134 lines
4.1 KiB
C
134 lines
4.1 KiB
C
/* Data Store Server.
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* This service implements a little publish/subscribe data store that is
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* crucial for the system's fault tolerance. Components that require state
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* can store it here, for later retrieval, e.g., after a crash and subsequent
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* restart by the reincarnation server.
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*
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* Created:
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* Oct 19, 2005 by Jorrit N. Herder
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*/
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#include "inc.h" /* include master header file */
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#include <minix/endpoint.h>
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/* Allocate space for the global variables. */
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PRIVATE endpoint_t who_e; /* caller's proc number */
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PRIVATE int callnr; /* system call number */
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/* Declare some local functions. */
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FORWARD _PROTOTYPE(void get_work, (message *m_ptr) );
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FORWARD _PROTOTYPE(void reply, (endpoint_t whom, message *m_ptr) );
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/* SEF functions and variables. */
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FORWARD _PROTOTYPE( void sef_local_startup, (void) );
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC int main(int argc, char **argv)
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{
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/* This is the main routine of this service. The main loop consists of
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* three major activities: getting new work, processing the work, and
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* sending the reply. The loop never terminates, unless a panic occurs.
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*/
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message m;
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int result;
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/* SEF local startup. */
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env_setargs(argc, argv);
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sef_local_startup();
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/* Main loop - get work and do it, forever. */
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while (TRUE) {
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/* Wait for incoming message, sets 'callnr' and 'who'. */
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get_work(&m);
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if (is_notify(callnr)) {
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printf("DS: warning, got illegal notify from: %d\n", m.m_source);
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result = EINVAL;
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goto send_reply;
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}
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switch (callnr) {
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case DS_PUBLISH:
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result = do_publish(&m);
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break;
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case DS_RETRIEVE:
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result = do_retrieve(&m);
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break;
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case DS_RETRIEVE_LABEL:
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result = do_retrieve_label(&m);
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break;
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case DS_DELETE:
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result = do_delete(&m);
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break;
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case DS_SUBSCRIBE:
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result = do_subscribe(&m);
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break;
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case DS_CHECK:
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result = do_check(&m);
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break;
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case DS_SNAPSHOT:
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result = do_snapshot(&m);
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break;
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case GETSYSINFO:
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result = do_getsysinfo(&m);
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break;
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default:
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printf("DS: warning, got illegal request from %d\n", m.m_source);
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result = EINVAL;
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}
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send_reply:
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/* Finally send reply message, unless disabled. */
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if (result != EDONTREPLY) {
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m.m_type = result; /* build reply message */
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reply(who_e, &m); /* send it away */
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}
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}
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return(OK); /* shouldn't come here */
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}
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/*===========================================================================*
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* sef_local_startup *
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*===========================================================================*/
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PRIVATE void sef_local_startup()
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{
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/* Register init callbacks. */
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sef_setcb_init_fresh(sef_cb_init_fresh);
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sef_setcb_init_restart(sef_cb_init_fail);
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/* No live update support for now. */
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/* Let SEF perform startup. */
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sef_startup();
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}
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/*===========================================================================*
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* get_work *
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*===========================================================================*/
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PRIVATE void get_work(
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message *m_ptr /* message buffer */
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)
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{
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int status = sef_receive(ANY, m_ptr); /* blocks until message arrives */
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if (OK != status)
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panic("failed to receive message!: %d", status);
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who_e = m_ptr->m_source; /* message arrived! set sender */
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callnr = m_ptr->m_type; /* set function call number */
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}
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/*===========================================================================*
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* reply *
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*===========================================================================*/
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PRIVATE void reply(
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endpoint_t who_e, /* destination */
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message *m_ptr /* message buffer */
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)
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{
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int s = send(who_e, m_ptr); /* send the message */
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if (OK != s)
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printf("DS: unable to send reply to %d: %d\n", who_e, s);
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}
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