source: libcfa/src/concurrency/monitor.cfa @ e235429

arm-ehjacob/cs343-translationnew-ast-unique-expr
Last change on this file since e235429 was e235429, checked in by Thierry Delisle <tdelisle@…>, 14 months ago

Removed last parker/unparker information is it was not particularly useful

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File size: 32.9 KB
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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.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( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
92                abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
93        }
94        else if( !this->owner ) {
95                // No one has the monitor, just take it
96                __set_owner( this, thrd );
97
98                __cfaabi_dbg_print_safe( "Kernel :  mon is free \n" );
99        }
100        else if( this->owner == thrd) {
101                // We already have the monitor, just note how many times we took it
102                this->recursion += 1;
103
104                __cfaabi_dbg_print_safe( "Kernel :  mon already owned \n" );
105        }
106        else if( is_accepted( this, group) ) {
107                // Some one was waiting for us, enter
108                __set_owner( this, thrd );
109
110                // Reset mask
111                reset_mask( this );
112
113                __cfaabi_dbg_print_safe( "Kernel :  mon accepts \n" );
114        }
115        else {
116                __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
117
118                // Some one else has the monitor, wait in line for it
119                /* paranoid */ verify( thrd->link.next == 0p );
120                append( this->entry_queue, thrd );
121                /* paranoid */ verify( thrd->link.next == 1p );
122
123                unlock( this->lock );
124                park();
125
126                __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
127
128                /* 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 );
129                return;
130        }
131
132        __cfaabi_dbg_print_safe( "Kernel : %10p Entered  mon %p\n", thrd, this);
133
134        /* 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 );
135        /* paranoid */ verify( this->lock.lock );
136
137        // Release the lock and leave
138        unlock( this->lock );
139        return;
140}
141
142static void __dtor_enter( $monitor * this, fptr_t func, bool join ) {
143        // Lock the monitor spinlock
144        lock( this->lock __cfaabi_dbg_ctx2 );
145        // Interrupts disable inside critical section
146        $thread * thrd = kernelTLS.this_thread;
147
148        __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
149
150
151        if( !this->owner ) {
152                __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
153
154                // No one has the monitor, just take it
155                __set_owner( this, thrd );
156
157                verifyf( kernelTLS.this_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", kernelTLS.this_thread, this->owner, this->recursion, this );
158
159                unlock( this->lock );
160                return;
161        }
162        else if( this->owner == thrd && !join) {
163                // We already have the monitor... but where about to destroy it so the nesting will fail
164                // Abort!
165                abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
166        }
167        // SKULLDUGGERY: join will act as a dtor so it would normally trigger to above check
168        // to avoid that it sets the owner to the special value thrd | 1p before exiting
169        else if( this->owner == ($thread*)(1 | (uintptr_t)thrd) ) {
170                // restore the owner and just return
171                __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
172
173                // No one has the monitor, just take it
174                this->owner = thrd;
175
176                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 );
177
178                unlock( this->lock );
179                return;
180        }
181
182        __lock_size_t count = 1;
183        $monitor ** monitors = &this;
184        __monitor_group_t group = { &this, 1, func };
185        if( is_accepted( this, group) ) {
186                __cfaabi_dbg_print_safe( "Kernel :  mon accepts dtor, block and signal it \n" );
187
188                // Wake the thread that is waiting for this
189                __condition_criterion_t * urgent = pop( this->signal_stack );
190                /* paranoid */ verify( urgent );
191
192                // Reset mask
193                reset_mask( this );
194
195                // Create the node specific to this wait operation
196                wait_ctx_primed( thrd, 0 )
197
198                // Some one else has the monitor, wait for him to finish and then run
