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diff --git a/tinySAK/src/tsk.c b/tinySAK/src/tsk.c new file mode 100644 index 0000000..93fc8e6 --- /dev/null +++ b/tinySAK/src/tsk.c @@ -0,0 +1,285 @@ +/**
+* @file tsk.c
+* @author Mamadou Diop <diopmamadou(at)doubango.org>
+* @version 1.0
+*
+* @section LICENSE
+*
+*
+* This file is part of Open Source Doubango Framework.
+*
+* DOUBANGO is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* DOUBANGO is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with DOUBANGO.
+*
+*/
+#include "tsk.h"
+
+/** @mainpage tinySAK API Overview
+*
+* This file is an overview of <b>tinySAK</b> API.
+*
+* <b>tinySAK</b> (a.k.a <b>T</b>iny <b>S</b>wiss <b>A</b>rmy <b>K</b>nife) is a tiny but fully featured utility API.
+* This API is designed to efficiently work on embedded systems with limited memory and low computing power.<br>
+* This library provide a base object class to ease Object Oriented Programming in C. There are many other
+* features like multi-threading, time management, encoding, encryption or content management.
+* <h1>6 ANSI-C Object Programming</h1>
+* As you probably know, C is not an object oriented language.<br>
+* Today, OOP (Object-Oriented Programing) is the best way to program well designed softwares.<br>
+* In this chapter a “well-defined object” is a special C structure. All functions shown in this chapter are part of tinySAK project.<br>
+* To explain how well-defined objects are implemented and used, I will give an example based on “Person” object.<br>
+* The person object is declared like this:<br>
+* @code
+* typedef struct person_s
+{
+ TSK_DECLARE_OBJECT; // Mandatory
+
+ char* name;
+ struct person_s* girlfriend;
+}
+person_t;
+* @endcode
+<h2>6.1 Object Definition</h2>
+* An object definition could be considered as a class definition. The definition holds the object’s mandatory functions, size and a reference counter.<br>
+* The mandatory functions are the constructor, the destructor and the comparator.<br>
+* A C structure is defined as an object by using @ref TSK_DECLARE_OBJECT macro in its body.<br>
+* A pointer to an object definition shall point to a struct @ref tsk_object_def_s.<br>
+* @code
+typedef struct tsk_object_def_s
+{
+ //! The size of the object.
+ tsk_size_t size;
+ //! Pointer to the constructor.
+ tsk_object_t* (* constructor) (tsk_object_t *, va_list *);
+ //! Pointer to the destructor.
+ tsk_object_t* (* destructor) (tsk_object_t *);
+ //! Pointer to the comparator.
+ int (*comparator) (const tsk_object_t *, const tsk_object_t *);
+}
+tsk_object_def_t;
+* @endcode
+*
+* <p>
+* An object is created in two phases. The first phase consists of dynamically allocating the object on the heap; this is why its size is mandatory in the object definition structure. When a new object is allocated on the heap, all its members (char*, void*, int, long …) will be zeroed. In the second phase, the newly created object will be initialized by calling the supplied constructor. To perform these two phases, you should call @ref tsk_object_new() or @ref tsk_object_new_2().
+* </p>
+* <p>
+* An object is destroyed in two phases. The first phase consists of freeing its members (void*, char* …). It’s the destructor which is responsible of this task. In the second phase, the object itself is destroyed. As the object cannot destroy itself, you should use @ref tsk_object_unref() or @ref tsk_object_delete() to perform these two phases. The difference between these two functions is explained in the coming sections.
