Operation.c

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/*
 * Objectively: Ultra-lightweight object oriented framework for GNU C.
 * Copyright (C) 2014 Jay Dolan <jay@jaydolan.com>
 *
 * This software is provided 'as-is', without any express or implied
 * warranty. In no event will the authors be held liable for any damages
 * arising from the use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not
 * claim that you wrote the original software. If you use this software
 * in a product, an acknowledgment in the product documentation would be
 * appreciated but is not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source distribution.
 */
 
#include <assert.h>
 
#include "Operation.h"
#include "OperationQueue.h"
 
#define _Class _Operation
 
#pragma mark - Object
 
static Object *copy(const Object *self) {
 
    return NULL;
}
 
static void dealloc(Object *self) {
 
    Operation *this = (Operation *) self;
 
    release(this->locals.condition);
    release(this->locals.dependencies);
 
    super(Object, self, dealloc);
}
 
#pragma mark - Operation
 
static void addDependency(Operation *self, Operation *dependency) {
 
    assert(dependency);
    assert(dependency != self);
 
    assert($((Array *) self->locals.dependencies, indexOfObject, dependency) == -1);
 
    $(self->locals.dependencies, addObject, dependency);
}
 
static void cancel(Operation *self) {
 
    if (self->isCancelled == false) {
        if (self->isFinished == false) {
            if (self->isExecuting == false) {
                self->isCancelled = true;
            }
        }
    }
}
 
static Array *dependencies(const Operation *self) {
 
    ident dependencies = $((Object *) self->locals.dependencies, copy);
 
    return (Array *) dependencies;
}
 
static Operation *init(Operation *self) {
 
    self = (Operation *) super(Object, self, init);
    if (self) {
 
        self->locals.condition = $(alloc(Condition), init);
        assert(self->locals.condition);
 
        self->locals.dependencies = $(alloc(MutableArray), init);
        assert(self->locals.dependencies);
    }
 
    return self;
}
 
static Operation *initWithFunction(Operation *self, OperationFunction function, ident data) {
 
    self = $(self, init);
    if (self) {
        self->function = function;
        self->data = data;
    }
 
    return self;
}
 
static _Bool isReady(const Operation *self) {
 
    if (self->isExecuting || self->isFinished) {
        return false;
    }
 
    if (self->isCancelled) {
        return true;
    }
 
    const Array *dependencies = (Array *) self->locals.dependencies;
    for (size_t i = 0; i < dependencies->count; i++) {
 
        Operation *dependency = $(dependencies, objectAtIndex, i);
        if (dependency->isFinished == false) {
            return false;
        }
    }
 
    return true;
}
 
static void removeDepdenency(Operation *self, Operation *dependency) {
 
    assert(dependency);
 
    $(self->locals.dependencies, removeObject, dependency);
}
 
static void start(Operation *self) {
 
    if (self->isFinished || self->isExecuting) {
        return;
    }
 
    if (self->isCancelled == false) {
        self->isExecuting = true;
        self->function(self);
        self->isExecuting = false;
    }
 
    self->isFinished = true;
 
    synchronized(self->locals.condition, {
        $(self->locals.condition, broadcast);
    });
 
    OperationQueue *currentQueue = $$(OperationQueue, currentQueue);
    if (currentQueue) {
        $(currentQueue, removeOperation, self);
    }
}
 
static void waitUntilFinished(const Operation *self) {
 
    synchronized(self->locals.condition, {
        while (self->isFinished == false) {
            $(self->locals.condition, wait);
        }
    });
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
    ((ObjectInterface *) clazz->interface)->copy = copy;
    ((ObjectInterface *) clazz->interface)->dealloc = dealloc;
 
    ((OperationInterface *) clazz->interface)->addDependency = addDependency;
    ((OperationInterface *) clazz->interface)->cancel = cancel;
    ((OperationInterface *) clazz->interface)->dependencies = dependencies;
    ((OperationInterface *) clazz->interface)->init = init;
    ((OperationInterface *) clazz->interface)->initWithFunction = initWithFunction;
    ((OperationInterface *) clazz->interface)->isReady = isReady;
    ((OperationInterface *) clazz->interface)->removeDependency = removeDepdenency;
    ((OperationInterface *) clazz->interface)->start = start;
    ((OperationInterface *) clazz->interface)->waitUntilFinished = waitUntilFinished;
}
 
Class *_Operation(void) {
    static Class *clazz;
    static Once once;
 
    do_once(&once, {
        clazz = _initialize(&(const ClassDef) {
            .name = "Operation",
            .superclass = _Object(),
            .instanceSize = sizeof(Operation),
            .interfaceOffset = offsetof(Operation, interface),
            .interfaceSize = sizeof(OperationInterface),
            .initialize = initialize,
        });
    });
 
    return clazz;
}
 
#undef _Class