initializeLibrary ran NimMain only on the thread that won
`initialized.exchange(true)`; concurrent first-time callers fell straight
through and used a half-initialized Nim runtime — a heap-corrupting race
when multiple foreign (e.g. Go) threads create the first context at once.
Add an `initDone` flag the winner sets after NimMain; the others spin
until it is set before proceeding.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
ffiNewReq derived the request id with `let typeStr = $T`, allocating a
Nim GC string on the *calling* thread for every request. Embedded in a
foreign host (e.g. Go) the callers are transient, concurrent OS threads;
running Nim's GC there corrupts the heap under load. The type name is
known at compile time, so emit it as a `cstring` literal (the same value
already used as the registry key) — no runtime allocation. Applies to
both the {.ffi.} and {.ffiCtor.} request builders.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
* protect against mem leak in case of failures sending requests to ffi thread
* better cleanup if failures in createFFIContext
* avoid dangling cstring in handleRes under ARC/ORC
* better resource cleanup in destroyFFIContext
* invoke onNotResponding if failure in destroyFFIContext
* correct seq copy in alloc
* make sure the lock is init before cleanUpResources
* better possible exception handling in processReq
* guard allocSharedSeq if given seq is empty
* enhance error handling in ffi_context
* add new tests and some corrections