199                unlock( this->lock );
200
201                // Release the next thread
202                /* 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 );
203                unpark( urgent->owner->waiting_thread );
204
205                // Park current thread waiting
206                park();
207
208                // Some one was waiting for us, enter
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        }
211        else {
212                __cfaabi_dbg_print_safe( "Kernel :  blocking \n" );
213
214                wait_ctx( thrd, 0 )
215                this->dtor_node = &waiter;
216
217                // Some one else has the monitor, wait in line for it
218                /* paranoid */ verify( thrd->link.next == 0p );
219                append( this->entry_queue, thrd );
220                /* paranoid */ verify( thrd->link.next == 1p );
221                unlock( this->lock );
222
223                // Park current thread waiting
224                park();
225
226                /* 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 );
227                return;
228        }
229
230        __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
231
232}
233
234// Leave single monitor
235void __leave( $monitor * this ) {
236        // Lock the monitor spinlock
237        lock( this->lock __cfaabi_dbg_ctx2 );
238
239        __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", kernelTLS.this_thread, this, this->owner);
240
241        /* 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 );
242
243        // Leaving a recursion level, decrement the counter
244        this->recursion -= 1;
245
246        // If we haven't left the last level of recursion
247        // it means we don't need to do anything
248        if( this->recursion != 0) {
249                __cfaabi_dbg_print_safe( "Kernel :  recursion still %d\n", this->recursion);
250                unlock( this->lock );
251                return;
252        }
253
254        // Get the next thread, will be null on low contention monitor
255        $thread * new_owner = next_thread( this );
256
257        // Check the new owner is consistent with who we wake-up
258        // new_owner might be null even if someone owns the monitor when the owner is still waiting for another monitor
259        /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
260
261        // We can now let other threads in safely
262        unlock( this->lock );
263
264        //We need to wake-up the thread
265        /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
266        unpark( new_owner );
267}
268
269// Leave single monitor for the last time
270void __dtor_leave( $monitor * this, bool join ) {
271        __cfaabi_dbg_debug_do(
272                if( TL_GET( this_thread ) != this->owner ) {
273                        abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, TL_GET( this_thread ), this->owner);
274                }
275                if( this->recursion != 1  && !join ) {
276                        abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
277                }
278        )
279
280        this->owner = ($thread*)(1 | (uintptr_t)this->owner);
281}
282
283extern "C" {
284        // Leave the thread monitor
285        // last routine called by a thread.
286        // Should never return
287        void __cfactx_thrd_leave() {
288                $thread * thrd = TL_GET( this_thread );
289                $monitor * this = &thrd->self_mon;
290
291                // Lock the monitor now
292                lock( this->lock __cfaabi_dbg_ctx2 );
293
294                disable_interrupts();
295
296                thrd->state = Halted;
297
298                /* paranoid */ verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
299
300                // Leaving a recursion level, decrement the counter
301                this->recursion -= 1;
302
303                // If we haven't left the last level of recursion
304                // it must mean there is an error
305                if( this->recursion != 0) { abort( "Thread internal monitor has unbalanced recursion" ); }
306
307                // Fetch the next thread, can be null
308                $thread * new_owner = next_thread( this );
309
310                // Release the monitor lock
311                unlock( this->lock );
312
313                // Unpark the next owner if needed
314                /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
315                /* paranoid */ verify( ! kernelTLS.preemption_state.enabled );
316                /* paranoid */ verify( ! kernelTLS.this_processor->destroyer );
317                /* paranoid */ verify( thrd->state == Halted );
318
319                kernelTLS.this_processor->destroyer = new_owner;
320
321                // Leave the thread
322                __leave_thread();
323
324                // Control flow should never reach here!
