linux之软看门狗的实现

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//softwareWdt.h
/*
*功能:  监测各线程间的运行状态(软看门狗)
*
*作者:JDSH
*
*时间:2015-01-15 22:20
*/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "Typedef.h"


#define REQUEST_WDT_MAX_NUM 20

class CSoftwareWdt 
{
private:
  bool m_fReqWdtFlg[REQUEST_WDT_MAX_NUM];  //=true 已经申请ID成功，=false反之

  WORD m_wWdtTimeout[REQUEST_WDT_MAX_NUM];

  WORD m_wWdtCount[REQUEST_WDT_MAX_NUM];

public:
  CSoftwareWdt();

  ~CSoftwareWdt();

  int RequestSoftwareWdtID(const char *cThreadName, WORD wTimeout);  

  bool ReleaseSoftwareWdtID(const char *cThreadName, WORD wTimeout);

  bool KeepSoftwareWdtAlive(WORD wWdtId);

  void MontiorWdtRunState();
};


#include "SoftwareWdt.h"

CSoftwareWdt::CSoftwareWdt()
{
  BYTE bId;

  for (bId = 0; bId < REQUEST_WDT_MAX_NUM; bId++)
    m_fReqWdtFlg[bId] = false;
  memset(m_wWdtTimeout, 0x00, sizeof(m_wWdtTimeout));
  memset(m_wWdtCount, 0x00, sizeof(m_wWdtCount));
}

CSoftwareWdt::~CSoftwareWdt()
{
  ;
}

/*
* 功能:申请软件狗的ID
* 返回:申请失败返回-1，成功返回申请到ID
*
*/
int CSoftwareWdt::RequestSoftwareWdtID(const char *cThreadName, WORD wTimeout)
{
  BYTE bId;
  int iRet = -1;

  for (bId = 0; bId < REQUEST_WDT_MAX_NUM; bId++)
  {
    if (m_fReqWdtFlg[bId] == false)  //等于0、表示该ID还没有被申请过,可以使用
    {
      m_wWdtTimeout[bId] = wTimeout;
      m_wWdtCount[bId] = 0;
      m_fReqWdtFlg[bId] = true;
      printf("The thread %s request ID=%d successful. Timeout=%d\n", 
        cThreadName, bId, wTimeout);
      return bId;
    }
  }

  return iRet;
}

bool CSoftwareWdt::ReleaseSoftwareWdtID(const char *cThreadName, WORD wWdtId)
{
  bool fRet = false;
  
  if (wWdtId > REQUEST_WDT_MAX_NUM)
  {
    printf("The thread %s ID=%d is over MAX ID=%d\n", 
      cThreadName, wWdtId, REQUEST_WDT_MAX_NUM);
    return false;
  }

  if (m_fReqWdtFlg[wWdtId] != 0)
  {
    fRet = true;
    m_fReqWdtFlg[wWdtId] = false;
    m_wWdtTimeout[wWdtId] = 0;
    m_wWdtCount[wWdtId] = 0;
    printf("Release thread %s ID=%d\n", cThreadName, wWdtId);
  }  

  return fRet;
}

bool CSoftwareWdt::KeepSoftwareWdtAlive(WORD wWdtId)
{
  if (wWdtId > REQUEST_WDT_MAX_NUM)
    return -1;

  printf("Keep software Wdt Id=%d\n", wWdtId);
  m_wWdtCount[wWdtId] =0;

  return true;
}

void CSoftwareWdt::MontiorWdtRunState()
{
  BYTE bId;

  for (bId = 0; bId < REQUEST_WDT_MAX_NUM; bId++)
  {
    if (m_fReqWdtFlg[bId])
    {
      if (m_wWdtCount[bId]++ > m_wWdtTimeout[bId])
      {
        printf("The Wdt ID=%d is timeout\n", bId);
        system("reboot");
      }
    }
  }
}

CSoftwareWdt *g_CsoftwareWdt;

int main(int argc, char *argv[])
{
  const char *sThreadName[10] = {"One", "Two", "Three", "Four", "Five", 
         "Six", "Seven", "Eight", "Nine", "Ten"};
  WORD wTimeout = 30;
  BYTE bId =0;
  
  printf("\n\n\n");
  printf("*********************************************\n");
  printf("**************Software wdt Test**************\n");
  printf("*********************************************\n");
  printf("\n");
  
  g_CsoftwareWdt = new CSoftwareWdt();
  
  for (bId = 0; bId < 10; bId++)
  {
    g_CsoftwareWdt->RequestSoftwareWdtID(sThreadName[bId], wTimeout);
  }

  bId = 0;
  while (1)
  {
    g_CsoftwareWdt->MontiorWdtRunState();
    sleep(1);
    g_CsoftwareWdt->KeepSoftwareWdtAlive(bId);
    bId++;
    if (bId > 10)
      bId = 0;
  }

  delete g_CsoftwareWdt;
}

说明：本部分的功能是实现一个软看门狗，用于监测各个线程的运行状态，使用时必须先申请看门狗线程的ID，为了合理的运用软看门狗的资源，线程退出时必须释放看门狗，某个线程超时，将通过调试信息打印超时线程，并最终唤起系统重启，注意这个软看门狗与硬件看门狗的区别。此程序原创，转载请指明出处，如存在缺陷，欢迎指正！