source: libcfa/src/concurrency/monitor.cfa@ e7e5b81

ADT ast-experimental enum forall-pointer-decay jacob/cs343-translation pthread-emulation qualifiedEnum
Last change on this file since e7e5b81 was af67ee1, checked in by caparsons <caparson@…>, 4 years ago

Added support for locks as parameters to mutex stmt
  • Property mode set to 100644
File size: 35.2 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.cfa --
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#define _GNU_SOURCE
18
19#include "monitor.hfa"
20
21#include <stdlib.hfa>
22#include <inttypes.h>
23
24#include "kernel_private.hfa"
25
26#include "bits/algorithm.hfa"
27
28//-----------------------------------------------------------------------------
29// Forward declarations
30static inline void __set_owner ( monitor$ * this, thread$ * owner );
31static inline void __set_owner ( monitor$ * storage [], __lock_size_t count, thread$ * owner );
32static inline void set_mask ( monitor$ * storage [], __lock_size_t count, const __waitfor_mask_t & mask );
33static inline void reset_mask( monitor$ * this );
34
35static inline thread$ * next_thread( monitor$ * this );
36static inline bool is_accepted( monitor$ * this, const __monitor_group_t & monitors );
37
38static inline void lock_all ( __spinlock_t * locks [], __lock_size_t count );
39static inline void lock_all ( monitor$ * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count );
40static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count );
41static inline void unlock_all( monitor$ * locks [], __lock_size_t count );
42
43static inline void save ( monitor$ * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*out*/ recursions [], __waitfor_mask_t /*out*/ masks [] );
44static inline void restore( monitor$ * ctx [], __lock_size_t count, __spinlock_t * locks [], unsigned int /*in */ recursions [], __waitfor_mask_t /*in */ masks [] );
45
46static inline void init ( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
47static inline void init_push( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
48
49static inline thread$ * check_condition ( __condition_criterion_t * );
50static inline void brand_condition ( condition & );
51static inline [thread$ *, int] search_entry_queue( const __waitfor_mask_t &, monitor$ * monitors [], __lock_size_t count );
52
53forall(T & | sized( T ))
54static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val );
55static inline __lock_size_t count_max ( const __waitfor_mask_t & mask );
56static inline __lock_size_t aggregate ( monitor$ * storage [], const __waitfor_mask_t & mask );
57
58//-----------------------------------------------------------------------------
59// Useful defines
60#define wait_ctx(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
61 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
62 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
63 init( count, monitors, waiter, criteria ); /* Link everything together */ \
64
65#define wait_ctx_primed(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
66 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
67 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
68 init_push( count, monitors, waiter, criteria ); /* Link everything together and push it to the AS-Stack */ \
69
70#define monitor_ctx( mons, cnt ) /* Define that create the necessary struct for internal/external scheduling operations */ \
71 monitor$ ** monitors = mons; /* Save the targeted monitors */ \
72 __lock_size_t count = cnt; /* Save the count to a local variable */ \
73 unsigned int recursions[ count ]; /* Save the current recursion levels to restore them later */ \
74 __waitfor_mask_t masks [ count ]; /* Save the current waitfor masks to restore them later */ \
75 __spinlock_t * locks [ count ]; /* We need to pass-in an array of locks to BlockInternal */ \
76
77#define monitor_save save ( monitors, count, locks, recursions, masks )
78#define monitor_restore restore( monitors, count, locks, recursions, masks )
79
80
81//-----------------------------------------------------------------------------
82// Enter/Leave routines
83// Enter single monitor
84static void __enter( monitor$ * this, const __monitor_group_t & group ) {
85 thread$ * thrd = active_thread();
86
87 // Lock the monitor spinlock
88 lock( this->lock __cfaabi_dbg_ctx2 );
89
