Ignore:
Timestamp:
Dec 27, 2020, 5:59:35 PM (3 years ago)
Author:
Peter A. Buhr <pabuhr@…>
Branches:
ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum
Children:
9536761, ee56a4f
Parents:
62a7cc0 (diff), ac5816d (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.
Message:

Merge branch 'master' of plg.uwaterloo.ca:software/cfa/cfa-cc

File:
1 edited

Legend:

Unmodified
Added
Removed
  • libcfa/src/concurrency/locks.cfa

    r62a7cc0 r1e6f632f  
    55#include <stdlib.hfa>
    66
    7 ///////////////////////////////////////////////////////////////////
    8 //// info_thread
    9 ///////////////////////////////////////////////////////////////////
    10 
     7//-----------------------------------------------------------------------------
     8// info_thread
    119forall(dtype L | is_blocking_lock(L)) {
    12         void ?{}( info_thread(L) & this, $thread * t ) {
    13                 ((Seqable &) this){};
    14                 this.t = t;
    15                 this.lock = 0p;
    16         }
    17 
    18         void ?{}( info_thread(L) & this, $thread * t, uintptr_t info ) {
     10        struct info_thread {
     11                // used to put info_thread on a dl queue (aka sequence)
     12                inline Seqable;
     13
     14                // waiting thread
     15                struct $thread * t;
     16
     17                // shadow field
     18                uintptr_t info;
     19
     20                // lock that is passed to wait() (if one is passed)
     21                L * lock;
     22
     23                // true when signalled and false when timeout wakes thread
     24                bool signalled;
     25        };
     26
     27        void ?{}( info_thread(L) & this, $thread * t, uintptr_t info, L * l ) {
    1928                ((Seqable &) this){};
    2029                this.t = t;
    2130                this.info = info;
    22                 this.lock = 0p;
    23         }
    24 
    25         void ^?{}( info_thread(L) & this ){ }
     31                this.lock = l;
     32        }
     33
     34        void ^?{}( info_thread(L) & this ) {}
    2635
    2736        info_thread(L) *& Back( info_thread(L) * this ) {
     
    3443}
    3544
    36 ///////////////////////////////////////////////////////////////////
    37 //// Blocking Locks
    38 ///////////////////////////////////////////////////////////////////
    39 
     45//-----------------------------------------------------------------------------
     46// Blocking Locks
    4047void ?{}( blocking_lock & this, bool multi_acquisition, bool strict_owner ) {
    4148        this.lock{};
     
    4956
    5057void ^?{}( blocking_lock & this ) {}
    51 void ?{}( single_acquisition_lock & this ) {((blocking_lock &)this){ false, false };}
     58void  ?{}( single_acquisition_lock & this ) {((blocking_lock &)this){ false, false };}
    5259void ^?{}( single_acquisition_lock & this ) {}
    53 void ?{}( owner_lock & this ) {((blocking_lock &)this){ true, true };}
     60void  ?{}( owner_lock & this ) {((blocking_lock &)this){ true, true };}
    5461void ^?{}( owner_lock & this ) {}
    55 void ?{}( multiple_acquisition_lock & this ) {((blocking_lock &)this){ true, false };}
     62void  ?{}( multiple_acquisition_lock & this ) {((blocking_lock &)this){ true, false };}
    5663void ^?{}( multiple_acquisition_lock & this ) {}
    5764
    5865void lock( blocking_lock & this ) with( this ) {
    5966        lock( lock __cfaabi_dbg_ctx2 );
    60         if ( owner == active_thread() && !multi_acquisition) { // single acquisition lock is held by current thread
    61                 abort("A single acquisition lock holder attempted to reacquire the lock resulting in a deadlock.");
    62         } else if ( owner != 0p && owner != active_thread() ) { // lock is held by some other thread
    63                 addTail( blocked_threads, *active_thread() );
     67        $thread * thrd = active_thread();
     68
     69        // single acquisition lock is held by current thread
     70        /* paranoid */ verifyf( owner != thrd || multi_acquisition, "Single acquisition lock holder (%p) attempted to reacquire the lock %p resulting in a deadlock.", owner, &this );
     71
     72        // lock is held by some other thread
     73        if ( owner != 0p && owner != thrd ) {
     74                addTail( blocked_threads, *thrd );
    6475                wait_count++;
    6576                unlock( lock );
    6677                park( );
    67         } else if ( owner == active_thread() && multi_acquisition ) { // multi acquisition lock is held by current thread
     78        }
     79        // multi acquisition lock is held by current thread
     80        else if ( owner == thrd && multi_acquisition ) {
    6881                recursion_count++;
    6982                unlock( lock );
    70         } else { // lock isn't held
    71                 owner = active_thread();
     83        }
     84        // lock isn't held
     85        else {
     86                owner = thrd;
    7287                recursion_count = 1;
    7388                unlock( lock );
     
