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）

			mwWrite("relink: mwTail (%p) is damaged, skipping reverse scan\n", mwTail );
			mwTail = NULL;
			goto analyze;
		}
		if( mwTail->next != NULL )
		{
			mwWrite("relink: the mwTail pointer's 'next' member is %p, not NULL\n", mwTail->next );
		}
        for( mw2=mwTail; mw2; mw2=mw2->prev )
		{
            if( mw2->prev )
			{
				if( !mwIsReadAddr(mw2->prev,mwDataSize) ||
					!mw2->prev->check != CHKVAL(mw2) ||
					mw2->prev->next != mw2 )
				{
					mwWrite("relink: reverse chain's last intact MW is MW-%p, %ld %sbytes at %s(%d)\n",
						mw2, mw2->size, (mw->flag & MW_NML)?"NoMansLand ":"", mw2->file, mw2->line );
					if( mwIsReadAddr(mw2->prev,mwDataSize ) )
					{
						mwWrite("relink: reverse chain's first damaged MW is MW-%p, %ld %sbytes at %s(%d)\n",
							mw2->prev, mw2->size, (mw->flag & MW_NML)?"NoMansLand ":"",
							mwIsReadAddr(mw2->file,16)?mw2->file:"<garbage-pointer>", mw2->line );
					}
					else
					{
						mwWrite("relink: the 'prev' pointer of this MW points to %p, which is out-of-legal-access\n",
							mw2->prev );
					}
					break;
				}
			}
        }
	}

analyze:
	if( mwHead == NULL && mwTail == NULL )
	{
        mwWrite("relink: both head and tail pointers damaged, aborting program\n");
        mwFlushW(1);
        FLUSH();
        abort();
	}
	if( mwHead == NULL )
	{
		mwHead = mw2;
		mwWrite("relink: heap truncated, MW-%p designated as new mwHead\n", mw2 );
		mw2->prev = NULL;
		mw1 = mw2 = NULL;
	}
	if( mwTail == NULL )
	{
		mwTail = mw1;
		mwWrite("relink: heap truncated, MW-%p designated as new mwTail\n", mw1 );
		mw1->next = NULL;
		mw1 = mw2 = NULL;
	}
    if( mw1 == NULL && mw2 == NULL &&
        mwHead->prev == NULL && mwTail->next == NULL ) {
        mwWrite("relink: verifying heap integrity...\n" );
        FLUSH();
        goto verifyok;
        }
    if( mw1 && mw2 && mw1 != mw2 ) {
        mw1->next = mw2;
        mw2->prev = mw1;
        mwWrite("relink: emergency repairs successful, assessing damage...\n");
        FLUSH();
        }
    else {
        mwWrite("relink: heap totally destroyed, aborting program\n");
        mwFlushW(1);
        FLUSH();
        abort();
        }

    /* Verify by checking that the number of active allocations */
    /* match the number of entries in the chain */
verifyok:
    if( !mwIsHeapOK( NULL ) ) {
        mwWrite("relink: heap verification FAILS - aborting program\n");
        mwFlushW(1);
        FLUSH();
        abort();
        }
    for( size=count=0, mw1=mwHead; mw1; mw1=mw1->next ) {
        count ++;
        size += (long) mw1->size;
        }
    if( count == mwNumCurAlloc ) {
        mwWrite("relink: successful, ");
        if( size == mwStatCurAlloc ) {
            mwWrite("no allocations lost\n");
            }
        else {
            if( mw != NULL ) {
                mwWrite("size information lost for MW-%p\n", mw);
                mw->size = 0;
                }
            }
        }
    else {
        mwWrite("relink: partial, %ld MW-blocks of %ld bytes lost\n",
			mwNmlNumAlloc+mwNumCurAlloc-count, mwNmlCurAlloc+mwStatCurAlloc-size );
        return 0;
        }

