ) {
312        for( __lock_size_t i = 0; i < monitors.size; i++) {
313                __enter( monitors[i], monitors );
314        }
315}
316
317// Leave multiple monitor
318// relies on the monitor array being sorted
319static inline void leave($monitor * monitors [], __lock_size_t count) {
320        for( __lock_size_t i = count - 1; i >= 0; i--) {
321                __leave( monitors[i] );
322        }
323}
324
325// Ctor for monitor guard
326// Sorts monitors before entering
327void ?{}( monitor_guard_t & this, $monitor * m [], __lock_size_t count, fptr_t func ) {
328        $thread * thrd = TL_GET( this_thread );
329
330        // Store current array
331        this.m = m;
332        this.count = count;
333
334        // Sort monitors based on address
335        __libcfa_small_sort(this.m, count);
336
337        // Save previous thread context
338        this.prev = thrd->monitors;
339
340        // Update thread context (needed for conditions)
341        (thrd->monitors){m, count, func};
342
343        // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
344
345        // Enter the monitors in order
346        __monitor_group_t group = {this.m, this.count, func};
347        enter( group );
348
349        // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
350}
351
352
353// Dtor for monitor guard
354void ^?{}( monitor_guard_t & this ) {
355        // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
356
357        // Leave the monitors in order
358        leave( this.m, this.count );
359
360        // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
361
362        // Restore thread context
363        TL_GET( this_thread )->monitors = this.prev;
364}
365
366// Ctor for monitor guard
367// Sorts monitors before entering
368void ?{}( monitor_dtor_guard_t & this, $monitor * m [], fptr_t func ) {
369        // optimization
370        $thread * thrd = TL_GET( this_thread );
371
372        // Store current array
373        this.m = *m;
374
375        // Save previous thread context
376        this.prev = thrd->monitors;
377
378        // Update thread context (needed for conditions)
379        (thrd->monitors){m, 1, func};
380
381        __dtor_enter( this.m, func );
382}
383
384// Dtor for monitor guard
385void ^?{}( monitor_dtor_guard_t & this ) {
386        // Leave the monitors in order
387        __dtor_leave( this.m );
388
389        // Restore thread context
390        TL_GET( this_thread )->monitors = this.prev;
391}
392
393//-----------------------------------------------------------------------------
394// Internal scheduling types
395void ?{}(__condition_node_t & this, $thread * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
396        this.waiting_thread = waiting_thread;
397        this.count = count;
398        this.next = 0p;
399        this.user_info = user_info;
400}
401
402void ?{}(__condition_criterion_t & this ) with( this ) {
403        ready  = false;
404        target = 0p;
405        owner  = 0p;
406        next   = 0p;
407}
408
409void ?{}(__condition_criterion_t & this, $monitor * target, __condition_node_t & owner ) {
410        this.ready  = false;
411        this.target = target;
412        this.owner  = &owner;
413        this.next   = 0p;
414}
415
416//-----------------------------------------------------------------------------
417// Internal scheduling
418void wait( condition & this, uintptr_t user_info = 0 ) {
419        brand_condition( this );
420
421        // Check that everything is as expected
422        assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
423        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
424        verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
425
426        // Create storage for monitor context
427        monitor_ctx( this.monitors, this.monitor_count );
428
429        // Create the node specific to this wait operation
430        wait_ctx( TL_GET( this_thread ), user_info );
431
432        // Append the current wait operation to the ones already queued on the condition
433        // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
434        /* paranoid */ verify( waiter.next == 0p );
435        append( this.blocked, &waiter );
436        /* paranoid */ verify( waiter.next == 1p );
437
438        // Lock all monitors (aggregates the locks as well)
439        lock_all( monitors, locks, count );
440
441        // Find the next thread(s) to run
442        __lock_size_t thread_count = 0;
443        $thread * threads[ count ];
444        __builtin_memset( threads, 0, sizeof( threads ) );
445
446        // Save monitor states
447        monitor_save;
448
449        // Remove any duplicate threads
