Module: ConcurrentSHM

Defined in:
lib/concurrent-shm/gem.rb,
lib/concurrent-shm/channel.rb,
lib/concurrent-shm/int_ptr.rb,
ext/concurrent-shm/main.c

Overview

Shared Memory Concurrency

Defined Under Namespace

Modules: Gem, Value Classes: Channel, Condition, Mutex, Region, SharedMemory

Class Method Summary collapse

Class Method Details

.size_of(type) ⇒ Object

Calculate the number of shared memory space bytes required by instances of the specified class. Recognized classes are Mutex and Condition.

Parameters:

  • type (Class) —

    the specified class.

Raises:

  • (ArgumentError) —

    if type is not a class or is an unrecognized class.



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# File 'ext/concurrent-shm/posix.c', line 749

static VALUE size_of(VALUE self, VALUE type)
{
    UNUSED(self);

    if (!RB_TYPE_P(type, T_CLASS)) {
        rb_raise(rb_eArgError, "Expected a class");
    }

    size_t s;
    if (type == Mutex) {
        s = sizeof(struct mutex_shared);
    } else if (type == Condition) {
        s = sizeof(struct condition_shared);
    } else {
        rb_raise(rb_eArgError, "Unrecognized type");
    }

    size_t o = s % 16;
    if (o) {
        s += 16-o;
    }
    return INT2FIX(s);
}