memwatch.c

程序代码使用说明： (1)所有源代码目录下都提供了Makefile（非Qt）

    /* stupid compilers from squeaking about differing return modes. */
    /* Smart compilers instead say 'code unreachable...' */
    /*lint -save -e527 */
    return 0;
    /*lint -restore */
    }

void mwTrace( const char *format, ... ) {
    int tot, oflow = 0;
    va_list mark;

    mwAutoInit();
	MW_MUTEX_LOCK();
    TESTS(NULL,0);
    if( mwOutFunction == NULL ) mwOutFunction = mwDefaultOutFunc;

    va_start( mark, format );
    tot = vsprintf( mwPrintBuf, format, mark );
    va_end( mark );
    if( tot >= MW_TRACE_BUFFER ) { mwPrintBuf[MW_TRACE_BUFFER] = 0; oflow = 1; }
    for(tot=0;mwPrintBuf[tot];tot++)
        (*mwOutFunction)( mwPrintBuf[tot] );
    if( oflow ) {
        mwIncErr();
        mwTrace( " [WARNING: OUTPUT BUFFER OVERFLOW - SYSTEM UNSTABLE]\n" );
        }

    FLUSH();
	MW_MUTEX_UNLOCK();
    }


/***********************************************************************
** Grab & Drop
***********************************************************************/

unsigned mwGrab( unsigned kb ) {
    TESTS(NULL,0);
    return mwGrab_( kb, MW_VAL_GRB, 0 );
    }

unsigned mwDrop( unsigned kb ) {
    TESTS(NULL,0);
    return mwDrop_( kb, MW_VAL_GRB, 0 );
    }

static void mwDropAll() {
    TESTS(NULL,0);
    (void) mwDrop_( 0, MW_VAL_GRB, 0 );
    (void) mwDrop_( 0, MW_VAL_NML, 0 );
    if( mwGrabList != NULL )
        mwWrite( "internal: the grab list is not empty after mwDropAll()\n");
    }

static const char *mwGrabType( int type ) {
    switch( type ) {
        case MW_VAL_GRB:
            return "grabbed";
        case MW_VAL_NML:
            return "no-mans-land";
        default:
            /* do nothing */
            ;
        }
    return "<unknown type>";
    }

static unsigned mwGrab_( unsigned kb, int type, int silent ) {
    unsigned i = kb;
    mwGrabData *gd;
    if( !kb ) i = kb = 65000U;

    for(;kb;kb--) {
        if( mwUseLimit &&
            (mwStatCurAlloc + mwGrabSize + (long)sizeof(mwGrabData) > mwAllocLimit) ) {
            if( !silent ) {
                mwWrite("grabbed: all allowed memory to %s (%u kb)\n",
                    mwGrabType(type), i-kb);
                FLUSH();
                }
            return i-kb;
            }
        gd = (mwGrabData*) malloc( sizeof(mwGrabData) );
        if( gd == NULL ) {
            if( !silent ) {
                mwWrite("grabbed: all available memory to %s (%u kb)\n",
                    mwGrabType(type), i-kb);
                FLUSH();
                }
            return i-kb;
            }
        mwGrabSize += (long) sizeof(mwGrabData);
        gd->next = mwGrabList;
        memset( gd->blob, type, sizeof(gd->blob) );
        gd->type = type;
        mwGrabList = gd;
        }
    if( !silent ) {
        mwWrite("grabbed: %u kilobytes of %s memory\n", i, mwGrabType(type) );
        FLUSH();
        }
    return i;
    }

static unsigned mwDrop_( unsigned kb, int type, int silent ) {
    unsigned i = kb;
    mwGrabData *gd,*tmp,*pr;
    const void *p;

    if( mwGrabList == NULL && kb == 0 ) return 0;
    if( !kb ) i = kb = 60000U;

    pr = NULL;
    gd = mwGrabList;
    for(;kb;) {
        if( gd == NULL ) {
            if( i-kb > 0 && !silent ) {
                mwWrite("dropped: all %s memory (%u kb)\n", mwGrabType(type), i-kb);
                FLUSH();
                }
            return i-kb;
            }
        if( gd->type == type ) {
            if( pr ) pr->next = gd->next;
            kb --;
            tmp = gd;
            if( mwGrabList == gd ) mwGrabList = gd->next;
            gd = gd->next;
            p = mwTestMem( tmp->blob, sizeof( tmp->blob ), type );
            if( p != NULL ) {
                mwWrite( "wild pointer: <%ld> %s memory hit at %p\n",
                    mwCounter, mwGrabType(type), p );
                FLUSH();
                }
            mwGrabSize -= (long) sizeof(mwGrabData);
            free( tmp );
            }
        else {
            pr = gd;
            gd = gd->next;
            }
        }
    if( !silent ) {
        mwWrite("dropped: %u kilobytes of %s memory\n", i, mwGrabType(type) );
        FLUSH();
        }
    return i;
    }

