ABAP 實現多線程（二）

第一步：初始化server group ,server group 可以用RZ12進行維護，參數直接複製即可，不要修改。
CONSTANTS: serv_group LIKE rzllitab-classname VALUE ‘JOBRUN’.

CALL FUNCTION ‘SPBT_INITIALIZE’
EXPORTING
group_name = serv_group

• IMPORTING
  

•   MAX_PBT_WPS                          =
  

•   FREE_PBT_WPS                         =
  

  EXCEPTIONS
  invalid_group_name = 1
  internal_error = 2
  pbt_env_already_initialized = 3
  currently_no_resources_avail = 4
  no_pbt_resources_found = 5
  cant_init_different_pbt_groups = 6
  OTHERS = 7
  .
  第二步：分別寫多個FM的調用，注意：如果多個FM都共用的參數，數據寫在主程序中，然後用參數傳到FM裏。
  CALL FUNCTION ‘Z_BAPI_FM1’
  STARTING NEW TASK ‘FM1TASK’ DESTINATION IN GROUP serv_group
  PERFORMING sub_fm1_back ON END OF TASK
  TABLES
  date_ra = date_ra.
  CALL FUNCTION ‘Z_BAPI_FM2’
  STARTING NEW TASK ‘FM2TASK’ DESTINATION IN GROUP serv_group
  PERFORMING sub_FM2_back ON END OF TASK
  TABLES
  date_ra = date_ra.
  第三步.FM執行完之後數據反回，數據返回的參數是全局的，在Z_BAPI_FM*中對全局參數進行賦值。
  FORM sub_fm1_back USING name.
  RECEIVE RESULTS FROM FUNCTION ‘Z_BAPI_FM1’
  TABLES
  ret_par = gdt_ret_pars "返回的參數
  return = gdt_gr_return.
  APPEND LINES OF gdt_gr_return TO gdt_return.
  gr_flag = ‘X’. "這個很重要，根據這個參數判斷FM是否執行完畢
  ENDFORM. "sub_fm1_back

  FORM sub_fm2_back USING name.
  RECEIVE RESULTS FROM FUNCTION ‘Z_BAPI_FM2’
  TABLES
  returnpo = gdt_ret_pos
  return = gdt_returnpo_return.
  APPEND LINES OF gdt_returnpo_return TO gdt_return.
  returnpo_flag = ‘X’.
  ENDFORM. "sub_fm2_back

第四步：收尾工作，判斷各個FM是否執行完畢
WAIT UNTIL gr_flag = ‘X’ AND returnpo_flag = ‘X’ .
ret_pars[] = gdt_ret_pars. “返回的結果
returnpo[] = gdt_ret_pos. “返回的結果
APPEND LINES OF gdt_return TO return. “最終返回的return ，一般FM都有返回值，返回錯誤，警告等信息。