90 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
91
92 if( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
93 abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
94 }
95 else if( !this->owner ) {
96 // No one has the monitor, just take it
97 __set_owner( this, thrd );
98
99 __cfaabi_dbg_print_safe( "Kernel : mon is free \n" );
100 }
101 else if( this->owner == thrd) {
102 // We already have the monitor, just note how many times we took it
103 this->recursion += 1;
104
105 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n" );
106 }
107 else if( is_accepted( this, group) ) {
108 // Some one was waiting for us, enter
109 __set_owner( this, thrd );
110
111 // Reset mask
112 reset_mask( this );
113
114 __cfaabi_dbg_print_safe( "Kernel : mon accepts \n" );
115 }
116 else {
117 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
118
119 // Some one else has the monitor, wait in line for it
120 /* paranoid */ verify( thrd->link.next == 0p );
121 append( this->entry_queue, thrd );
122 /* paranoid */ verify( thrd->link.next == 1p );
123
124 unlock( this->lock );
125 park();
126
127 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
128
129 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
130 return;
131 }
132
133 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
134
135 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
136 /* paranoid */ verify( this->lock.lock );
137
138 // Release the lock and leave
139 unlock( this->lock );
140 return;
141}
142
143static void __dtor_enter( monitor$ * this, fptr_t func, bool join ) {
144 thread$ * thrd = active_thread();
145 #if defined( __CFA_WITH_VERIFY__ )
146 bool is_thrd = this == &thrd->self_mon;
147 #endif
148
149 // Lock the monitor spinlock
150 lock( this->lock __cfaabi_dbg_ctx2 );
151
152 __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
153
154
155 if( !this->owner ) {
156 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
157
158 // No one has the monitor, just take it
159 __set_owner( this, thrd );
160
161 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
162 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
163
164 unlock( this->lock );
165 return;
166 }
167 else if( this->owner == thrd && !join) {
168 // We already have the monitor... but where about to destroy it so the nesting will fail
169 // Abort!
170 abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
171 }
172 // SKULLDUGGERY: join will act as a dtor so it would normally trigger to above check
173 // because join will not release the monitor after it executed.
174 // to avoid that it sets the owner to the special value thrd | 1p before exiting
175 else if( this->owner == (thread$*)(1 | (uintptr_t)thrd) ) {
176 // restore the owner and just return
177 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
178
179 // No one has the monitor, just take it
180 __set_owner( this, thrd );
181
182 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
183 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
184
185 unlock( this->lock );
186 return;
187 }
188
189 // The monitor is busy, if this is a thread and the thread owns itself, it better be active
190 /* paranoid */ verify( !is_thrd || this->owner != thrd || (thrd->state != Halted && thrd->state != Cancelled) );
191
192 __lock_size_t count = 1;
193 monitor$ ** monitors = &this;
194 __monitor_group_t group = { &this, 1, func };
195 if( is_accepted( this, group) ) {
196 __cfaabi_dbg_print_safe( "Kernel : mon accepts dtor, block and signal it \n" );
197
198 // Wake the thread that is waiting for this
199 __condition_criterion_t * urgent = pop( this->signal_stack );
200 /* paranoid */ verify( urgent );
201
202 // Reset mask
203 reset_mask( this );
204
205 // Create the node specific to this wait operation
206 wait_ctx_primed( thrd, 0 )
207
208 // Some one else has the monitor, wait for him to finish and then run
209 unlock( this->lock );
210
211 // Release the next thread
212 /* 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 );
213 unpark( urgent->owner->waiting_thread );
214
215 // Park current thread waiting
216 park();
217
218 // Some one was waiting for us, enter
219 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
220
221 __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
222 return;
223 }
224 else {
225 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
226
