source: libcfa/src/concurrency/monitor.cfa@ 8446c18

ADT ast-experimental pthread-emulation qualifiedEnum
Last change on this file since 8446c18 was c18bf9e, checked in by Thierry Delisle <tdelisle@…>, 3 years ago

Visibility concurrency
  • Property mode set to 100644
File size: 35.6 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// monitor.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 ?{}(__condition_node_t & this, thread$ * waiting_thread, __lock_size_t count, uintptr_t user_info );
47static inline void ?{}(__condition_criterion_t & this );
48static inline void ?{}(__condition_criterion_t & this, monitor$ * target, __condition_node_t * owner );
49
50static inline void init ( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
51static inline void init_push( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] );
52
53static inline thread$ * check_condition ( __condition_criterion_t * );
54static inline void brand_condition ( condition & );
55static inline [thread$ *, int] search_entry_queue( const __waitfor_mask_t &, monitor$ * monitors [], __lock_size_t count );
56
57forall(T & | sized( T ))
58static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val );
59static inline __lock_size_t count_max ( const __waitfor_mask_t & mask );
60static inline __lock_size_t aggregate ( monitor$ * storage [], const __waitfor_mask_t & mask );
61
62//-----------------------------------------------------------------------------
63// Useful defines
64#define wait_ctx(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( count, monitors, waiter, criteria ); /* Link everything together */ \
68
69#define wait_ctx_primed(thrd, user_info) /* Create the necessary information to use the signaller stack */ \
70 __condition_node_t waiter = { thrd, count, user_info }; /* Create the node specific to this wait operation */ \
71 __condition_criterion_t criteria[count]; /* Create the creteria this wait operation needs to wake up */ \
72 init_push( count, monitors, waiter, criteria ); /* Link everything together and push it to the AS-Stack */ \
73
74#define monitor_ctx( mons, cnt ) /* Define that create the necessary struct for internal/external scheduling operations */ \
75 monitor$ ** monitors = mons; /* Save the targeted monitors */ \
76 __lock_size_t count = cnt; /* Save the count to a local variable */ \
77 unsigned int recursions[ count ]; /* Save the current recursion levels to restore them later */ \
78 __waitfor_mask_t masks [ count ]; /* Save the current waitfor masks to restore them later */ \
79 __spinlock_t * locks [ count ]; /* We need to pass-in an array of locks to BlockInternal */ \
80
81#define monitor_save save ( monitors, count, locks, recursions, masks )
82#define monitor_restore restore( monitors, count, locks, recursions, masks )
83
84
85//-----------------------------------------------------------------------------
86// Enter/Leave routines
87// Enter single monitor
88static void __enter( monitor$ * this, const __monitor_group_t & group ) {
89 thread$ * thrd = active_thread();
90
91 // Lock the monitor spinlock
92 lock( this->lock __cfaabi_dbg_ctx2 );
93
94 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
95
96 if( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
97 abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
98 }
99 else if( !this->owner ) {
100 // No one has the monitor, just take it
101 __set_owner( this, thrd );
102
103 __cfaabi_dbg_print_safe( "Kernel : mon is free \n" );
104 }
105 else if( this->owner == thrd) {
106 // We already have the monitor, just note how many times we took it
107 this->recursion += 1;
108
109 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n" );
110 }
111 else if( is_accepted( this, group) ) {
112 // Some one was waiting for us, enter
113 __set_owner( this, thrd );
114
115 // Reset mask
116 reset_mask( this );
117
118 __cfaabi_dbg_print_safe( "Kernel : mon accepts \n" );
119 }
120 else {
121 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
122
123 // Some one else has the monitor, wait in line for it
124 /* paranoid */ verify( thrd->link.next == 0p );
125 append( this->entry_queue, thrd );
126 /* paranoid */ verify( thrd->link.next == 1p );
127
128 unlock( this->lock );
129 park();
130
131 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
132
133 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
134 return;
135 }
136
137 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
138
139 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
140 /* paranoid */ verify( this->lock.lock );
141
142 // Release the lock and leave
143 unlock( this->lock );
144 return;
145}
146
147static void __dtor_enter( monitor$ * this, fptr_t func, bool join ) {
148 thread$ * thrd = active_thread();
149 #if defined( __CFA_WITH_VERIFY__ )
150 bool is_thrd = this == &thrd->self_mon;
151 #endif
152
153 // Lock the monitor spinlock
154 lock( this->lock __cfaabi_dbg_ctx2 );
155
156 __cfaabi_dbg_print_safe( "Kernel : %10p Entering dtor for mon %p (%p)\n", thrd, this, this->owner);
157
158
159 if( !this->owner ) {
160 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
161
162 // No one has the monitor, just take it
163 __set_owner( this, thrd );
164
165 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
166 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
167
168 unlock( this->lock );
169 return;
170 }
171 else if( this->owner == thrd && !join) {
172 // We already have the monitor... but where about to destroy it so the nesting will fail
173 // Abort!