/***********************************************************************
** No-Mans-Land
***********************************************************************/

void mwNoMansLand( int level ) {
    mwAutoInit();
    TESTS(NULL,0);
    switch( level ) {
        case MW_NML_NONE:
            (void) mwDrop_( 0, MW_VAL_NML, 0 );
            break;
        case MW_NML_FREE:
            break;
        case MW_NML_ALL:
            (void) mwGrab_( 0, MW_VAL_NML, 0 );
            break;
        default:
            return;
        }
    mwNML = level;
    }

/***********************************************************************
** Static functions
***********************************************************************/

static void mwAutoInit( void )
{
    if( mwInited ) return;
    mwUseAtexit = 1;
    mwInit();
    return;
}

static FILE *mwLogR() {
    if( (mwLog == mwLogB1) && (mwLog == mwLogB2) ) return mwLog;
    if( mwLog == mwLogB1 ) mwLogB2 = mwLog;
    if( mwLog == mwLogB2 ) mwLogB1 = mwLog;
    if( mwLogB1 == mwLogB2 ) mwLog = mwLogB1;
    if( (mwLog == mwLogB1) && (mwLog == mwLogB2) ) {
        mwWrite("internal: log file handle damaged and recovered\n");
        FLUSH();
        return mwLog;
        }
    fprintf(mwSTDERR,"\nMEMWATCH: log file handle destroyed, using mwSTDERR\n" );
    mwLog = mwLogB1 = mwLogB2 = mwSTDERR;
    return mwSTDERR;
    }

static void mwLogW( FILE *p ) {
    mwLog = mwLogB1 = mwLogB2 = p;
    }

static int mwFlushR() {
    if( (mwFlushing == mwFlushingB1) && (mwFlushing == mwFlushingB2) ) return mwFlushing;
    if( mwFlushing == mwFlushingB1 ) mwFlushingB2 = mwFlushing;
    if( mwFlushing == mwFlushingB2 ) mwFlushingB1 = mwFlushing;
    if( mwFlushingB1 == mwFlushingB2 ) mwFlushing = mwFlushingB1;
    if( (mwFlushing == mwFlushingB1) && (mwFlushing == mwFlushingB2) ) {
        mwWrite("internal: flushing flag damaged and recovered\n");
        FLUSH();
        return mwFlushing;
        }
    mwWrite("internal: flushing flag destroyed, so set to true\n");
    mwFlushing = mwFlushingB1 = mwFlushingB2 = 1;
    return 1;
    }

static void mwFlushW( int n ) {
    mwFlushing = mwFlushingB1 = mwFlushingB2 = n;
    }

static void mwIncErr() {
    mwErrors++;
    mwFlushW( mwFlushR()+1 );
    FLUSH();
    }

static void mwFlush() {
    if( mwLogR() == NULL ) return;
#ifdef MW_FLUSH
    fflush( mwLogR() );
#else
    if( mwFlushR() ) fflush( mwLogR() );
#endif
    return;
    }

static void mwUnlink( mwData* mw, const char* file, int line ) {
    if( mw->prev == NULL ) {
        if( mwHead != mw )
            mwWrite( "internal: <%ld> %s(%d), MW-%p: link1 NULL, but not head\n",
                mwCounter, file, line, mw );
        mwHead = mw->next;
        }
    else {
        if( mw->prev->next != mw )
            mwWrite( "internal: <%ld> %s(%d), MW-%p: link1 failure\n",
                mwCounter, file, line, mw );
        else mw->prev->next = mw->next;
        }
    if( mw->next == NULL ) {
        if( mwTail != mw )
            mwWrite( "internal: <%ld> %s(%d), MW-%p: link2 NULL, but not tail\n",
                mwCounter, file, line, mw );
        mwTail = mw->prev;
        }
    else {
        if( mw->next->prev != mw )
            mwWrite( "internal: <%ld> %s(%d), MW-%p: link2 failure\n",
                mwCounter, file, line, mw );
        else mw->next->prev = mw->prev;
        }
    }

/*
** Relinking tries to repair a damaged mw block.
** Returns nonzero if it thinks it successfully
** repaired the heap chain.
*/
static int mwRelink( mwData* mw, const char* file, int line ) {
    int fails;
    mwData *mw1, *mw2;
    long count, size;
    mwStat *ms;

	if( file == NULL ) file = "unknown";

    if( mw == NULL ) {
        mwWrite("relink: cannot repair MW at NULL\n");
        FLUSH();
        goto emergency;
        }

    if( !mwIsSafeAddr(mw, mwDataSize) ) {
        mwWrite("relink: MW-%p is a garbage pointer\n", mw);
        FLUSH();
        goto emergency;
        }

    mwWrite("relink: <%ld> %s(%d) attempting to repair MW-%p...\n", mwCounter, file, line, mw );
    FLUSH();
    fails = 0;