325        }
326}
327
328// Join a thread
329forall( dtype T | is_thread(T) )
330T & join( T & this ) {
331        $monitor *    m = get_monitor(this);
332        void (*dtor)(T& mutex this) = ^?{};
333        monitor_dtor_guard_t __guard = { &m, (fptr_t)dtor, true };
334        {
335                return this;
336        }
337}
338
339// Enter multiple monitor
340// relies on the monitor array being sorted
341static inline void enter( __monitor_group_t monitors ) {
342        for( __lock_size_t i = 0; i < monitors.size; i++) {
343                __enter( monitors[i], monitors );
344        }
345}
346
347// Leave multiple monitor
348// relies on the monitor array being sorted
349static inline void leave($monitor * monitors [], __lock_size_t count) {
350        for( __lock_size_t i = count - 1; i >= 0; i--) {
351                __leave( monitors[i] );
352        }
353}
354
355// Ctor for monitor guard
356// Sorts monitors before entering
357void ?{}( monitor_guard_t & this, $monitor * m [], __lock_size_t count, fptr_t func ) {
358        $thread * thrd = TL_GET( this_thread );
359
360        // Store current array
361        this.m = m;
362        this.count = count;
363
364        // Sort monitors based on address
365        __libcfa_small_sort(this.m, count);
366
367        // Save previous thread context
368        this.prev = thrd->monitors;
369
370        // Update thread context (needed for conditions)
371        (thrd->monitors){m, count, func};
372
373        // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
374
375        // Enter the monitors in order
376        __monitor_group_t group = {this.m, this.count, func};
377        enter( group );
378
379        // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
380}
381
382
383// Dtor for monitor guard
384void ^?{}( monitor_guard_t & this ) {
385        // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
386
387        // Leave the monitors in order
388        leave( this.m, this.count );
389
390        // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
391
392        // Restore thread context
393        TL_GET( this_thread )->monitors = this.prev;
394}
395
396// Ctor for monitor guard
397// Sorts monitors before entering
398void ?{}( monitor_dtor_guard_t & this, $monitor * m [], fptr_t func, bool join ) {
399        // optimization
400        $thread * thrd = TL_GET( this_thread );
401
402        // Store current array
403        this.m = *m;
404
405        // Save previous thread context
406        this.prev = thrd->monitors;
407
408        // Save whether we are in a join or not
409        this.join = join;
410
411        // Update thread context (needed for conditions)
412        (thrd->monitors){m, 1, func};
413
414        __dtor_enter( this.m, func, join );
415}
416
417// Dtor for monitor guard
418void ^?{}( monitor_dtor_guard_t & this ) {
419        // Leave the monitors in order
420        __dtor_leave( this.m, this.join );
421
422        // Restore thread context
423        TL_GET( this_thread )->monitors = this.prev;
424}
425
426//-----------------------------------------------------------------------------
427// Internal scheduling types
428void ?{}(__condition_node_t & this, $thread * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
429        this.waiting_thread = waiting_thread;
430        this.count = count;
431        this.next = 0p;
432        this.user_info = user_info;
433}
434
435void ?{}(__condition_criterion_t & this ) with( this ) {
436        ready  = false;
437        target = 0p;
438        owner  = 0p;
439        next   = 0p;
440}
441
442void ?{}(__condition_criterion_t & this, $monitor * target, __condition_node_t & owner ) {
443        this.ready  = false;
444        this.target = target;
445        this.owner  = &owner;
446        this.next   = 0p;
447}
448
449//-----------------------------------------------------------------------------
450// Internal scheduling
451void wait( condition & this, uintptr_t user_info = 0 ) {
452        brand_condition( this );
453
454        // Check that everything is as expected
455        assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
456        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
457        verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
458
459        // Create storage for monitor context
460        monitor_ctx( this.monitors, this.monitor_count );
461
462        // Create the node specific to this wait operation
463        wait_ctx( TL_GET( this_thread ), user_info );
464
465        // Append the current wait operation to the ones already queued on the condition
466        // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
467        /* paranoid */ verify( waiter.next == 0p );
468        append( this.blocked, &waiter );
469        /* paranoid */ verify( waiter.next == 1p );
470
471        // Lock all monitors (aggregates the locks as well)
472        lock_all( monitors, locks, count );
473
