source: src/libcfa/concurrency/monitor.c @ a933dcf4

aaron-thesisarm-ehcleanup-dtorsdeferred_resndemanglerjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerresolv-newwith_gc
Last change on this file since a933dcf4 was a933dcf4, checked in by Thierry Delisle <tdelisle@…>, 4 years ago
  • updated internal scheduler test for multi monitors
  • fixed branding for monitors
  • Property mode set to 100644
File size: 11.2 KB
Line 
1//                              -*- Mode: CFA -*-
2//
3// Cforall Version 1.0.0 Copyright (C) 2016 University of Waterloo
4//
5// The contents of this file are covered under the licence agreement in the
6// file "LICENCE" distributed with Cforall.
7//
8// monitor_desc.c --
9//
10// Author           : Thierry Delisle
11// Created On       : Thd Feb 23 12:27:26 2017
12// Last Modified By : Thierry Delisle
13// Last Modified On : --
14// Update Count     : 0
15//
16
17#include "monitor"
18
19#include <stdlib>
20
21#include "kernel_private.h"
22#include "libhdr.h"
23
24//-----------------------------------------------------------------------------
25// Forward declarations
26static inline void set_owner( monitor_desc * this, thread_desc * owner );
27static inline thread_desc * next_thread( monitor_desc * this );
28
29static inline void lock_all( spinlock ** locks, unsigned short count );
30static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count );
31static inline void unlock_all( spinlock ** locks, unsigned short count );
32static inline void unlock_all( monitor_desc ** locks, unsigned short count );
33
34static inline void save_recursion   ( monitor_desc ** ctx, unsigned int * /*out*/ recursions, unsigned short count );
35static inline void restore_recursion( monitor_desc ** ctx, unsigned int * /*in */ recursions, unsigned short count );
36
37static inline thread_desc * check_condition( __condition_criterion_t * );
38static inline void brand_condition( condition * );
39static inline unsigned short insert_unique( thread_desc ** thrds, unsigned short end, thread_desc * val );
40
41//-----------------------------------------------------------------------------
42// Enter/Leave routines
43
44
45extern "C" {
46        void __enter_monitor_desc(monitor_desc * this) {
47                lock( &this->lock );
48                thread_desc * thrd = this_thread();
49
50                LIB_DEBUG_PRINT_SAFE("%p Entering %p (o: %p, r: %i)\n", thrd, this, this->owner, this->recursion);
51
52                if( !this->owner ) {
53                        //No one has the monitor, just take it
54                        set_owner( this, thrd );
55                }
56                else if( this->owner == thrd) {
57                        //We already have the monitor, just not how many times we took it
58                        assert( this->recursion > 0 );
59                        this->recursion += 1;
60                }
61                else {
62                        //Some one else has the monitor, wait in line for it
63                        append( &this->entry_queue, thrd );
64                        ScheduleInternal( &this->lock );
65
66                        //ScheduleInternal will unlock spinlock, no need to unlock ourselves
67                        return; 
68                }
69
70                unlock( &this->lock );
71                return;
72        }
73
74        // leave pseudo code :
75        //      TODO
76        void __leave_monitor_desc(monitor_desc * this) {
77                lock( &this->lock );
78
79                thread_desc * thrd = this_thread();
80
81                LIB_DEBUG_PRINT_SAFE("%p Leaving %p (o: %p, r: %i)\n", thrd, this, this->owner, this->recursion);
82                assertf( thrd == this->owner, "Expected owner to be %p, got %p (r: %i)", thrd, this->owner, this->recursion );
83
84                //Leaving a recursion level, decrement the counter
85                this->recursion -= 1;
86
87                //If we haven't left the last level of recursion
88                //it means we don't need to do anything
89                if( this->recursion != 0) {
90                        unlock( &this->lock );
91                        return;
92                }
93
94                thread_desc * new_owner = next_thread( this );
95
96                //We can now let other threads in safely
97                unlock( &this->lock );
98
99                //We need to wake-up the thread
100                ScheduleThread( new_owner );
101        }
102}
103
104static inline void enter(monitor_desc ** monitors, int count) {
105        for(int i = 0; i < count; i++) {
106                __enter_monitor_desc( monitors[i] );
107        }
108}
109
110static inline void leave(monitor_desc ** monitors, int count) {
111        for(int i = count - 1; i >= 0; i--) {
112                __leave_monitor_desc( monitors[i] );
113        }
114}
115
116void ?{}( monitor_guard_t * this, monitor_desc ** m, int count ) {
117        this->m = m;
118        this->count = count;
119        qsort(this->m, count);
120        enter( this->m, this->count );
121
122        this->prev_mntrs = this_thread()->current_monitors;
