com.gemstone.gemfire.internal.utl.hf Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of gemfire-core Show documentation
SnappyData store based off Pivotal GemFireXD
There is a newer version: 2.0-BETA
/*
 * Copyright (c) 2010-2015 Pivotal Software, Inc. 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. See accompanying
 * LICENSE file.
 */
#ifndef UTL_HF
#define UTL_HF TRUE

#include "global.ht"
#include "host.hf"

/*=========================================================================
 * Description:
 *
 * This file consists largely of some obscurely written macros.  It will
 * probably end up serving as a prototype for journeyman C programmers needing
 * to compose macros for Heaven knows how long to come.
 * As such, a number of rules are worth enumerating here:  Note -- there
 * is an exception to every rule, but when these occur, they should be
 * documented profusely.
 *
 * 1) A macro shall either be an expression or a block ({}).  Any other
 *    use of macros is obscure to both humans and prettyprinters.
 *
 * 2) An identifier has highest precedence, and a function argument has
 *    lowest precedence.  This means that a macro argument will usually
 *    have the wrong precedence when expanded.  Thus, you should always
 *    enclose macro arguments in parentheses (foo) so that it has the correct
 *    level of precedence.
 *
 * 3) Function arguments are evaluated once, whereas macro arguments are
 *    textually substituted.  If a function argument has side effects, it
 *    can screw up in a macro evaluation.  Solution:  Refer to each function
 *    argument exactly once, if possible.
 *
 *    Note that even lvals can have side effects, e.g., i++ = 10;
 *
 * 4) A block ({}) is NOT equivalent to a statement.  Thus, if we have
 *
 * #define FOO_MACRO { i = 3; j = 4;}
 *
 * if (i = j)
 *   FOO_MACRO;
 * else
 *   somethingElse();
 *
 * The resulting expansion will have an illegal semicolon (";") before the
 * "else".  It seems (no guarantees!) that this will always generate a message
 * from the C compiler.  Solution:  Write the previous as,
 *
 * if (i = j)
 *   {FOO_MACRO;}
 * else
 *   somethingElse();
 *
 * The advantage to this approach is that it is clear to humans as well as
 * prettyprinters.
 *
 * 5) Blocks can have temporaries.  This sounds really useful until you consider
 * that the temporaries can override names used as local variables.  In other
 * words, if we have,
 *
 * #define FOO_MACRO(x) {int i; i = (x) + 3; j = i * i;}
 *
 * int i;
 *
 * i = 10;
 * z = FOO_MACRO(i);
 *
 * you will get incorrect behavior at run-time.  Note that the compiler will
 * be completely silent, but the execution will be wrong!
 *
 * To circumvent this, temporaries used in macro blocks should NOT be the
 * same as those used in a macro.  In this module, temporaries are preceded
 * with "utl_" which is against GemStone variable name conventions for all
 * other purposes.
 *
 * 6) If you don't follow all of the above, HAVE SOMEONE LOOK AT YOUR MACRO!!!!
 *
 * --djp
 *
 *
 *
 *=========================================================================
 */

/*******  C Run-Time Library files ******************************************/

/*******  GemStone constants/types defined in this and other modules ********/
#include "global.ht"

/* no more includes. KEEP THIS LINE */

#ifdef __cplusplus
extern "C" {
#endif

EXTERN_GS_DEC(void)
UtlGuaranteeFailure(const char *fileName, int lineNum); 

/* UTL_GUARANTEE is active in both fast and slow */
#define UTL_GUARANTEE( x ) { \
  if (! ( x )) { \
    UtlGuaranteeFailure(__FILE__, __LINE__); \
  } \
}

#if defined(FLG_DEBUG)
#define UTL_ASSERT( x ) { \
  if (! ( x )) { \
    printf("UTL_ASSERT failure file %s line %d \n", __FILE__, __LINE__); \
    HostCallDebuggerMsg("UTL_ASSERT failed"); \
    } \
  }
#define UTL_IF_DEBUG( x ) { x }
#define UTL_DEBUG_DEF( x ) x
#define UTL_IS_DEBUG 1
#else
/* fast */
#define UTL_ASSERT( x ) { }
#define UTL_IF_DEBUG( x ) { }
#define UTL_DEBUG_DEF( x ) /*  */
#define UTL_IS_DEBUG 0
#endif

EXTERN_GS_DEC(int) UtlFirstFunction(void);

EXTERN_GS_DEC(int) UtlLastFunction(void);


/*========================================================================
 * malloc tracing support
 * 
 *========================================================================
 */
#define UTL_FREE(x) { UtlFree(x); (x) = NULL; }

void* UtlMalloc(int32 aSize, const char* msg);
  /* calls HostCallDebugger if out of C heap memory */

void* UtlMallocNoErr(int32 aSize, const char* msg);
  /* returns null if out of C heap memory */

void* UtlCalloc(size_t nelem, size_t elsize);
  /* returns null if out of C heap memory */

#if !defined(UTL_C)
#define malloc mallocBadUsage 
#endif

#ifdef FLG_DEBUG
void  UtlFree(void *x);
  /* calls free() */
#if !defined(UTL_C)
#define free freeBadUsage 
#endif

#else
#define UtlFree free 
#endif  /* FLG_DEBUG*/

#ifdef __cplusplus
} /* extern "C" */
#endif /* __cplusplus */

#endif /* endif utl.hf */