os.h

基于sip协议的网络电话源码

/* $Id: os.h 974 2007-02-19 01:13:53Z bennylp $ */
/* 
 * Copyright (C)2003-2007 Benny Prijono <[e-mail]>
 *
 * This program 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 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
 */
#ifndef __PJ_OS_H__
#define __PJ_OS_H__

/**
 * @file os.h
 * @brief OS dependent functions
 */
#include <pj/types.h>

PJ_BEGIN_DECL

/**
 * @defgroup PJ_OS Operating System Dependent Functionality.
 * @ingroup PJ
 */


/* **************************************************************************/
/**
 * @defgroup PJ_THREAD Threads
 * @ingroup PJ_OS
 * @{
 * This module provides multithreading API.
 *
 * \section pj_thread_examples_sec Examples
 *
 * For examples, please see:
 *  - \ref page_pjlib_thread_test
 *  - \ref page_pjlib_sleep_test
 *
 */

/**
 * Thread creation flags:
 * - PJ_THREAD_SUSPENDED: specify that the thread should be created suspended.
 */
typedef enum pj_thread_create_flags
{
    PJ_THREAD_SUSPENDED = 1
} pj_thread_create_flags;


/**
 * Type of thread entry function.
 */
typedef int (PJ_THREAD_FUNC pj_thread_proc)(void*);

/**
 * Size of thread struct.
 */
#if !defined(PJ_THREAD_DESC_SIZE)
#   define PJ_THREAD_DESC_SIZE	    (64)
#endif

/**
 * Thread structure, to thread's state when the thread is created by external
 * or native API. 
 */
typedef long pj_thread_desc[PJ_THREAD_DESC_SIZE];

/**
 * Get process ID.
 * @return process ID.
 */
PJ_DECL(pj_uint32_t) pj_getpid(void);

/**
 * Create a new thread.
 *
 * @param pool          The memory pool from which the thread record 
 *                      will be allocated from.
 * @param thread_name   The optional name to be assigned to the thread.
 * @param proc          Thread entry function.
 * @param arg           Argument to be passed to the thread entry function.
 * @param stack_size    The size of the stack for the new thread, or ZERO or
 *                      PJ_THREAD_DEFAULT_STACK_SIZE to let the 
 *		        library choose the reasonable size for the stack. 
 *                      For some systems, the stack will be allocated from 
 *                      the pool, so the pool must have suitable capacity.
 * @param flags         Flags for thread creation, which is bitmask combination 
 *                      from enum pj_thread_create_flags.
 * @param thread        Pointer to hold the newly created thread.
 *
 * @return	        PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_thread_create(  pj_pool_t *pool, 
                                        const char *thread_name,
				        pj_thread_proc *proc, 
                                        void *arg,
				        pj_size_t stack_size, 
                                        unsigned flags,
					pj_thread_t **thread );

/**
 * Register a thread that was created by external or native API to PJLIB.
 * This function must be called in the context of the thread being registered.
 * When the thread is created by external function or API call,
 * it must be 'registered' to PJLIB using pj_thread_register(), so that it can
 * cooperate with PJLIB's framework. During registration, some data needs to
 * be maintained, and this data must remain available during the thread's 
 * lifetime.
 *
 * @param thread_name   The optional name to be assigned to the thread.
 * @param desc          Thread descriptor, which must be available throughout 
 *                      the lifetime of the thread.
 * @param thread        Pointer to hold the created thread handle.
 *
 * @return              PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_thread_register ( const char *thread_name,
					  pj_thread_desc desc,
					  pj_thread_t **thread);

/**
 * Check if this thread has been registered to PJLIB.
 *
 * @return		Non-zero if it is registered.
 */
PJ_DECL(pj_bool_t) pj_thread_is_registered(void);


/**
 * Get thread name.
 *
 * @param thread    The thread handle.
 *
 * @return Thread name as null terminated string.
 */
PJ_DECL(const char*) pj_thread_get_name(pj_thread_t *thread);