450        for( __lock_size_t i = 0; i < count; i++) {
451                $thread * new_owner = next_thread( monitors[i] );
452                insert_unique( threads, thread_count, new_owner );
453        }
454
455        // Unlock the locks, we don't need them anymore
456        for(int i = 0; i < count; i++) {
457                unlock( *locks[i] );
458        }
459
460        // Wake the threads
461        for(int i = 0; i < thread_count; i++) {
462                unpark( threads[i] );
463        }
464
465        // Everything is ready to go to sleep
466        park();
467
468        // We are back, restore the owners and recursions
469        monitor_restore;
470}
471
472bool signal( condition & this ) {
473        if( is_empty( this ) ) { return false; }
474
475        //Check that everything is as expected
476        verify( this.monitors );
477        verify( this.monitor_count != 0 );
478
479        //Some more checking in debug
480        __cfaabi_dbg_debug_do(
481                $thread * this_thrd = TL_GET( this_thread );
482                if ( this.monitor_count != this_thrd->monitors.size ) {
483                        abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
484                }
485
486                for(int i = 0; i < this.monitor_count; i++) {
487                        if ( this.monitors[i] != this_thrd->monitors[i] ) {
488                                abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
489                        }
490                }
491        );
492
493        __lock_size_t count = this.monitor_count;
494
495        // Lock all monitors
496        lock_all( this.monitors, 0p, count );
497
498        //Pop the head of the waiting queue
499        __condition_node_t * node = pop_head( this.blocked );
500
501        //Add the thread to the proper AS stack
502        for(int i = 0; i < count; i++) {
503                __condition_criterion_t * crit = &node->criteria[i];
504                assert( !crit->ready );
505                push( crit->target->signal_stack, crit );
506        }
507
508        //Release
509        unlock_all( this.monitors, count );
510
511        return true;
512}
513
514bool signal_block( condition & this ) {
515        if( !this.blocked.head ) { return false; }
516
517        //Check that everything is as expected
518        verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
519        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
520
521        // Create storage for monitor context
522        monitor_ctx( this.monitors, this.monitor_count );
523
524        // Lock all monitors (aggregates the locks them as well)
525        lock_all( monitors, locks, count );
526
527
528        // Create the node specific to this wait operation
529        wait_ctx_primed( kernelTLS.this_thread, 0 )
530
531        //save contexts
532        monitor_save;
533
534        //Find the thread to run
535        $thread * signallee = pop_head( this.blocked )->waiting_thread;
536        /* paranoid */ verify( signallee->next == 0p );
537        __set_owner( monitors, count, signallee );
538
539        __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
540
541        // unlock all the monitors
542        unlock_all( locks, count );
543
544        // unpark the thread we signalled
545        unpark( signallee );
546
547        //Everything is ready to go to sleep
548        park();
549
550
551        // WE WOKE UP
552
553
554        __cfaabi_dbg_print_buffer_local( "Kernel :   signal_block returned\n" );
555
556        //We are back, restore the masks and recursions
557        monitor_restore;
558
559        return true;
560}
561
562// Access the user_info of the thread waiting at the front of the queue
563uintptr_t front( condition & this ) {
564        verifyf( !is_empty(this),
565                "Attempt to access user data on an empty condition.\n"
566                "Possible cause is not checking if the condition is empty before reading stored data."
567        );
568        return ((typeof(this.blocked.head))this.blocked.head)->user_info;
569}
570
571//-----------------------------------------------------------------------------
572// External scheduling
573// cases to handle :
574//      - target already there :
575//              block and wake
576//      - dtor already there
577//              put thread on signaller stack
578//      - non-blocking
579//              return else
580//      - timeout
581//              return timeout
582//      - block
583//              setup mask
584//              block
585void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
586        // This statment doesn't have a contiguous list of monitors...
587        // Create one!
