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Re: "No aliasing = no garbage collection"
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From: Ruth Ivimey-Cook <Ruth.Ivimey-Cook@xxxxxxxxxx>
Subject: Re: "No aliasing = no garbage collection"
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At 13:30 22/09/00 +0100, you wrote:
>} In my opinion, garbage collection is an efficiency mechanism.
>} Conclusion (assuming I remembered correctly that the proof can be done):
>} if you are not bothered with performance, use a garbage collector,
>} and save on memory budget, use virtual memory as well.
>} if you are bothered with performance, buy twice as much memory, and
>} do not use a garbage collector, nor virtual memory. Simply, use
>} enough memory.
>Yes, I agree...
>The temptation to attach every bell and whistle is a strong one.
>But that problem becomes an opportunity when you remember that
>implies that the niche of clean, understandable simplicity is
I am slightly worried by this view. The experience of many ARM customers,
working in the embedded space, is that memory is definitely not cheap. The
1. What memory you have must be on-chip with the processor, which mostly
limits it to small quantities of SRAM and slightly larger quantities of ROM
2. The cost of many consumer items is a multiple of the manufacturing cost.
That is, if it costs $5 to build, it costs $50 at the retailer (and that is
perhaps understating the multiple). Consequently, adding a $10 DRAM to a
design is not an option -- it would add $100 to the selling price.
3. Items like mobile phones typically have huge memory requirements --
3-5MB ROMS is not unusual, and RAM is also needed in large quantity. And
yet if you look inside these devices you find only a couple of chips.
Doubling the physical space required for memory is not possible -- it
I believe there should be a garbage collection scheme added to occam. It is
a great language for many things, but it is let down in areas which people
care about intensely.