Introduction to unsafe C#: Calling native code and crashing in entirely new ways
summary
Shows how C# can use pointers, fixed and stackalloc to mutate memory (yes even mutating supposedly immutable strings), explain packing/explicit layout and unions, and call native libraries via P/Invoke. Demonstrates building a minimal SQLite wrapper using SafeHandle and NativeMemory/HeapAlloc that works, then reproduces crashes: buffer overflows, dangling delegate kills process when GC collects callback thunks, and fixes via unmanaged function pointers and SafeHandle reference counting. Gives concrete signatures, marshalling notes and platform calling‑convention caveats.
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chapters (13)
- 0:00Welcome
- 0:45Why call native code
- 2:12Unsafe C# basics
- 5:23New kinds of bugs
- 9:16Unsafe features & examples
- 15:34Pointer arithmetic
- 21:32Memory layout & struct packing
- 29:39Platform Invoke
- 36:30Calling conventions
- 38:56Safe handles
- 45:42Native callbacks
- 51:44Function pointers
- 54:12Further resources
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