    7893        bool ret = false;
    7994        lock( lock __cfaabi_dbg_ctx2 );
    80         if ( owner == 0p ) { // lock isn't held
     95
     96        // lock isn't held
     97        if ( owner == 0p ) {
    8198                owner = active_thread();
    8299                recursion_count = 1;
    83100                ret = true;
    84         } else if ( owner == active_thread() && multi_acquisition ) { // multi acquisition lock is held by current thread
     101        }
     102        // multi acquisition lock is held by current thread
     103        else if ( owner == active_thread() && multi_acquisition ) {
    85104                recursion_count++;
    86105                ret = true;
    87106        }
     107
    88108        unlock( lock );
    89109        return ret;
    90 }
    91 
    92 void unlock_error_check( blocking_lock & this ) with( this ) {
    93         if ( owner == 0p ){ // lock isn't held
    94                 abort( "There was an attempt to release a lock that isn't held" );
    95         } else if ( strict_owner && owner != active_thread() ) {
    96                 abort( "A thread other than the owner attempted to release an owner lock" );
    97         }
    98110}
    99111
     
    108120void unlock( blocking_lock & this ) with( this ) {
    109121        lock( lock __cfaabi_dbg_ctx2 );
    110         unlock_error_check( this );
     122        /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this );
     123        /* paranoid */ verifyf( owner == active_thread() || !strict_owner, "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this );
     124
     125        // if recursion count is zero release lock and set new owner if one is waiting
    111126        recursion_count--;
    112         if ( recursion_count == 0 ) { // if recursion count is zero release lock and set new owner if one is waiting
     127        if ( recursion_count == 0 ) {
    113128                pop_and_set_new_owner( this );
    114129        }
     
    129144
    130145void on_notify( blocking_lock & this, $thread * t ) with( this ) {
    131     lock( lock __cfaabi_dbg_ctx2 );
    132         if ( owner != 0p ) { // lock held
     146        lock( lock __cfaabi_dbg_ctx2 );
     147        // lock held
     148        if ( owner != 0p ) {
    133149                addTail( blocked_threads, *t );
    134150                wait_count++;
    135151                unlock( lock );
    136         } else {        // lock not held
     152        }
     153        // lock not held
     154        else {
    137155                owner = t;
    138156                recursion_count = 1;
     