    return 1;
    }

/*
**  If mwData* is NULL:
**      Returns 0 if heap chain is broken.
**      Returns 1 if heap chain is intact.
**  If mwData* is not NULL:
**      Returns 0 if mwData* is missing or if chain is broken.
**      Returns 1 if chain is intact and mwData* is found.
*/
static int mwIsHeapOK( mwData *includes_mw ) {
    int found = 0;
    mwData *mw;

    for( mw = mwHead; mw; mw=mw->next ) {
        if( includes_mw == mw ) found++;
        if( !mwIsSafeAddr( mw, mwDataSize ) ) return 0;
        if( mw->prev ) {
            if( !mwIsSafeAddr( mw->prev, mwDataSize ) ) return 0;
            if( mw==mwHead || mw->prev->next != mw ) return 0;
            }
        if( mw->next ) {
            if( !mwIsSafeAddr( mw->next, mwDataSize ) ) return 0;
            if( mw==mwTail || mw->next->prev != mw ) return 0;
            }
        else if( mw!=mwTail ) return 0;
        }

    if( includes_mw != NULL && !found ) return 0;

    return 1;
    }

static int mwIsOwned( mwData* mw, const char *file, int line ) {
    int retv;
    mwStat *ms;

    /* see if the address is legal according to OS */
    if( !mwIsSafeAddr( mw, mwDataSize ) ) return 0;

    /* make sure we have _anything_ allocated */
    if( mwHead == NULL && mwTail == NULL && mwStatCurAlloc == 0 )
        return 0;

    /* calculate checksum */
    if( mw->check != CHKVAL(mw) ) {
        /* may be damaged checksum, see if block is in heap */
        if( mwIsHeapOK( mw ) ) {
            /* damaged checksum, repair it */
            mwWrite( "internal: <%ld> %s(%d), checksum for MW-%p is incorrect\n",
                mwCounter, file, line, mw );
            mwIncErr();
            if( mwIsReadAddr( mw->file, 1 ) ) {
                ms = mwStatGet( mw->file, -1, 0 );
                if( ms == NULL ) mw->file = "<relinked>";
                }
            else mw->file = "<unknown>";
            mw->size = 0;
            mw->check = CHKVAL(mw);
            return 1;
            }
        /* no, it's just some garbage data */
        return 0;
        }

	/* check that the non-NULL pointers are safe */
	if( mw->prev && !mwIsSafeAddr( mw->prev, mwDataSize ) ) mwRelink( mw, file, line );
	if( mw->next && !mwIsSafeAddr( mw->next, mwDataSize ) ) mwRelink( mw, file, line );

    /* safe address, checksum OK, proceed with heap checks */

    /* see if the block is in the heap */
    retv = 0;
    if( mw->prev ) { if( mw->prev->next == mw ) retv ++; }
    else { if( mwHead == mw ) retv++; }
    if( mw->next ) { if( mw->next->prev == mw ) retv ++; }
    else { if( mwTail == mw ) retv++; }
    if( mw->check == CHKVAL(mw) ) retv ++;
    if( retv > 2 ) return 1;

    /* block not in heap, check heap for corruption */

    if( !mwIsHeapOK( mw ) ) {
        if( mwRelink( mw, file, line ) )
            return 1;
        }

    /* unable to repair */
    mwWrite( "internal: <%ld> %s(%d), mwIsOwned fails for MW-%p\n",
       mwCounter, file, line, mw );
    mwIncErr();

    return 0;
    }

/*
** mwTestBuf:
**  Checks a buffers links and pre/postfixes.
**  Writes errors found to the log.
**  Returns zero if no errors found.
*/
static int mwTestBuf( mwData* mw, const char* file, int line ) {
    int retv = 0;
    char *p;

