class Monitor

Use the Monitor class when you want to have a lock object for blocks with mutual exclusion.

require 'monitor'

lock = Monitor.new
lock.synchronize do
  # exclusive access
end

Public Instance Methods

enter → nil

Enters exclusive section.

static VALUE
monitor_enter(VALUE monitor)
{
    struct rb_monitor *mc = monitor_ptr(monitor);
    if (!mc_owner_p(mc)) {
        rb_mutex_lock(mc->mutex);
        RB_OBJ_WRITE(monitor, &mc->owner, rb_fiber_current());
        mc->count = 0;
    }
    mc->count++;
    return Qnil;
}

Also aliased as: mon_enter

exit → nil

Leaves exclusive section.

static VALUE
monitor_exit(VALUE monitor)
{
    monitor_check_owner(monitor);

    struct rb_monitor *mc = monitor_ptr(monitor);

    if (mc->count <= 0) rb_bug("monitor_exit: count:%d", (int)mc->count);
    mc->count--;

    if (mc->count == 0) {
        RB_OBJ_WRITE(monitor, &mc->owner, Qnil);
        rb_mutex_unlock(mc->mutex);
    }
    return Qnil;
}

Also aliased as: mon_exit

mon_enter

Alias for: enter

mon_exit

Alias for: exit

mon_synchronize

Alias for: synchronize

mon_try_enter

Alias for: try_enter

new_cond ()

Creates a new MonitorMixin::ConditionVariable associated with the Monitor object.

# File ext/monitor/lib/monitor.rb, line 263
def new_cond
  ::MonitorMixin::ConditionVariable.new(self)
end

synchronize { } → result of the block

Enters exclusive section and executes the block. Leaves the exclusive section automatically when the block exits. See example under MonitorMixin.

static VALUE
monitor_synchronize(VALUE monitor)
{
    monitor_enter(monitor);
    return rb_ensure(monitor_sync_body, monitor, monitor_sync_ensure, monitor);
}

Also aliased as: mon_synchronize

try_enter → true or false

Attempts to enter exclusive section. Returns false if lock fails.

static VALUE
monitor_try_enter(VALUE monitor)
{
    struct rb_monitor *mc = monitor_ptr(monitor);

    if (!mc_owner_p(mc)) {
        if (!rb_mutex_trylock(mc->mutex)) {
            return Qfalse;
        }
        RB_OBJ_WRITE(monitor, &mc->owner, rb_fiber_current());
        mc->count = 0;
    }
    mc->count += 1;
    return Qtrue;
}

Also aliased as: try_mon_enter, mon_try_enter

try_mon_enter

Alias for: try_enter