/**
 * Resume a suspended thread.
 *
 * @param thread    The thread handle.
 *
 * @return zero on success.
 */
PJ_DECL(pj_status_t) pj_thread_resume(pj_thread_t *thread);

/**
 * Get the current thread.
 *
 * @return Thread handle of current thread.
 */
PJ_DECL(pj_thread_t*) pj_thread_this(void);

/**
 * Join thread, and block the caller thread until the specified thread exits.
 * If the specified thread has already been dead, or it does not exist,
 * the function will return immediately with successfull status.
 *
 * @param thread    The thread handle.
 *
 * @return PJ_SUCCESS on success.
 */
PJ_DECL(pj_status_t) pj_thread_join(pj_thread_t *thread);


/**
 * Destroy thread and release resources allocated for the thread.
 * However, the memory allocated for the pj_thread_t itself will only be released
 * when the pool used to create the thread is destroyed.
 *
 * @param thread    The thread handle.
 *
 * @return zero on success.
 */
PJ_DECL(pj_status_t) pj_thread_destroy(pj_thread_t *thread);


/**
 * Put the current thread to sleep for the specified miliseconds.
 *
 * @param msec Miliseconds delay.
 *
 * @return zero if successfull.
 */
PJ_DECL(pj_status_t) pj_thread_sleep(unsigned msec);

/**
 * @def PJ_CHECK_STACK()
 * PJ_CHECK_STACK() macro is used to check the sanity of the stack.
 * The OS implementation may check that no stack overflow occurs, and
 * it also may collect statistic about stack usage.
 */
#if defined(PJ_OS_HAS_CHECK_STACK) && PJ_OS_HAS_CHECK_STACK!=0

#  define PJ_CHECK_STACK() pj_thread_check_stack(__FILE__, __LINE__)

/** @internal
 * The implementation of stack checking. 
 */
PJ_DECL(void) pj_thread_check_stack(const char *file, int line);

/** @internal
 * Get maximum stack usage statistic. 
 */
PJ_DECL(pj_uint32_t) pj_thread_get_stack_max_usage(pj_thread_t *thread);

/** @internal
 * Dump thread stack status. 
 */
PJ_DECL(pj_status_t) pj_thread_get_stack_info(pj_thread_t *thread,
					      const char **file,
					      int *line);
#else

#  define PJ_CHECK_STACK()
/** pj_thread_get_stack_max_usage() for the thread */
#  define pj_thread_get_stack_max_usage(thread)	    0
/** pj_thread_get_stack_info() for the thread */
#  define pj_thread_get_stack_info(thread,f,l)	    (*(f)="",*(l)=0)
#endif	/* PJ_OS_HAS_CHECK_STACK */

/**
 * @}
 */

/* **************************************************************************/
/**
 * @defgroup PJ_TLS Thread Local Storage.
 * @ingroup PJ_OS
 * @{
 */

/** 
 * Allocate thread local storage index. The initial value of the variable at
 * the index is zero.
 *
 * @param index	    Pointer to hold the return value.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_thread_local_alloc(long *index);

/**
 * Deallocate thread local variable.
 *
 * @param index	    The variable index.
 */
PJ_DECL(void) pj_thread_local_free(long index);

/**
 * Set the value of thread local variable.
 *
 * @param index	    The index of the variable.
 * @param value	    The value.
 */
PJ_DECL(pj_status_t) pj_thread_local_set(long index, void *value);

/**
 * Get the value of thread local variable.
 *
 * @param index	    The index of the variable.
 * @return	    The value.
 */
PJ_DECL(void*) pj_thread_local_get(long index);


/**
 * @}
 */


/* **************************************************************************/
/**
 * @defgroup PJ_ATOMIC Atomic Variables
 * @ingroup PJ_OS
 * @{
 *
 * This module provides API to manipulate atomic variables.
 *
 * \section pj_atomic_examples_sec Examples
 *
 * For some example codes, please see:
 *  - @ref page_pjlib_atomic_test
 */