174 abort( "Attempt to destroy monitor %p by thread \"%.256s\" (%p) in nested mutex.", this, thrd->self_cor.name, thrd );
175 }
176 // SKULLDUGGERY: join will act as a dtor so it would normally trigger to above check
177 // because join will not release the monitor after it executed.
178 // to avoid that it sets the owner to the special value thrd | 1p before exiting
179 else if( this->owner == (thread$*)(1 | (uintptr_t)thrd) ) {
180 // restore the owner and just return
181 __cfaabi_dbg_print_safe( "Kernel : Destroying free mon %p\n", this);
182
183 // No one has the monitor, just take it
184 __set_owner( this, thrd );
185
186 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
187 /* paranoid */ verify( !is_thrd || thrd->state == Halted || thrd->state == Cancelled );
188
189 unlock( this->lock );
190 return;
191 }
192
193 // The monitor is busy, if this is a thread and the thread owns itself, it better be active
194 /* paranoid */ verify( !is_thrd || this->owner != thrd || (thrd->state != Halted && thrd->state != Cancelled) );
195
196 __lock_size_t count = 1;
197 monitor$ ** monitors = &this;
198 __monitor_group_t group = { &this, 1, func };
199 if( is_accepted( this, group) ) {
200 __cfaabi_dbg_print_safe( "Kernel : mon accepts dtor, block and signal it \n" );
201
202 // Wake the thread that is waiting for this
203 __condition_criterion_t * urgent = pop( this->signal_stack );
204 /* paranoid */ verify( urgent );
205
206 // Reset mask
207 reset_mask( this );
208
209 // Create the node specific to this wait operation
210 wait_ctx_primed( thrd, 0 )
211
212 // Some one else has the monitor, wait for him to finish and then run
213 unlock( this->lock );
214
215 // Release the next thread
216 /* 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 );
217 unpark( urgent->owner->waiting_thread );
218
219 // Park current thread waiting
220 park();
221
222 // Some one was waiting for us, enter
223 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
224
225 __cfaabi_dbg_print_safe( "Kernel : Destroying %p\n", this);
226 return;
227 }
228 else {
229 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
230
231 wait_ctx( thrd, 0 )
232 this->dtor_node = &waiter;
233
234 // Some one else has the monitor, wait in line for it
235 /* paranoid */ verify( thrd->link.next == 0p );
236 append( this->entry_queue, thrd );
237 /* paranoid */ verify( thrd->link.next == 1p );
238 unlock( this->lock );
239
240 // Park current thread waiting
241 park();
242
243 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
244 return;
245 }
246}
247
248// Leave single monitor
249static void __leave( monitor$ * this ) {
250 // Lock the monitor spinlock
251 lock( this->lock __cfaabi_dbg_ctx2 );
252
253 __cfaabi_dbg_print_safe( "Kernel : %10p Leaving mon %p (%p)\n", active_thread(), this, this->owner);
254
255 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
256
257 // Leaving a recursion level, decrement the counter
258 this->recursion -= 1;
259
260 // If we haven't left the last level of recursion
261 // it means we don't need to do anything
262 if( this->recursion != 0) {
263 __cfaabi_dbg_print_safe( "Kernel : recursion still %d\n", this->recursion);
264 unlock( this->lock );
265 return;
266 }
267
268 // Get the next thread, will be null on low contention monitor
269 thread$ * new_owner = next_thread( this );
270
271 // Check the new owner is consistent with who we wake-up
272 // new_owner might be null even if someone owns the monitor when the owner is still waiting for another monitor
273 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
274
275 // We can now let other threads in safely
276 unlock( this->lock );
277
278 //We need to wake-up the thread
279 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
280 unpark( new_owner );
281}
282
283// Leave single monitor for the last time
284static void __dtor_leave( monitor$ * this, bool join ) {
285 __cfaabi_dbg_debug_do(
286 if( active_thread() != this->owner ) {
287 abort( "Destroyed monitor %p has inconsistent owner, expected %p got %p.\n", this, active_thread(), this->owner);
288 }
289 if( this->recursion != 1 && !join ) {
290 abort( "Destroyed monitor %p has %d outstanding nested calls.\n", this, this->recursion - 1);
291 }
292 )
293
294 this->owner = (thread$*)(1 | (uintptr_t)this->owner);
295}
296
297void __thread_finish( thread$ * thrd ) {
298 monitor$ * this = &thrd->self_mon;
299
300 // Lock the monitor now
301 /* paranoid */ verify( 0x0D15EA5E0D15EA5Ep == thrd->canary );
302 /* paranoid */ verify( this->lock.lock );
303 /* paranoid */ verify( thrd->context.SP );
304 /* 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 );
