/*
Copyright (c) 2012, Broadcom Europe Ltd
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the copyright holder nor the
      names of its contributors may be used to endorse or promote products
      derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/*=============================================================================
VideoCore OS Abstraction Layer - public header file
=============================================================================*/

/**
  * \mainpage OS Abstraction Layer
  *
  * \section intro Introduction
  *
  * This abstraction layer is here to allow the underlying OS to be easily changed (e.g. from
  * Nucleus to ThreadX) and to aid in porting host applications to new targets.
  *
  * \subsection error Error handling
  *
  * Wherever possible, VCOS functions assert internally and return void. The only exceptions
  * are creation functions (which might fail due to lack of resources) and functions that
  * might timeout or fail due to lack of space. Errors that might be reported by the underlying
  * OS API (e.g. invalid mutex) are treated as a programming error, and are merely asserted on.
  *
  * \section thread_synch Threads and synchronisation
  *
  * \subsection thread Threads
  *
  * The thread API is somewhat different to that found in Nucleus. In particular, threads
  * cannot just be destroyed at arbitrary times and nor can they merely exit. This is so
  * that the same API can be implemented across all interesting platforms without too much
  * difficulty. See vcos_thread.h for details. Thread attributes are configured via
  * the VCOS_THREAD_ATTR_T structure, found in vcos_thread_attr.h.
  *
  * \subsection sema Semaphores
  *
  * Counted semaphores (c.f. Nucleus NU_SEMAPHORE) are created with VCOS_SEMAPHORE_T.
  * Under ThreadX on VideoCore, semaphores are implemented using VideoCore spinlocks, and
  * so are quite a lot faster than ordinary ThreadX semaphores. See vcos_semaphore.h.
  *
  * \subsection mtx Mutexes
  *
  * Mutexes are used for locking. Attempts to take a mutex twice, or to unlock it
  * in a different thread to the one in which it was locked should be expected to fail.
  * Mutexes are not re-entrant (see vcos_reentrant_mutex.h for a slightly slower
  * re-entrant mutex).
  *
  * \subsection evflags Event flags
  *
  * Event flags (the ThreadX name - also known as event groups under Nucleus) provide
  * 32 flags which can be waited on by multiple clients, and signalled by multiple clients.
  * A timeout can be specified. See vcos_event_flags.h. An alternative to this is the
  * VCOS_EVENT_T (see vcos_event.h) which is akin to the Win32 auto-reset event, or a
  * saturating counted semaphore.
  *
  * \subsection event Events
  *
  * A VCOS_EVENT_T is a bit like a saturating semaphore. No matter how many times it
  * is signalled, the waiter will only wake up once. See vcos_event.h. You might think this
  * is useful if you suspect that the cost of reading the semaphore count (perhaps via a
  * system call) is expensive on your platform.
  *
  * \subsection tls Thread local storage
  *
  * Thread local storage is supported using vcos_tls.h. This is emulated on Nucleus
  * and ThreadX.
  *
  * \section int Interrupts
  *
  * The legacy LISR/HISR scheme found in Nucleus is supported via the legacy ISR API,
  * which is also supported on ThreadX. New code should avoid this, and old code should
  * be migrated away from it, since it is slow. See vcos_legacy_isr.h.
  *
  * Registering an interrupt handler, and disabling/restoring interrupts, is handled
  * using the functions in vcos_isr.h.
  *
  */

/**
  * \file vcos.h
  *
  * This is the top level header file. Clients include this. It pulls in the platform-specific
  * header file (vcos_platform.h) together with header files defining the expected APIs, such
  * as vcos_mutex.h, vcos_semaphore.h, etc. It is also possible to include these header files
  * directly.
  *
  */

#ifndef VCOS_H
#define VCOS_H

#include "interface/vcos/vcos_assert.h"
#include "vcos_types.h"

#if defined(__unix__) && !defined(__ANDROID__)
#include "interface/vcos/pthreads/vcos_platform.h"
#else
#include "vcos_platform.h"
#endif

#ifndef VCOS_INIT_H
#include "interface/vcos/vcos_init.h"
#endif

#ifndef VCOS_SEMAPHORE_H
#include "interface/vcos/vcos_semaphore.h"
#endif

#ifndef VCOS_THREAD_H
#include "interface/vcos/vcos_thread.h"
#endif

#ifndef VCOS_MUTEX_H
#include "interface/vcos/vcos_mutex.h"
#endif

#ifndef VCOS_MEM_H
#include "interface/vcos/vcos_mem.h"
#endif

#ifndef VCOS_LOGGING_H
#include "interface/vcos/vcos_logging.h"
#endif

#ifndef VCOS_STRING_H
#include "interface/vcos/vcos_string.h"
#endif

#ifndef VCOS_EVENT_H
#include "interface/vcos/vcos_event.h"
#endif

#ifndef VCOS_THREAD_ATTR_H
#include "interface/vcos/vcos_thread_attr.h"
#endif

#ifndef VCOS_TLS_H
#include "interface/vcos/vcos_tls.h"
#endif

#ifndef VCOS_REENTRANT_MUTEX_H
#include "interface/vcos/vcos_reentrant_mutex.h"
#endif

#ifndef VCOS_NAMED_SEMAPHORE_H
#include "interface/vcos/vcos_named_semaphore.h"
#endif

#ifndef VCOS_QUICKSLOW_MUTEX_H
#include "interface/vcos/vcos_quickslow_mutex.h"
#endif

/* Headers with predicates */

#if VCOS_HAVE_EVENT_FLAGS
#include "interface/vcos/vcos_event_flags.h"
#endif

#if VCOS_HAVE_QUEUE
#include "interface/vcos/vcos_queue.h"
#endif

#if VCOS_HAVE_LEGACY_ISR
#include "interface/vcos/vcos_legacy_isr.h"
#endif

#if VCOS_HAVE_TIMER
#include "interface/vcos/vcos_timer.h"
#endif

#if VCOS_HAVE_MEMPOOL
#include "interface/vcos/vcos_mempool.h"
#endif

#if VCOS_HAVE_ISR
#include "interface/vcos/vcos_isr.h"
#endif

#if VCOS_HAVE_ATOMIC_FLAGS
#include "interface/vcos/vcos_atomic_flags.h"
#endif

#if VCOS_HAVE_ONCE
#include "interface/vcos/vcos_once.h"
#endif

#if VCOS_HAVE_BLOCK_POOL
#include "interface/vcos/vcos_blockpool.h"
#endif

#if VCOS_HAVE_FILE
#include "interface/vcos/vcos_file.h"
#endif

#if VCOS_HAVE_CFG
#include "interface/vcos/vcos_cfg.h"
#endif

#if VCOS_HAVE_CMD
#include "interface/vcos/vcos_cmd.h"
#endif

#endif /* VCOS_H */
