serial.c

Open DMT Client C Source code

// ----------------------------------------------------------------------------
// Copyright 2006-2007, Martin D. Flynn
// All rights reserved
// ----------------------------------------------------------------------------
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
// http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// ----------------------------------------------------------------------------
// Description:
//  Serial RS232 transport support.
// Notes:
//  - This implementation requires pthread support.
//  - Serial port connections are typically always duplex, and always remain 
//    'connected' until the media is physically disconnected.  A client may not 
//    be aware that a physical disconnection/reconnection has occured, thus it 
//    is the servers responibility to initiate all conversations when 
//    connecting/reconnecting with a client.
// ---
// Change History:
//  2006/02/19  Martin D. Flynn
//     -Initial release
//  2007/01/28  Martin D. Flynn
//     -Initial support for Window CE (may not be fully complete)
// ----------------------------------------------------------------------------

#include "stdafx.h" // TARGET_WINCE
#include "custom/defaults.h"

// ----------------------------------------------------------------------------

#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#include "custom/log.h"
#include "custom/transport/serial.h"

#include "tools/stdtypes.h"
#include "tools/strtools.h"
#include "tools/bintools.h"
#include "tools/comport.h"
#include "tools/buffer.h"
#include "tools/threads.h"

#include "base/props.h"
#include "base/propman.h"
#include "base/packet.h"

// ----------------------------------------------------------------------------

/* transport structure */
typedef struct {
    TransportType_t     type;
} SerialTransport_t;

static SerialTransport_t        serialXport;

// ----------------------------------------------------------------------------

// This should be set to the appropriate configured serial port speed
#define SERIAL_SPEED_BPS        BPS_57600

// size of packet buffer
#define MAX_PACKET_BUFFER       (30000L)

// ----------------------------------------------------------------------------

#if defined(TARGET_WINCE)
#  include <winsock2.h>
#endif

// ----------------------------------------------------------------------------

static TransportFtns_t          serXportFtns = { MEDIA_SERIAL, "XportSerial" };

static ComPort_t                serComPort;

static UInt32                   serOpenTime  = 0L;
static UInt32                   serCloseTime = 0L;

static CircleBuffer_t           *serBuffer;

static utBool                   serRunThread = utFalse;
static threadThread_t           serThread;
static threadMutex_t            serMutex;
static threadCond_t             serCond;
static struct timespec          serCondWaitTime;

#define BUFFER_LOCK             MUTEX_LOCK(&serMutex);
#define BUFFER_UNLOCK           MUTEX_UNLOCK(&serMutex);
#define BUFFER_WAIT(T)          CONDITION_TIMED_WAIT(&serCond,&serMutex,utcGetAbsoluteTimespec(&serCondWaitTime,(T)));
#define BUFFER_NOTIFY           CONDITION_NOTIFY(&serCond);

#define OPEN_LOCK               BUFFER_LOCK
#define OPEN_UNLOCK             BUFFER_UNLOCK

// ----------------------------------------------------------------------------

/* test for active Serial/BT connection */
static utBool btIsConnected(ComPort_t *com)
{
    utBool ready = utTrue;
#if defined(COMPORT_SUPPORT_BLUETOOTH)
    ready = comPortIsBluetoothReady(com);
#else
    // ready = comPortGetCTS(com);
#endif
    //logDEBUG(LOGSRC,"Bluetoth ready = %d", (int)ready);
    return ready;
}

// ----------------------------------------------------------------------------

#define OPEN_FAILED_INVERVAL_SEC   MINUTE_SECONDS(60)
static long serLastOpenFailedMessageTime = 0L;

/* open serial port (and check for Serial connection) */
static utBool _serdevOpenCom(ComPort_t *com, utBool log)
{

    /* port config */
    const char *portName = propGetString(PROP_CFG_XPORT_PORT, "");
    if (!portName || !*portName) {
        logERROR(LOGSRC,"Serial transport port name not specified");
        threadSleepMS(MINUTE_SECONDS(3) * 1000L); // long sleep
        return utFalse;
    }
    UInt32 portBPS = propGetUInt32(PROP_CFG_XPORT_BPS, 0L);
    if (portBPS == 0L) { portBPS = SERIAL_SPEED_BPS; }