305 /* 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 );
306 /* paranoid */ verify( ! __preemption_enabled() );
307
308 /* paranoid */ verifyf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", thrd, this->owner, this->recursion, this );
309 /* paranoid */ verify( thrd->state == Halting );
310 /* paranoid */ verify( this->recursion == 1 );
311
312 // Leaving a recursion level, decrement the counter
313 this->recursion -= 1;
314 this->owner = 0p;
315
316 // Fetch the next thread, can be null
317 thread$ * new_owner = next_thread( this );
318
319 // Mark the state as fully halted
320 thrd->state = Halted;
321
322 // Release the monitor lock
323 unlock( this->lock );
324
325 // Unpark the next owner if needed
326 /* paranoid */ verifyf( !new_owner || new_owner == this->owner, "Expected owner to be %p, got %p (m: %p)", new_owner, this->owner, this );
327 /* paranoid */ verify( ! __preemption_enabled() );
328 /* paranoid */ verify( thrd->state == Halted );
329 unpark( new_owner );
330}
331
332// Enter multiple monitor
333// relies on the monitor array being sorted
334static inline void enter( __monitor_group_t monitors ) {
335 for( __lock_size_t i = 0; i < monitors.size; i++) {
336 __enter( monitors[i], monitors );
337 }
338}
339
340// Leave multiple monitor
341// relies on the monitor array being sorted
342static inline void leave(monitor$ * monitors [], __lock_size_t count) {
343 for( __lock_size_t i = count - 1; i >= 0; i--) {
344 __leave( monitors[i] );
345 }
346}
347
348// Ctor for monitor guard
349// Sorts monitors before entering
350void ?{}( monitor_guard_t & this, monitor$ * m [], __lock_size_t count, fptr_t func ) libcfa_public {
351 thread$ * thrd = active_thread();
352
353 // Store current array
354 this.m = m;
355 this.count = count;
356
357 // Sort monitors based on address
358 __libcfa_small_sort(this.m, count);
359
360 // Save previous thread context
361 this.prev = thrd->monitors;
362
363 // Update thread context (needed for conditions)
364 (thrd->monitors){m, count, func};
365
366 // __cfaabi_dbg_print_safe( "MGUARD : enter %d\n", count);
367
368 // Enter the monitors in order
369 __monitor_group_t group = {this.m, this.count, func};
370 enter( group );
371
372 // __cfaabi_dbg_print_safe( "MGUARD : entered\n" );
373}
374
375void ?{}( monitor_guard_t & this, monitor$ * m [], __lock_size_t count ) libcfa_public {
376 this{ m, count, 0p };
377}
378
379
380// Dtor for monitor guard
381void ^?{}( monitor_guard_t & this ) libcfa_public {
382 // __cfaabi_dbg_print_safe( "MGUARD : leaving %d\n", this.count);
383
384 // Leave the monitors in order
385 leave( this.m, this.count );
386
387 // __cfaabi_dbg_print_safe( "MGUARD : left\n" );
388
389 // Restore thread context
390 active_thread()->monitors = this.prev;
391}
392
393// Ctor for monitor guard
394// Sorts monitors before entering
395void ?{}( monitor_dtor_guard_t & this, monitor$ * m [], fptr_t func, bool join ) libcfa_public {
396 // optimization
397 thread$ * thrd = active_thread();
398
399 // Store current array
400 this.m = *m;
401
402 // Save previous thread context
403 this.prev = thrd->monitors;
404
405 // Save whether we are in a join or not
406 this.join = join;
407
408 // Update thread context (needed for conditions)
409 (thrd->monitors){m, 1, func};
410
411 __dtor_enter( this.m, func, join );
412}
413
414// Dtor for monitor guard
415void ^?{}( monitor_dtor_guard_t & this ) libcfa_public {
416 // Leave the monitors in order
417 __dtor_leave( this.m, this.join );
418
419 // Restore thread context
420 active_thread()->monitors = this.prev;
421}
422
423//-----------------------------------------------------------------------------
424// Internal scheduling types
425static void ?{}(__condition_node_t & this, thread$ * waiting_thread, __lock_size_t count, uintptr_t user_info ) {
426 this.waiting_thread = waiting_thread;
427 this.count = count;
428 this.next = 0p;
429 this.user_info = user_info;
430}
431
432static void ?{}(__condition_criterion_t & this ) with( this ) {
433 ready = false;
434 target = 0p;
435 owner = 0p;
436 next = 0p;
437}
438
439static void ?{}(__condition_criterion_t & this, monitor$ * target, __condition_node_t & owner ) {
440 this.ready = false;
441 this.target = target;
442 this.owner = &owner;
443 this.next = 0p;
444}
445
446//-----------------------------------------------------------------------------
447// Internal scheduling
448void wait( condition & this, uintptr_t user_info = 0 ) libcfa_public {
449 brand_condition( this );
450
451 // Check that everything is as expected
452 assertf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