    /* Repair from head */
    if( mwHead != mw ) {
        if( !mwIsSafeAddr( mwHead, mwDataSize ) ) {
            mwWrite("relink: failed for MW-%p; head pointer destroyed\n", mw );
            FLUSH();
            goto emergency;
            }
        for( mw1=mwHead; mw1; mw1=mw1->next ) {
            if( mw1->next == mw ) {
                mw->prev = mw1;
                break;
                }
            if( mw1->next &&
                ( !mwIsSafeAddr(mw1->next, mwDataSize ) || mw1->next->prev != mw1) ) {
                mwWrite("relink: failed for MW-%p; forward chain fragmented at MW-%p: 'next' is %p\n", mw, mw1, mw1->next );
                FLUSH();
                goto emergency;
                }
            }
        if( mw1 == NULL ) {
            mwWrite("relink: MW-%p not found in forward chain search\n", mw );
            FLUSH();
            fails ++;
            }
        }
	else
	{
		mwWrite( "relink: MW-%p is the head (first) allocation\n", mw );
		if( mw->prev != NULL )
		{
			mwWrite( "relink: MW-%p prev pointer is non-NULL, you have a wild pointer\n", mw );
			mw->prev = NULL;
		}
	}

    /* Repair from tail */
    if( mwTail != mw ) {
        if( !mwIsSafeAddr( mwTail, mwDataSize ) ) {
            mwWrite("relink: failed for MW-%p; tail pointer destroyed\n", mw );
            FLUSH();
            goto emergency;
            }
        for( mw1=mwTail; mw1; mw1=mw1->prev ) {
            if( mw1->prev == mw ) {
                mw->next = mw1;
                break;
                }
            if( mw1->prev && (!mwIsSafeAddr(mw1->prev, mwDataSize ) || mw1->prev->next != mw1) ) {
                mwWrite("relink: failed for MW-%p; reverse chain fragmented at MW-%p, 'prev' is %p\n", mw, mw1, mw1->prev );
                FLUSH();
                goto emergency;
                }
            }
        if( mw1 == NULL ) {
            mwWrite("relink: MW-%p not found in reverse chain search\n", mw );
            FLUSH();
            fails ++;
            }
        }
	else
	{
		mwWrite( "relink: MW-%p is the tail (last) allocation\n", mw );
		if( mw->next != NULL )
		{
			mwWrite( "relink: MW-%p next pointer is non-NULL, you have a wild pointer\n", mw );
			mw->next = NULL;
		}
	}

    if( fails > 1 ) {
        mwWrite("relink: heap appears intact, MW-%p probably garbage pointer\n", mw );
        FLUSH();
        goto verifyok;
        }

    /* restore MW info where possible */
    if( mwIsReadAddr( mw->file, 1 ) ) {
        ms = mwStatGet( mw->file, -1, 0 );
        if( ms == NULL ) mw->file = "<relinked>";
        }
    mw->check = CHKVAL(mw);
    goto verifyok;

    /* Emergency repair */
    emergency:

    if( mwHead == NULL && mwTail == NULL )
    {
        if( mwStatCurAlloc == 0 )
            mwWrite("relink: <%ld> %s(%d) heap is empty, nothing to repair\n", mwCounter, file, line );
        else
            mwWrite("relink: <%ld> %s(%d) heap damaged beyond repair\n", mwCounter, file, line );
        FLUSH();
        return 0;
    }

    mwWrite("relink: <%ld> %s(%d) attempting emergency repairs...\n", mwCounter, file, line );
    FLUSH();

	if( mwHead == NULL || mwTail == NULL )
	{
		if( mwHead == NULL ) mwWrite("relink: mwHead is NULL, but mwTail is %p\n", mwTail );
		else mwWrite("relink: mwTail is NULL, but mwHead is %p\n", mwHead );
	}

    mw1=NULL;
    if( mwHead != NULL )
	{
		if( !mwIsReadAddr( mwHead, mwDataSize ) || mwHead->check != CHKVAL(mwHead) )
		{
			mwWrite("relink: mwHead (MW-%p) is damaged, skipping forward scan\n", mwHead );
			mwHead = NULL;
			goto scan_reverse;
		}
		if( mwHead->prev != NULL )
		{
			mwWrite("relink: the mwHead pointer's 'prev' member is %p, not NULL\n", mwHead->prev );
		}
        for( mw1=mwHead; mw1; mw1=mw1->next )
		{
			if( mw1->next )
			{
				if( !mwIsReadAddr(mw1->next,mwDataSize) ||
					!mw1->next->check != CHKVAL(mw1) ||
					mw1->next->prev != mw1 )
				{
					mwWrite("relink: forward chain's last intact MW is MW-%p, %ld %sbytes at %s(%d)\n",
						mw1, mw1->size, (mw->flag & MW_NML)?"NoMansLand ":"", mw1->file, mw1->line );
					if( mwIsReadAddr(mw1->next,mwDataSize ) )
					{
						mwWrite("relink: forward chain's first damaged MW is MW-%p, %ld %sbytes at %s(%d)\n",
							mw1->next, mw1->size, (mw->flag & MW_NML)?"NoMansLand ":"",
							mwIsReadAddr(mw1->file,16)?mw1->file:"<garbage-pointer>", mw1->line );
					}
					else
					{
						mwWrite("relink: the 'next' pointer of this MW points to %p, which is out-of-legal-access\n",
							mw1->next );
					}
					break;
				}
			}
        }
	}


scan_reverse:
    mw2=NULL;
    if( mwTail != NULL )
	{
		if( !mwIsReadAddr(mwTail,mwDataSize) || mwTail->check != CHKVAL(mwTail) )
		{