227 wait_ctx( thrd, 0 )
228 this->dtor_node = &waiter;
229
230 // Some one else has the monitor, wait in line for it
231 /* paranoid */ verify( thrd->link.next == 0p );
232 append( this->entry_queue, thrd );
233 /* paranoid */ verify( thrd->link.next == 1p );
234 unlock( this->lock );
235
236 // Park current thread waiting
237 park();
238
239 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
240 return;
241 }
242}
243
244// Leave single monitor
245void __leave( monitor$ * this ) {
246 // Lock the monitor spinlock
247 lock( this->lock __cfaabi_dbg_ctx2 );
248
249 __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", active_thread(), this, this->owner);
250
251 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
252
253 // Leaving a recursion level, decrement the counter
254 this->recursion -= 1;
255
256 // If we haven't left the last level of recursion
257 // it means we don't need to do anything
258 if( this->recursion != 0) {
259 __cfaabi_dbg_print_safe( "Kernel : recursion still %d\n", this->recursion);
260 unlock( this->lock );
261 return;
262 }
263
264 // Get the next thread, will be null on low contention monitor
265 thread$ * new_owner = next_thread( this );
266
267 // Check the new owner is consistent with who we wake-up
268 // new_owner might be null even if someone owns the monitor when the owner is still waiting for another monitor
269 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
270
271 // We can now let other threads in safely
272 unlock( this->lock );
273
274 //We need to wake-up the thread
275 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
276 unpark( new_owner );
277}
278
279// Leave single monitor for the last time
280void __dtor_leave( monitor$ * this, bool join ) {
281 __cfaabi_dbg_debug_do(
282 if( active_thread() != this->owner ) {
283 abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, active_thread(), this->owner);
284 }
285 if( this->recursion != 1 && !join ) {
286 abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
287 }
288 )
289
290 this->owner = (thread$*)(1 | (uintptr_t)this->owner);
291}
292
293void __thread_finish( thread$ * thrd ) {
294 monitor$ * this = &thrd->self_mon;
295
296 // Lock the monitor now
297 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
298 /* paranoid */ verify( this->lock.lock );
299 /* paranoid */ verify( thrd->context.SP );
300 /* 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 );
301 /* 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 );
302 /* paranoid */ verify( ! __preemption_enabled() );
303
304 /* paranoid */ verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
305 /* paranoid */ verify( thrd->state == Halting );
306 /* paranoid */ verify( this->recursion == 1 );
307
308 // Leaving a recursion level, decrement the counter
309 this->recursion -= 1;
310 this->owner = 0p;
311
312 // Fetch the next thread, can be null
313 thread$ * new_owner = next_thread( this );
314
315 // Mark the state as fully halted
316 thrd->state = Halted;
317
318 // Release the monitor lock
319 unlock( this->lock );
320
321 // Unpark the next owner if needed
322 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
323 /* paranoid */ verify( ! __preemption_enabled() );
324 /* paranoid */ verify( thrd->state == Halted );
325 unpark( new_owner );
326}
327
328// Enter multiple monitor
329// relies on the monitor array being sorted
330static inline void enter( __monitor_group_t monitors ) {
331 for( __lock_size_t i = 0; i < monitors.size; i++) {
332 __enter( monitors[i], monitors );
333 }
334}
335
336// Leave multiple monitor
337// relies on the monitor array being sorted
338static inline void leave(monitor$ * monitors [], __lock_size_t count) {
339 for( __lock_size_t i = count - 1; i >= 0; i--) {
340 __leave( monitors[i] );
341 }
342}
343
344// Ctor for monitor guard
345// Sorts monitors before entering
346void ?{}( monitor_guard_t & this, monitor$ * m [], __lock_size_t count, fptr_t func ) {
347 thread$ * thrd = active_thread();
348
349 // Store current array
350 this.m = m;
351 this.count = count;
352
353 // Sort monitors based on address
354 __libcfa_small_sort(this.m, count);
355
356 // Save previous thread context
357 this.prev = thrd->monitors;
358
359 // Update thread context (needed for conditions)
360 (thrd->monitors){m, count, func};
361
