Thread.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 <errno.h>
#include <signal.h>
#include <stdlib.h>
 
#include <pthread.h>
 
#include "Thread.h"
 
#define _Class _Thread
 
#pragma mark - Object
 
static Object *copy(const Object *self) {
  return NULL;
}
 
static void dealloc(Object *self) {
 
  Thread *this = (Thread *) self;
 
  assert(this->isExecuting == false);
 
  free(this->thread);
 
  super(Object, self, dealloc);
}
 
#pragma mark - Thread
 
static void cancel(Thread *self) {
 
  assert(self->isCancelled == false);
 
  // https://stackoverflow.com/a/4760758
  // int err = pthread_cancel(*((pthread_t *) self->thread));
  // assert(err == 0);
 
  self->isCancelled = true;
}
 
static __thread Thread *_currentThread;
 
static Thread *currentThread(void) {
 
  return _currentThread;
}
 
static void detach(Thread *self) {
 
  assert(self->isDetached == false);
 
  int err = pthread_detach(*((pthread_t *) self->thread));
  assert(err == 0);
 
  self->isDetached = true;
}
 
static Thread *init(Thread *self) {
 
  return $(self, initWithFunction, NULL, NULL);
}
 
static Thread *initWithFunction(Thread *self, ThreadFunction function, ident data) {
 
  self = (Thread *) super(Object, self, init);
  if (self) {
    self->function = function;
    self->data = data;
 
    self->thread = calloc(1, sizeof(pthread_t));
    assert(self->thread);
  }
 
  return self;
}
 
static void join(Thread *self, ident *status) {
 
  int err = pthread_join(*((pthread_t *) self->thread), status);
  assert(err == 0);
}
 
static void _kill(Thread *self, int signal) {
 
  int err = pthread_kill(*((pthread_t *) self->thread), signal);
  assert(err == 0);
}
 
static ident run(ident obj) {
 
  Thread *self = _currentThread = (Thread *) obj;
 
  self->isExecuting = true;
 
  ident ret = self->function(self);
 
  self->isFinished = true;
 
  self->isExecuting = false;
 
  return ret;
}
 
static void start(Thread *self) {
 
  assert(self->function);
 
  assert(self->isCancelled == false);
  assert(self->isDetached == false);
  assert(self->isExecuting == false);
  assert(self->isFinished == false);
 
  int err = pthread_create(self->thread, NULL, run, self);
  assert(err == 0);
}
 
#pragma mark - Class lifecycle
 
static void initialize(Class *clazz) {
 
  ((ObjectInterface *) clazz->interface)->copy = copy;
  ((ObjectInterface *) clazz->interface)->dealloc = dealloc;
 
  ((ThreadInterface *) clazz->interface)->cancel = cancel;
  ((ThreadInterface *) clazz->interface)->currentThread = currentThread;
  ((ThreadInterface *) clazz->interface)->detach = detach;
  ((ThreadInterface *) clazz->interface)->init = init;
  ((ThreadInterface *) clazz->interface)->initWithFunction = initWithFunction;
  ((ThreadInterface *) clazz->interface)->join = join;
  ((ThreadInterface *) clazz->interface)->kill = _kill;
  ((ThreadInterface *) clazz->interface)->start = start;
}
 
Class *_Thread(void) {
  static Class *clazz;
  static Once once;
 
  do_once(&once, {
    clazz = _initialize(&(const ClassDef) {
      .name = "Thread",
      .superclass = _Object(),
      .instanceSize = sizeof(Thread),
      .interfaceOffset = offsetof(Thread, interface),
      .interfaceSize = sizeof(ThreadInterface),
      .initialize = initialize,
    });
  });
 
  return clazz;
}
 
#undef _Class