syslog.c

tkernel操作系统的源代码,是一位日本教授领导开发的,占有很大市场

/*
 *----------------------------------------------------------------------
 *    T-Kernel
 *
 *    Copyright (C) 2004 by Ken Sakamura. All rights reserved.
 *    T-Kernel is distributed under the T-License.
 *----------------------------------------------------------------------
 *
 *    Version:   1.01.00
 *    Released by T-Engine Forum(http://www.t-engine.org) at 2004/6/28.
 *
 *----------------------------------------------------------------------
 */

/*
 *	syslog.c (T-Kernel/SM)
 *	System Log Task
 */

#include <basic.h>
#include <tk/tkernel.h>
#include <tk/util.h>
#include <tm/tmonitor.h>
#include <sys/debug.h>
#include "syslog.h"

#if USE_SYSLOG_CONSIO
#include <sys/consio.h>
#endif

EXPORT	W	logtask_alive = 0;	/* Is log task running? */

#if USE_SYSLOG_CONSIO
LOCAL	W	log_msg_maxmsz;		/* Maximum length of log message */
LOCAL	ID	log_mbfid;		/* Message buffer ID for log */
#endif

/*
 * Low level output using monitor
 */
LOCAL void sys_write( const char *s, int len )
{
	while ( len-- > 0 ) tm_putchar(*s++);
}

/*
 * Wait until log is completed.
 */
LOCAL ER svc_syslog_wait( void )
{
#if USE_SYSLOG_CONSIO
	T_RMBF	rmbf;
	W	i;
	ER	er;

	if ( logtask_alive ) {
		for ( i = 0; i < 50; i++ ) {
			tk_dly_tsk(100);
			er = tk_ref_mbf(log_mbfid, &rmbf);
			if ( er != E_OK || rmbf.wtsk > 0 ) break;
		}
	}
#endif

	return E_OK;
}

/*
 * Extension SVC handler for log
 */
EXPORT ER __syslog_send( const char *string, int len )
{
	ER	er;

	if ( string == NULL ) return svc_syslog_wait();

	if ( len <= 0 ) return E_OK;

#if USE_SYSLOG_CONSIO
	if ( logtask_alive ) {
		/* When log task is running, send message to log task */
		if ( len > log_msg_maxmsz ) len = log_msg_maxmsz;
		er = tk_snd_mbf(log_mbfid, (VP)string, len, TMO_POL);
		if ( er != E_OK ) logtask_alive = 0;
	}
#endif

	if ( !logtask_alive ) {
		/* When it is not running, use low level character
		   output routine directly. */
		sys_write(string, len);
		sys_write("\n", 1);
	}

	return E_OK;
}

#if USE_SYSLOG_CONSIO
/*
 * Log task
 */
LOCAL void log_task( INT logtask_port )
{
	static B	logtask_buf[MBF_LOG_MAXMSZ+1];
	INT		msgsz;
	ER		er;

	logtask_alive = 1;
	log_msg_maxmsz = MBF_LOG_MAXMSZ;

	for ( ;; ) {
		er = tk_rcv_mbf(log_mbfid, logtask_buf, TMO_FEVR);
		if ( er < E_OK ) break;
		msgsz = er;
		logtask_buf[msgsz++] = '\n';

		er = console_out(logtask_port, logtask_buf, msgsz);
		if ( er < E_OK ) {
			sys_write(logtask_buf, msgsz);
		}
	}

	logtask_alive = 0;
	tk_exd_tsk();
}
#endif

/*
 * syslog initialization
 */
EXPORT ER initialize_syslog( void )
{
#if USE_SYSLOG_CONSIO
	T_CMBF	cmbf;
	T_CTSK	ctsk;
	ID	tskid;
	ER	err;

	/* Generate message buffer */
	SetOBJNAME(cmbf.exinf, "SLog");
	cmbf.mbfatr = TA_TFIFO | TA_NODISWAI;
	cmbf.bufsz  = MBF_LOG_BUFSZ;
	cmbf.maxmsz = MBF_LOG_MAXMSZ;
	err = tk_cre_mbf(&cmbf);
	if ( err < E_OK ) goto err_ret1;
	log_mbfid = err;

	/* Temporarily lower the local task priority 
	   so that the system log task executes initialization sequence. */
	tk_chg_pri(TSK_SELF, 10);

	/* Start log task */
	SetOBJNAME(ctsk.exinf, "SLog");
	ctsk.tskatr  = TA_HLNG | TA_RNG0;
	ctsk.task    = log_task;
	ctsk.itskpri = 6;
	ctsk.stksz   = 512;
	err = tk_cre_tsk(&ctsk);
	if ( err < E_OK ) goto err_ret1;
	tskid = err;
	err = tk_sta_tsk(tskid, CONSOLE_PORT);
	if ( err < E_OK ) goto err_ret2;

	/* Return local task priority */
	tk_chg_pri(TSK_SELF, TPRI_INI);

	return E_OK;

err_ret2:
	tk_del_tsk(tskid);
err_ret1:
	DEBUG_PRINT(("initialize_syslog err = %d\n", err));
	return err;
#else
	return E_OK;
#endif
}

/*
 * syslog finalization sequence
 */
EXPORT ER finish_syslog( void )
{
#if USE_SYSLOG_CONSIO
	ER	err, error = E_OK;

	/* Delete message buffer
	   This also stops log task */
	err = tk_del_mbf(log_mbfid);
	if ( err < E_OK ) error = err;

#ifdef DEBUG
	if ( error < E_OK ) DEBUG_PRINT(("finish_syslog err = %d\n", error));
#endif
	return error;
#else
	return E_OK;
#endif
}