362 // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
363
364 // Enter the monitors in order
365 __monitor_group_t group = {this.m, this.count, func};
366 enter( group );
367
368 // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
369}
370
371void ?{}( monitor_guard_t & this, monitor$ * m [], __lock_size_t count ) {
372 this{ m, count, 0p };
373}
374
375
376// Dtor for monitor guard
377void ^?{}( monitor_guard_t & this ) {
378 // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
379
380 // Leave the monitors in order
381 leave( this.m, this.count );
382
383 // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
384
385 // Restore thread context
386 active_thread()->monitors = this.prev;
387}
388
389// Ctor for monitor guard
390// Sorts monitors before entering
391void ?{}( monitor_dtor_guard_t & this, monitor$ * m [], fptr_t func, bool join ) {
392 // optimization
393 thread$ * thrd = active_thread();
394
395 // Store current array
396 this.m = *m;
397
398 // Save previous thread context
399 this.prev = thrd->monitors;
400
401 // Save whether we are in a join or not
402 this.join = join;
403
404 // Update thread context (needed for conditions)
405 (thrd->monitors){m, 1, func};
406
407 __dtor_enter( this.m, func, join );
408}
409
410// Dtor for monitor guard
411void ^?{}( monitor_dtor_guard_t & this ) {
412 // Leave the monitors in order
413 __dtor_leave( this.m, this.join );
414
415 // Restore thread context
416 active_thread()->monitors = this.prev;
417}
418
419//-----------------------------------------------------------------------------
420// Internal scheduling types
421void ?{}(__condition_node_t & this, thread$ * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
422 this.waiting_thread = waiting_thread;
423 this.count = count;
424 this.next = 0p;
425 this.user_info = user_info;
426}
427
428void ?{}(__condition_criterion_t & this ) with( this ) {
429 ready = false;
430 target = 0p;
431 owner = 0p;
432 next = 0p;
433}
434
435void ?{}(__condition_criterion_t & this, monitor$ * target, __condition_node_t & owner ) {
436 this.ready = false;
437 this.target = target;
438 this.owner = &owner;
439 this.next = 0p;
440}
441
442//-----------------------------------------------------------------------------
443// Internal scheduling
444void wait( condition & this, uintptr_t user_info = 0 ) {
445 brand_condition( this );
446
447 // Check that everything is as expected
448 assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
449 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
450 verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
451
452 // Create storage for monitor context
453 monitor_ctx( this.monitors, this.monitor_count );
454
455 // Create the node specific to this wait operation
456 wait_ctx( active_thread(), user_info );
457
458 // Append the current wait operation to the ones already queued on the condition
459 // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
460 /* paranoid */ verify( waiter.next == 0p );
461 append( this.blocked, &waiter );
462 /* paranoid */ verify( waiter.next == 1p );
463
464 // Lock all monitors (aggregates the locks as well)
465 lock_all( monitors, locks, count );
466
467 // Find the next thread(s) to run
468 __lock_size_t thread_count = 0;
469 thread$ * threads[ count ];
470 __builtin_memset( threads, 0, sizeof( threads ) );
471
472 // Save monitor states
473 monitor_save;
474
475 // Remove any duplicate threads
476 for( __lock_size_t i = 0; i < count; i++) {
477 thread$ * new_owner = next_thread( monitors[i] );
478 insert_unique( threads, thread_count, new_owner );
479 }
480
481 // Unlock the locks, we don't need them anymore
482 for(int i = 0; i < count; i++) {
483 unlock( *locks[i] );
484 }
485
486 // Wake the threads
487 for(int i = 0; i < thread_count; i++) {
488 unpark( threads[i] );
489 }
490
491 // Everything is ready to go to sleep
492 park();
493
494 // We are back, restore the owners and recursions
495 monitor_restore;
496}
497
498bool signal( condition & this ) {
499 if( is_empty( this ) ) { return false; }
500
501 //Check that everything is as expected
502 verify( this.monitors );
503 verify( this.monitor_count != 0 );
504
505 //Some more checking in debug
506 __cfaabi_dbg_debug_do(
507 thread$ * this_thrd = active_thread();
508 if ( this.monitor_count != this_thrd->monitors.size ) {