474        // Find the next thread(s) to run
475        __lock_size_t thread_count = 0;
476        $thread * threads[ count ];
477        __builtin_memset( threads, 0, sizeof( threads ) );
478
479        // Save monitor states
480        monitor_save;
481
482        // Remove any duplicate threads
483        for( __lock_size_t i = 0; i < count; i++) {
484                $thread * new_owner = next_thread( monitors[i] );
485                insert_unique( threads, thread_count, new_owner );
486        }
487
488        // Unlock the locks, we don't need them anymore
489        for(int i = 0; i < count; i++) {
490                unlock( *locks[i] );
491        }
492
493        // Wake the threads
494        for(int i = 0; i < thread_count; i++) {
495                unpark( threads[i] );
496        }
497
498        // Everything is ready to go to sleep
499        park();
500
501        // We are back, restore the owners and recursions
502        monitor_restore;
503}
504
505bool signal( condition & this ) {
506        if( is_empty( this ) ) { return false; }
507
508        //Check that everything is as expected
509        verify( this.monitors );
510        verify( this.monitor_count != 0 );
511
512        //Some more checking in debug
513        __cfaabi_dbg_debug_do(
514                $thread * this_thrd = TL_GET( this_thread );
515                if ( this.monitor_count != this_thrd->monitors.size ) {
516                        abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
517                }
518
519                for(int i = 0; i < this.monitor_count; i++) {
520                        if ( this.monitors[i] != this_thrd->monitors[i] ) {
521                                abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
522                        }
523                }
524        );
525
526        __lock_size_t count = this.monitor_count;
527
528        // Lock all monitors
529        lock_all( this.monitors, 0p, count );
530
531        //Pop the head of the waiting queue
532        __condition_node_t * node = pop_head( this.blocked );
533
534        //Add the thread to the proper AS stack
535        for(int i = 0; i < count; i++) {
536                __condition_criterion_t * crit = &node->criteria[i];
537                assert( !crit->ready );
538                push( crit->target->signal_stack, crit );
539        }
540
541        //Release
542        unlock_all( this.monitors, count );
543
544        return true;
545}
546
547bool signal_block( condition & this ) {
548        if( !this.blocked.head ) { return false; }
549
550        //Check that everything is as expected
551        verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
552        verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
553
554        // Create storage for monitor context
555        monitor_ctx( this.monitors, this.monitor_count );
556
557        // Lock all monitors (aggregates the locks them as well)
558        lock_all( monitors, locks, count );
559
560
561        // Create the node specific to this wait operation
562        wait_ctx_primed( kernelTLS.this_thread, 0 )
563
564        //save contexts
565        monitor_save;
566
567        //Find the thread to run
568        $thread * signallee = pop_head( this.blocked )->waiting_thread;
569        __set_owner( monitors, count, signallee );
570
571        __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
572
573        // unlock all the monitors
574        unlock_all( locks, count );
575
576        // unpark the thread we signalled
577        unpark( signallee );
578
579        //Everything is ready to go to sleep
580        park();
581
582
583        // WE WOKE UP
584
585
586        __cfaabi_dbg_print_buffer_local( "Kernel :   signal_block returned\n" );
587
588        //We are back, restore the masks and recursions
589        monitor_restore;
590
591        return true;
592}
593
594// Access the user_info of the thread waiting at the front of the queue
595uintptr_t front( condition & this ) {
596        verifyf( !is_empty(this),
597                "Attempt to access user data on an empty condition.\n"
598                "Possible cause is not checking if the condition is empty before reading stored data."
599        );
600        return ((typeof(this.blocked.head))this.blocked.head)->user_info;
601}
602
603//-----------------------------------------------------------------------------
604// External scheduling
605// cases to handle :
606//      - target already there :
607//              block and wake
608//      - dtor already there
609//              put thread on signaller stack
610//      - non-blocking
611//              return else
612//      - timeout
613//              return timeout
614//      - block
615//              setup mask
616//              block
617void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
618        // This statment doesn't have a contiguous list of monitors...
619        // Create one!