453 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
454 verifyf( this.monitor_count < 32u, "Excessive monitor count (%"PRIiFAST16")", this.monitor_count );
455
456 // Create storage for monitor context
457 monitor_ctx( this.monitors, this.monitor_count );
458
459 // Create the node specific to this wait operation
460 wait_ctx( active_thread(), user_info );
461
462 // Append the current wait operation to the ones already queued on the condition
463 // We don't need locks for that since conditions must always be waited on inside monitor mutual exclusion
464 /* paranoid */ verify( waiter.next == 0p );
465 append( this.blocked, &waiter );
466 /* paranoid */ verify( waiter.next == 1p );
467
468 // Lock all monitors (aggregates the locks as well)
469 lock_all( monitors, locks, count );
470
471 // Find the next thread(s) to run
472 __lock_size_t thread_count = 0;
473 thread$ * threads[ count ];
474 __builtin_memset( threads, 0, sizeof( threads ) );
475
476 // Save monitor states
477 monitor_save;
478
479 // Remove any duplicate threads
480 for( __lock_size_t i = 0; i < count; i++) {
481 thread$ * new_owner = next_thread( monitors[i] );
482 insert_unique( threads, thread_count, new_owner );
483 }
484
485 // Unlock the locks, we don't need them anymore
486 for(int i = 0; i < count; i++) {
487 unlock( *locks[i] );
488 }
489
490 // Wake the threads
491 for(int i = 0; i < thread_count; i++) {
492 unpark( threads[i] );
493 }
494
495 // Everything is ready to go to sleep
496 park();
497
498 // We are back, restore the owners and recursions
499 monitor_restore;
500}
501
502bool signal( condition & this ) libcfa_public {
503 if( is_empty( this ) ) { return false; }
504
505 //Check that everything is as expected
506 verify( this.monitors );
507 verify( this.monitor_count != 0 );
508
509 //Some more checking in debug
510 __cfaabi_dbg_debug_do(
511 thread$ * this_thrd = active_thread();
512 if ( this.monitor_count != this_thrd->monitors.size ) {
513 abort( "Signal on condition %p made with different number of monitor(s), expected %zi got %zi", &this, this.monitor_count, this_thrd->monitors.size );
514 }
515
516 for(int i = 0; i < this.monitor_count; i++) {
517 if ( this.monitors[i] != this_thrd->monitors[i] ) {
518 abort( "Signal on condition %p made with different monitor, expected %p got %p", &this, this.monitors[i], this_thrd->monitors[i] );
519 }
520 }
521 );
522
523 __lock_size_t count = this.monitor_count;
524
525 // Lock all monitors
526 lock_all( this.monitors, 0p, count );
527
528 //Pop the head of the waiting queue
529 __condition_node_t * node = pop_head( this.blocked );
530
531 //Add the thread to the proper AS stack
532 for(int i = 0; i < count; i++) {
533 __condition_criterion_t * crit = &node->criteria[i];
534 assert( !crit->ready );
535 push( crit->target->signal_stack, crit );
536 }
537
538 //Release
539 unlock_all( this.monitors, count );
540
541 return true;
542}
543
544bool signal_block( condition & this ) libcfa_public {
545 if( !this.blocked.head ) { return false; }
546
547 //Check that everything is as expected
548 verifyf( this.monitors != 0p, "Waiting with no monitors (%p)", this.monitors );
549 verifyf( this.monitor_count != 0, "Waiting with 0 monitors (%"PRIiFAST16")", this.monitor_count );
550
551 // Create storage for monitor context
552 monitor_ctx( this.monitors, this.monitor_count );
553
554 // Lock all monitors (aggregates the locks them as well)
555 lock_all( monitors, locks, count );
556
557
558 // Create the node specific to this wait operation
559 wait_ctx_primed( active_thread(), 0 )
560
561 //save contexts
562 monitor_save;
563
564 //Find the thread to run
565 thread$ * signallee = pop_head( this.blocked )->waiting_thread;
566 __set_owner( monitors, count, signallee );
567
568 __cfaabi_dbg_print_buffer_decl( "Kernel : signal_block condition %p (s: %p)\n", &this, signallee );
569
570 // unlock all the monitors
571 unlock_all( locks, count );
572
573 // unpark the thread we signalled
574 unpark( signallee );
575
576 //Everything is ready to go to sleep
577 park();
578
579
580 // WE WOKE UP
581
582
583 __cfaabi_dbg_print_buffer_local( "Kernel : signal_block returned\n" );
584
585 //We are back, restore the masks and recursions
586 monitor_restore;
587
588 return true;
589}
590
591// Access the user_info of the thread waiting at the front of the queue
592uintptr_t front( condition & this ) libcfa_public {
593 verifyf( !is_empty(this),
594 "Attempt to access user data on an empty condition.\n"
595 "Possible cause is not checking if the condition is empty before reading stored data."