509 abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
510 }
511
512 for(int i = 0; i < this.monitor_count; i++) {
513 if ( this.monitors[i] != this_thrd->monitors[i] ) {
514 abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
515 }
516 }
517 );
518
519 __lock_size_t count = this.monitor_count;
520
521 // Lock all monitors
522 lock_all( this.monitors, 0p, count );
523
524 //Pop the head of the waiting queue
525 __condition_node_t * node = pop_head( this.blocked );
526
527 //Add the thread to the proper AS stack
528 for(int i = 0; i < count; i++) {
529 __condition_criterion_t * crit = &node->criteria[i];
530 assert( !crit->ready );
531 push( crit->target->signal_stack, crit );
532 }
533
534 //Release
535 unlock_all( this.monitors, count );
536
537 return true;
538}
539
540bool signal_block( condition & this ) {
541 if( !this.blocked.head ) { return false; }
542
543 //Check that everything is as expected
544 verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
545 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
546
547 // Create storage for monitor context
548 monitor_ctx( this.monitors, this.monitor_count );
549
550 // Lock all monitors (aggregates the locks them as well)
551 lock_all( monitors, locks, count );
552
553
554 // Create the node specific to this wait operation
555 wait_ctx_primed( active_thread(), 0 )
556
557 //save contexts
558 monitor_save;
559
560 //Find the thread to run
561 thread$ * signallee = pop_head( this.blocked )->waiting_thread;
562 __set_owner( monitors, count, signallee );
563
564 __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
565
566 // unlock all the monitors
567 unlock_all( locks, count );
568
569 // unpark the thread we signalled
570 unpark( signallee );
571
572 //Everything is ready to go to sleep
573 park();
574
575
576 // WE WOKE UP
577
578
579 __cfaabi_dbg_print_buffer_local( "Kernel : signal_block returned\n" );
580
581 //We are back, restore the masks and recursions
582 monitor_restore;
583
584 return true;
585}
586
587// Access the user_info of the thread waiting at the front of the queue
588uintptr_t front( condition & this ) {
589 verifyf( !is_empty(this),
590 "Attempt to access user data on an empty condition.\n"
591 "Possible cause is not checking if the condition is empty before reading stored data."
592 );
593 return ((typeof(this.blocked.head))this.blocked.head)->user_info;
594}
595
596//-----------------------------------------------------------------------------
597// External scheduling
598// cases to handle :
599// - target already there :
600// block and wake
601// - dtor already there
602// put thread on signaller stack
603// - non-blocking
604// return else
605// - timeout
606// return timeout
607// - block
608// setup mask
609// block
610void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) {
611 // This statment doesn't have a contiguous list of monitors...
612 // Create one!
613 __lock_size_t max = count_max( mask );
614 monitor$ * mon_storage[max];
615 __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
616 __lock_size_t actual_count = aggregate( mon_storage, mask );
617
618 __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
619
620 if(actual_count == 0) return;
621
622 __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
623
624 // Create storage for monitor context
625 monitor_ctx( mon_storage, actual_count );
626
627 // Lock all monitors (aggregates the locks as well)
628 lock_all( monitors, locks, count );
629
630 {
631 // Check if the entry queue
632 thread$ * next; int index;
633 [next, index] = search_entry_queue( mask, monitors, count );
634
635 if( next ) {
636 *mask.accepted = index;
637 __acceptable_t& accepted = mask[index];
638 if( accepted.is_dtor ) {
639 __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
640 verifyf( accepted.size == 1, "ERROR: Accepted dtor has more than 1 mutex parameter." );
641
642 monitor$ * mon2dtor = accepted[0];
643 verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
644
645 __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
646 push( mon2dtor->signal_stack, dtor_crit );
647
648 unlock_all( locks, count );
649 }
650 else {
651 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
652
653 // Create the node specific to this wait operation
654 wait_ctx_primed( active_thread(), 0 );
655
656 // Save monitor states
657 monitor_save;
658
