Stream: git-wasmtime

Topic: wasmtime / PR #557 Implement `__wasi_fd_fdstat_get` for W...

Wasmtime GitHub notifications bot (Mar 25 2020 at 17:20):

peterhuene edited PR #557 from implement-windows-fdstat-flags to master:

This PR fully implements __wasi_fd_fdstat_get on Windows so that
the descriptor flags can be determined.

It does this by calling into NtQueryInformationFile (safe to call from
user mode) to get the open mode and access of the underlying OS handle.

NtQueryInformationFile isn't included in the winapi crate, so it is
manually being linked against.

This PR also fixes several bugs on Windows:

• Ignore __WASI_FDFLAG_NONBLOCK by not setting FILE_FLAG_OVERLAPPED
  on file handles (the POSIX behavior for O_NONBLOCK on files).

• Use FILE_FLAG_WRITE_THROUGH for the __WASI_FDFLAG_?SYNC flags.

• __WASI_FDFLAG_APPEND should disallow FILE_WRITE_DATA access to
  force append-only on write operations.

• Use GENERIC_READ and GENERIC_WRITE access flags. The
  latter is required when opening a file for truncation.

Last updated: Dec 13 2025 at 19:03 UTC