    143161
    144162void on_wait( blocking_lock & this ) with( this ) {
    145     lock( lock __cfaabi_dbg_ctx2 );
    146         unlock_error_check( this );
     163        lock( lock __cfaabi_dbg_ctx2 );
     164        /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this );
     165        /* paranoid */ verifyf( owner == active_thread() || !strict_owner, "Thread %p other than the owner %p attempted to release owner lock %p", owner, active_thread(), &this );
     166
    147167        pop_and_set_new_owner( this );
    148168        unlock( lock );
    149169}
    150170
    151 ///////////////////////////////////////////////////////////////////
    152 //// Overloaded routines for traits
    153 ///////////////////////////////////////////////////////////////////
    154 
     171//-----------------------------------------------------------------------------
     172// Overloaded routines for traits
    155173// These routines are temporary until an inheritance bug is fixed
    156 
    157 void lock( single_acquisition_lock & this ){ lock( (blocking_lock &)this ); }
    158 void unlock( single_acquisition_lock & this ){ unlock( (blocking_lock &)this ); }
    159 void on_notify( single_acquisition_lock & this, struct $thread * t ){ on_notify( (blocking_lock &)this, t ); }
    160 void on_wait( single_acquisition_lock & this ){ on_wait( (blocking_lock &)this ); }
    161 void set_recursion_count( single_acquisition_lock & this, size_t recursion ){ set_recursion_count( (blocking_lock &)this, recursion ); }
    162 size_t get_recursion_count( single_acquisition_lock & this ){ return get_recursion_count( (blocking_lock &)this ); }
    163 
    164 void lock( owner_lock & this ){ lock( (blocking_lock &)this ); }
    165 void unlock( owner_lock & this ){ unlock( (blocking_lock &)this ); }
    166 void on_notify( owner_lock & this, struct $thread * t ){ on_notify( (blocking_lock &)this, t ); }
    167 void on_wait( owner_lock & this ){ on_wait( (blocking_lock &)this ); }
    168 void set_recursion_count( owner_lock & this, size_t recursion ){ set_recursion_count( (blocking_lock &)this, recursion ); }
    169 size_t get_recursion_count( owner_lock & this ){ return get_recursion_count( (blocking_lock &)this ); }
    170 
    171 void lock( multiple_acquisition_lock & this ){ lock( (blocking_lock &)this ); }
    172 void unlock( multiple_acquisition_lock & this ){ unlock( (blocking_lock &)this ); }
    173 void on_notify( multiple_acquisition_lock & this, struct $thread * t ){ on_notify( (blocking_lock &)this, t ); }
    174 void on_wait( multiple_acquisition_lock & this ){ on_wait( (blocking_lock &)this ); }
    175 void set_recursion_count( multiple_acquisition_lock & this, size_t recursion ){ set_recursion_count( (blocking_lock &)this, recursion ); }
     174void   lock      ( single_acquisition_lock & this ) { lock   ( (blocking_lock &)this ); }
     175void   unlock    ( single_acquisition_lock & this ) { unlock ( (blocking_lock &)this ); }
     176void   on_wait   ( single_acquisition_lock & this ) { on_wait( (blocking_lock &)this ); }
     177void   on_notify ( single_acquisition_lock & this, struct $thread * t ) { on_notify( (blocking_lock &)this, t ); }
     178void   set_recursion_count( single_acquisition_lock & this, size_t recursion ) { set_recursion_count( (blocking_lock &)this, recursion ); }
     179size_t get_recursion_count( single_acquisition_lock & this ) { return get_recursion_count( (blocking_lock &)this ); }
     180
     181void   lock     ( owner_lock & this ) { lock   ( (blocking_lock &)this ); }
     182void   unlock   ( owner_lock & this ) { unlock ( (blocking_lock &)this ); }
     183void   on_wait  ( owner_lock & this ) { on_wait( (blocking_lock &)this ); }
     184void   on_notify( owner_lock & this, struct $thread * t ) { on_notify( (blocking_lock &)this, t ); }
     185void   set_recursion_count( owner_lock & this, size_t recursion ) { set_recursion_count( (blocking_lock &)this, recursion ); }
     186size_t get_recursion_count( owner_lock & this ) { return get_recursion_count( (blocking_lock &)this ); }
     187
     188void   lock     ( multiple_acquisition_lock & this ) { lock   ( (blocking_lock &)this ); }
     189void   unlock   ( multiple_acquisition_lock & this ) { unlock ( (blocking_lock &)this ); }
