src/share/util.h

   1 /*****************************************************************************
   2  * Copyright 2005 Daniel Ferullo                                             *
   3  *                                                                           *
   4  * Licensed under the Apache License, Version 2.0 (the "License");           *
   5  * you may not use this file except in compliance with the License.          *
   6  * You may obtain a copy of the License at                                   *
   7  *                                                                           *
   8  *    http://www.apache.org/licenses/LICENSE-2.0                             *
   9  *                                                                           *
  10  * Unless required by applicable law or agreed to in writing, software       *
  11  * distributed under the License is distributed on an "AS IS" BASIS,         *
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  *
  13  * See the License for the specific language governing permissions and       *
  14  * limitations under the License.                                            *
  15  *                                                                           *
  16  *****************************************************************************/
  17
  18 /**
  19  * @file util.h
  20  * @author Daniel Ferullo (ferullo@cmu.edu)
  21  *
  22  * @brief contains useful utility functions
  23  */
  24
  25 #ifndef __UTIL_H__
  26 #define __UTIL_H__
  27
  28 #include "errorcodes.h"
  29 #include "flag.h"
  30
  31 /**
  32  * @brief decrements a signed number by one, but not past zero
  33  *
  34  * @param x The number to decrement
  35  * @return The decremented value
  36  **/
  37 int inline DEC_UNTIL_ZERO(int x);
  38
  39 /** @brief a macro to determine if two boolean values are the same (ie both
  40  *  true or both false */
  41 #define BOOL_MATCH(x,y) ( (((x)!=0)&&((y)!=0))||(((x)==0)&&((y)==0)) ? 1 : 0)
  42
  43 /**
  44  * @brief a 'safe' free
  45  *
  46  * @param memory pointer to the memory to free
  47  *
  48  * @return SUCCESS, errorcode on failure
  49  */
  50 errorcode safe_free(void *memory);
  51
  52 /**
  53  * @brief waits for a flag to take one of many specified values
  54  *
  55  * Success if the check_flag takes on any one of the stop_flags before timeout
  56  *
  57  * @param check_flag pointer to the flag to watch
  58  * @param stop_flags all the flags to wait for or'ed together.
  59  * @param timeout the timeout time, in seconds
  60  *
  61  * @return SUCCESS, errorcode on failure
  62  */
  63 errorcode wait_for_flag(flag_t *check_flag, flag_t stop_flags, int timeout);
  64
  65 #endif /* __UTIL_H__ */
  66