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

    if( !mwIsSafeAddr( mw, mwDataSize + mwOverflowZoneSize ) ) {
        mwWrite( "internal: <%ld> %s(%d): pointer MW-%p is invalid\n",
            mwCounter, file, line, mw );
        mwIncErr();
        return 2;
        }

    if( mw->check != CHKVAL(mw) ) {
        mwWrite( "internal: <%ld> %s(%d), info trashed; relinking\n",
            mwCounter, file, line );
        mwIncErr();
        if( !mwRelink( mw, file, line ) ) return 2;
        }

    if( mw->prev && mw->prev->next != mw ) {
        mwWrite( "internal: <%ld> %s(%d), buffer <%ld> %s(%d) link1 broken\n",
            mwCounter,file,line, (long)mw->size, mw->count, mw->file, mw->line );
        mwIncErr();
        if( !mwRelink( mw, file, line ) ) retv = 2;
        }
    if( mw->next && mw->next->prev != mw ) {
        mwWrite( "internal: <%ld> %s(%d), buffer <%ld> %s(%d) link2 broken\n",
            mwCounter,file,line, (long)mw->size, mw->count, mw->file, mw->line );
        mwIncErr();
        if( !mwRelink( mw, file, line ) ) retv = 2;
        }

    p = ((char*)mw) + mwDataSize;
    if( mwCheckOF( p ) ) {
        mwWrite( "underflow: <%ld> %s(%d), %ld bytes alloc'd at <%ld> %s(%d)\n",
            mwCounter,file,line, (long)mw->size, mw->count, mw->file, mw->line );
        mwIncErr();
        retv = 1;
        }
    p += mwOverflowZoneSize + mw->size;
    if( mwIsReadAddr( p, mwOverflowZoneSize ) && mwCheckOF( p ) ) {
        mwWrite( "overflow: <%ld> %s(%d), %ld bytes alloc'd at <%ld> %s(%d)\n",
            mwCounter,file,line, (long)mw->size, mw->count, mw->file, mw->line );
        mwIncErr();
        retv = 1;
        }

    return retv;
    }

static void mwDefaultOutFunc( int c ) {
    if( mwLogR() ) fputc( c, mwLogR() );
    }

static void mwWrite( const char *format, ... ) {
    int tot, oflow = 0;
    va_list mark;
    mwAutoInit();
    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 ) {
        mwWrite( "\ninternal: mwWrite(): WARNING! OUTPUT EXCEEDED %u CHARS: SYSTEM UNSTABLE\n", MW_TRACE_BUFFER-1 );
        FLUSH();
        }
    return;
    }

static void mwLogFile( const char *name ) {
    time_t tid;
    (void) time( &tid );
    if( mwLogR() != NULL ) {
        fclose( mwLogR() );
        mwLogW( NULL );
        }
    if( name == NULL ) return;
    mwLogW( fopen( name, "a" COMMIT ) );
    if( mwLogR() == NULL )
        mwWrite( "logfile: failed to open/create file '%s'\n", name );
    }

/*
** Try to free NML memory until a contiguous allocation of
** 'needed' bytes can be satisfied. If this is not enough
** and the 'urgent' parameter is nonzero, grabbed memory is
** also freed.
*/
static size_t mwFreeUp( size_t needed, int urgent ) {
    void *p;
    mwData *mw, *mw2;
    char *data;

    /* free grabbed NML memory */
    for(;;) {
        if( mwDrop_( 1, MW_VAL_NML, 1 ) == 0 ) break;
        p = malloc( needed );
        if( p == NULL ) continue;
        free( p );
        return needed;
        }

    /* free normal NML memory */
    mw = mwHead;
    while( mw != NULL ) {
        if( !(mw->flag & MW_NML) ) mw = mw->next;
        else {
            data = ((char*)mw)+mwDataSize+mwOverflowZoneSize;
            if( mwTestMem( data, mw->size, MW_VAL_NML ) ) {
                mwIncErr();
                mwWrite( "wild pointer: <%ld> NoMansLand %p alloc'd at %s(%d)\n",
                    mw->count, data + mwOverflowZoneSize, mw->file, mw->line );
                }
            mw2 = mw->next;
            mwUnlink( mw, "mwFreeUp", 0 );
            free( mw );
            mw = mw2;
            p = malloc( needed );
            if( p == NULL ) continue;
            free( p );
            return needed;
            }
        }