+* </p>
+* A well-defined object must never be freed using free() standard C function.<br>
+* Below, an example of how to declare an object definition:<br>
+* @code
+* //(Object defnition)
+ static const tsk_object_def_t person_def_t =
+ {
+ sizeof(person_t),
+ person_ctor,
+ person_dtor,
+ person_cmp
+ };
+* @endcode
+* <h2>6.2 Constructor</h2>
+* The constructor is only responsible for the initialization and won’t allocate the object. When passed to the constructor, the object is already allocated.<br>
+* Here is an example:<br>
+* @code
+// (constructor)
+static tsk_object_t* person_ctor(tsk_object_t * self, va_list * app)
+{
+ person_t *person = self;
+ if(person){
+ person->name = tsk_strdup(va_arg(*app, const char *));
+ }
+ return self;
+ }
+* @endcode
+* <h2>6.3 Destructor</h2>
+* The destructor will free the object’s members and won’t destroy the object itself (Phase 1). The destructor function must return a pointer to itself to allow the caller to perform the second phase.<br>
+* Here is an example:<br>
+* @code
+// (destructor)
+ static tsk_object_t * person_dtor(tsk_object_t * self)
+ {
+ person_t *person = self;
+ if(person){
+ TSK_FREE(person->name);
+ tsk_object_unref(person->girlfriend);
+ }
+ return self;
+ }
+* @endcode
+* <h2>6.4 Comparator</h2>
+* The comparator function is used to compare two well-defined objects. The objects to compare shall have the same definition (or type). <br>
+* Here is an example:<br>
+* @code
+// (comparator)
+static int person_cmp(const tsk_object_t *_p1, const tsk_object_t *_p2)
+ {
+ const person_t *p1 = _p1;
+ const person_t *p1 = _p2;
+ int ret;
+
+ // do they have the same name?
+ if((ret = tsk_stricmp(p1->name, p2->name))){
+ return ret;
+ }
+ // do they have the same girlfriend?
+ if((ret = tsk_object_cmp(p1->girlfriend, p2->girlfriend))){
+ return ret;
+ }
+
+ // they are the same
+ return 0;
+ }
+* @endcode
+<h2>6.5 Reference counting</h2>
+* Reference counting is used to emulate garbage collection. Each well-defined object contains a reference counter field which indicates how many object have a reference to the actual object.<br>
+* When an object is created (see below) the counter value is initialized to 1; this is automatically done and you have nothing to do. The counter is incremented by 1 when you call @ref tsk_object_ref() and decremented (by 1) when you call @ref tsk_object_unref().<br>
+* When the counter value reaches zero, then the object is garbaged (freed).<br>
+*
+* <h2>6.6 Inheritence</h2>
+* As you expect, inheritance is not supported in ANSI-C. <br>
+* As any C Structure could be casted to a pointer to its first element, inheritance could be achieved like this:<br>
+* @code
+#include "tsk.h"
+// (a student is a person)
+typedef struct student_s
+{
+ person_t* person; // Must be the first element
+ char* school;
+}
+student_t;
+
+// (as a student is a person you can do)
+student_t* s = tsk_null;
+//....
+((person_t*)s)->name = tsk_strdup("bob");
+* @endcode
+*
+* As @code person_t is a well-defined object, then @code student_t is also well-defined.<br>
+* <h2>6.7 Usage</h2>
+* Once the object’s definition is declared and all its mandatory functions implemented, it is used like this:<br>
+* @code
+// creates a person: will call the constructor
+person_t* bob = tsk_object_new(&person_def_t, "bob");
+// creates bob's girlfriend
+bob->girlfriend = tsk_object_new(&person_def_t, "alice");
+// deletes bob: will delete both bob and bob's girlfriend field by calling their destructors
+tsk_object_unref(bob);
+* @endcode
+* As it’s hard to guest which parameters the construct expects, it’s common to use macro (or function) helpers. In our example the macro will look like this:
+* @code
+// create a person
+#define PERSON_CREATE(name) tsk_object_new(&person_def_t, (const char*)name)
+* @endcode
+*
+* As the destructor has fixed parameters, there is a common macro to destroy all kind of well-defined objects. <br>
+* TSK_OBJECT_SAFE_FREE() is used to destroy any object. <br>
+* The object will be freed only if; when decremented by 1 the reference count of the object is equal to zero. In all case (freed or not) the pointer value will be set to NULL.<br>
+* The above example can be rewritten like this:<br>
+* @code
+#include "tsk.h"
+
+// create a person: will call the constructor
+person_t* bob = PERSON_CREATE("bob");
+// create bob's girlfriend
+bob->girlfriend = PERSON_CREATE("alice");
