os_core_unix.c

一个开源SIP协议栈

/* $Id: os_core_unix.c 1075 2007-03-16 18:41:07Z 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 
 */
/*
 * Contributors:
 * - Thanks for Zetron, Inc. (Phil Torre, [e-mail]) for donating
 *   the RTEMS port.
 */
#define _GNU_SOURCE
#include <pj/os.h>
#include <pj/assert.h>
#include <pj/pool.h>
#include <pj/log.h>
#include <pj/rand.h>
#include <pj/string.h>
#include <pj/guid.h>
#include <pj/except.h>
#include <pj/errno.h>

#if defined(PJ_HAS_SEMAPHORE) && PJ_HAS_SEMAPHORE != 0
#  include <semaphore.h>
#endif

#include <unistd.h>	    // getpid()
#include <errno.h>	    // errno

#include <pthread.h>

#define THIS_FILE   "os_core_unix.c"

#define SIGNATURE1  0xDEAFBEEF
#define SIGNATURE2  0xDEADC0DE

struct pj_thread_t
{
    char	    obj_name[PJ_MAX_OBJ_NAME];
    pthread_t	    thread;
    pj_thread_proc *proc;
    void	   *arg;
    pj_uint32_t	    signature1;
    pj_uint32_t	    signature2;

    pj_mutex_t	   *suspended_mutex;

#if defined(PJ_OS_HAS_CHECK_STACK) && PJ_OS_HAS_CHECK_STACK!=0
    pj_uint32_t	    stk_size;
    pj_uint32_t	    stk_max_usage;
    char	   *stk_start;
    const char	   *caller_file;
    int		    caller_line;
#endif
};

struct pj_atomic_t
{
    pj_mutex_t	       *mutex;
    pj_atomic_value_t	value;
};

struct pj_mutex_t
{
    pthread_mutex_t     mutex;
    char		obj_name[PJ_MAX_OBJ_NAME];
#if PJ_DEBUG
    int		        nesting_level;
    pj_thread_t	       *owner;
    char		owner_name[PJ_MAX_OBJ_NAME];
#endif
};

#if defined(PJ_HAS_SEMAPHORE) && PJ_HAS_SEMAPHORE != 0
struct pj_sem_t
{
    sem_t		sem;
    char		obj_name[PJ_MAX_OBJ_NAME];
};
#endif /* PJ_HAS_SEMAPHORE */

#if defined(PJ_HAS_EVENT_OBJ) && PJ_HAS_EVENT_OBJ != 0
struct pj_event_t
{
    char		obj_name[PJ_MAX_OBJ_NAME];
};
#endif	/* PJ_HAS_EVENT_OBJ */


#if PJ_HAS_THREADS
    static pj_thread_t main_thread;
    static long thread_tls_id;
    static pj_mutex_t critical_section;
#else
#   define MAX_THREADS 32
    static int tls_flag[MAX_THREADS];
    static void *tls[MAX_THREADS];
#endif

static unsigned atexit_count;
static void (*atexit_func[32])(void);

static pj_status_t init_mutex(pj_mutex_t *mutex, const char *name, int type);

/*
 * pj_init(void).
 * Init PJLIB!
 */
PJ_DEF(pj_status_t) pj_init(void)
{
    char dummy_guid[PJ_GUID_MAX_LENGTH];
    pj_str_t guid;
    pj_status_t rc;

#if PJ_HAS_THREADS
    /* Init this thread's TLS. */
    if ((rc=pj_thread_init()) != 0) {
	return rc;
    }

    /* Critical section. */
    if ((rc=init_mutex(&critical_section, "critsec", PJ_MUTEX_RECURSE)) != 0)
	return rc;

#endif

    /* Initialize exception ID for the pool. 
     * Must do so after critical section is configured.
     */
    rc = pj_exception_id_alloc("PJLIB/No memory", &PJ_NO_MEMORY_EXCEPTION);
    if (rc != PJ_SUCCESS)
        return rc;
    