    /* if not urgent (for internal purposes), fail */
    if( !urgent ) return 0;

    /* free grabbed memory */
    for(;;) {
        if( mwDrop_( 1, MW_VAL_GRB, 1 ) == 0 ) break;
        p = malloc( needed );
        if( p == NULL ) continue;
        free( p );
        return needed;
        }

    return 0;
    }

static const void * mwTestMem( const void *p, unsigned len, int c ) {
    const unsigned char *ptr;
    ptr = (const unsigned char *) p;
    while( len-- ) {
        if( *ptr != (unsigned char)c ) return (const void*)ptr;
        ptr ++;
        }
    return NULL;
    }

static int mwStrCmpI( const char *s1, const char *s2 ) {
    if( s1 == NULL || s2 == NULL ) return 0;
    while( *s1 ) {
        if( toupper(*s2) == toupper(*s1) ) { s1++; s2++; continue; }
        return 1;
        }
    return 0;
    }

#define AIPH() if( always_invoked ) { mwWrite("autocheck: <%ld> %s(%d) ", mwCounter, file, line ); always_invoked = 0; }

static int mwTestNow( const char *file, int line, int always_invoked ) {
    int retv = 0;
    mwData *mw;
    char *data;

    if( file && !always_invoked )
        mwWrite("check: <%ld> %s(%d), checking %s%s%s\n",
            mwCounter, file, line,
			(mwTestFlags & MW_TEST_CHAIN) ? "chain ": "",
		    (mwTestFlags & MW_TEST_ALLOC) ? "alloc ": "",
		    (mwTestFlags & MW_TEST_NML) ? "nomansland ": ""
			);

    if( mwTestFlags & MW_TEST_CHAIN ) {
        for( mw = mwHead; mw; mw=mw->next ) {
			if( !mwIsSafeAddr(mw, mwDataSize) ) {
				AIPH();
				mwWrite("check: heap corruption detected\n");
				mwIncErr();
				return retv + 1;
				}
			if( mw->prev ) {
				if( !mwIsSafeAddr(mw->prev, mwDataSize) ) {
					AIPH();
					mwWrite("check: heap corruption detected\n");
					mwIncErr();
					return retv + 1;
					}
				if( mw==mwHead || mw->prev->next != mw ) {
					AIPH();
					mwWrite("check: heap chain broken, prev link incorrect\n");
					mwIncErr();
					retv ++;
					}
				}
			if( mw->next ) {
				if( !mwIsSafeAddr(mw->next, mwDataSize) ) {
					AIPH();
					mwWrite("check: heap corruption detected\n");
					mwIncErr();
					return retv + 1;
					}
				if( mw==mwTail || mw->next->prev != mw ) {
					AIPH();
					mwWrite("check: heap chain broken, next link incorrect\n");
					mwIncErr();
					retv ++;
					}
				}
			else if( mw!=mwTail ) {
				AIPH();
				mwWrite("check: heap chain broken, tail incorrect\n");
				mwIncErr();
				retv ++;
				}
            }
        }
    if( mwTestFlags & MW_TEST_ALLOC ) {
        for( mw = mwHead; mw; mw=mw->next ) {
            if( mwTestBuf( mw, file, line ) ) retv ++;
            }
        }
    if( mwTestFlags & MW_TEST_NML ) {
        for( mw = mwHead; mw; mw=mw->next ) {
            if( (mw->flag & MW_NML) ) {
                data = ((char*)mw)+mwDataSize+mwOverflowZoneSize;
                if( mwTestMem( data, mw->size, MW_VAL_NML ) ) {
                    mwIncErr();
                    mwWrite( "wild pointer: <%ld> NoMansLand %p alloc'd at %s(%d)\n",
                        mw-