620        __lock_size_t max = count_max( mask );
621        $monitor * mon_storage[max];
622        __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
623        __lock_size_t actual_count = aggregate( mon_storage, mask );
624
625        __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
626
627        if(actual_count == 0) return;
628
629        __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
630
631        // Create storage for monitor context
632        monitor_ctx( mon_storage, actual_count );
633
634        // Lock all monitors (aggregates the locks as well)
635        lock_all( monitors, locks, count );
636
637        {
638                // Check if the entry queue
639                $thread * next; int index;
640                [next, index] = search_entry_queue( mask, monitors, count );
641
642                if( next ) {
643                        *mask.accepted = index;
644                        __acceptable_t& accepted = mask[index];
645                        if( accepted.is_dtor ) {
646                                __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
647                                verifyf( accepted.size == 1,  "ERROR: Accepted dtor has more than 1 mutex parameter." );
648
649                                $monitor * mon2dtor = accepted[0];
650                                verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
651
652                                __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
653                                push( mon2dtor->signal_stack, dtor_crit );
654
655                                unlock_all( locks, count );
656                        }
657                        else {
658                                __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
659
660                                // Create the node specific to this wait operation
661                                wait_ctx_primed( kernelTLS.this_thread, 0 );
662
663                                // Save monitor states
664                                monitor_save;
665
666                                __cfaabi_dbg_print_buffer_local( "Kernel :  baton of %"PRIdFAST16" monitors : ", count );
667                                #ifdef __CFA_DEBUG_PRINT__
668                                        for( int i = 0; i < count; i++) {
669                                                __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
670                                        }
671                                #endif
672                                __cfaabi_dbg_print_buffer_local( "\n" );
673
674                                // Set the owners to be the next thread
675                                __set_owner( monitors, count, next );
676
677                                // unlock all the monitors
678                                unlock_all( locks, count );
679
680                                // unpark the thread we signalled
681                                unpark( next );
682
683                                //Everything is ready to go to sleep
684                                park();
685
686                                // We are back, restore the owners and recursions
687                                monitor_restore;
688
689                                __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
690                        }
691
692                        __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
693                        return;
694                }
695        }
696
697
698        if( duration == 0 ) {
699                __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
700
701                unlock_all( locks, count );
702
703                __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
704                return;
705        }
706
707
708        verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
709
710        __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
711
712        // Create the node specific to this wait operation
713        wait_ctx_primed( kernelTLS.this_thread, 0 );
714
715        monitor_save;
716        set_mask( monitors, count, mask );
717
718        for( __lock_size_t i = 0; i < count; i++) {
719                verify( monitors[i]->owner == kernelTLS.this_thread );
720        }
721
722        // unlock all the monitors
723        unlock_all( locks, count );
724
725        //Everything is ready to go to sleep
726        park();
727
728
729        // WE WOKE UP
730
731
732        //We are back, restore the masks and recursions
733        monitor_restore;
734
735        __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
736
737        __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
738}
739
740//-----------------------------------------------------------------------------
741// Utilities
742
743static inline void __set_owner( $monitor * this, $thread * owner ) {
744        /* paranoid */ verify( this->lock.lock );