588        __lock_size_t max = count_max( mask );
589        $monitor * mon_storage[max];
590        __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
591        __lock_size_t actual_count = aggregate( mon_storage, mask );
592
593        __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
594
595        if(actual_count == 0) return;
596
597        __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
598
599        // Create storage for monitor context
600        monitor_ctx( mon_storage, actual_count );
601
602        // Lock all monitors (aggregates the locks as well)
603        lock_all( monitors, locks, count );
604
605        {
606                // Check if the entry queue
607                $thread * next; int index;
608                [next, index] = search_entry_queue( mask, monitors, count );
609
610                if( next ) {
611                        *mask.accepted = index;
612                        __acceptable_t& accepted = mask[index];
613                        if( accepted.is_dtor ) {
614                                __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
615                                verifyf( accepted.size == 1,  "ERROR: Accepted dtor has more than 1 mutex parameter." );
616
617                                $monitor * mon2dtor = accepted[0];
618                                verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
619
620                                __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
621                                push( mon2dtor->signal_stack, dtor_crit );
622
623                                unlock_all( locks, count );
624                        }
625                        else {
626                                __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
627
628                                // Create the node specific to this wait operation
629                                wait_ctx_primed( kernelTLS.this_thread, 0 );
630
631                                // Save monitor states
632                                monitor_save;
633
634                                __cfaabi_dbg_print_buffer_local( "Kernel :  baton of %"PRIdFAST16" monitors : ", count );
635                                #ifdef __CFA_DEBUG_PRINT__
636                                        for( int i = 0; i < count; i++) {
637                                                __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
638                                        }
639                                #endif
640                                __cfaabi_dbg_print_buffer_local( "\n" );
641
642                                // Set the owners to be the next thread
643                                __set_owner( monitors, count, next );
644
645                                // unlock all the monitors
646                                unlock_all( locks, count );
647
648                                // unpark the thread we signalled
649                                unpark( next );
650
651                                //Everything is ready to go to sleep
652                                park();
653
654                                // We are back, restore the owners and recursions
655                                monitor_restore;
656
657                                __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
658                        }
659
660                        __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
661                        return;
662                }
663        }
664
665
666        if( duration == 0 ) {
667                __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
668
669                unlock_all( locks, count );
670
671                __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
672                return;
673        }
674
675
676        verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
677
678        __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
679
680        // Create the node specific to this wait operation
681        wait_ctx_primed( kernelTLS.this_thread, 0 );
682
683        monitor_save;
684        set_mask( monitors, count, mask );
685
686        for( __lock_size_t i = 0; i < count; i++) {
687                verify( monitors[i]->owner == kernelTLS.this_thread );
688        }
689
690        // unlock all the monitors
691        unlock_all( locks, count );
692
693        //Everything is ready to go to sleep
694        park();
695
696
697        // WE WOKE UP
698
699
700        //We are back, restore the masks and recursions
701        monitor_restore;
702
703        __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
704
705        __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
706}
707
708//-----------------------------------------------------------------------------
709// Utilities
710
711static inline void __set_owner( $monitor * this, $thread * owner ) {
712        /* paranoid */ verify( this->lock.lock );
713
714        //Pass the monitor appropriately
715        this->owner = owner;
716