659 __cfaabi_dbg_print_buffer_local( "Kernel : baton of %"PRIdFAST16" monitors : ", count );
660 #ifdef __CFA_DEBUG_PRINT__
661 for( int i = 0; i < count; i++) {
662 __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
663 }
664 #endif
665 __cfaabi_dbg_print_buffer_local( "\n" );
666
667 // Set the owners to be the next thread
668 __set_owner( monitors, count, next );
669
670 // unlock all the monitors
671 unlock_all( locks, count );
672
673 // unpark the thread we signalled
674 unpark( next );
675
676 //Everything is ready to go to sleep
677 park();
678
679 // We are back, restore the owners and recursions
680 monitor_restore;
681
682 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
683 }
684
685 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
686 return;
687 }
688 }
689
690
691 if( duration == 0 ) {
692 __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
693
694 unlock_all( locks, count );
695
696 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
697 return;
698 }
699
700
701 verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
702
703 __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
704
705 // Create the node specific to this wait operation
706 wait_ctx_primed( active_thread(), 0 );
707
708 monitor_save;
709 set_mask( monitors, count, mask );
710
711 for( __lock_size_t i = 0; i < count; i++) {
712 verify( monitors[i]->owner == active_thread() );
713 }
714
715 // unlock all the monitors
716 unlock_all( locks, count );
717
718 //Everything is ready to go to sleep
719 park();
720
721
722 // WE WOKE UP
723
724
725 //We are back, restore the masks and recursions
726 monitor_restore;
727
728 __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
729
730 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
731}
732
733//-----------------------------------------------------------------------------
734// Utilities
735
736static inline void __set_owner( monitor$ * this, thread$ * owner ) {
737 /* paranoid */ verify( this->lock.lock );
738
739 //Pass the monitor appropriately
740 this->owner = owner;
741
742 //We are passing the monitor to someone else, which means recursion level is not 0
743 this->recursion = owner ? 1 : 0;
744}
745
746static inline void __set_owner( monitor$ * monitors [], __lock_size_t count, thread$ * owner ) {
747 /* paranoid */ verify ( monitors[0]->lock.lock );
748 /* 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] );
749 monitors[0]->owner = owner;
750 monitors[0]->recursion = 1;
751 for( __lock_size_t i = 1; i < count; i++ ) {
752 /* paranoid */ verify ( monitors[i]->lock.lock );
753 /* 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] );
754 monitors[i]->owner = owner;
755 monitors[i]->recursion = 0;
756 }
757}
758
759static inline void set_mask( monitor$ * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
760 for( __lock_size_t i = 0; i < count; i++) {
761 storage[i]->mask = mask;
762 }
763}
764
765static inline void reset_mask( monitor$ * this ) {
766 this->mask.accepted = 0p;
767 this->mask.data = 0p;
768 this->mask.size = 0;
769}
770
771static inline thread$ * next_thread( monitor$ * this ) {
772 //Check the signaller stack
773 __cfaabi_dbg_print_safe( "Kernel : mon %p AS-stack top %p\n", this, this->signal_stack.top);
774 __condition_criterion_t * urgent = pop( this->signal_stack );
775 if( urgent ) {
776 //The signaller stack is not empty,
777 //regardless of if we are ready to baton pass,
778 //we need to set the monitor as in use
779 /* 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 );
780 __set_owner( this, urgent->owner->waiting_thread );
781
782 return check_condition( urgent );
783 }
784
785 // No signaller thread
786 // Get the next thread in the entry_queue
787 thread$ * new_owner = pop_head( this->entry_queue );
788 /* 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 );
789 /* paranoid */ verify( !new_owner || new_owner->link.next == 0p );
790 __set_owner( this, new_owner );
791
792 return new_owner;
793}
794
795static inline bool is_accepted( monitor$ * this, const __monitor_group_t & group ) {
796 __acceptable_t * it = this->mask.data; // Optim
797 __lock_size_t count = this->mask.size;
798
799 // Check if there are any acceptable functions
800 if( !it ) return false;
801
802 // If this isn't the first monitor to test this, there is no reason to repeat the test.
