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| author | Max Romanov <max.romanov@nginx.com> | 2020-10-28 00:01:46 +0300 |
|---|---|---|
| committer | Max Romanov <max.romanov@nginx.com> | 2020-10-28 00:01:46 +0300 |
| commit | 4cb8aeb31a8cf47f6c61aaccb95bbbf47cbc2393 (patch) | |
| tree | 381eed08e9d478216eed51ea0301dae63b7dc4da /src/nxt_port.h | |
| parent | 131b6a7ffab7b3303a00a50f5cf764dc99e23cc0 (diff) | |
| download | unit-4cb8aeb31a8cf47f6c61aaccb95bbbf47cbc2393.tar.gz unit-4cb8aeb31a8cf47f6c61aaccb95bbbf47cbc2393.tar.bz2 | |
Router: introducing the PORT_ACK message.
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.
Diffstat (limited to 'src/nxt_port.h')
| -rw-r--r-- | src/nxt_port.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/src/nxt_port.h b/src/nxt_port.h index 3ac8c735..5ece3bfa 100644 --- a/src/nxt_port.h +++ b/src/nxt_port.h @@ -26,6 +26,7 @@ struct nxt_port_handlers_s { nxt_port_handler_t change_file; nxt_port_handler_t new_port; nxt_port_handler_t get_port; + nxt_port_handler_t port_ack; nxt_port_handler_t mmap; nxt_port_handler_t get_mmap; @@ -84,6 +85,7 @@ typedef enum { _NXT_PORT_MSG_CHANGE_FILE = nxt_port_handler_idx(change_file), _NXT_PORT_MSG_NEW_PORT = nxt_port_handler_idx(new_port), _NXT_PORT_MSG_GET_PORT = nxt_port_handler_idx(get_port), + _NXT_PORT_MSG_PORT_ACK = nxt_port_handler_idx(port_ack), _NXT_PORT_MSG_MMAP = nxt_port_handler_idx(mmap), _NXT_PORT_MSG_GET_MMAP = nxt_port_handler_idx(get_mmap), @@ -120,6 +122,7 @@ typedef enum { NXT_PORT_MSG_CHANGE_FILE = nxt_msg_last(_NXT_PORT_MSG_CHANGE_FILE), NXT_PORT_MSG_NEW_PORT = nxt_msg_last(_NXT_PORT_MSG_NEW_PORT), NXT_PORT_MSG_GET_PORT = nxt_msg_last(_NXT_PORT_MSG_GET_PORT), + NXT_PORT_MSG_PORT_ACK = nxt_msg_last(_NXT_PORT_MSG_PORT_ACK), NXT_PORT_MSG_MMAP = nxt_msg_last(_NXT_PORT_MSG_MMAP) | NXT_PORT_MSG_SYNC, NXT_PORT_MSG_GET_MMAP = nxt_msg_last(_NXT_PORT_MSG_GET_MMAP), |