596 );
597 return ((typeof(this.blocked.head))this.blocked.head)->user_info;
598}
599
600//-----------------------------------------------------------------------------
601// External scheduling
602// cases to handle :
603// - target already there :
604// block and wake
605// - dtor already there
606// put thread on signaller stack
607// - non-blocking
608// return else
609// - timeout
610// return timeout
611// - block
612// setup mask
613// block
614void __waitfor_internal( const __waitfor_mask_t & mask, int duration ) libcfa_public {
615 // This statment doesn't have a contiguous list of monitors...
616 // Create one!
617 __lock_size_t max = count_max( mask );
618 monitor$ * mon_storage[max];
619 __builtin_memset( mon_storage, 0, sizeof( mon_storage ) );
620 __lock_size_t actual_count = aggregate( mon_storage, mask );
621
622 __cfaabi_dbg_print_buffer_decl( "Kernel : waitfor %"PRIdFAST16" (s: %"PRIdFAST16", m: %"PRIdFAST16")\n", actual_count, mask.size, (__lock_size_t)max);
623
624 if(actual_count == 0) return;
625
626 __cfaabi_dbg_print_buffer_local( "Kernel : waitfor internal proceeding\n" );
627
628 // Create storage for monitor context
629 monitor_ctx( mon_storage, actual_count );
630
631 // Lock all monitors (aggregates the locks as well)
632 lock_all( monitors, locks, count );
633
634 {
635 // Check if the entry queue
636 thread$ * next; int index;
637 [next, index] = search_entry_queue( mask, monitors, count );
638
639 if( next ) {
640 *mask.accepted = index;
641 __acceptable_t& accepted = mask[index];
642 if( accepted.is_dtor ) {
643 __cfaabi_dbg_print_buffer_local( "Kernel : dtor already there\n" );
644 verifyf( accepted.size == 1, "ERROR: Accepted dtor has more than 1 mutex parameter." );
645
646 monitor$ * mon2dtor = accepted[0];
647 verifyf( mon2dtor->dtor_node, "ERROR: Accepted monitor has no dtor_node." );
648
649 __condition_criterion_t * dtor_crit = mon2dtor->dtor_node->criteria;
650 push( mon2dtor->signal_stack, dtor_crit );
651
652 unlock_all( locks, count );
653 }
654 else {
655 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, baton-passing\n" );
656
657 // Create the node specific to this wait operation
658 wait_ctx_primed( active_thread(), 0 );
659
660 // Save monitor states
661 monitor_save;
662
663 __cfaabi_dbg_print_buffer_local( "Kernel : baton of %"PRIdFAST16" monitors : ", count );
664 #ifdef __CFA_DEBUG_PRINT__
665 for( int i = 0; i < count; i++) {
666 __cfaabi_dbg_print_buffer_local( "%p %p ", monitors[i], monitors[i]->signal_stack.top );
667 }
668 #endif
669 __cfaabi_dbg_print_buffer_local( "\n" );
670
671 // Set the owners to be the next thread
672 __set_owner( monitors, count, next );
673
674 // unlock all the monitors
675 unlock_all( locks, count );
676
677 // unpark the thread we signalled
678 unpark( next );
679
680 //Everything is ready to go to sleep
681 park();
682
683 // We are back, restore the owners and recursions
684 monitor_restore;
685
686 __cfaabi_dbg_print_buffer_local( "Kernel : thread present, returned\n" );
687 }
688
689 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
690 return;
691 }
692 }
693
694
695 if( duration == 0 ) {
696 __cfaabi_dbg_print_buffer_local( "Kernel : non-blocking, exiting\n" );
697
698 unlock_all( locks, count );
699
700 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
701 return;
702 }
703
704
705 verifyf( duration < 0, "Timeout on waitfor statments not supported yet." );
706