/**
 * Create atomic variable.
 *
 * @param pool	    The pool.
 * @param initial   The initial value of the atomic variable.
 * @param atomic    Pointer to hold the atomic variable upon return.
 *
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_atomic_create( pj_pool_t *pool, 
				       pj_atomic_value_t initial,
				       pj_atomic_t **atomic );

/**
 * Destroy atomic variable.
 *
 * @param atomic_var	the atomic variable.
 *
 * @return PJ_SUCCESS if success.
 */
PJ_DECL(pj_status_t) pj_atomic_destroy( pj_atomic_t *atomic_var );

/**
 * Set the value of an atomic type, and return the previous value.
 *
 * @param atomic_var	the atomic variable.
 * @param value		value to be set to the variable.
 */
PJ_DECL(void) pj_atomic_set( pj_atomic_t *atomic_var, 
			     pj_atomic_value_t value);

/**
 * Get the value of an atomic type.
 *
 * @param atomic_var	the atomic variable.
 *
 * @return the value of the atomic variable.
 */
PJ_DECL(pj_atomic_value_t) pj_atomic_get(pj_atomic_t *atomic_var);

/**
 * Increment the value of an atomic type.
 *
 * @param atomic_var	the atomic variable.
 */
PJ_DECL(void) pj_atomic_inc(pj_atomic_t *atomic_var);

/**
 * Increment the value of an atomic type and get the result.
 *
 * @param atomic_var	the atomic variable.
 *
 * @return              The incremented value.
 */
PJ_DECL(pj_atomic_value_t) pj_atomic_inc_and_get(pj_atomic_t *atomic_var);

/**
 * Decrement the value of an atomic type.
 *
 * @param atomic_var	the atomic variable.
 */
PJ_DECL(void) pj_atomic_dec(pj_atomic_t *atomic_var);

/**
 * Decrement the value of an atomic type and get the result.
 *
 * @param atomic_var	the atomic variable.
 *
 * @return              The decremented value.
 */
PJ_DECL(pj_atomic_value_t) pj_atomic_dec_and_get(pj_atomic_t *atomic_var);

/**
 * Add a value to an atomic type.
 *
 * @param atomic_var	The atomic variable.
 * @param value		Value to be added.
 */
PJ_DECL(void) pj_atomic_add( pj_atomic_t *atomic_var,
			     pj_atomic_value_t value);

/**
 * Add a value to an atomic type and get the result.
 *
 * @param atomic_var	The atomic variable.
 * @param value		Value to be added.
 *
 * @return              The result after the addition.
 */
PJ_DECL(pj_atomic_value_t) pj_atomic_add_and_get( pj_atomic_t *atomic_var,
			                          pj_atomic_value_t value);

/**
 * @}
 */

/* **************************************************************************/
/**
 * @defgroup PJ_MUTEX Mutexes.
 * @ingroup PJ_OS
 * @{
 *
 * Mutex manipulation. Alternatively, application can use higher abstraction
 * for lock objects, which provides uniform API for all kinds of lock 
 * mechanisms, including mutex. See @ref PJ_LOCK for more information.
 */

/**
 * Mutex types:
 *  - PJ_MUTEX_DEFAULT: default mutex type, which is system dependent.
 *  - PJ_MUTEX_SIMPLE: non-recursive mutex.
 *  - PJ_MUTEX_RECURSIVE: recursive mutex.
 */
typedef enum pj_mutex_type_e
{
    PJ_MUTEX_DEFAULT,
    PJ_MUTEX_SIMPLE,
    PJ_MUTEX_RECURSE
} pj_mutex_type_e;


