source: libcfa/src/concurrency/monitor.cfa@ aa88cb9a

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since aa88cb9a was fd54fef, checked in by Michael Brooks <mlbrooks@…>, 5 years ago

Converting the project to use the new syntax for otype, dtype and ttytpe.

Changed prelude (gen), libcfa and test suite to use it. Added a simple deprecation rule of the old syntax to the parser; we might wish to support both syntaxes "officially," like with an extra CLI switch, but this measure should serve as a simple reminder for our team to try the new syntax.
  • Property mode set to 100644
File size: 33.1 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(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 $thread * thrd = active_thread();
85
86 // Lock the monitor spinlock
87 lock( this->lock __cfaabi_dbg_ctx2 );
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( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_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( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_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 $thread * thrd = active_thread();
144 #if defined( __CFA_WITH_VERIFY__ )
145 bool is_thrd = this == &thrd->self_mon;
146 #endif
147
148 // Lock the monitor spinlock
149 lock( this->lock __cfaabi_dbg_ctx2 );
150
151 __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
152
153
154 if( !this->owner ) {
155 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
156
157 // No one has the monitor, just take it
158 __set_owner( this, thrd );
159
160 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
161 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
162
163 unlock( this->lock );
164 return;
165 }
166 else if( this->owner == thrd && !join) {
167 // We already have the monitor... but where about to destroy it so the nesting will fail
168 // Abort!
169 abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
170 }
171 // SKULLDUGGERY: join will act as a dtor so it would normally trigger to above check
172 // because join will not release the monitor after it executed.
173 // to avoid that it sets the owner to the special value thrd | 1p before exiting
174 else if( this->owner == ($thread*)(1 | (uintptr_t)thrd) ) {
175 // restore the owner and just return
176 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
177
178 // No one has the monitor, just take it
179 __set_owner( this, thrd );
180
181 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
182 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
183
184 unlock( this->lock );
185 return;
186 }
187
188 // The monitor is busy, if this is a thread and the thread owns itself, it better be active
189 /* paranoid */ verify( !is_thrd || this->owner != thrd || (thrd->state != Halted && thrd->state != Cancelled) );
190
191 __lock_size_t count = 1;
192 $monitor ** monitors = &this;
193 __monitor_group_t group = { &this, 1, func };
194 if( is_accepted( this, group) ) {
195 __cfaabi_dbg_print_safe( "Kernel : mon accepts dtor, block and signal it \n" );
196
197 // Wake the thread that is waiting for this
198 __condition_criterion_t * urgent = pop( this->signal_stack );
199 /* paranoid */ verify( urgent );
200
201 // Reset mask
202 reset_mask( this );
203
204 // Create the node specific to this wait operation
205 wait_ctx_primed( thrd, 0 )
206
207 // Some one else has the monitor, wait for him to finish and then run
208 unlock( this->lock );
209
210 // Release the next thread
211 /* paranoid */ verifyf( urgent->owner->waiting_thread == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
212 unpark( urgent->owner->waiting_thread );
213
214 // Park current thread waiting
215 park();
216
217 // Some one was waiting for us, enter
218 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
219
220 __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
221 return;
222 }
223 else {
224 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
225
226 wait_ctx( thrd, 0 )
227 this->dtor_node = &waiter;
228
229 // Some one else has the monitor, wait in line for it
230 /* paranoid */ verify( thrd->link.next == 0p );
231 append( this->entry_queue, thrd );
232 /* paranoid */ verify( thrd->link.next == 1p );
233 unlock( this->lock );
234
235 // Park current thread waiting
236 park();
237
238 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
239 return;
240 }
241}
242
243// Leave single monitor
244void __leave( $monitor * this ) {
245 // Lock the monitor spinlock
246 lock( this->lock __cfaabi_dbg_ctx2 );
247
248 __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", active_thread(), this, this->owner);
249
250 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
251
252 // Leaving a recursion level, decrement the counter
253 this->recursion -= 1;
254
255 // If we haven't left the last level of recursion
256 // it means we don't need to do anything
257 if( this->recursion != 0) {
258 __cfaabi_dbg_print_safe( "Kernel : recursion still %d\n", this->recursion);
259 unlock( this->lock );
260 return;
261 }
262