    /* Init random seed. */
    pj_srand( clock() );

    /* Startup GUID. */
    guid.ptr = dummy_guid;
    pj_generate_unique_string( &guid );

    /* Startup timestamp */
#if defined(PJ_HAS_HIGH_RES_TIMER) && PJ_HAS_HIGH_RES_TIMER != 0
    {
	pj_timestamp dummy_ts;
	if ((rc=pj_get_timestamp(&dummy_ts)) != 0) {
	    return rc;
	}
    }
#endif   

    PJ_LOG(4,(THIS_FILE, "pjlib %s for POSIX initialized",
	      PJ_VERSION));

    return PJ_SUCCESS;
}

/*
 * pj_atexit()
 */
PJ_DEF(pj_status_t) pj_atexit(void (*func)(void))
{
    if (atexit_count >= PJ_ARRAY_SIZE(atexit_func))
	return PJ_ETOOMANY;

    atexit_func[atexit_count++] = func;
    return PJ_SUCCESS;
}

/*
 * pj_shutdown(void)
 */
PJ_DEF(void) pj_shutdown()
{
    int i;

    /* Call atexit() functions */
    for (i=atexit_count-1; i>=0; --i) {
	(*atexit_func[i])();
    }
    atexit_count = 0;

    /* Free exception ID */
    if (PJ_NO_MEMORY_EXCEPTION != -1) {
	pj_exception_id_free(PJ_NO_MEMORY_EXCEPTION);
	PJ_NO_MEMORY_EXCEPTION = -1;
    }

#if PJ_HAS_THREADS
    /* Destroy PJLIB critical section */
    pj_mutex_destroy(&critical_section);

    /* Free PJLIB TLS */
    if (thread_tls_id != -1) {
	pj_thread_local_free(thread_tls_id);
	thread_tls_id = -1;
    }
#endif

    /* Clear static variables */
    pj_errno_clear_handlers();
}


/*
 * pj_getpid(void)
 */
PJ_DEF(pj_uint32_t) pj_getpid(void)
{
    PJ_CHECK_STACK();
    return getpid();
}

/*
 * Check if this thread has been registered to PJLIB.
 */
PJ_DEF(pj_bool_t) pj_thread_is_registered(void)
{
#if PJ_HAS_THREADS
    return pj_thread_local_get(thread_tls_id) != 0;
#else
    pj_assert("pj_thread_is_registered() called in non-threading mode!");
    return PJ_TRUE;
#endif
}


/*
 * pj_thread_register(..)
 */
PJ_DEF(pj_status_t) pj_thread_register ( const char *cstr_thread_name,
					 pj_thread_desc desc,
					 pj_thread_t **ptr_thread)
{
#if PJ_HAS_THREADS
    char stack_ptr;
    pj_status_t rc;
    pj_thread_t *thread = (pj_thread_t *)desc;
    pj_str_t thread_name = pj_str((char*)cstr_thread_name);

    /* Size sanity check. */
    if (sizeof(pj_thread_desc) < sizeof(pj_thread_t)) {
	pj_assert(!"Not enough pj_thread_desc size!");
	return PJ_EBUG;
    }

    /* Warn if this thread has been registered before */
    if (pj_thread_local_get (thread_tls_id) != 0) {
	// 2006-02-26 bennylp:
	//  This wouldn't work in all cases!.
	//  If thread is created by external module (e.g. sound thread),
	//  thread may be reused while the pool used for the thread descriptor
	//  has been deleted by application.
	//*thread_ptr = (pj_thread_t*)pj_thread_local_get (thread_tls_id);
        //return PJ_SUCCESS;
	PJ_LOG(4,(THIS_FILE, "Info: possibly re-registering existing "
			     "thread"));
    }

    /* On the other hand, also warn if the thread descriptor buffer seem to
     * have been used to register other threads.
     */
    pj_assert(thread->signature1 != SIGNATURE1 ||
	      thread->signature2 != SIGNATURE2 ||
	      (thread->thread == pthread_self()));