745
746        //Pass the monitor appropriately
747        this->owner = owner;
748
749        //We are passing the monitor to someone else, which means recursion level is not 0
750        this->recursion = owner ? 1 : 0;
751}
752
753static inline void __set_owner( $monitor * monitors [], __lock_size_t count, $thread * owner ) {
754        /* paranoid */ verify ( monitors[0]->lock.lock );
755        /* 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] );
756        monitors[0]->owner        = owner;
757        monitors[0]->recursion    = 1;
758        for( __lock_size_t i = 1; i < count; i++ ) {
759                /* paranoid */ verify ( monitors[i]->lock.lock );
760                /* 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] );
761                monitors[i]->owner        = owner;
762                monitors[i]->recursion    = 0;
763        }
764}
765
766static inline void set_mask( $monitor * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
767        for( __lock_size_t i = 0; i < count; i++) {
768                storage[i]->mask = mask;
769        }
770}
771
772static inline void reset_mask( $monitor * this ) {
773        this->mask.accepted = 0p;
774        this->mask.data = 0p;
775        this->mask.size = 0;
776}
777
778static inline $thread * next_thread( $monitor * this ) {
779        //Check the signaller stack
780        __cfaabi_dbg_print_safe( "Kernel :  mon %p AS-stack top %p\n", this, this->signal_stack.top);
781        __condition_criterion_t * urgent = pop( this->signal_stack );
782        if( urgent ) {
783                //The signaller stack is not empty,
784                //regardless of if we are ready to baton pass,
785                //we need to set the monitor as in use
786                /* 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 );
787                __set_owner( this,  urgent->owner->waiting_thread );
788
789                return check_condition( urgent );
790        }
791
792        // No signaller thread
793        // Get the next thread in the entry_queue
794        $thread * new_owner = pop_head( this->entry_queue );
795        /* 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 );
796        /* paranoid */ verify( !new_owner || new_owner->link.next == 0p );
797        __set_owner( this, new_owner );
798
799        return new_owner;
800}
801
802static inline bool is_accepted( $monitor * this, const __monitor_group_t & group ) {
803        __acceptable_t * it = this->mask.data; // Optim
804        __lock_size_t count = this->mask.size;
805
806        // Check if there are any acceptable functions
807        if( !it ) return false;
808
809        // If this isn't the first monitor to test this, there is no reason to repeat the test.
810        if( this != group[0] ) return group[0]->mask.accepted >= 0;
811
812        // For all acceptable functions check if this is the current function.
813        for( __lock_size_t i = 0; i < count; i++, it++ ) {
814                if( *it == group ) {
815                        *this->mask.accepted = i;
816                        return true;
817                }
818        }
819
820        // No function matched
821        return false;
822}
823
824static inline void init( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
825        for( __lock_size_t i = 0; i < count; i++) {
826                (criteria[i]){ monitors[i], waiter };
827        }
828
829        waiter.criteria = criteria;
830}
831
832static inline void init_push( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
833        for( __lock_size_t i = 0; i < count; i++) {
834                (criteria[i]){ monitors[i], waiter };
835                __cfaabi_dbg_print_safe( "Kernel :  target %p = %p\n", criteria[i].target, &criteria[i] );
836                push( criteria[i].target->signal_stack, &criteria[i] );
837        }
838
839        waiter.criteria = criteria;
840}
841
842static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
843        for( __lock_size_t i = 0; i < count; i++ ) {
844                lock( *locks[i] __cfaabi_dbg_ctx2 );
845        }
846}
847
848static inline void lock_all( $monitor * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
849        for( __lock_size_t i = 0; i < count; i++ ) {
850                __spinlock_t * l = &source[i]->lock;
851                lock( *l __cfaabi_dbg_ctx2 );
852                if(locks) locks[i] = l;
853        }
854}
855
856static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
857        for( __lock_size_t i = 0; i < count; i++ ) {
858                unlock( *locks[i] );
859        }
860}
861
862static inline void unlock_all( $monitor * locks [], __lock_size_t count ) {
863        for( __lock_size_t i = 0; i < count; i++ ) {
864                unlock( locks[i]->lock );
865        }
866}
867
868static inline void save(
869        $monitor * ctx [],
870        __lock_size_t count,
871        __attribute((unused)) __spinlock_t * locks [],
872        unsigned int /*out*/ recursions [],