263 // Get the next thread, will be null on low contention monitor
264 $thread * new_owner = next_thread( this );
265
266 // Check the new owner is consistent with who we wake-up
267 // new_owner might be null even if someone owns the monitor when the owner is still waiting for another monitor
268 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
269
270 // We can now let other threads in safely
271 unlock( this->lock );
272
273 //We need to wake-up the thread
274 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
275 unpark( new_owner );
276}
277
278// Leave single monitor for the last time
279void __dtor_leave( $monitor * this, bool join ) {
280 __cfaabi_dbg_debug_do(
281 if( active_thread() != this->owner ) {
282 abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, active_thread(), this->owner);
283 }
284 if( this->recursion != 1 && !join ) {
285 abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
286 }
287 )
288
289 this->owner = ($thread*)(1 | (uintptr_t)this->owner);
290}
291
292void __thread_finish( $thread * thrd ) {
293 $monitor * this = &thrd->self_mon;
294
295 // Lock the monitor now
296 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
297 /* paranoid */ verify( this->lock.lock );
298 /* paranoid */ verify( thrd->context.SP );
299 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) > ((uintptr_t)__get_stack(thrd->curr_cor)->limit), "ERROR : $thread %p has been corrupted.\n StackPointer too large.\n", thrd );
300 /* paranoid */ verifyf( ((uintptr_t)thrd->context.SP) < ((uintptr_t)__get_stack(thrd->curr_cor)->base ), "ERROR : $thread %p has been corrupted.\n StackPointer too small.\n", thrd );
301 /* paranoid */ verify( ! __preemption_enabled() );
302
303 /* paranoid */ verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
304 /* paranoid */ verify( thrd->state == Halting );
305 /* paranoid */ verify( this->recursion == 1 );
306
307 // Leaving a recursion level, decrement the counter
308 this->recursion -= 1;
309 this->owner = 0p;
310
311 // Fetch the next thread, can be null
312 $thread * new_owner = next_thread( this );
313
314 // Mark the state as fully halted
315 thrd->state = Halted;
316
317 // Release the monitor lock
318 unlock( this->lock );
319
320 // Unpark the next owner if needed
321 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
322 /* paranoid */ verify( ! __preemption_enabled() );
323 /* paranoid */ verify( thrd->state == Halted );
324 unpark( new_owner );
325}
326
327// Enter multiple monitor
328// relies on the monitor array being sorted
329static inline void enter( __monitor_group_t monitors ) {
330 for( __lock_size_t i = 0; i < monitors.size; i++) {
331 __enter( monitors[i], monitors );
332 }
333}
334
335// Leave multiple monitor
336// relies on the monitor array being sorted
337static inline void leave($monitor * monitors [], __lock_size_t count) {
338 for( __lock_size_t i = count - 1; i >= 0; i--) {
339 __leave( monitors[i] );
340 }
341}
342
343// Ctor for monitor guard
344// Sorts monitors before entering
345void ?{}( monitor_guard_t & this, $monitor * m [], __lock_size_t count, fptr_t func ) {
346 $thread * thrd = active_thread();
347
348 // Store current array
349 this.m = m;
350 this.count = count;
351
352 // Sort monitors based on address
353 __libcfa_small_sort(this.m, count);
354
355 // Save previous thread context
356 this.prev = thrd->monitors;
357
358 // Update thread context (needed for conditions)
359 (thrd->monitors){m, count, func};
360
361 // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
362
363 // Enter the monitors in order
364 __monitor_group_t group = {this.m, this.count, func};
365 enter( group );
366
367 // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
368}
369
370
371// Dtor for monitor guard
372void ^?{}( monitor_guard_t & this ) {
373 // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
374
375 // Leave the monitors in order
376 leave( this.m, this.count );
377
378 // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
379
380 // Restore thread context
381 active_thread()->monitors = this.prev;
382}
383
384// Ctor for monitor guard
385// Sorts monitors before entering
386void ?{}( monitor_dtor_guard_t & this, $monitor * m [], fptr_t func, bool join ) {
387 // optimization
388 $thread * thrd = active_thread();
389
390 // Store current array
391 this.m = *m;
392
393 // Save previous thread context
394 this.prev = thrd->monitors;
395
396 // Save whether we are in a join or not
397 this.join = join;
398
399 // Update thread context (needed for conditions)
400 (thrd->monitors){m, 1, func};
401
402 __dtor_enter( this.m, func, join );
403}
404
405// Dtor for monitor guard
406void ^?{}( monitor_dtor_guard_t & this ) {
407 // Leave the monitors in order
408 __dtor_leave( this.m, this.join );
409
410 // Restore thread context
411 active_thread()->monitors = this.prev;
412}
413
414//-----------------------------------------------------------------------------
415// Internal scheduling types