    /* Initialize and set the thread entry. */
    pj_bzero(desc, sizeof(struct pj_thread_t));
    thread->thread = pthread_self();
    thread->signature1 = SIGNATURE1;
    thread->signature2 = SIGNATURE2;

    if(cstr_thread_name && pj_strlen(&thread_name) < sizeof(thread->obj_name)-1)
	pj_ansi_snprintf(thread->obj_name, sizeof(thread->obj_name), 
			 cstr_thread_name, thread->thread);
    else
	pj_ansi_snprintf(thread->obj_name, sizeof(thread->obj_name), 
			 "thr%p", (void*)thread->thread);
    
    rc = pj_thread_local_set(thread_tls_id, thread);
    if (rc != PJ_SUCCESS) {
	pj_bzero(desc, sizeof(struct pj_thread_t));
	return rc;
    }

#if defined(PJ_OS_HAS_CHECK_STACK) && PJ_OS_HAS_CHECK_STACK!=0
    thread->stk_start = &stack_ptr;
    thread->stk_size = 0xFFFFFFFFUL;
    thread->stk_max_usage = 0;
#else
    stack_ptr = '\0';
#endif

    *ptr_thread = thread;
    return PJ_SUCCESS;
#else
    pj_thread_t *thread = (pj_thread_t*)desc;
    *ptr_thread = thread;
    return PJ_SUCCESS;
#endif
}

/*
 * pj_thread_init(void)
 */
pj_status_t pj_thread_init(void)
{
#if PJ_HAS_THREADS
    pj_status_t rc;
    pj_thread_t *dummy;

    rc = pj_thread_local_alloc(&thread_tls_id );
    if (rc != PJ_SUCCESS) {
	return rc;
    }
    return pj_thread_register("thr%p", (long*)&main_thread, &dummy);
#else
    PJ_LOG(2,(THIS_FILE, "Thread init error. Threading is not enabled!"));
    return PJ_EINVALIDOP;
#endif
}

#if PJ_HAS_THREADS
/*
 * thread_main()
 *
 * This is the main entry for all threads.
 */
static void *thread_main(void *param)
{
    pj_thread_t *rec = param;
    void *result;
    pj_status_t rc;

#if defined(PJ_OS_HAS_CHECK_STACK) && PJ_OS_HAS_CHECK_STACK!=0
    rec->stk_start = (char*)&rec;
#endif

    /* Set current thread id. */
    rc = pj_thread_local_set(thread_tls_id, rec);
    if (rc != PJ_SUCCESS) {
	pj_assert(!"Thread TLS ID is not set (pj_init() error?)");
    }

    /* Check if suspension is required. */
    if (rec->suspended_mutex)
	pj_mutex_lock(rec->suspended_mutex);

    PJ_LOG(6,(rec->obj_name, "Thread started"));

    /* Call user's entry! */
    result = (void*)(long)(*rec->proc)(rec->arg);

    /* Done. */
    PJ_LOG(6,(rec->obj_name, "Thread quitting"));

    return result;
}
#endif

/*
 * pj_thread_create(...)
 */
PJ_DEF(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 **ptr_thread)
{
#if PJ_HAS_THREADS
    pj_thread_t *rec;
    pthread_attr_t thread_attr;
    void *stack_addr;
    int rc;

    PJ_UNUSED_ARG(stack_addr);

    PJ_CHECK_STACK();
    PJ_ASSERT_RETURN(pool && proc && ptr_thread, PJ_EINVAL);

    /* Create thread record and assign name for the thread */
    rec = (struct pj_thread_t*) pj_pool_zalloc(pool, sizeof(pj_thread_t));
    PJ_ASSERT_RETURN(rec, PJ_ENOMEM);
    