123        this->prev_count = this_thread()->current_monitor_count;
124
125        this_thread()->current_monitors      = m;
126        this_thread()->current_monitor_count = count;
127}
128
129void ^?{}( monitor_guard_t * this ) {
130        leave( this->m, this->count );
131
132        this_thread()->current_monitors      = this->prev_mntrs;
133        this_thread()->current_monitor_count = this->prev_count;
134}
135
136void debug_break() __attribute__(( noinline ))
137{
138       
139}
140
141//-----------------------------------------------------------------------------
142// Internal scheduling
143void wait( condition * this ) {
144        LIB_DEBUG_PRINT_SAFE("Waiting\n");
145
146        brand_condition( this );
147
148        //Check that everything is as expected
149        assertf( this->monitors != NULL, "Waiting with no monitors (%p)", this->monitors );
150        assertf( this->monitor_count != 0, "Waiting with 0 monitors (%i)", this->monitor_count );
151
152        unsigned short count = this->monitor_count;
153        unsigned int recursions[ count ];               //Save the current recursion levels to restore them later
154        spinlock *   locks     [ count ];               //We need to pass-in an array of locks to ScheduleInternal
155
156        LIB_DEBUG_PRINT_SAFE("count %i\n", count);
157
158        __condition_node_t waiter;
159        waiter.waiting_thread = this_thread();
160        waiter.count = count;
161        waiter.next = NULL;
162
163        __condition_criterion_t criteria[count];
164        for(int i = 0; i < count; i++) {
165                criteria[i].ready  = false;
166                criteria[i].target = this->monitors[i];
167                criteria[i].owner  = &waiter;
168                criteria[i].next   = NULL;
169                LIB_DEBUG_PRINT_SAFE( "Criterion %p\n", &criteria[i] );
170        }
171
172        waiter.criteria = criteria;
173        append( &this->blocked, &waiter );
174
175        lock_all( this->monitors, locks, count );
176        save_recursion( this->monitors, recursions, count );
177        //DON'T unlock, ask the kernel to do it
178
179        //Find the next thread(s) to run
180        unsigned short thread_count = 0;
181        thread_desc * threads[ count ];
182        for(int i = 0; i < count; i++) {
183                threads[i] = 0;
184        }
185
186        debug_break();
187
188        for( int i = 0; i < count; i++) {
189                thread_desc * new_owner = next_thread( this->monitors[i] );
190                thread_count = insert_unique( threads, thread_count, new_owner );
191        }
192
193        debug_break();
194
195        LIB_DEBUG_PRINT_SAFE("Will unblock: ");
196        for(int i = 0; i < thread_count; i++) {
197                LIB_DEBUG_PRINT_SAFE("%p ", threads[i]);
198        }
199        LIB_DEBUG_PRINT_SAFE("\n");
200
201        // Everything is ready to go to sleep
202        ScheduleInternal( locks, count, threads, thread_count );
203
204
205        //WE WOKE UP
206
207
208        //We are back, restore the owners and recursions
209        lock_all( locks, count );
210        restore_recursion( this->monitors, recursions, count );
211        unlock_all( locks, count );
212}
213
214void signal( condition * this ) {
215        if( !this->blocked.head ) {
216                LIB_DEBUG_PRINT_SAFE("Nothing to signal\n");
217                return;
218        }
219
220        //Check that everything is as expected
221        assert( this->monitors );
222        assert( this->monitor_count != 0 );
223
224        unsigned short count = this->monitor_count;
225       
226        LIB_DEBUG_DO(
227                thread_desc * this_thrd = this_thread();
228                if ( this->monitor_count != this_thrd->current_monitor_count ) {
229                        abortf( "Signal on condition %p made with different number of monitor(s), expected %i got %i", this, this->monitor_count, this_thrd->current_monitor_count );
230                } // if
231
232                for(int i = 0; i < this->monitor_count; i++) {
233                        if ( this->monitors[i] != this_thrd->current_monitors[i] ) {
234                                abortf( "Signal on condition %p made with different monitor, expected %p got %i", this, this->monitors[i], this_thrd->current_monitors[i] );
235                        } // if
236                }
237        );
238
239        lock_all( this->monitors, NULL, count );
240        LIB_DEBUG_PRINT_SAFE("Signalling");
241
242        __condition_node_t * node = pop_head( &this->blocked );
243        for(int i = 0; i < count; i++) {
244                __condition_criterion_t * crit = &node->criteria[i];
245                LIB_DEBUG_PRINT_SAFE(" %p", crit->target);
246                assert( !crit->ready );
247                push( &crit->target->signal_stack, crit );
248        }
249
250        LIB_DEBUG_PRINT_SAFE("\n");
251
252        unlock_all( this->monitors, count );
253}
254
255//-----------------------------------------------------------------------------
256// Utilities
257
258static inline void set_owner( monitor_desc * this, thread_desc * owner ) {