416void ?{}(__condition_node_t & this, $thread * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
417 this.waiting_thread = waiting_thread;
418 this.count = count;
419 this.next = 0p;
420 this.user_info = user_info;
421}
422
423void ?{}(__condition_criterion_t & this ) with( this ) {
424 ready = false;
425 target = 0p;
426 owner = 0p;
427 next = 0p;
428}
429
430void ?{}(__condition_criterion_t & this, $monitor * target, __condition_node_t & owner ) {
431 this.ready = false;
432 this.target = target;
433 this.owner = &owner;
434 this.next = 0p;
435}
436
437//-----------------------------------------------------------------------------
438// Internal scheduling
439void wait( condition & this, uintptr_t user_info = 0 ) {
440 brand_condition( this );
441
442 // Check that everything is as expected
443 assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
444 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
445 verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
446
447 // Create storage for monitor context
448 monitor_ctx( this.monitors, this.monitor_count );
449
450 // Create the node specific to this wait operation
451 wait_ctx( active_thread(), user_info );
452
453 // Append the current wait operation to the ones already queued on the condition
454 // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
455 /* paranoid */ verify( waiter.next == 0p );
456 append( this.blocked, &waiter );
457 /* paranoid */ verify( waiter.next == 1p );
458
459 // Lock all monitors (aggregates the locks as well)
460 lock_all( monitors, locks, count );
461
462 // Find the next thread(s) to run
463 __lock_size_t thread_count = 0;
464 $thread * threads[ count ];
465 __builtin_memset( threads, 0, sizeof( threads ) );
466
467 // Save monitor states
468 monitor_save;
469
470 // Remove any duplicate threads
471 for( __lock_size_t i = 0; i < count; i++) {
472 $thread * new_owner = next_thread( monitors[i] );
473 insert_unique( threads, thread_count, new_owner );
474 }
475
476 // Unlock the locks, we don't need them anymore
477 for(int i = 0; i < count; i++) {
478 unlock( *locks[i] );
479 }
480
481 // Wake the threads
482 for(int i = 0; i < thread_count; i++) {
483 unpark( threads[i] );
484 }
485
486 // Everything is ready to go to sleep
487 park();
488
489 // We are back, restore the owners and recursions
490 monitor_restore;
491}
492
493bool signal( condition & this ) {
494 if( is_empty( this ) ) { return false; }
495
496 //Check that everything is as expected
497 verify( this.monitors );
498 verify( this.monitor_count != 0 );
499
500 //Some more checking in debug
501 __cfaabi_dbg_debug_do(
502 $thread * this_thrd = active_thread();
503 if ( this.monitor_count != this_thrd->monitors.size ) {
504 abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
505 }
506
507 for(int i = 0; i < this.monitor_count; i++) {
508 if ( this.monitors[i] != this_thrd->monitors[i] ) {
509 abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
510 }
511 }
512 );
513
514 __lock_size_t count = this.monitor_count;
515
516 // Lock all monitors
517 lock_all( this.monitors, 0p, count );
518
519 //Pop the head of the waiting queue
520 __condition_node_t * node = pop_head( this.blocked );
521
522 //Add the thread to the proper AS stack
523 for(int i = 0; i < count; i++) {
524 __condition_criterion_t * crit = &node->criteria[i];
525 assert( !crit->ready );
526 push( crit->target->signal_stack, crit );
527 }
528
529 //Release
530 unlock_all( this.monitors, count );
531
532 return true;
533}
534
535bool signal_block( condition & this ) {
536 if( !this.blocked.head ) { return false; }
537
538 //Check that everything is as expected
539 verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
540 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
541
542 // Create storage for monitor context
543 monitor_ctx( this.monitors, this.monitor_count );
544
545 // Lock all monitors (aggregates the locks them as well)
546 lock_all( monitors, locks, count );
547
548
549 // Create the node specific to this wait operation
550 wait_ctx_primed( active_thread(), 0 )
551
552 //save contexts
553 monitor_save;
554
555 //Find the thread to run
556 $thread * signallee = pop_head( this.blocked )->waiting_thread;
557 __set_owner( monitors, count, signallee );
558
559 __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
560
561 // unlock all the monitors
562 unlock_all( locks, count );
563
564 // unpark the thread we signalled
565 unpark( signallee );
566
567 //Everything is ready to go to sleep
568 park();
569
570
571 // WE WOKE UP
572
573
574 __cfaabi_dbg_print_buffer_local( "Kernel : signal_block returned\n" );
575
576 //We are back, restore the masks and recursions
577 monitor_restore;
578
579 return true;
580}
581
582// Access the user_info of the thread waiting at the front of the queue
583uintptr_t front( condition & this ) {
584 verifyf( !is_empty(this),
585 "Attempt to access user data on an empty condition.\n"
586 "Possible cause is not checking if the condition is empty before reading stored data."