     190void   on_wait  ( multiple_acquisition_lock & this ) { on_wait( (blocking_lock &)this ); }
     191void   on_notify( multiple_acquisition_lock & this, struct $thread * t ){ on_notify( (blocking_lock &)this, t ); }
     192void   set_recursion_count( multiple_acquisition_lock & this, size_t recursion ){ set_recursion_count( (blocking_lock &)this, recursion ); }
    176193size_t get_recursion_count( multiple_acquisition_lock & this ){ return get_recursion_count( (blocking_lock &)this ); }
    177194
    178 ///////////////////////////////////////////////////////////////////
    179 //// condition variable
    180 ///////////////////////////////////////////////////////////////////
    181 
     195//-----------------------------------------------------------------------------
     196// alarm node wrapper
    182197forall(dtype L | is_blocking_lock(L)) {
     198        struct alarm_node_wrap {
     199                alarm_node_t alarm_node;
     200                condition_variable(L) * cond;
     201                info_thread(L) * i;
     202        };
     203
     204        void ?{}( alarm_node_wrap(L) & this, Time alarm, Duration period, Alarm_Callback callback, condition_variable(L) * c, info_thread(L) * i ) {
     205                this.alarm_node{ callback, alarm, period };
     206                this.cond = c;
     207                this.i = i;
     208        }
     209
     210        void ^?{}( alarm_node_wrap(L) & this ) { }
    183211
    184212        void timeout_handler ( alarm_node_wrap(L) & this ) with( this ) {
    185         // This condition_variable member is called from the kernel, and therefore, cannot block, but it can spin.
    186             lock( cond->lock __cfaabi_dbg_ctx2 );
    187 
    188             // this check is necessary to avoid a race condition since this timeout handler
    189             //  may still be called after a thread has been removed from the queue but
    190             //  before the alarm is unregistered
    191             if ( listed(i) ) {                                                  // is thread on queue
    192                 i->signalled = false;
    193                         remove( cond->blocked_threads, *i );    // remove this thread O(1)
     213                // This condition_variable member is called from the kernel, and therefore, cannot block, but it can spin.
     214                lock( cond->lock __cfaabi_dbg_ctx2 );
     215
     216                // this check is necessary to avoid a race condition since this timeout handler
     217                //      may still be called after a thread has been removed from the queue but
     218                //      before the alarm is unregistered
     219                if ( listed(i) ) {      // is thread on queue
     220                        i->signalled = false;
     221                        // remove this thread O(1)
     222                        remove( cond->blocked_threads, *i );
    194223                        cond->count--;
    195224                        if( i->lock ) {
    196                                 on_notify(*i->lock, i->t);                      // call lock's on_notify if a lock was passed
    197                 } else {
    198                         unpark( i->t );                                         // otherwise wake thread
    199                 }
    200             }
    201             unlock( cond->lock );
     225                                // call lock's on_notify if a lock was passed
     226                                on_notify(*i->lock, i->t);
     227                        } else {
     228                                // otherwise wake thread
     229                                unpark( i->t );
     230                        }
     231                }
     232                unlock( cond->lock );
    202233        }
    203234
    204235        // this casts the alarm node to our wrapped type since we used type erasure
    205236        void alarm_node_wrap_cast( alarm_node_t & a ) { timeout_handler( (alarm_node_wrap(L) &)a ); }
     237}
     238
     239//-----------------------------------------------------------------------------
     240// condition variable
     241forall(dtype L | is_blocking_lock(L)) {
    206242
    207243        void ?{}( condition_variable(L) & this ){
     
