ggml-org/llama.cpp b12249

on GitHub

ggml-rpc : fail gracefully on unreachable endpoints and failed handshakes (#30415)

• ggml-rpc: fail gracefully on unreachable endpoints and failed handshakes

rpc_dispatcher::start() aborted the whole process (GGML_ABORT -> SIGABRT) when
the endpoint could not be parsed, the transport failed to initialise, the socket
could not connect, or the HELLO handshake failed. A typo in --rpc or a
temporarily down node killed the host application, and the reason went to a log
stream the host may never see.

Make the connect-time failure reportable instead of fatal: start() returns bool
(LOG_ERROR + false; the dispatcher thread only starts after a successful
handshake), negotiate_hello() returns false on a half-open socket,
get_dispatcher() returns nullptr and does not cache failed attempts, and every
consumer treats nullptr as "endpoint did not answer" with the conservative
behaviour of its domain (allocation -> nullptr, alloc-size -> lower bound,
device memory -> 0/0, events -> no-op, device count -> 0, and add_server()
already maps 0 devices to nullptr).

Mid-stream failures keep the existing RPC_STATUS_ASSERT by design (fail fast
against silent corruption) and are intentionally out of scope.

Field motivation: on Android (llama.rn + phone RPC cluster) an unreachable
worker crashed the app; the crash buffer showed
abort <- ggml_abort <- rpc_dispatcher::start <- ggml_backend_rpc_add_server.

• tests : add a regression test for unreachable rpc endpoints

Calls ggml_backend_rpc_add_server with a socket that nothing listens on and with a
malformed endpoint, and expects nullptr from both. Without the fix in this branch
the first call aborts the process, so the test cannot even fail cleanly.

• ggml-rpc remove low-value comments

• tests : drop the internal device-count check after the rpc registry refactor

Co-authored-by: figkcoci-debug figkcoci-debug@users.noreply.github.com