16-bit Windows applications tried to deal with OOM

Posted Oct 11, 2020 12:38 UTC (Sun) by quboid (subscriber, #54017)
In reply to: Zig heading toward a self-hosting compiler by dvdeug
Parent article: Zig heading toward a self-hosting compiler

Perhaps it was when 32-bit Windows arrived that applications stopped caring about running out of memory.

The 16-bit Windows SDK had a tool called STRESS.EXE which, among other things, could cause memory allocation failures in order to check that your program coped with them correctly.

16-bit Windows required large memory allocations (GlobalAlloc) to be locked when being used and unlocked when not so that Windows could move the memory around without an MMU. It was even possible to specify that allocated memory was discardable and you didn't know whether you'd still have the memory when you tried to lock it to use it again - this was great for caches and is a feature I wish my web browser had today. :-)

Mike.

16-bit Windows applications tried to deal with OOM

Posted Oct 11, 2020 21:14 UTC (Sun) by dtlin (subscriber, #36537) [Link]

Android has discardable memory - ashmem can be unpinned, and the system may purge it if under memory pressure. I think you can simulate this with madvise(MADV_FREE), but ashmem will tell you if it was purged or not and MADV_FREE won't (the pages will just be silently zero'ed).

16-bit Windows applications tried to deal with OOM

Posted Oct 11, 2020 22:28 UTC (Sun) by roc (subscriber, #30627) [Link] (1 responses)

You should be glad browsers don't have that today. If they did, people would use it, and browsers on developer machines would rarely discard memory, so when your machine discards memory applications would break.

16-bit Windows applications tried to deal with OOM

Posted Oct 15, 2020 16:19 UTC (Thu) by lysse (guest, #3190) [Link]

Better they break by themselves than freeze up the entire system while it tries to page every single executable VM page through a single 4K page of physical RAM, because the rest of it has been overcommitted to memory that just got written to.