    212248
    213249        void ^?{}( condition_variable(L) & this ){ }
    214 
    215         void ?{}( alarm_node_wrap(L) & this, Time alarm, Duration period, Alarm_Callback callback ) {
    216                 this.alarm_node{ callback, alarm, period };
    217         }
    218 
    219         void ^?{}( alarm_node_wrap(L) & this ) { }
    220250
    221251        void process_popped( condition_variable(L) & this, info_thread(L) & popped ) with( this ) {
     
    224254                        count--;
    225255                        if (popped.lock) {
    226                                 on_notify(*popped.lock, popped.t); // if lock passed call on_notify
     256                                // if lock passed call on_notify
     257                                on_notify(*popped.lock, popped.t);
    227258                        } else {
    228                                 unpark(popped.t); // otherwise wake thread
     259                                // otherwise wake thread
     260                                unpark(popped.t);
    229261                        }
    230262                }
     
    258290
    259291        size_t queue_and_get_recursion( condition_variable(L) & this, info_thread(L) * i ) with(this) {
    260                 addTail( blocked_threads, *i ); // add info_thread to waiting queue
     292                // add info_thread to waiting queue
     293                addTail( blocked_threads, *i );
    261294                count++;
    262295                size_t recursion_count = 0;
    263                 if (i->lock) { // if lock was passed get recursion count to reset to after waking thread
     296                if (i->lock) {
     297                        // if lock was passed get recursion count to reset to after waking thread
    264298                        recursion_count = get_recursion_count(*i->lock);
    265299                        on_wait( *i->lock );
     
    273307                size_t recursion_count = queue_and_get_recursion(this, &i);
    274308                unlock( lock );
    275                 park( ); // blocks here
    276                 if (i.lock) set_recursion_count(*i.lock, recursion_count); // resets recursion count here after waking
    277         }
     309
     310                // blocks here
     311                park( );
     312
     313                // resets recursion count here after waking
     314                if (i.lock) set_recursion_count(*i.lock, recursion_count);
     315        }
     316
     317        #define WAIT( u, l ) \
     318                info_thread( L ) i = { active_thread(), u, l }; \
     319                queue_info_thread( this, i );
    278320
    279321        // helper for wait()'s' with a timeout
     