587 );
588 return ((typeof(this.blocked.head))this.blocked.head)->user_info;
589}
590
591//-----------------------------------------------------------------------------
592// External scheduling
593// cases to handle :
594// - target already there :
595// block and wake
596// - dtor already there
597// put thread on signaller stack
598// - non-blocking
599// return else
600// - timeout
601// return timeout
602// - block
603// setup mask
604// block
605void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
606 // This statment doesn't have a contiguous list of monitors...
607 // Create one!
608 __lock_size_t max = count_max( mask );
609 $monitor * mon_storage[max];
610 __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
611 __lock_size_t actual_count = aggregate( mon_storage, mask );
612
613 __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
614
615 if(actual_count == 0) return;
616
617 __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
618
619 // Create storage for monitor context
620 monitor_ctx( mon_storage, actual_count );
621
622 // Lock all monitors (aggregates the locks as well)
623 lock_all( monitors, locks, count );
624
625 {
626 // Check if the entry queue
627 $thread * next; int index;
628 [next, index] = search_entry_queue( mask, monitors, count );
629
630 if( next ) {
631 *mask.accepted = index;
632 __acceptable_t& accepted = mask[index];
633 if( accepted.is_dtor ) {
634 __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
635 verifyf( accepted.size == 1, "ERROR: Accepted dtor has more than 1 mutex parameter." );
636
637 $monitor * mon2dtor = accepted[0];
638 verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
639
640 __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
641 push( mon2dtor->signal_stack, dtor_crit );
642
643 unlock_all( locks, count );
644 }
645 else {
646 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
647
648 // Create the node specific to this wait operation
649 wait_ctx_primed( active_thread(), 0 );
650
651 // Save monitor states
652 monitor_save;
653
654 __cfaabi_dbg_print_buffer_local( "Kernel : baton of %"PRIdFAST16" monitors : ", count );
655 #ifdef __CFA_DEBUG_PRINT__
656 for( int i = 0; i < count; i++) {
657 __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
658 }
659 #endif
660 __cfaabi_dbg_print_buffer_local( "\n" );
661
662 // Set the owners to be the next thread
663 __set_owner( monitors, count, next );
664
665 // unlock all the monitors
666 unlock_all( locks, count );
667
668 // unpark the thread we signalled
669 unpark( next );
670
671 //Everything is ready to go to sleep
672 park();
673
674 // We are back, restore the owners and recursions
675 monitor_restore;
676
677 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
678 }
679
680 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
681 return;
682 }
683 }
684
685
686 if( duration == 0 ) {
687 __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
688
689 unlock_all( locks, count );
690
691 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
692 return;
693 }
694
695
696 verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
697
698 __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
699
700 // Create the node specific to this wait operation
701 wait_ctx_primed( active_thread(), 0 );
702
703 monitor_save;
704 set_mask( monitors, count, mask );
705
706 for( __lock_size_t i = 0; i < count; i++) {
707 verify( monitors[i]->owner == active_thread() );
708 }
709
710 // unlock all the monitors
711 unlock_all( locks, count );
712
713 //Everything is ready to go to sleep
714 park();
715
716
717 // WE WOKE UP
718
719
720 //We are back, restore the masks and recursions
721 monitor_restore;
722
723 __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
724
725 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
726}
727
728//-----------------------------------------------------------------------------
729// Utilities
730
731static inline void __set_owner( $monitor * this, $thread * owner ) {
732 /* paranoid */ verify( this->lock.lock );
733
734 //Pass the monitor appropriately
735 this->owner = owner;
736
737 //We are passing the monitor to someone else, which means recursion level is not 0
