Ignore:
Timestamp:
Aug 16, 2022, 4:01:54 PM (19 months ago)
Author:
Thierry Delisle <tdelisle@…>
Branches:
ADT, ast-experimental, master, pthread-emulation
Children:
71cf630
Parents:
ee0176b
Message:

Fixed potential false sharing on ready-schedule mutate lock

File:
1 edited

Legend:

Unmodified
Added
Removed
  • libcfa/src/concurrency/kernel/cluster.cfa

    ree0176b r741e22c  
    9393//=======================================================================
    9494void  ?{}(__scheduler_RWLock_t & this) {
    95         this.max   = __max_processors();
    96         this.alloc = 0;
    97         this.ready = 0;
    98         this.data  = alloc(this.max);
    99         this.write_lock  = false;
    100 
    101         /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.alloc), &this.alloc));
    102         /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.ready), &this.ready));
     95        this.lock.max   = __max_processors();
     96        this.lock.alloc = 0;
     97        this.lock.ready = 0;
     98        this.lock.data  = alloc(this.lock.max);
     99        this.lock.write_lock  = false;
     100
     101        /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.lock.alloc), &this.lock.alloc));
     102        /*paranoid*/ verify(__atomic_is_lock_free(sizeof(this.lock.ready), &this.lock.ready));
    103103
    104104}
    105105void ^?{}(__scheduler_RWLock_t & this) {
    106         free(this.data);
     106        free(this.lock.data);
    107107}
    108108
     
    110110//=======================================================================
    111111// Lock-Free registering/unregistering of threads
    112 unsigned register_proc_id( void ) with(*__scheduler_lock) {
     112unsigned register_proc_id( void ) with(__scheduler_lock->lock) {
    113113        __kernel_rseq_register();
    114114
     
    132132        }
    133133
    134         if(max <= alloc) abort("Trying to create more than %ud processors", __scheduler_lock->max);
     134        if(max <= alloc) abort("Trying to create more than %ud processors", __scheduler_lock->lock.max);
    135135
    136136        // Step - 2 : F&A to get a new spot in the array.
    137137        uint_fast32_t n = __atomic_fetch_add(&alloc, 1, __ATOMIC_SEQ_CST);
    138         if(max <= n) abort("Trying to create more than %ud processors", __scheduler_lock->max);
     138        if(max <= n) abort("Trying to create more than %ud processors", __scheduler_lock->lock.max);
    139139
    140140        // Step - 3 : Mark space as used and then publish it.
     
    154154}
    155155
    156 void unregister_proc_id( unsigned id ) with(*__scheduler_lock) {
     156void unregister_proc_id( unsigned id ) with(__scheduler_lock->lock) {
    157157        /* paranoid */ verify(id < ready);
    158158        /* paranoid */ verify(id == kernelTLS().sched_id);
     
    169169// Writer side : acquire when changing the ready queue, e.g. adding more
    170170//  queues or removing them.
    171 uint_fast32_t ready_mutate_lock( void ) with(*__scheduler_lock) {
     171uint_fast32_t ready_mutate_lock( void ) with(__scheduler_lock->lock) {
    172172        /* paranoid */ verify( ! __preemption_enabled() );
    173173
     
    196196}
    197197
    198 void ready_mutate_unlock( uint_fast32_t last_s ) with(*__scheduler_lock) {
     198void ready_mutate_unlock( uint_fast32_t last_s ) with(__scheduler_lock->lock) {
    199199        /* paranoid */ verify( ! __preemption_enabled() );
    200200
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