Make all the low-level init code synchronous to avoid weird blocks on `close`.
Also move the net and ctl file descriptor at the beginning of the fd space for
the calf.
The SDK also allow to spamn multiple exec calves, which will all have the same
fd map:
- 0: stdin = /dev/null
- 1: stdout = pipe to parent stdout
- 2: stderr = pipe to parent stderr
- 3: net = socketpair to parent "net" pipe
- 4: ctl = socketpair to parent "ctl" pipe
Signed-off-by: Thomas Gazagnaire <thomas@gazagnaire.org>
The protocol allows the client to send concurrent RPCs to the server.
The server replies by keeping the client ID, and the client keeps a
dispatch table of queries to route the retries. By doing things like
that, the server has a strong control over resource allocation, so
a bad client cannot exhaust all the server memory.
Also add some simple tests for the serialization + wire protocol which
are all passing. Proper concurrency/resource exhaustion usage will be
added later.
Signed-off-by: Thomas Gazagnaire <thomas@gazagnaire.org>
