The PORT_ACK message is the router's response to the application's NEW_PORT
message. After receiving PORT_ACK, the application is safe to process requests
using this port.
This message avoids a racing condition when the application starts processing a
request from the shared queue and sends REQ_HEADERS_ACK. The REQ_HEADERS_ACK
message contains the application port ID as reply_port, which the router uses
to send request data. When the application creates a new port, it
immediately sends it to the main router thread. Because the request is
processed outside the main thread, a racing condition can occur between the
receipt of the new port in the main thread and the receipt of REQ_HEADERS_ACK
in the worker router thread where the same port is specified as reply_port.
This fixes the router's crash on buildbot; the reason was an unexpected 'last'
response from the application to the router arriving before the response
headers. The last buffer is not a memory buffer, so the result of accessing
memory fields is unpredictable.
The unexpected 'last' message was caused by an error in libunit; fixed in
fee8fd855a00.
This variant will be more interoperable across various systems
and it's already used in Ruby module.
Otherwise, configure tests fail on NetBSD with:
gcc: Missing argument for -Wl,-rpath
PyUnicode_GET_SIZE() in deprecated since 3.3 and will be removed in 3.12.
In version 3.9 it was explicitly marked by deprecation warning causing
compilation error with Unit.
PyUnicode_GET_LENGTH() must be used instead.
Data in the queue and the socket are transmitted independently; special
READ_QUEUE and READ_SOCKET message types are used for synchronization.
The warning was accidentally committed with changeset 1d84b9e4b459.
The connection's local socket address is allocated from the connection
pool before the request is passed to the application; however, with keep-alive
connections, this field was unconditionally reset by a socket configuration
value that could be NULL. For the next request, the address was allocated
again from the same connection pool. Nonetheless, all leaked addresses
were released when the connection was closed.
The issue introduced in changeset 5c7dd85fabd5.
Large-bodied requests are added to the request hash to be found when the body
arrives. However, changeset 1d84b9e4b459 introduced a bug: the 'in_hash' flag,
used to remove the request from the hash at request release, was cleared after
the first successful request lookup. As a result, the entry was never removed.