803 if( this != group[0] ) return group[0]->mask.accepted >= 0;
804
805 // For all acceptable functions check if this is the current function.
806 for( __lock_size_t i = 0; i < count; i++, it++ ) {
807 if( *it == group ) {
808 *this->mask.accepted = i;
809 return true;
810 }
811 }
812
813 // No function matched
814 return false;
815}
816
817static inline void init( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
818 for( __lock_size_t i = 0; i < count; i++) {
819 (criteria[i]){ monitors[i], waiter };
820 }
821
822 waiter.criteria = criteria;
823}
824
825static inline void init_push( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
826 for( __lock_size_t i = 0; i < count; i++) {
827 (criteria[i]){ monitors[i], waiter };
828 __cfaabi_dbg_print_safe( "Kernel : target %p = %p\n", criteria[i].target, &criteria[i] );
829 push( criteria[i].target->signal_stack, &criteria[i] );
830 }
831
832 waiter.criteria = criteria;
833}
834
835static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
836 for( __lock_size_t i = 0; i < count; i++ ) {
837 lock( *locks[i] __cfaabi_dbg_ctx2 );
838 }
839}
840
841static inline void lock_all( monitor$ * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
842 for( __lock_size_t i = 0; i < count; i++ ) {
843 __spinlock_t * l = &source[i]->lock;
844 lock( *l __cfaabi_dbg_ctx2 );
845 if(locks) locks[i] = l;
846 }
847}
848
849static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
850 for( __lock_size_t i = 0; i < count; i++ ) {
851 unlock( *locks[i] );
852 }
853}
854
855static inline void unlock_all( monitor$ * locks [], __lock_size_t count ) {
856 for( __lock_size_t i = 0; i < count; i++ ) {
857 unlock( locks[i]->lock );
858 }
859}
860
861static inline void save(
862 monitor$ * ctx [],
863 __lock_size_t count,
864 __attribute((unused)) __spinlock_t * locks [],
865 unsigned int /*out*/ recursions [],
866 __waitfor_mask_t /*out*/ masks []
867) {
868 for( __lock_size_t i = 0; i < count; i++ ) {
869 recursions[i] = ctx[i]->recursion;
870 masks[i] = ctx[i]->mask;
871 }
872}
873
874static inline void restore(
875 monitor$ * ctx [],
876 __lock_size_t count,
877 __spinlock_t * locks [],
878 unsigned int /*out*/ recursions [],
879 __waitfor_mask_t /*out*/ masks []
880) {
881 lock_all( locks, count );
882 for( __lock_size_t i = 0; i < count; i++ ) {
883 ctx[i]->recursion = recursions[i];
884 ctx[i]->mask = masks[i];
885 }
886 unlock_all( locks, count );
887}
888
889// Function has 2 different behavior
890// 1 - Marks a monitors as being ready to run
891// 2 - Checks if all the monitors are ready to run
892// if so return the thread to run
893static inline thread$ * check_condition( __condition_criterion_t * target ) {
894 __condition_node_t * node = target->owner;
895 unsigned short count = node->count;
896 __condition_criterion_t * criteria = node->criteria;
897
898 bool ready2run = true;
899
900 for( int i = 0; i < count; i++ ) {
901
902 // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
903 if( &criteria[i] == target ) {
904 criteria[i].ready = true;
905 // __cfaabi_dbg_print_safe( "True\n" );
906 }
907
908 ready2run = criteria[i].ready && ready2run;
909 }
910
911 __cfaabi_dbg_print_safe( "Kernel : Runing %i (%p)\n", ready2run, ready2run ? (thread*)node->waiting_thread : (thread*)0p );
912 return ready2run ? node->waiting_thread : 0p;
913}
914
915static inline void brand_condition( condition & this ) {
916 thread$ * thrd = active_thread();
917 if( !this.monitors ) {
918 // __cfaabi_dbg_print_safe( "Branding\n" );
919 assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
920 this.monitor_count = thrd->monitors.size;
921
922 this.monitors = (monitor$ **)malloc( this.monitor_count * sizeof( *this.monitors ) );
923 for( int i = 0; i < this.monitor_count; i++ ) {
924 this.monitors[i] = thrd->monitors[i];
925 }
926 }
927}
928
