1 /* Data Store Server.
2 * This service implements a little publish/subscribe data store that is
3 * crucial for the system's fault tolerance. Components that require state
4 * can store it here, for later retrieval, e.g., after a crash and subsequent
5 * restart by the reincarnation server.
6 *
7 * Created:
8 * Oct 19, 2005 by Jorrit N. Herder
9 */
10
11 #include "inc.h" /* include master header file */
12 #include <minix/endpoint.h>
13
14 /* Allocate space for the global variables. */
15 static endpoint_t who_e; /* caller's proc number */
16 static int callnr; /* system call number */
17
18 /* Declare some local functions. */
19 static void get_work(message *m_ptr);
20 static void reply(endpoint_t whom, message *m_ptr);
21
22 /* SEF functions and variables. */
23 static void sef_local_startup(void);
24
25 /*===========================================================================*
26 * main *
27 *===========================================================================*/
main(int argc,char ** argv)28 int main(int argc, char **argv)
29 {
30 /* This is the main routine of this service. The main loop consists of
31 * three major activities: getting new work, processing the work, and
32 * sending the reply. The loop never terminates, unless a panic occurs.
33 */
34 message m;
35 int result;
36
37 /* SEF local startup. */
38 env_setargs(argc, argv);
39 sef_local_startup();
40
41 /* Main loop - get work and do it, forever. */
42 while (TRUE) {
43
44 /* Wait for incoming message, sets 'callnr' and 'who'. */
45 get_work(&m);
46
47 if (is_notify(callnr)) {
48 printf("DS: warning, got illegal notify from: %d\n", m.m_source);
49 result = EINVAL;
50 goto send_reply;
51 }
52
53 switch (callnr) {
54 case DS_PUBLISH:
55 result = do_publish(&m);
56 break;
57 case DS_RETRIEVE:
58 result = do_retrieve(&m);
59 break;
60 case DS_RETRIEVE_LABEL:
61 result = do_retrieve_label(&m);
62 break;
63 case DS_DELETE:
64 result = do_delete(&m);
65 break;
66 case DS_SUBSCRIBE:
67 result = do_subscribe(&m);
68 break;
69 case DS_CHECK:
70 result = do_check(&m);
71 break;
72 case DS_GETSYSINFO:
73 result = do_getsysinfo(&m);
74 break;
75 default:
76 printf("DS: warning, got illegal request from %d\n", m.m_source);
77 result = EINVAL;
78 }
79
80 send_reply:
81 /* Finally send reply message, unless disabled. */
82 if (result != EDONTREPLY) {
83 m.m_type = result; /* build reply message */
84 reply(who_e, &m); /* send it away */
85 }
86 }
87 return(OK); /* shouldn't come here */
88 }
89
90 /*===========================================================================*
91 * sef_local_startup *
92 *===========================================================================*/
sef_local_startup()93 static void sef_local_startup()
94 {
95 /* Register init callbacks. */
96 sef_setcb_init_fresh(sef_cb_init_fresh);
97 sef_setcb_init_restart(SEF_CB_INIT_RESTART_STATEFUL);
98
99 /* Register state transfer callbacks. */
100 sef_llvm_ds_st_init();
101
102 /* Let SEF perform startup. */
103 sef_startup();
104 }
105
106 /*===========================================================================*
107 * get_work *
108 *===========================================================================*/
get_work(message * m_ptr)109 static void get_work(
110 message *m_ptr /* message buffer */
111 )
112 {
113 int status = sef_receive(ANY, m_ptr); /* blocks until message arrives */
114 if (OK != status)
115 panic("failed to receive message!: %d", status);
116 who_e = m_ptr->m_source; /* message arrived! set sender */
117 callnr = m_ptr->m_type; /* set function call number */
118 }
119
120 /*===========================================================================*
121 * reply *
122 *===========================================================================*/
reply(endpoint_t who_e,message * m_ptr)123 static void reply(
124 endpoint_t who_e, /* destination */
125 message *m_ptr /* message buffer */
126 )
127 {
128 int s = ipc_send(who_e, m_ptr); /* send the message */
129 if (OK != s)
130 printf("DS: unable to send reply to %d: %d\n", who_e, s);
131 }
132
133