707 __cfaabi_dbg_print_buffer_local( "Kernel : blocking waitfor\n" );
708
709 // Create the node specific to this wait operation
710 wait_ctx_primed( active_thread(), 0 );
711
712 monitor_save;
713 set_mask( monitors, count, mask );
714
715 for( __lock_size_t i = 0; i < count; i++) {
716 verify( monitors[i]->owner == active_thread() );
717 }
718
719 // unlock all the monitors
720 unlock_all( locks, count );
721
722 //Everything is ready to go to sleep
723 park();
724
725
726 // WE WOKE UP
727
728
729 //We are back, restore the masks and recursions
730 monitor_restore;
731
732 __cfaabi_dbg_print_buffer_local( "Kernel : exiting\n" );
733
734 __cfaabi_dbg_print_buffer_local( "Kernel : accepted %d\n", *mask.accepted);
735}
736
737//-----------------------------------------------------------------------------
738// Utilities
739
740static inline void __set_owner( monitor$ * this, thread$ * owner ) {
741 /* paranoid */ verify( this->lock.lock );
742
743 //Pass the monitor appropriately
744 this->owner = owner;
745
746 //We are passing the monitor to someone else, which means recursion level is not 0
747 this->recursion = owner ? 1 : 0;
748}
749
750static inline void __set_owner( monitor$ * monitors [], __lock_size_t count, thread$ * owner ) {
751 /* paranoid */ verify ( monitors[0]->lock.lock );
752 /* 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] );
753 monitors[0]->owner = owner;
754 monitors[0]->recursion = 1;
755 for( __lock_size_t i = 1; i < count; i++ ) {
756 /* paranoid */ verify ( monitors[i]->lock.lock );
757 /* 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] );
758 monitors[i]->owner = owner;
759 monitors[i]->recursion = 0;
760 }
761}
762
763static inline void set_mask( monitor$ * storage [], __lock_size_t count, const __waitfor_mask_t & mask ) {
764 for( __lock_size_t i = 0; i < count; i++) {
765 storage[i]->mask = mask;
766 }
767}
768
769static inline void reset_mask( monitor$ * this ) {
770 this->mask.accepted = 0p;
771 this->mask.data = 0p;
772 this->mask.size = 0;
773}
774
775static inline thread$ * next_thread( monitor$ * this ) {
776 //Check the signaller stack
777 __cfaabi_dbg_print_safe( "Kernel : mon %p AS-stack top %p\n", this, this->signal_stack.top);
778 __condition_criterion_t * urgent = pop( this->signal_stack );
779 if( urgent ) {
780 //The signaller stack is not empty,
781 //regardless of if we are ready to baton pass,
782 //we need to set the monitor as in use
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 __set_owner( this, urgent->owner->waiting_thread );
785
786 return check_condition( urgent );
787 }
788
789 // No signaller thread
790 // Get the next thread in the entry_queue
791 thread$ * new_owner = pop_head( this->entry_queue );
792 /* 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 );
793 /* paranoid */ verify( !new_owner || new_owner->link.next == 0p );
794 __set_owner( this, new_owner );
795
796 return new_owner;
797}
798
799static inline bool is_accepted( monitor$ * this, const __monitor_group_t & group ) {
800 __acceptable_t * it = this->mask.data; // Optim
801 __lock_size_t count = this->mask.size;
802
803 // Check if there are any acceptable functions
804 if( !it ) return false;
805
806 // If this isn't the first monitor to test this, there is no reason to repeat the test.
807 if( this != group[0] ) return group[0]->mask.accepted >= 0;
808
809 // For all acceptable functions check if this is the current function.