+// delete bob: will delete both bob and bob's girlfriend field by calling their destructors
+TSK_OBJECT_SAFE_FREE(bob);
+* @endcode
+*
+* <h2>6.8 Lists</h2>
+*
+* <h2>7 Threading</h2>
+* The framework provides an operating system agnostic threading functions for both WIN32 and Unix-like systems.<br>
+*
+* <h2>7.1 Threads</h2>
+* You don’t need thousands of functions to manage threads. In the Framework we only need to create, pause and destroy threads.<br>
+* Threads can be created using @ref tsk_thread_create() and joined using @ref tsk_thread_join().<br>
+* You can temporary cease the executing of a thread by calling @ref tsk_thread_sleep().<br>
+* @code
+#include "tsk.h"
+
+void* MyThreadFunction(void *arg)
+{
+ printf("arg=%d", *((int*)arg));
+ return tsk_null;
+}
+
+void test_threads()
+{
+ void* tid[1] = {tsk_null}; // thread id
+ int arg = 112; // arg to pass to the function
+
+ // creates the thread
+ tsk_thread_create(&tid[0], MyThreadFunction, &arg);
+
+ // joins the thread
+ tsk_thread_join(&(tid[0]));
+}
+* @endcode
+*
+* <h2>7.2 Mutexes</h2>
+* Mutexes (Mutual exclusion) are used to protect a portion of code or function against concurrent access. Concurrent access happens when two or several threads try to execute the same portion of code at nearly the same time.<br>
+* @code
+#include "tsk.h"
+
+// create the mutext
+tsk_mutex_handle_t *mutex = tsk_mutex_create();
+
+tsk_mutex_lock(mutex);
+// ...portion of code to protect
+tsk_mutex_unlock(mutex);
+
+// destroy the mutex
+tsk_mutex_destroy(&mutex);
+* @endcode
+* Mutexes are not well-defined objects; you should use @ref tsk_mutex_destroy instead of TSK_OBJECT_SAFE_FREE() to destroy them.<br>
+*
+* <h2>7.3 Thread-Safe Objects</h2>
+*
+* Any C Structure could be declared as thread-safe using @ref TSK_DECLARE_SAFEOBJ macro. It’s not mandatory for the object to be well-defined.<br>
+* A thread-safe object is initialized using @ref tsk_safeobj_init() and deinitilized using @ref tsk_safeobj_deinit(). To lock and unlock a portion of code which accesses the object you should use @ref tsk_safeobj_lock() and @ref tsk_safeobj_unlock() respectively.<br>
+*
+* <h2>7.4 Semaphores</h2>
+* Only counting semaphores are supported by the framework.
+* Counting semaphores are used to control the access to a portion of code which might be executed by multiple threads. A thread will have rights to execute the portion of code only if the semaphore’s internal counter value is different than zero. Before executing the code to control, a thread should decrement the counter to check if it has permit.<br>
+* @code
+#include "tsk.h"
+
+// (create the semaphore)
+tsk_semaphore_handle_t *sem = tsk_semaphore_create();
+// (increment the counter)
+tsk_semaphore_increment(sem);
+// (decrement the counter)
+tsk_semaphore_decrement(sem);
+// (destoy the semaphore)
+tsk_semaphore_destroy(&sem);
+* @endcode
+* Semaphores are not well-defined objects; you should use @ref tsk_semaphore_destroy instead of TSK_OBJECT_SAFE_FREE() to destroy them.<br>
+* Mutexes are binary semaphores (counter value is always equals to 1 or 0).<br>
+*
+* <h2>7.5 Condition Variables</h2>
+* Condition variables are used to control the access to a portion of code which might be executed by multiple threads. Each thread will block until a certain condition is signaled or ms milliseconds have passed.<br>
+* @ref tsk_condwait_create is used to create a condition variable, @ref tsk_condwait_wait() to wait indefinitely until the condition is signaled and @ref tsk_condwait_timedwait() to wait until the condition is signaled or ms milliseconds have passed.<br>
+* @ref tsk_condwait_signal() is used to alert the first waiting thread that the condition is now true and @ref tsk_condwait_broadcast() is used to alert all waiting threads.<br>
+* Condition variables are not well-defined objects; you should use @ref tsk_condwait_destroy() instead of TSK_OBJECT_SAFE_FREE() to destroy them.<br>
+*
+* <h2>7.6 Runnable</h2>
+* A <i>runnable</i> object is a well-defined object and is declared using @ref TSK_DECLARE_RUNNABLE() macro.<br>
+* A <i>runnable</i> object must be explicitly started using @ref tsk_runnable_start() and is implicitly stopped when destroyed. You can explicitly stop the object by calling @ref tsk_runnable_stop().<br>
+*
+* <h2>8 Final Sate Machine</h2>
+*
+* <h2>9 Timer Manager</h2>
+*
+*/
+
+
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