处理 "除以零" 异常的示例

在线编辑
在此示例中：
  • 可绑定 API CEEHDLR 在函数 main()中注册 main_hdlr 。
  • 可绑定 API CEEHDLR 在函数 fred()中注册 fred_hdlr 。
  • 发生 MCH1211 (除以零) 异常。
  • 调用处理程序 fred_hdlr 以测试异常是否为 MCH1211。
  • 条件处理程序中的结果代码设置为渗入到下一个条件处理程序。
  • 处理程序 fred_hdlr 返回而不处理异常，导致调用 main_hdlr 。
  • 用户提供的令牌将更新为值 "1" ，并设置结果代码以处理异常。
  • 将返回处理程序 main_hdlr ，并处理异常。
  • 在导致除零的语句之后，控制将在 fred() 中恢复。
此示例使用 T1520IC7 -ILE C Source to Percolate a Message to Handle a Condition中显示的源。
  1. 要创建程序 T1520IC7，请输入:
    CRTBNDC PGM(MYLIB/T1520IC7) SRCFILE(QCPPLE/QACSRC)
  2. 要运行程序 T1520IC7，请输入:
    CALL PGM(MYLIB/T1520IC7)
    输出为：
    in fred_hdlr, percolate exception.
in main hdlr: Facility_ID = MCH, MsgNo = 0x1211
Resume here because resume cursor not moved and main_hdlr handled the exception.
A condition was percolated from fred() to main() and was then handled.
Press ENTER to end terminal session.

T1520IC7 -ILE C 源以执行 "要处理条件的消息"

/* This program uses the ILE bindable API CEEHDLR to enable handlers  */
/* that percolate and handle a condition.                             */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <leawi.h>
/* A condition handler registered by a call to CEEHDLR in fred().     */
void fred_hdlr( _FEEDBACK *cond, _POINTER *token, _INT4 *rc, _FEEDBACK *new )
{
  if (!memcmp(cond->Facility_ID, "MCH", 3) && cond->MsgNo == 0x1211)
  {
    *rc = CEE_HDLR_PERC;  /* ... let it percolate to main ...         */
    printf("in fred_hdlr, percolate exception.\n");
  }
  else
  {
    *rc = CEE_HDLR_RESUME;  /* ... otherwise handle it.               */
    printf("in fred_hdlr, handle exception.\n");
  }
}
/* A condition handler registered by a call to CEEHDLR in main().     */
void main_hdlr( _FEEDBACK *cond, _POINTER *token, _INT4 *rc, _FEEDBACK *new )
{
  printf("in main hdlr: Facility_ID = %.3s, MsgNo = 0x%4.4x\n",
         cond->Facility_ID, cond->MsgNo);
  **(_INT4 **)token = 1;   /* Update the user's token.                */
  *rc = CEE_HDLR_RESUME;    /* Handle the condition                   */
}
int fred(void)
{
  _HDLR_ENTRY hdlr = fred_hdlr;
  _FEEDBACK fc;
  int x,y, zero = 0;
/* Register the handler without a token.                              */
  CEEHDLR(&hdlr, NULL, &fc);
  if (fc.MsgNo != CEE0000)
  {
    printf("Failed to register the condition handler\n");
    exit(88);
  }
/* Cause a divide by zero condition.                                  */
    x = y / zero;
    printf("Resume here because resume cursor not moved and main_hdlr"
           " handled the exception\n");
}

int main(void)
{
  _HDLR_ENTRY hdlr = main_hdlr;
  _FEEDBACK fc;
  volatile _INT4 token=0, *tokenp = &token;
/* Register the handler with a token of type _INT4.                   */
  CEEHDLR(&hdlr, (_POINTER *)&tokenp, &fc);

  if (fc.MsgNo != CEE0000)
  {
    printf("Failed to register the condition handler\n");
    exit(99);
  }
  fred();
/* See if the condition handler for main() updated the token.         */
  if (*tokenp == 1)
    printf("A condition was percolated from fred() to main() and"
           " was then handled.\n");
}