717        //We are passing the monitor to someone else, which means recursion level is not 0
718        this->recursion = owner ? 1 : 0;
719}
720
721static inline void __set_owner( $monitor * monitors [], __lock_size_t count, $thread * owner ) {
722        /* paranoid */ verify ( monitors[0]->lock.lock );
723        /* paranoid */ verifyf( monitors[0]->owner == kernelTLS.this_thread, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, monitors[0]->owner, monitors[0]->recursion, monitors[0] );
724        monitors[0]->owner        = owner;
725        monitors[0]->recursion    = 1;
726        for( __lock_size_t i = 1; i < count; i++ ) {
727                /* paranoid */ verify ( monitors[i]->lock.lock );
728                /* paranoid */ verifyf( monitors[i]->owner == kernelTLS.this_thread, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, monitors[i]->owner, monitors[i]->recursion, monitors[i] );
729                monitors[i]->owner        = owner;
730                monitors[i]->recursion    = 0;
731        }
732}
733
734static inline void set_mask( $monitor * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
735        for( __lock_size_t i = 0; i < count; i++) {
736                storage[i]->mask = mask;
737        }
738}
739
740static inline void reset_mask( $monitor * this ) {
741        this->mask.accepted = 0p;
742        this->mask.data = 0p;
743        this->mask.size = 0;
744}
745
746static inline $thread * next_thread( $monitor * this ) {
747        //Check the signaller stack
748        __cfaabi_dbg_print_safe( "Kernel :  mon %p AS-stack top %p\n", this, this->signal_stack.top);
749        __condition_criterion_t * urgent = pop( this->signal_stack );
750        if( urgent ) {
751                //The signaller stack is not empty,
752                //regardless of if we are ready to baton pass,
753                //we need to set the monitor as in use
754                /* paranoid */ verifyf( !this->owner || kernelTLS.this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, this->owner, this->recursion, this );
755                __set_owner( this,  urgent->owner->waiting_thread );
756
757                return check_condition( urgent );
758        }
759
760        // No signaller thread
761        // Get the next thread in the entry_queue
762        $thread * new_owner = pop_head( this->entry_queue );
763        /* paranoid */ verifyf( !this->owner || kernelTLS.this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, this->owner, this->recursion, this );
764        /* paranoid */ verify( !new_owner || new_owner->next == 0p );
765        __set_owner( this, new_owner );
766
767        return new_owner;
768}
769
770static inline bool is_accepted( $monitor * this, const __monitor_group_t & group ) {
771        __acceptable_t * it = this->mask.data; // Optim
772        __lock_size_t count = this->mask.size;
773
774        // Check if there are any acceptable functions
775        if( !it ) return false;
776
777        // If this isn't the first monitor to test this, there is no reason to repeat the test.
778        if( this != group[0] ) return group[0]->mask.accepted >= 0;
779
780        // For all acceptable functions check if this is the current function.
781        for( __lock_size_t i = 0; i < count; i++, it++ ) {
782                if( *it == group ) {
783                        *this->mask.accepted = i;
784                        return true;
785                }
786        }
787
788        // No function matched
789        return false;
790}
791
792static inline void init( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
793        for( __lock_size_t i = 0; i < count; i++) {
794                (criteria[i]){ monitors[i], waiter };
795        }
796
797        waiter.criteria = criteria;
798}
799
800static inline void init_push( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
801        for( __lock_size_t i = 0; i < count; i++) {
802                (criteria[i]){ monitors[i], waiter };
803                __cfaabi_dbg_print_safe( "Kernel :  target %p = %p\n", criteria[i].target, &criteria[i] );
804                push( criteria[i].target->signal_stack, &criteria[i] );
805        }
806
807        waiter.criteria = criteria;
808}
809
810static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
811        for( __lock_size_t i = 0; i < count; i++ ) {
812                lock( *locks[i] __cfaabi_dbg_ctx2 );
813        }
814}
815
816static inline void lock_all( $monitor * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
817        for( __lock_size_t i = 0; i < count; i++ ) {
818                __spinlock_t * l = &source[i]->lock;
819                lock( *l __cfaabi_dbg_ctx2 );
820                if(locks) locks[i] = l;
821        }
822}
823
824static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
825        for( __lock_size_t i = 0; i < count; i++ ) {
826                unlock( *locks[i] );
827        }
828}
829
830static inline void unlock_all( $monitor * locks [], __lock_size_t count ) {
831        for( __lock_size_t i = 0; i < count; i++ ) {
832                unlock( locks[i]->lock );
833        }
834}
835
836static inline void save(
