Like Linux (and other Unix-es), any calls of pwrite (and other functions to read or write) for a regular file by other threads in the WASI process should not be interleaved while pwrite is executed.
Errno fdPwrite(Fd fd, const(Ciovec) * iovs, Size iovsLen, FileSize offset, Size * outSize) @importName("fd_pwrite")Write to a file descriptor, without using and updating the file descriptor's offset.
Like Linux (and other Unix-es), any calls of pwrite (and other functions to read or write) for a regular file by other threads in the WASI process should not be interleaved while pwrite is executed.