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 "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;
 
        OperationQueue *queue = self->locals.queue;
        if (queue) {
          synchronized(queue->locals.condition, {
            $(queue->locals.condition, signal);
          });
        }
      }
    }
  }
}
 
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(Array), 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->isDispatched || 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);
  });
}
 
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