738 this->recursion = owner ? 1 : 0;
739}
740
741static inline void __set_owner( $monitor * monitors [], __lock_size_t count, $thread * owner ) {
742 /* paranoid */ verify ( monitors[0]->lock.lock );
743 /* paranoid */ verifyf( monitors[0]->owner == active_thread(), "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), monitors[0]->owner, monitors[0]->recursion, monitors[0] );
744 monitors[0]->owner = owner;
745 monitors[0]->recursion = 1;
746 for( __lock_size_t i = 1; i < count; i++ ) {
747 /* paranoid */ verify ( monitors[i]->lock.lock );
748 /* paranoid */ verifyf( monitors[i]->owner == active_thread(), "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), monitors[i]->owner, monitors[i]->recursion, monitors[i] );
749 monitors[i]->owner = owner;
750 monitors[i]->recursion = 0;
751 }
752}
753
754static inline void set_mask( $monitor * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
755 for( __lock_size_t i = 0; i < count; i++) {
756 storage[i]->mask = mask;
757 }
758}
759
760static inline void reset_mask( $monitor * this ) {
761 this->mask.accepted = 0p;
762 this->mask.data = 0p;
763 this->mask.size = 0;
764}
765
766static inline $thread * next_thread( $monitor * this ) {
767 //Check the signaller stack
768 __cfaabi_dbg_print_safe( "Kernel : mon %p AS-stack top %p\n", this, this->signal_stack.top);
769 __condition_criterion_t * urgent = pop( this->signal_stack );
770 if( urgent ) {
771 //The signaller stack is not empty,
772 //regardless of if we are ready to baton pass,
773 //we need to set the monitor as in use
774 /* paranoid */ verifyf( !this->owner || active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
775 __set_owner( this, urgent->owner->waiting_thread );
776
777 return check_condition( urgent );
778 }
779
780 // No signaller thread
781 // Get the next thread in the entry_queue
782 $thread * new_owner = pop_head( this->entry_queue );
783 /* paranoid */ verifyf( !this->owner || active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
784 /* paranoid */ verify( !new_owner || new_owner->link.next == 0p );
785 __set_owner( this, new_owner );
786
787 return new_owner;
788}
789
790static inline bool is_accepted( $monitor * this, const __monitor_group_t & group ) {
791 __acceptable_t * it = this->mask.data; // Optim
792 __lock_size_t count = this->mask.size;
793
794 // Check if there are any acceptable functions
795 if( !it ) return false;
796
797 // If this isn't the first monitor to test this, there is no reason to repeat the test.
798 if( this != group[0] ) return group[0]->mask.accepted >= 0;
799
800 // For all acceptable functions check if this is the current function.
801 for( __lock_size_t i = 0; i < count; i++, it++ ) {
802 if( *it == group ) {
803 *this->mask.accepted = i;
804 return true;
805 }
806 }
807
808 // No function matched
809 return false;
810}
811
812static inline void init( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
813 for( __lock_size_t i = 0; i < count; i++) {
814 (criteria[i]){ monitors[i], waiter };
815 }
816
817 waiter.criteria = criteria;
818}
819
820static inline void init_push( __lock_size_t count, $monitor * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
821 for( __lock_size_t i = 0; i < count; i++) {
822 (criteria[i]){ monitors[i], waiter };
823 __cfaabi_dbg_print_safe( "Kernel : target %p = %p\n", criteria[i].target, &criteria[i] );
824 push( criteria[i].target->signal_stack, &criteria[i] );
825 }
826
827 waiter.criteria = criteria;
828}
829
830static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
831 for( __lock_size_t i = 0; i < count; i++ ) {
832 lock( *locks[i] __cfaabi_dbg_ctx2 );
833 }
834}
835
836static inline void lock_all( $monitor * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
837 for( __lock_size_t i = 0; i < count; i++ ) {
838 __spinlock_t * l = &source[i]->lock;
839 lock( *l __cfaabi_dbg_ctx2 );
840 if(locks) locks[i] = l;
841 }
842}
843
844static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
845 for( __lock_size_t i = 0; i < count; i++ ) {
846 unlock( *locks[i] );
847 }
848}
849
850static inline void unlock_all( $monitor * locks [], __lock_size_t count ) {
851 for( __lock_size_t i = 0; i < count; i++ ) {
