minix3/servers/ipc/main.c

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C
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2020-02-21 00:59:27 +05:30
#include "inc.h"
int identifier = 0x1234;
endpoint_t who_e;
int call_type;
static struct {
int type;
int (*func)(message *);
int reply; /* whether the reply action is passed through */
} ipc_calls[] = {
{ IPC_SHMGET, do_shmget, 0 },
{ IPC_SHMAT, do_shmat, 0 },
{ IPC_SHMDT, do_shmdt, 0 },
{ IPC_SHMCTL, do_shmctl, 0 },
{ IPC_SEMGET, do_semget, 0 },
{ IPC_SEMCTL, do_semctl, 0 },
{ IPC_SEMOP, do_semop, 1 },
};
#define SIZE(a) (sizeof(a)/sizeof(a[0]))
static int verbose = 0;
/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
static void sef_cb_signal_handler(int signo);
int main(int argc, char *argv[])
{
message m;
/* SEF local startup. */
env_setargs(argc, argv);
sef_local_startup();
while (TRUE) {
int r;
int ipc_number;
if ((r = sef_receive(ANY, &m)) != OK)
printf("sef_receive failed %d.\n", r);
who_e = m.m_source;
call_type = m.m_type;
if(verbose)
printf("IPC: get %d from %d\n", call_type, who_e);
if (call_type & NOTIFY_MESSAGE) {
switch (who_e) {
case VM_PROC_NR:
/* currently, only semaphore needs such information. */
sem_process_vm_notify();
break;
default:
printf("IPC: ignoring notify() from %d\n",
who_e);
break;
}
continue;
}
/*
* The ipc number in the table can be obtained
* with a simple equation because the values of
* IPC system calls are consecutive and begin
* at ( IPC_BASE + 1 )
*/
ipc_number = call_type - (IPC_BASE + 1);
/* dispatch message */
if (ipc_number >= 0 && ipc_number < SIZE(ipc_calls)) {
int result;
if (ipc_calls[ipc_number].type != call_type)
panic("IPC: call table order mismatch");
/* If any process does an IPC call,
* we have to know about it exiting.
* Tell VM to watch it for us.
*/
if(vm_watch_exit(m.m_source) != OK) {
printf("IPC: watch failed on %d\n", m.m_source);
}
result = ipc_calls[ipc_number].func(&m);
/*
* The handler of the IPC call did not
* post a reply.
*/
if (!ipc_calls[ipc_number].reply) {
m.m_type = result;
if(verbose && result != OK)
printf("IPC: error for %d: %d\n",
call_type, result);
if ((r = ipc_sendnb(who_e, &m)) != OK)
printf("IPC send error %d.\n", r);
}
} else {
/* warn and then ignore */
printf("IPC unknown call type: %d from %d.\n",
call_type, who_e);
}
update_refcount_and_destroy();
}
/* no way to get here */
return -1;
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
static void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fresh);
/* No live update support for now. */
/* Register signal callbacks. */
sef_setcb_signal_handler(sef_cb_signal_handler);
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info))
{
/* Initialize the ipc server. */
if(verbose)
printf("IPC: self: %d\n", sef_self());
return(OK);
}
/*===========================================================================*
* sef_cb_signal_handler *
*===========================================================================*/
static void sef_cb_signal_handler(int signo)
{
/* Only check for termination signal, ignore anything else. */
if (signo != SIGTERM) return;
/* Checkout if there are still IPC keys. Inform the user in that case. */
if (!is_sem_nil() || !is_shm_nil())
printf("IPC: exit with un-clean states.\n");
}