259        //Pass the monitor appropriately
260        this->owner = owner;
261
262        //We are passing the monitor to someone else, which means recursion level is not 0
263        this->recursion = owner ? 1 : 0;
264}
265
266static inline thread_desc * next_thread( monitor_desc * this ) {
267        //Check the signaller stack
268        __condition_criterion_t * urgent = pop( &this->signal_stack );
269        if( urgent ) {
270                //The signaller stack is not empty,
271                //regardless of if we are ready to baton pass,
272                //we need to set the monitor as in use
273                set_owner( this,  urgent->owner->waiting_thread );
274
275                return check_condition( urgent );
276        }
277
278        // No signaller thread
279        // Get the next thread in the entry_queue
280        thread_desc * new_owner = pop_head( &this->entry_queue );
281        set_owner( this, new_owner );
282
283        return new_owner;
284}
285
286static inline void lock_all( spinlock ** locks, unsigned short count ) {
287        for( int i = 0; i < count; i++ ) {
288                lock( locks[i] );
289        }
290}
291
292static inline void lock_all( monitor_desc ** source, spinlock ** /*out*/ locks, unsigned short count ) {
293        for( int i = 0; i < count; i++ ) {
294                spinlock * l = &source[i]->lock;
295                lock( l );
296                if(locks) locks[i] = l;
297        }
298}
299
300static inline void unlock_all( spinlock ** locks, unsigned short count ) {
301        for( int i = 0; i < count; i++ ) {
302                unlock( locks[i] );
303        }
304}
305
306static inline void unlock_all( monitor_desc ** locks, unsigned short count ) {
307        for( int i = 0; i < count; i++ ) {
308                unlock( &locks[i]->lock );
309        }
310}
311
312
313static inline void save_recursion   ( monitor_desc ** ctx, unsigned int * /*out*/ recursions, unsigned short count ) {
314        for( int i = 0; i < count; i++ ) {
315                recursions[i] = ctx[i]->recursion;
316        }
317}
318
319static inline void restore_recursion( monitor_desc ** ctx, unsigned int * /*in */ recursions, unsigned short count ) {
320        for( int i = 0; i < count; i++ ) {
321                ctx[i]->recursion = recursions[i];
322        }
323}
324
325// Function has 2 different behavior
326// 1 - Marks a monitors as being ready to run
327// 2 - Checks if all the monitors are ready to run
328//     if so return the thread to run
329static inline thread_desc * check_condition( __condition_criterion_t * target ) {
330        __condition_node_t * node = target->owner;
331        unsigned short count = node->count;
332        __condition_criterion_t * criteria = node->criteria;
333
334        bool ready2run = true;
335
336        for(    int i = 0; i < count; i++ ) {
337                LIB_DEBUG_PRINT_SAFE( "Checking %p for %p\n", &criteria[i], target );
338                if( &criteria[i] == target ) {
339                        criteria[i].ready = true;
340                        LIB_DEBUG_PRINT_SAFE( "True\n" );
341                }
342
343                ready2run = criteria[i].ready && ready2run;
344        }
345
346        LIB_DEBUG_PRINT_SAFE( "Runing %i\n", ready2run );
347        return ready2run ? node->waiting_thread : NULL;
348}
349
350static inline void brand_condition( condition * this ) {
351        thread_desc * thrd = this_thread();
352        if( !this->monitors ) {
353                LIB_DEBUG_PRINT_SAFE("Branding\n");
354                assertf( thrd->current_monitors != NULL, "No current monitor to brand condition", thrd->current_monitors );
355                this->monitor_count = thrd->current_monitor_count;
356
357                this->monitors = malloc( this->monitor_count * sizeof( *this->monitors ) );
358                for( int i = 0; i < this->monitor_count; i++ ) {
359                        this->monitors[i] = thrd->current_monitors[i];
360                }
361        }
362}
363
364static inline unsigned short insert_unique( thread_desc ** thrds, unsigned short end, thread_desc * val ) {
365        if( !val ) return end;
366
367        for(int i = 0; i <= end; i++) {
368                if( thrds[i] == val ) return end;
369        }
370
371        thrds[end] = val;
372        return end + 1;
373}
374
375void ?{}( __condition_blocked_queue_t * this ) {
376        this->head = NULL;
377        this->tail = &this->head;
378}
379
380void append( __condition_blocked_queue_t * this, __condition_node_t * c ) {
381        assert(this->tail != NULL);
382        *this->tail = c;
383        this->tail = &c->next;
384}
385
386__condition_node_t * pop_head( __condition_blocked_queue_t * this ) {
387        __condition_node_t * head = this->head;
388        if( head ) {
389                this->head = head->next;
390                if( !head->next ) {
391                        this->tail = &this->head;
392                }
393                head->next = NULL;
394        }
395        return head;
396}
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