OperationQueue.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 "OperationQueue.h"
 
#define _Class _OperationQueue
 
#pragma mark - Object
 
static Object *copy(const Object *self) {
 
    return NULL;
}
 
static void dealloc(Object *self) {
 
    OperationQueue *this = (OperationQueue *) self;
 
    $(this->locals.thread, cancel);
    $(this->locals.thread, join, NULL);
 
    release(this->locals.thread);
    release(this->locals.condition);
    release(this->locals.operations);
 
    super(Object, self, dealloc);
}
 
#pragma mark - OperationQueue
 
static void addOperation(OperationQueue *self, Operation *operation) {
 
    assert(operation);
    assert(operation->isCancelled == false);
    assert(operation->isExecuting == false);
    assert(operation->isFinished == false);
 
    synchronized(self->locals.condition, {
        $(self->locals.operations, addObject, operation);
        $(self->locals.condition, broadcast);
    });
}
 
static void cancelAllOperations(OperationQueue *self) {
 
    Array *operations = $(self, operations);
 
    for (size_t i = 0; i < operations->count; i++) {
        $((Operation *) $(operations, objectAtIndex, i), cancel);
    }
 
    release(operations);
}
 
static __thread OperationQueue *_currentQueue;
 
static OperationQueue *currentQueue(void) {
 
    return _currentQueue;
}
 
static ident run(Thread *thread) {
 
    OperationQueue *self = _currentQueue = thread->data;
 
    while (thread->isCancelled == false) {
 
        if (self->isSuspended == false) {
            Array *operations = NULL;
 
            retry:
 
            release(operations);
            operations = $(self, operations);
 
            for (size_t i = 0; i < operations->count; i++) {
 
                Operation *operation = $(operations, objectAtIndex, i);
                if ($(operation, isReady)) {
                    $(operation, start);
                    goto retry;
                }
            }
 
            release(operations);
        }
 
        const Time interval = { .tv_usec = 10 };
        Date *date = $$(Date, dateWithTimeSinceNow, &interval);
 
        synchronized(self->locals.condition, {
            $(self->locals.condition, waitUntilDate, date);
        });
 
        release(date);
    }
 
    return NULL;
}
 
static OperationQueue *init(OperationQueue *self) {
 
    self = (OperationQueue *) super(Object, self, init);
    if (self) {
 
        self->locals.condition = $(alloc(Condition), init);
        assert(self->locals.condition);
 
        self->locals.operations = $(alloc(MutableArray), init);
        assert(self->locals.operations);
 
        self->locals.thread = $(alloc(Thread), initWithFunction, run, self);
        assert(self->locals.thread);
 
        $(self->locals.thread, start);
    }
 
    return self;
}
 
static size_t operationCount(const OperationQueue *self) {
 
    size_t count;
 
    synchronized(self->locals.condition, {
        count = ((Array *) self->locals.operations)->count;
    });
 
    return count;
}
 
static Array *operations(const OperationQueue *self) {
 
    ident operations;
 
    synchronized(self->locals.condition, {
        operations = $((Object * ) self->locals.operations, copy);
    });
 
    return (Array *) operations;
}
 
static void removeOperation(OperationQueue *self, Operation *operation) {
 
    assert(operation);
    assert(operation->isExecuting == false);
 
    synchronized(self->locals.condition, {
        $(self->locals.operations, removeObject, operation);
        $(self->locals.condition, broadcast);
    });
}
 
static void waitUntilAllOperationsAreFinished(OperationQueue *self) {
 
    Array *operations = (Array *) self->locals.operations;
    while (operations->count > 0) {
 
        synchronized(self->locals.condition, {
            $(self->locals.condition, wait);
        });
    }
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
    ((ObjectInterface *) clazz->interface)->copy = copy;
    ((ObjectInterface *) clazz->interface)->dealloc = dealloc;
 
    ((OperationQueueInterface *) clazz->interface)->addOperation = addOperation;
    ((OperationQueueInterface *) clazz->interface)->cancelAllOperations = cancelAllOperations;
    ((OperationQueueInterface *) clazz->interface)->currentQueue = currentQueue;
    ((OperationQueueInterface *) clazz->interface)->init = init;
    ((OperationQueueInterface *) clazz->interface)->operationCount = operationCount;
    ((OperationQueueInterface *) clazz->interface)->operations = operations;
    ((OperationQueueInterface *) clazz->interface)->removeOperation = removeOperation;
    ((OperationQueueInterface *) clazz->interface)->waitUntilAllOperationsAreFinished = waitUntilAllOperationsAreFinished;
}
 
Class *_OperationQueue(void) {
    static Class *clazz;
    static Once once;
 
    do_once(&once, {
        clazz = _initialize(&(const ClassDef) {
            .name = "OperationQueue",
            .superclass = _Object(),
            .instanceSize = sizeof(OperationQueue),
            .interfaceOffset = offsetof(OperationQueue, interface),
            .interfaceSize = sizeof(OperationQueueInterface),
            .initialize = initialize,
        });
    });
 
    return clazz;
}
 
#undef _Class