    /* Set name. */
    if (!thread_name) 
	thread_name = "thr%p";
    
    if (strchr(thread_name, '%')) {
	pj_ansi_snprintf(rec->obj_name, PJ_MAX_OBJ_NAME, thread_name, rec);
    } else {
	strncpy(rec->obj_name, thread_name, PJ_MAX_OBJ_NAME);
	rec->obj_name[PJ_MAX_OBJ_NAME-1] = '\0';
    }

    /* Set default stack size */
    if (stack_size == 0)
	stack_size = PJ_THREAD_DEFAULT_STACK_SIZE;

#if defined(PJ_OS_HAS_CHECK_STACK) && PJ_OS_HAS_CHECK_STACK!=0
    rec->stk_size = stack_size;
    rec->stk_max_usage = 0;
#endif

    /* Emulate suspended thread with mutex. */
    if (flags & PJ_THREAD_SUSPENDED) {
	rc = pj_mutex_create_simple(pool, NULL, &rec->suspended_mutex);
	if (rc != PJ_SUCCESS) {
	    return rc;
	}

	pj_mutex_lock(rec->suspended_mutex);
    } else {
	pj_assert(rec->suspended_mutex == NULL);
    }
    

    /* Init thread attributes */
    pthread_attr_init(&thread_attr);

#if defined(PJ_THREAD_SET_STACK_SIZE) && PJ_THREAD_SET_STACK_SIZE!=0
    /* Set thread's stack size */
    rc = pthread_attr_setstacksize(&thread_attr, stack_size);
    if (rc != 0)
	return PJ_RETURN_OS_ERROR(rc);
#endif	/* PJ_THREAD_SET_STACK_SIZE */


#if defined(PJ_THREAD_ALLOCATE_STACK) && PJ_THREAD_ALLOCATE_STACK!=0
    /* Allocate memory for the stack */
    stack_addr = pj_pool_alloc(pool, stack_size);
    PJ_ASSERT_RETURN(stack_addr, PJ_ENOMEM);

    rc = pthread_attr_setstackaddr(&thread_attr, stack_addr);
    if (rc != 0)
	return PJ_RETURN_OS_ERROR(rc);
#endif	/* PJ_THREAD_ALLOCATE_STACK */


    /* Create the thread. */
    rec->proc = proc;
    rec->arg = arg;
    rc = pthread_create( &rec->thread, &thread_attr, &thread_main, rec);
    if (rc != 0) {
	return PJ_RETURN_OS_ERROR(rc);
    }

    *ptr_thread = rec;

    PJ_LOG(6, (rec->obj_name, "Thread created"));
    return PJ_SUCCESS;
#else
    pj_assert(!"Threading is disabled!");
    return PJ_EINVALIDOP;
#endif
}

/*
 * pj_thread-get_name()
 */
PJ_DEF(const char*) pj_thread_get_name(pj_thread_t *p)
{
#if PJ_HAS_THREADS
    pj_thread_t *rec = (pj_thread_t*)p;

    PJ_CHECK_STACK();
    PJ_ASSERT_RETURN(p, "");

    return rec->obj_name;
#else
    return "";
#endif
}

/*
 * pj_thread_resume()
 */
PJ_DEF(pj_status_t) pj_thread_resume(pj_thread_t *p)
{
    pj_status_t rc;

    PJ_CHECK_STACK();
    PJ_ASSERT_RETURN(p, PJ_EINVAL);

    rc = pj_mutex_unlock(p->suspended_mutex);

    return rc;
}

/*
 * pj_thread_this()
 */
PJ_DEF(pj_thread_t*) pj_thread_this(void)
{
#if PJ_HAS_THREADS
    pj_thread_t *rec = pj_thread_local_get(thread_tls_id);
    
    if (rec == NULL) {
	pj_assert(!"Calling pjlib from unknown/external thread. You must "
		   "register external threads with pj_thread_register() "
		   "before calling any pjlib functions.");
    }

    /*
     * MUST NOT check stack because this function is called
     * by PJ_CHECK_STACK() itself!!!
     *
     */