929static inline [thread$ *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor$ * monitors [], __lock_size_t count ) {
930
931 __queue_t(thread$) & entry_queue = monitors[0]->entry_queue;
932
933 // For each thread in the entry-queue
934 for( thread$ ** thrd_it = &entry_queue.head;
935 (*thrd_it) != 1p;
936 thrd_it = &(*thrd_it)->link.next
937 ) {
938 // For each acceptable check if it matches
939 int i = 0;
940 __acceptable_t * end = end (mask);
941 __acceptable_t * begin = begin(mask);
942 for( __acceptable_t * it = begin; it != end; it++, i++ ) {
943 // Check if we have a match
944 if( *it == (*thrd_it)->monitors ) {
945
946 // If we have a match return it
947 // after removeing it from the entry queue
948 return [remove( entry_queue, thrd_it ), i];
949 }
950 }
951 }
952
953 return [0, -1];
954}
955
956forall(T & | sized( T ))
957static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
958 if( !val ) return size;
959
960 for( __lock_size_t i = 0; i <= size; i++) {
961 if( array[i] == val ) return size;
962 }
963
964 array[size] = val;
965 size = size + 1;
966 return size;
967}
968
969static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
970 __lock_size_t max = 0;
971 for( __lock_size_t i = 0; i < mask.size; i++ ) {
972 __acceptable_t & accepted = mask[i];
973 max += accepted.size;
974 }
975 return max;
976}
977
978static inline __lock_size_t aggregate( monitor$ * storage [], const __waitfor_mask_t & mask ) {
979 __lock_size_t size = 0;
980 for( __lock_size_t i = 0; i < mask.size; i++ ) {
981 __acceptable_t & accepted = mask[i];
982 __libcfa_small_sort( accepted.data, accepted.size );
983 for( __lock_size_t j = 0; j < accepted.size; j++) {
984 insert_unique( storage, size, accepted[j] );
985 }
986 }
987 // TODO insertion sort instead of this
988 __libcfa_small_sort( storage, size );
989 return size;
990}
991
992//-----------------------------------------------------------------------------
993// Enter routine for mutex stmt
994// Can't be accepted since a mutex stmt is effectively an anonymous routine
995// Thus we do not need a monitor group
996void lock( monitor$ * this ) {
997 thread$ * thrd = active_thread();
998
999 // Lock the monitor spinlock
1000 lock( this->lock __cfaabi_dbg_ctx2 );
1001
1002 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
1003
1004 if( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
1005 abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
1006 }
1007 else if( !this->owner ) {
1008 // No one has the monitor, just take it
1009 __set_owner( this, thrd );
1010
1011 __cfaabi_dbg_print_safe( "Kernel : mon is free \n" );
1012 }
1013 else if( this->owner == thrd) {
1014 // We already have the monitor, just note how many times we took it
1015 this->recursion += 1;
1016
1017 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n" );
1018 }
1019 else {
1020 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
1021
1022 // Some one else has the monitor, wait in line for it
1023 /* paranoid */ verify( thrd->link.next == 0p );
1024 append( this->entry_queue, thrd );
1025 /* paranoid */ verify( thrd->link.next == 1p );
1026
1027 unlock( this->lock );
1028 park();
1029
1030 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
1031
1032 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
1033 return;
1034 }
1035
1036 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
1037
1038 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
1039 /* paranoid */ verify( this->lock.lock );
1040
1041 // Release the lock and leave
1042 unlock( this->lock );
1043 return;
1044}
1045
1046// Leave routine for mutex stmt
1047// Is just a wrapper around __leave for the is_lock trait to see
1048void unlock( monitor$ * this ) { __leave( this ); }
1049
1050// Local Variables: //
1051// mode: c //
1052// tab-width: 4 //
1053// End: //
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