852 unlock( locks[i]->lock );
853 }
854}
855
856static inline void save(
857 $monitor * ctx [],
858 __lock_size_t count,
859 __attribute((unused)) __spinlock_t * locks [],
860 unsigned int /*out*/ recursions [],
861 __waitfor_mask_t /*out*/ masks []
862) {
863 for( __lock_size_t i = 0; i < count; i++ ) {
864 recursions[i] = ctx[i]->recursion;
865 masks[i] = ctx[i]->mask;
866 }
867}
868
869static inline void restore(
870 $monitor * ctx [],
871 __lock_size_t count,
872 __spinlock_t * locks [],
873 unsigned int /*out*/ recursions [],
874 __waitfor_mask_t /*out*/ masks []
875) {
876 lock_all( locks, count );
877 for( __lock_size_t i = 0; i < count; i++ ) {
878 ctx[i]->recursion = recursions[i];
879 ctx[i]->mask = masks[i];
880 }
881 unlock_all( locks, count );
882}
883
884// Function has 2 different behavior
885// 1 - Marks a monitors as being ready to run
886// 2 - Checks if all the monitors are ready to run
887// if so return the thread to run
888static inline $thread * check_condition( __condition_criterion_t * target ) {
889 __condition_node_t * node = target->owner;
890 unsigned short count = node->count;
891 __condition_criterion_t * criteria = node->criteria;
892
893 bool ready2run = true;
894
895 for( int i = 0; i < count; i++ ) {
896
897 // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
898 if( &criteria[i] == target ) {
899 criteria[i].ready = true;
900 // __cfaabi_dbg_print_safe( "True\n" );
901 }
902
903 ready2run = criteria[i].ready && ready2run;
904 }
905
906 __cfaabi_dbg_print_safe( "Kernel : Runing %i (%p)\n", ready2run, ready2run ? (thread*)node->waiting_thread : (thread*)0p );
907 return ready2run ? node->waiting_thread : 0p;
908}
909
910static inline void brand_condition( condition & this ) {
911 $thread * thrd = active_thread();
912 if( !this.monitors ) {
913 // __cfaabi_dbg_print_safe( "Branding\n" );
914 assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
915 this.monitor_count = thrd->monitors.size;
916
917 this.monitors = ($monitor **)malloc( this.monitor_count * sizeof( *this.monitors ) );
918 for( int i = 0; i < this.monitor_count; i++ ) {
919 this.monitors[i] = thrd->monitors[i];
920 }
921 }
922}
923
924static inline [$thread *, int] search_entry_queue( const __waitfor_mask_t & mask, $monitor * monitors [], __lock_size_t count ) {
925
926 __queue_t($thread) & entry_queue = monitors[0]->entry_queue;
927
928 // For each thread in the entry-queue
929 for( $thread ** thrd_it = &entry_queue.head;
930 (*thrd_it) != 1p;
931 thrd_it = &(*thrd_it)->link.next
932 ) {
933 // For each acceptable check if it matches
934 int i = 0;
935 __acceptable_t * end = end (mask);
936 __acceptable_t * begin = begin(mask);
937 for( __acceptable_t * it = begin; it != end; it++, i++ ) {
938 // Check if we have a match
939 if( *it == (*thrd_it)->monitors ) {
940
941 // If we have a match return it
942 // after removeing it from the entry queue
943 return [remove( entry_queue, thrd_it ), i];
944 }
945 }
946 }
947
948 return [0, -1];
949}
950
951forall(T & | sized( T ))
952static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
953 if( !val ) return size;
954
955 for( __lock_size_t i = 0; i <= size; i++) {
956 if( array[i] == val ) return size;
957 }
958
959 array[size] = val;
960 size = size + 1;
961 return size;
962}
963
964static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
965 __lock_size_t max = 0;
966 for( __lock_size_t i = 0; i < mask.size; i++ ) {
967 __acceptable_t & accepted = mask[i];
968 max += accepted.size;
969 }
970 return max;
971}
972
973static inline __lock_size_t aggregate( $monitor * storage [], const __waitfor_mask_t & mask ) {
974 __lock_size_t size = 0;
975 for( __lock_size_t i = 0; i < mask.size; i++ ) {
976 __acceptable_t & accepted = mask[i];
977 __libcfa_small_sort( accepted.data, accepted.size );
978 for( __lock_size_t j = 0; j < accepted.size; j++) {
979 insert_unique( storage, size, accepted[j] );
980 }
981 }
982 // TODO insertion sort instead of this
983 __libcfa_small_sort( storage, size );
984 return size;
985}
986
987// Local Variables: //
988// mode: c //
989// tab-width: 4 //
990// End: //
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