    /* open port */
    //logDEBUG(LOGSRC,"Openning Serial port '%s' ...", portName);
    //comPortInitStruct(com); <-- port may already be open, don't initialize
    ComPort_t *openCom = (ComPort_t*)0;
    utBool portFound = utFalse;
    OPEN_LOCK {
        serOpenTime = 0L;
        if (comPortIsOpen(com)) {
            // ComPort already openned
            openCom = com;
        } else {
            // Open ComPort
            openCom = comPortOpen(com, portName, portBPS, "8N1", utFalse);
        }
        if (openCom) {
            // Serial port open
            portFound = utTrue;
            if (!btIsConnected(com)) {
                // No Serial connection
                openCom = (ComPort_t*)0;
            } else {
                // We have an active Serial connection
                serOpenTime  = utcGetTimeSec();
                serCloseTime = 0L;
            }
        } else {
            // Still closed
            // leave 'serCloseTime' as-is
        }
    } OPEN_UNLOCK
    
    /* open failed */
    if (!openCom) {
        // The outer loop will retry the open later
        // We expect this to occur when the Serial port device is no longer available
        // (ie. when the Serial device has disconnected)
        if (utcIsTimerExpired(serLastOpenFailedMessageTime,OPEN_FAILED_INVERVAL_SEC)) {
            serLastOpenFailedMessageTime = utcGetTimer();
            if (portFound) {
                logINFO(LOGSRC,"Waiting for Serial transport connection: %s", portName);
            } else {
                logERROR(LOGSRC,"Serial transport open failed: %s", portName);
            }
        }
        return utFalse;
    }

    /* additional port attributes */
    //comPortAddOptions(com, COMOPT_NOESCAPE);
    //if (PORT_IsCONSOLE(com->port)) {
    //    logINFO(LOGSRC,"Console port, backspace/echo enabled ...");
    //    comPortAddOptions(com, COMOPT_BACKSPACE);
    //    comPortAddOptions(com, COMOPT_ECHO);
    //}

    /* return success */
    logINFO(LOGSRC,"Serial port '%s' openned", portName);
    return utTrue;
    
}

/* close serial port */
static void _serdevCloseCom(utBool closePort)
{
    ComPort_t *com = &serComPort;
    OPEN_LOCK {
        comPortClose(com);
        serOpenTime  = 0L;
        serCloseTime = utcGetTimeSec();
    } OPEN_UNLOCK
}

/* return the time the connection was opened, or 0L if the connection is closed */
static UInt32 serdevGetOpenTime()
{
    UInt32 openTime = 0L;
    OPEN_LOCK {
        openTime = serOpenTime;
    } OPEN_UNLOCK
    return openTime;
}

// ----------------------------------------------------------------------------

/* initialize serial communications */
static void serdevInitialize()
{
        
    /* init comport */
    comPortInitStruct(&serComPort);
    
    /* create mutex */
    threadMutexInit(&serMutex);
    threadConditionInit(&serCond);

    /* create buffer */
    serBuffer = bufferCreate(MAX_PACKET_BUFFER);

}

// ----------------------------------------------------------------------------

//static double maxBufferLoad = 0.0;

/* continue reading until comport error, end of thread, or Serial disconnects */
static int _serdevReadData()
{
    ComPort_t *com = &serComPort;

    /* flush everything currently in the comport buffers */
    comPortFlush(com, 0L);

    /* read Serial device packet */
    // continues until port read error, or Serial disconnects
    char buf[PACKET_MAX_ENCODED_LENGTH];
    while (serRunThread) {
        
        /* test serial connection */
        if (!btIsConnected(com)) {
            // no active connection
            return 0;
        }

        /* read data */
        int cmdLen = comPortReadLine(com, buf, sizeof(buf), -1L);
        if (cmdLen < 0) {
            // com port closed?
            return -1;
        } else
        if ((cmdLen == 0) && COMERR_IsTimeout(com)) {
            // timeout, try again
            //logDEBUG(LOGSRC,"Serial device timeout");
            continue;
        }

        /* check for EOL */
        if (buf[cmdLen - 1] == 13) {