Shulou(Shulou.com)06/01 Report--

Main- > PostmasterMain- > ServerLoop: for (;;) {. / / will block here and monitor for changes in file descriptors selres = select (nSockets, & rmask, NULL, NULL, & timeout); if (selres > 0) {for (I = 0; I)

< MAXLISTEN; i++){ //找一个有效的fd if (ListenSocket[i] == PGINVALID_SOCKET) break; if (FD_ISSET(ListenSocket[i], &rmask)){ port = ConnCreate(ListenSocket[i]);->

StreamConnection- > accept BackendStartup (port); / / fork process |-- pid = fork_process (); | if (pid = = 0) {/ / child | InitPostmasterChild () | | ClosePostmasterPorts (false); | BackendInitialize (port) | | | / / this function will not return | BackendRun (port);-> PostgresMain: | |-- for ( ) {| | if (send_ready_for_query) {| |... | | | ReadyForQuery (whereToSendOutput) | -> pq_flush ();-> internal_flush- > secure_write- > secure_raw_write- > send | | send_ready_for_query = false |} | | firstchar = ReadCommand (& input_message) | | switch (firstchar): {| | case 'Q':exec_simple_query (query_string) | | |. | |} | |--} | |} |... father |-- return STATUS_OK / / disable father socket StreamClose (port- > sock) | ConnFree (port);}}

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