    281323                lock( lock __cfaabi_dbg_ctx2 );
    282324                size_t recursion_count = queue_and_get_recursion(this, &info);
    283                 alarm_node_wrap(L) node_wrap = { t, 0`s, alarm_node_wrap_cast };
    284                 node_wrap.cond = &this;
    285                 node_wrap.i = &info;
     325                alarm_node_wrap(L) node_wrap = { t, 0`s, alarm_node_wrap_cast, &this, &info };
    286326                register_self( &node_wrap.alarm_node );
    287327                unlock( lock );
     328
     329                // blocks here
    288330                park();
    289                 unregister_self( &node_wrap.alarm_node ); // unregisters alarm so it doesn't go off if this happens first
    290                 if (info.lock) set_recursion_count(*info.lock, recursion_count); // resets recursion count here after waking
    291         }
    292 
    293         void wait( condition_variable(L) & this ) with(this) {
    294                 info_thread( L ) i = { active_thread() };
    295                 queue_info_thread( this, i );
    296         }
    297 
    298         void wait( condition_variable(L) & this, uintptr_t info ) with(this) {
    299                 info_thread( L ) i = { active_thread(), info };
    300                 queue_info_thread( this, i );
    301         }
    302        
    303         bool wait( condition_variable(L) & this, Duration duration ) with(this) {
    304                 info_thread( L ) i = { active_thread() };
    305                 queue_info_thread_timeout(this, i, __kernel_get_time() + duration );
     331
     332                // unregisters alarm so it doesn't go off if this happens first
     333                unregister_self( &node_wrap.alarm_node );
     334
     335                // resets recursion count here after waking
     336                if (info.lock) set_recursion_count(*info.lock, recursion_count);
     337        }
     338
     339        #define WAIT_TIME( u, l, t ) \
     340                info_thread( L ) i = { active_thread(), u, l }; \
     341                queue_info_thread_timeout(this, i, t ); \
    306342                return i.signalled;
    307         }
    308 
    309         bool wait( condition_variable(L) & this, uintptr_t info, Duration duration ) with(this) {
    310                 info_thread( L ) i = { active_thread(), info };
    311                 queue_info_thread_timeout(this, i, __kernel_get_time() + duration );
    312                 return i.signalled;
    313         }
    314 
    315         bool wait( condition_variable(L) & this, Time time ) with(this) {
    316                 info_thread( L ) i = { active_thread() };
    317                 queue_info_thread_timeout(this, i, time);
    318                 return i.signalled;
    319         }
    320 
    321         bool wait( condition_variable(L) & this, uintptr_t info, Time time ) with(this) {
    322                 info_thread( L ) i = { active_thread(), info };
    323                 queue_info_thread_timeout(this, i, time);
    324                 return i.signalled;
    325         }
    326 
    327         void wait( condition_variable(L) & this, L & l ) with(this) {
    328                 info_thread(L) i = { active_thread() };
    329                 i.lock = &l;
    330                 queue_info_thread( this, i );
    331         }
    332 
    333         void wait( condition_variable(L) & this, L & l, uintptr_t info ) with(this) {
    334                 info_thread(L) i = { active_thread(), info };
    335                 i.lock = &l;
    336                 queue_info_thread( this, i );
    337         }
    338        
    339         bool wait( condition_variable(L) & this, L & l, Duration duration ) with(this) {
    340                 info_thread(L) i = { active_thread() };
    341                 i.lock = &l;
    342                 queue_info_thread_timeout(this, i, __kernel_get_time() + duration );
    343                 return i.signalled;
    344         }
    345        
    346         bool wait( condition_variable(L) & this, L & l, uintptr_t info, Duration duration ) with(this) {
    347                 info_thread(L) i = { active_thread(), info };
    348                 i.lock = &l;
    349                 queue_info_thread_timeout(this, i, __kernel_get_time() + duration );
    350                 return i.signalled;
    351         }
    352        
    353         bool wait( condition_variable(L) & this, L & l, Time time ) with(this) {
    354                 info_thread(L) i = { active_thread() };
    355                 i.lock = &l;
    356                 queue_info_thread_timeout(this, i, time );
    357                 return i.signalled;
    358         }
    359        
    360         bool wait( condition_variable(L) & this, L & l, uintptr_t info, Time time ) with(this) {
    361                 info_thread(L) i = { active_thread(), info };
    362                 i.lock = &l;
    363                 queue_info_thread_timeout(this, i, time );
    364                 return i.signalled;
    365         }
    366 }
     343
     344        void wait( condition_variable(L) & this                        ) with(this) { WAIT( 0, 0p    ) }
     345        void wait( condition_variable(L) & this, uintptr_t info        ) with(this) { WAIT( info, 0p ) }
     346        void wait( condition_variable(L) & this, L & l                 ) with(this) { WAIT( 0, &l    ) }
     347        void wait( condition_variable(L) & this, L & l, uintptr_t info ) with(this) { WAIT( info, &l ) }
     348
     349        bool wait( condition_variable(L) & this, Duration duration                        ) with(this) { WAIT_TIME( 0   , 0p , __kernel_get_time() + duration ) }
     350        bool wait( condition_variable(L) & this, uintptr_t info, Duration duration        ) with(this) { WAIT_TIME( info, 0p , __kernel_get_time() + duration ) }
     351        bool wait( condition_variable(L) & this, Time time                                ) with(this) { WAIT_TIME( 0   , 0p , time ) }
     352        bool wait( condition_variable(L) & this, uintptr_t info, Time time                ) with(this) { WAIT_TIME( info, 0p , time ) }
     353        bool wait( condition_variable(L) & this, L & l, Duration duration                 ) with(this) { WAIT_TIME( 0   , &l , __kernel_get_time() + duration ) }
     354        bool wait( condition_variable(L) & this, L & l, uintptr_t info, Duration duration ) with(this) { WAIT_TIME( info, &l , __kernel_get_time() + duration ) }
     355        bool wait( condition_variable(L) & this, L & l, Time time                         ) with(this) { WAIT_TIME( 0   , &l , time ) }
     356        bool wait( condition_variable(L) & this, L & l, uintptr_t info, Time time         ) with(this) { WAIT_TIME( info, &l , time ) }
     357}
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