On Friday 21 March 2003 13:09, you wrote: > > On Friday 21 March 2003 12:29, you wrote: > >> >> > But, when I use fail in my simple example program, it returns > >> >> > >> >> NIL okay but > >> >> > >> >> > the Heaptrace function tells me I have two unfreed memory blocks > >> > >> (36 > >> > >> >> > bytes). > >> >> > I can't see a memory leak anywhere else in that program, what > >> >> > >> >> could cause > >> >> > >> >> > this? (Heaptrace output is as follows: I am using FPC 1.0.6 btw) > >> >> > >> >> [snip heap dump] > >> >> > >> >> That is the exception frame that is left on the heap. I don't have > >> > >> the > >> > >> >> time to analyze what the cause is that the exception frame is not > >> >> removed. > >> > > >> > It may be a bug in 1.0.6 which has subsequently been fixed. I > >> > >> downloaded > >> > >> > and > >> > installed the 1.1 snapshots and compiled the same source code, and the > >> > memory leak vanishes.... > >> > >> The reason why 1.1 has no leak is that it uses the stack to store the > >> exception frames. The real problem is still there, because exception > >> stack > >> is still not updated > > > > some months ago i had a discussion with a friend, converning global > > (static, > > absolute) variables. his point of view was that they're not necessary > > when using oop; mine was, sometimes they're absoulutely necessary. > > > > if we have just one level of exception processing above normal program > > execution (i. e. while an exception is being processed, no other > > exception will gain control), we can use absolute variables for the > > exception frame. > > > > it's even possible to define a fixed whole number of exception layers and > > allocate absolute memory for N exception levels. > > > > that memory space would not get lost, as it can be saved by allocating > > the 'normal' stack or 'normal' heap more tightly - the old system has to > > reserve > > exception spae implicitely on the stack or on the heap. > > > > what do you think about that? > > It does not fix the problem, the frame is then still left on the stack. > > The allocation on the heap has already been changed to allocation on the > stack in 1.1, because hat is much faster. Using a predefined storage of N > exception levels is adding a limit and that is something we want to > prevent.
but also the power-switch, the data bus width, and the exception vectors in ROM now are limits. i think limits cannot be prevented, but they can be chosen knowingly, harmonic, and safe or so. every limit should include the overhead to overcome it later, as things get better. ---------- "Adas Methode war, wie sich zeigen wird, Tagträume in offenbar korrekte Berechnungen einzuweben." Doris Langley Moore: Ada, Countess of Lovelace (London 1977). ---------- Anton Tichawa Volkertstrasse 19 / 20 A-1020 Wien mobil: +43 664 52 07 907 email: [EMAIL PROTECTED] ---------- _______________________________________________ fpc-pascal maillist - [EMAIL PROTECTED] http://lists.freepascal.org/mailman/listinfo/fpc-pascal
