Ignore:
Timestamp:
Feb 28, 2017, 12:40:47 PM (5 years ago)
Author:
Thierry Delisle <tdelisle@…>
Branches:
aaron-thesis, arm-eh, cleanup-dtors, deferred_resn, demangler, enum, forall-pointer-decay, jacob/cs343-translation, jenkins-sandbox, master, new-ast, new-ast-unique-expr, new-env, no_list, persistent-indexer, resolv-new, with_gc
Children:
2781e65, fd061ed3
Parents:
4868be4
Message:
  • renamed monitor to monitor_t since the type should not be exposed to users
  • added support for recursion in monitors
File:
1 edited

Legend:

Unmodified
Added
Removed
  • src/libcfa/concurrency/monitor.c

    r4868be4 rcc7f4b1  
    66// file "LICENCE" distributed with Cforall.
    77//
    8 // monitor.c --
     8// __monitor_t.c --
    99//
    1010// Author           : Thierry Delisle
     
    1919#include "kernel_private.h"
    2020
    21 void enter(monitor * this) {
     21void enter(__monitor_t * this) {
    2222        lock( &this->lock );
    2323        thread * thrd = this_thread();
    2424
    25         if( this->holder ) {
     25        if( !this->owner ) {
     26                //No one has the monitor, just take it
     27                this->owner = thrd;
     28                this->recursion = 1;
     29        }
     30        else if( this->owner == thrd) {
     31                //We already have the monitor, just not how many times we took it
     32                assert( this->recursion > 0 );
     33                this->recursion += 1;
     34        }
     35        else {
     36                //Some one else has the monitor, wait in line for it
    2637                append( &this->entry_queue, thrd );
    2738                ScheduleInternal( &this->lock );
    28                 return;
    29         }
    30         else {
    31                 this->holder = thrd;
     39
     40                //ScheduleInternal will unlock spinlock, no need to unlock ourselves
     41                return;
    3242        }
    3343
     
    3545}
    3646
    37 void leave(monitor * this) {
     47void leave(__monitor_t * this) {
    3848        lock( &this->lock );
    3949
    4050        thread * thrd = this_thread();
    41         assert( thrd == this->holder );
     51        assert( thrd == this->owner );
    4252
    43         this->holder = pop_head( &this->entry_queue );
     53        //Leaving a recursion level, decrement the counter
     54        this->recursion -= 1;
     55
     56        //If we left the last level of recursion it means we are changing who owns the monitor
     57        thread * new_owner = 0;
     58        if( this->recursion == 0) {
     59                //Get the next thread in the list
     60                new_owner = this->owner = pop_head( &this->entry_queue );
     61
     62                //We are passing the monitor to someone else, which means recursion level is not 0
     63                this->recursion = new_owner ? 1 : 0;
     64        }       
    4465
    4566        unlock( &this->lock );
    4667
    47         if( this->holder ) ScheduleThread( this->holder );
     68        //If we have a new owner, we need to wake-up the thread
     69        if( new_owner ) {
     70                ScheduleThread( new_owner );
     71        }
    4872}
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