810 for( __lock_size_t i = 0; i < count; i++, it++ ) {
811 if( *it == group ) {
812 *this->mask.accepted = i;
813 return true;
814 }
815 }
816
817 // No function matched
818 return false;
819}
820
821static inline void init( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
822 for( __lock_size_t i = 0; i < count; i++) {
823 (criteria[i]){ monitors[i], waiter };
824 }
825
826 waiter.criteria = criteria;
827}
828
829static inline void init_push( __lock_size_t count, monitor$ * monitors [], __condition_node_t & waiter, __condition_criterion_t criteria [] ) {
830 for( __lock_size_t i = 0; i < count; i++) {
831 (criteria[i]){ monitors[i], waiter };
832 __cfaabi_dbg_print_safe( "Kernel : target %p = %p\n", criteria[i].target, &criteria[i] );
833 push( criteria[i].target->signal_stack, &criteria[i] );
834 }
835
836 waiter.criteria = criteria;
837}
838
839static inline void lock_all( __spinlock_t * locks [], __lock_size_t count ) {
840 for( __lock_size_t i = 0; i < count; i++ ) {
841 lock( *locks[i] __cfaabi_dbg_ctx2 );
842 }
843}
844
845static inline void lock_all( monitor$ * source [], __spinlock_t * /*out*/ locks [], __lock_size_t count ) {
846 for( __lock_size_t i = 0; i < count; i++ ) {
847 __spinlock_t * l = &source[i]->lock;
848 lock( *l __cfaabi_dbg_ctx2 );
849 if(locks) locks[i] = l;
850 }
851}
852
853static inline void unlock_all( __spinlock_t * locks [], __lock_size_t count ) {
854 for( __lock_size_t i = 0; i < count; i++ ) {
855 unlock( *locks[i] );
856 }
857}
858
859static inline void unlock_all( monitor$ * locks [], __lock_size_t count ) {
860 for( __lock_size_t i = 0; i < count; i++ ) {
861 unlock( locks[i]->lock );
862 }
863}
864
865static inline void save(
866 monitor$ * ctx [],
867 __lock_size_t count,
868 __attribute((unused)) __spinlock_t * locks [],
869 unsigned int /*out*/ recursions [],
870 __waitfor_mask_t /*out*/ masks []
871) {
872 for( __lock_size_t i = 0; i < count; i++ ) {
873 recursions[i] = ctx[i]->recursion;
874 masks[i] = ctx[i]->mask;
875 }
876}
877
878static inline void restore(
879 monitor$ * ctx [],
880 __lock_size_t count,
881 __spinlock_t * locks [],
882 unsigned int /*out*/ recursions [],
883 __waitfor_mask_t /*out*/ masks []
884) {
885 lock_all( locks, count );
886 for( __lock_size_t i = 0; i < count; i++ ) {
887 ctx[i]->recursion = recursions[i];
888 ctx[i]->mask = masks[i];
889 }
890 unlock_all( locks, count );
891}
892
893// Function has 2 different behavior
894// 1 - Marks a monitors as being ready to run
895// 2 - Checks if all the monitors are ready to run
896// if so return the thread to run
897static inline thread$ * check_condition( __condition_criterion_t * target ) {
898 __condition_node_t * node = target->owner;
899 unsigned short count = node->count;
900 __condition_criterion_t * criteria = node->criteria;
901
902 bool ready2run = true;
903
904 for( int i = 0; i < count; i++ ) {
905
906 // __cfaabi_dbg_print_safe( "Checking %p for %p\n", &criteria[i], target );
907 if( &criteria[i] == target ) {
908 criteria[i].ready = true;
909 // __cfaabi_dbg_print_safe( "True\n" );
910 }
911
912 ready2run = criteria[i].ready && ready2run;
913 }
914
915 __cfaabi_dbg_print_safe( "Kernel : Runing %i (%p)\n", ready2run, ready2run ? (thread*)node->waiting_thread : (thread*)0p );
916 return ready2run ? node->waiting_thread : 0p;
917}
918
919static inline void brand_condition( condition & this ) {
920 thread$ * thrd = active_thread();
921 if( !this.monitors ) {
922 // __cfaabi_dbg_print_safe( "Branding\n" );
923 assertf( thrd->monitors.data != 0p, "No current monitor to brand condition %p", thrd->monitors.data );
924 this.monitor_count = thrd->monitors.size;
925
926 this.monitors = (monitor$ **)malloc( this.monitor_count * sizeof( *this.monitors ) );
927 for( int i = 0; i < this.monitor_count; i++ ) {
928 this.monitors[i] = thrd->monitors[i];
929 }
930 }
931}
932
933static inline [thread$ *, int] search_entry_queue( const __waitfor_mask_t & mask, monitor$ * monitors [], __lock_size_t count ) {
934