873        __waitfor_mask_t /*out*/ masks []
874) {
875        for( __lock_size_t i = 0; i < count; i++ ) {
876                recursions[i] = ctx[i]->recursion;
877                masks[i]      = ctx[i]->mask;
878        }
879}
880
881static inline void restore(
882        $monitor * ctx [],
883        __lock_size_t count,
884        __spinlock_t * locks [],
885        unsigned int /*out*/ recursions [],
886        __waitfor_mask_t /*out*/ masks []
887) {
888        lock_all( locks, count );
889        for( __lock_size_t i = 0; i < count; i++ ) {
890                ctx[i]->recursion = recursions[i];
891                ctx[i]->mask      = masks[i];
892        }
893        unlock_all( locks, count );
894}
895
896// Function has 2 different behavior
897// 1 - Marks a monitors as being ready to run
898// 2 - Checks if all the monitors are ready to run
899//     if so return the thread to run
900static inline $thread * check_condition( __condition_criterion_t * target ) {
901        __condition_node_t * node = target->owner;
902        unsigned short count = node->count;
903        __condition_criterion_t * criteria = node->criteria;
904
905        bool ready2run = true;
906
907        for(    int i = 0; i < count; i++ ) {
908
909                // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
910                if( &criteria[i] == target ) {
911                        criteria[i].ready = true;
912                        // __cfaabi_dbg_print_safe( "True\n" );
913                }
914
915                ready2run = criteria[i].ready && ready2run;
916        }
917
918        __cfaabi_dbg_print_safe( "Kernel :  Runing %i (%p)\n", ready2run, ready2run ? (thread*)node->waiting_thread : (thread*)0p );
919        return ready2run ? node->waiting_thread : 0p;
920}
921
922static inline void brand_condition( condition & this ) {
923        $thread * thrd = TL_GET( this_thread );
924        if( !this.monitors ) {
925                // __cfaabi_dbg_print_safe( "Branding\n" );
926                assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
927                this.monitor_count = thrd->monitors.size;
928
929                this.monitors = ($monitor **)malloc( this.monitor_count * sizeof( *this.monitors ) );
930                for( int i = 0; i < this.monitor_count; i++ ) {
931                        this.monitors[i] = thrd->monitors[i];
932                }
933        }
934}
935
936static inline [$thread *, int] search_entry_queue( const __waitfor_mask_t & mask, $monitor * monitors [], __lock_size_t count ) {
937
938        __queue_t($thread) & entry_queue = monitors[0]->entry_queue;
939
940        // For each thread in the entry-queue
941        for(    $thread ** thrd_it = &entry_queue.head;
942                (*thrd_it) != 1p;
943                thrd_it = &(*thrd_it)->link.next
944        ) {
945                // For each acceptable check if it matches
946                int i = 0;
947                __acceptable_t * end   = end  (mask);
948                __acceptable_t * begin = begin(mask);
949                for( __acceptable_t * it = begin; it != end; it++, i++ ) {
950                        // Check if we have a match
951                        if( *it == (*thrd_it)->monitors ) {
952
953                                // If we have a match return it
954                                // after removeing it from the entry queue
955                                return [remove( entry_queue, thrd_it ), i];
956                        }
957                }
958        }
959
960        return [0, -1];
961}
962
963forall(dtype T | sized( T ))
964static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
965        if( !val ) return size;
966
967        for( __lock_size_t i = 0; i <= size; i++) {
968                if( array[i] == val ) return size;
969        }
970
971        array[size] = val;
972        size = size + 1;
973        return size;
974}
975
976static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
977        __lock_size_t max = 0;
978        for( __lock_size_t i = 0; i < mask.size; i++ ) {
979                __acceptable_t & accepted = mask[i];
980                max += accepted.size;
981        }
982        return max;
983}
984
985static inline __lock_size_t aggregate( $monitor * storage [], const __waitfor_mask_t & mask ) {
986        __lock_size_t size = 0;
987        for( __lock_size_t i = 0; i < mask.size; i++ ) {
988                __acceptable_t & accepted = mask[i];
989                __libcfa_small_sort( accepted.data, accepted.size );
990                for( __lock_size_t j = 0; j < accepted.size; j++) {
991                        insert_unique( storage, size, accepted[j] );
992                }
993        }
994        // TODO insertion sort instead of this
995        __libcfa_small_sort( storage, size );
996        return size;
997}
998
999// Local Variables: //
1000// mode: c //
1001// tab-width: 4 //
1002// End: //
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