NativeAOT-LLVM: Do not use mmap/munmap#1510
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jkotas merged 2 commits intodotnet:feature/NativeAOT-LLVMfrom Sep 6, 2021
Merged
NativeAOT-LLVM: Do not use mmap/munmap#1510jkotas merged 2 commits intodotnet:feature/NativeAOT-LLVMfrom
jkotas merged 2 commits intodotnet:feature/NativeAOT-LLVMfrom
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jkotas
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Sep 5, 2021
src/coreclr/gc/wasm/gcenv.wasm.cpp
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| typedef struct _reserved reserved; | ||
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| static int nextPos = 0; | ||
| static reserved blocks[1000]; // better to allocate and grow this as needed (until malloc fails)? |
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This is really only used for argument validation. The GC should not be ever calling these APIs with invalid arguments.
I think you can omit this structure, and instead directly call posix_memalign / free / memset to implement reserve / release / decommit.
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Thanks, works with without that.
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This PR adds an emscripten friendly VirtualReserve/Release implementation. Emscripten does not fully implement mmap/munmap in particular it does not zero the memory in
mmapfor theMAP_ANONYMOUSflag. This continues from dotnet/corert#8330.When trying to merge the latest into NativeAOT-LLVM random memory crashes, usually inside the GC, have started to appear, so now seems a good time to ask for feedback on this change. This change does stop those crashes appearing so far at least.
Emscripten reports the page size as 0x4000, whereas
CommonMacros.hhasI don't know what the implications are there, if anything maybe just performance as
posix_memaligndoes not refer to the page size.