935 __queue_t(thread$) & entry_queue = monitors[0]->entry_queue;
936
937 // For each thread in the entry-queue
938 for( thread$ ** thrd_it = &entry_queue.head;
939 (*thrd_it) != 1p;
940 thrd_it = &(*thrd_it)->link.next
941 ) {
942 // For each acceptable check if it matches
943 int i = 0;
944 __acceptable_t * end = end (mask);
945 __acceptable_t * begin = begin(mask);
946 for( __acceptable_t * it = begin; it != end; it++, i++ ) {
947 // Check if we have a match
948 if( *it == (*thrd_it)->monitors ) {
949
950 // If we have a match return it
951 // after removeing it from the entry queue
952 return [remove( entry_queue, thrd_it ), i];
953 }
954 }
955 }
956
957 return [0, -1];
958}
959
960forall(T & | sized( T ))
961static inline __lock_size_t insert_unique( T * array [], __lock_size_t & size, T * val ) {
962 if( !val ) return size;
963
964 for( __lock_size_t i = 0; i <= size; i++) {
965 if( array[i] == val ) return size;
966 }
967
968 array[size] = val;
969 size = size + 1;
970 return size;
971}
972
973static inline __lock_size_t count_max( const __waitfor_mask_t & mask ) {
974 __lock_size_t max = 0;
975 for( __lock_size_t i = 0; i < mask.size; i++ ) {
976 __acceptable_t & accepted = mask[i];
977 max += accepted.size;
978 }
979 return max;
980}
981
982static inline __lock_size_t aggregate( monitor$ * storage [], const __waitfor_mask_t & mask ) {
983 __lock_size_t size = 0;
984 for( __lock_size_t i = 0; i < mask.size; i++ ) {
985 __acceptable_t & accepted = mask[i];
986 __libcfa_small_sort( accepted.data, accepted.size );
987 for( __lock_size_t j = 0; j < accepted.size; j++) {
988 insert_unique( storage, size, accepted[j] );
989 }
990 }
991 // TODO insertion sort instead of this
992 __libcfa_small_sort( storage, size );
993 return size;
994}
995
996//-----------------------------------------------------------------------------
997// Enter routine for mutex stmt
998// Can't be accepted since a mutex stmt is effectively an anonymous routine
999// Thus we do not need a monitor group
1000void lock( monitor$ * this ) libcfa_public {
1001 thread$ * thrd = active_thread();
1002
1003 // Lock the monitor spinlock
1004 lock( this->lock __cfaabi_dbg_ctx2 );
1005
1006 __cfaabi_dbg_print_safe( "Kernel : %10p Entering mon %p (%p)\n", thrd, this, this->owner);
1007
1008 if( unlikely(0 != (0x1 & (uintptr_t)this->owner)) ) {
1009 abort( "Attempt by thread \"%.256s\" (%p) to access joined monitor %p.", thrd->self_cor.name, thrd, this );
1010 }
1011 else if( !this->owner ) {
1012 // No one has the monitor, just take it
1013 __set_owner( this, thrd );
1014
1015 __cfaabi_dbg_print_safe( "Kernel : mon is free \n" );
1016 }
1017 else if( this->owner == thrd) {
1018 // We already have the monitor, just note how many times we took it
1019 this->recursion += 1;
1020
1021 __cfaabi_dbg_print_safe( "Kernel : mon already owned \n" );
1022 }
1023 else {
1024 __cfaabi_dbg_print_safe( "Kernel : blocking \n" );
1025
1026 // Some one else has the monitor, wait in line for it
1027 /* paranoid */ verify( thrd->link.next == 0p );
1028 append( this->entry_queue, thrd );
1029 /* paranoid */ verify( thrd->link.next == 1p );
1030
1031 unlock( this->lock );
1032 park();
1033
1034 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
1035
1036 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
1037 return;
1038 }
1039
1040 __cfaabi_dbg_print_safe( "Kernel : %10p Entered mon %p\n", thrd, this);
1041
1042 /* paranoid */ verifyf( active_thread() == this->owner, "Expected owner to be %p, got %p (r: %i, m: %p)", active_thread(), this->owner, this->recursion, this );
1043 /* paranoid */ verify( this->lock.lock );
1044
1045 // Release the lock and leave
1046 unlock( this->lock );
1047 return;
1048}
1049
1050// Leave routine for mutex stmt
1051// Is just a wrapper around __leave for the is_lock trait to see
1052void unlock( monitor$ * this ) libcfa_public { __leave( this ); }
1053
1054// Local Variables: //
1055// mode: c //
1056// tab-width: 4 //
1057// End: //
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