837        $monitor * ctx [],
838        __lock_size_t count,
839        __attribute((unused)) __spinlock_t * locks [],
840        unsigned int /*out*/ recursions [],
841        __waitfor_mask_t /*out*/ masks []
842) {
843        for( __lock_size_t i = 0; i < count; i++ ) {
844                recursions[i] = ctx[i]->recursion;
845                masks[i]      = ctx[i]->mask;
846        }
847}
848
849static inline void restore(
850        $monitor * ctx [],
851        __lock_size_t count,
852        __spinlock_t * locks [],
853        unsigned int /*out*/ recursions [],
854        __waitfor_mask_t /*out*/ masks []
855) {
856        lock_all( locks, count );
857        for( __lock_size_t i = 0; i < count; i++ ) {
858                ctx[i]->recursion = recursions[i];
859                ctx[i]->mask      = masks[i];
860        }
861        unlock_all( locks, count );
862}
863
864// Function has 2 different behavior
865// 1 - Marks a monitors as being ready to run
866// 2 - Checks if all the monitors are ready to run
867//     if so return the thread to run
868static inline $thread * check_condition( __condition_criterion_t * target ) {
869        __condition_node_t * node = target->owner;
870        unsigned short count = node->count;
871        __condition_criterion_t * criteria = node->criteria;
872
873        bool ready2run = true;
874
875        for(    int i = 0; i < count; i++ ) {
876
877                // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
878                if( &criteria[i] == target ) {
879                        criteria[i].ready = true;
880                        // __cfaabi_dbg_print_safe( "True\n" );
881                }
882
883                ready2run = criteria[i].ready && ready2run;
884        }
885
886        __cfaabi_dbg_print_safe( "Kernel :  Runing %i (%p)\n", ready2run, ready2run ? node->waiting_thread : 0p );
887        return ready2run ? node->waiting_thread : 0p;
888}
889
890static inline void brand_condition( condition & this ) {
891        $thread * thrd = TL_GET( this_thread );
892        if( !this.monitors ) {
893                // __cfaabi_dbg_print_safe( "Branding\n" );
894                assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
895                this.monitor_count = thrd->monitors.size;
896
897                this.monitors = ($monitor **)malloc( this.monitor_count * sizeof( *this.monitors ) );
898                for( int i = 0; i < this.monitor_count; i++ ) {
899                        this.monitors[i] = thrd->monitors[i];
900                }
901        }
902}
903
904static inline [$thread *, int] search_entry_queue( const __waitfor_mask_t & mask, $monitor * monitors [], __lock_size_t count ) {
905
906        __queue_t($thread) & entry_queue = monitors[0]->entry_queue;
907
908        // For each thread in the entry-queue
909        for(    $thread ** thrd_it = &entry_queue.head;
910                *thrd_it != 1p;
911                thrd_it = &(*thrd_it)->next
912        ) {
913                // For each acceptable check if it matches
914                int i = 0;
915                __acceptable_t * end   = end  (mask);
916                __acceptable_t * begin = begin(mask);
917                for( __acceptable_t * it = begin; it != end; it++, i++ ) {
918                        // Check if we have a match
919                        if( *it == (*thrd_it)->monitors ) {
920
921                                // If we have a match return it
922                                // after removeing it from the entry queue
923                                return [remove( entry_queue, thrd_it ), i];
924                        }
925                }
926        }
927
928        return [0, -1];
929}
930
931forall(dtype T | sized( T ))
932static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
933        if( !val ) return size;
934
935        for( __lock_size_t i = 0; i <= size; i++) {
936                if( array[i] == val ) return size;
937        }
938
939        array[size] = val;
940        size = size + 1;
941        return size;
942}
943
944static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
945        __lock_size_t max = 0;
946        for( __lock_size_t i = 0; i < mask.size; i++ ) {
947                __acceptable_t & accepted = mask[i];
948                max += accepted.size;
949        }
950        return max;
951}
952
953static inline __lock_size_t aggregate( $monitor * storage [], const __waitfor_mask_t & mask ) {
954        __lock_size_t size = 0;
955        for( __lock_size_t i = 0; i < mask.size; i++ ) {
956                __acceptable_t & accepted = mask[i];
957                __libcfa_small_sort( accepted.data, accepted.size );
958                for( __lock_size_t j = 0; j < accepted.size; j++) {
959                        insert_unique( storage, size, accepted[j] );
960                }
961        }
962        // TODO insertion sort instead of this
963        __libcfa_small_sort( storage, size );
964        return size;
965}
966
967// Local Variables: //
968// mode: c //
969// tab-width: 4 //
970// End: //
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