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A comment on Overview of cross-architecture portability problems.

Re:Overview of cross-architecture portability problems by magicalhippo on Monday September 23, 2024 @03:26PM (#41629598)
One I recall, working on a C++ program that we distributed to Windows, Linux and PowerPC OSX at the time, was how some platforms had memory zero-initialized by the OS memory manager, and some didn't.

Our code didn't mean to take advantage of this, but it sometimes meant buggy code would appear fine on one platform as pointers in structures would be zeroed out, but crash on others where they weren't.

As I recall, it was mostly that and the endianess that caused the most grief. Not that there was many issues at all since we used Qt and Boost...

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Re:Overview of cross-architecture portability problems by microtherion on Tuesday September 24, 2024 @07:15PM (#41642009)
On many platforms this can depend on the size and timing of the allocation. As soon as a new PAGE has to be allocated (either because the allocation is large, or because the rest of the heap became full), it is zero initialized (pretty sure all OSes do this, to prevent cross-process spying), but if it's just a malloc inside an existing page, it does not clear previous cruft.
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