/**
 * Create mutex of the specified type.
 *
 * @param pool	    The pool.
 * @param name	    Name to be associated with the mutex (for debugging).
 * @param type	    The type of the mutex, of type #pj_mutex_type_e.
 * @param mutex	    Pointer to hold the returned mutex instance.
 *
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_mutex_create(pj_pool_t *pool, 
                                     const char *name,
				     int type, 
                                     pj_mutex_t **mutex);

/**
 * Create simple, non-recursive mutex.
 * This function is a simple wrapper for #pj_mutex_create to create 
 * non-recursive mutex.
 *
 * @param pool	    The pool.
 * @param name	    Mutex name.
 * @param mutex	    Pointer to hold the returned mutex instance.
 *
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_mutex_create_simple( pj_pool_t *pool, const char *name,
					     pj_mutex_t **mutex );

/**
 * Create recursive mutex.
 * This function is a simple wrapper for #pj_mutex_create to create 
 * recursive mutex.
 *
 * @param pool	    The pool.
 * @param name	    Mutex name.
 * @param mutex	    Pointer to hold the returned mutex instance.
 *
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_mutex_create_recursive( pj_pool_t *pool,
					        const char *name,
						pj_mutex_t **mutex );

/**
 * Acquire mutex lock.
 *
 * @param mutex	    The mutex.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_mutex_lock(pj_mutex_t *mutex);

/**
 * Release mutex lock.
 *
 * @param mutex	    The mutex.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_mutex_unlock(pj_mutex_t *mutex);

/**
 * Try to acquire mutex lock.
 *
 * @param mutex	    The mutex.
 * @return	    PJ_SUCCESS on success, or the error code if the
 *		    lock couldn't be acquired.
 */
PJ_DECL(pj_status_t) pj_mutex_trylock(pj_mutex_t *mutex);

/**
 * Destroy mutex.
 *
 * @param mutex	    Te mutex.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_mutex_destroy(pj_mutex_t *mutex);

/**
 * Determine whether calling thread is owning the mutex (only available when
 * PJ_DEBUG is set).
 * @param mutex	    The mutex.
 * @return	    Non-zero if yes.
 */
#if defined(PJ_DEBUG) && PJ_DEBUG != 0
   PJ_DECL(pj_bool_t) pj_mutex_is_locked(pj_mutex_t *mutex);
#else
#  define pj_mutex_is_locked(mutex)	    1
#endif

/**
 * @}
 */

/* **************************************************************************/
/**
 * @defgroup PJ_RW_MUTEX Reader/Writer Mutex
 * @ingroup PJ_OS
 * @{
 * Reader/writer mutex is a classic synchronization object where multiple
 * readers can acquire the mutex, but only a single writer can acquire the 
 * mutex.
 */

/**
 * Opaque declaration for reader/writer mutex.
 * Reader/writer mutex is a classic synchronization object where multiple
 * readers can acquire the mutex, but only a single writer can acquire the 
 * mutex.
 */
typedef struct pj_rwmutex_t pj_rwmutex_t;

/**
 * Create reader/writer mutex.
 *
 * @param pool	    Pool to allocate memory for the mutex.
 * @param name	    Name to be assigned to the mutex.
 * @param mutex	    Pointer to receive the newly created mutex.
 *
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_rwmutex_create(pj_pool_t *pool, const char *name,
				       pj_rwmutex_t **mutex);

/**
 * Lock the mutex for reading.
 *
 * @param mutex	    The mutex.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_rwmutex_lock_read(pj_rwmutex_t *mutex);

/**
 * Lock the mutex for writing.
 *
 * @param mutex	    The mutex.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_rwmutex_lock_write(pj_rwmutex_t *mutex);

/**
 * Release read lock.
 *
 * @param mutex	    The mutex.
 * @return	    PJ_SUCCESS on success, or the error code.
 */
PJ_DECL(pj_status_t) pj_rwmutex_unlock_read(pj_rwmutex_t *mutex);

/**
 * Release write lock.
 *
 * @param mutex	    The mutex.