Add C examples.

tmp
Philippe Pittoli 2023-02-08 19:03:00 +01:00
parent 4ed4471c18
commit 75a77440e6
4 changed files with 237 additions and 0 deletions

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c/README.md Normal file
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Some C examples, nothing fancy.
Implementation is straightforward.
# Build
`make`

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c/makefile Normal file
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CC ?= cc
LDFLAGS ?= -lipc
include makefile.valgrind
all: build
BINS = pong pongd
build: $(BINS)
$(BINS):
$(CC) -o $@ $@.c $(LDFLAGS)
clean:
rm $(BINS) 2>/dev/null
# You can add your specific instructions there.
-include makefile.user

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c/pong.c Normal file
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
// Do not forget to install libipc.
#include <libipc.h>
#define SERVICE "pong"
#define SERVICE_LEN 4
#define MAX_MSG_SIZE 10000
int err(void *ctx, char *msg) {
printf("error: %s\n", msg);
printf("Free context\n");
ipc_context_deinit (&ctx);
return 1;
}
int main(void) {
int ret = 0;
int servicefd = 0;
char message[MAX_MSG_SIZE];
memset (message, 0, 1000);
size_t size = MAX_MSG_SIZE;
char event_type;
size_t index = 0;
int originfd = 0;
void *ctx = NULL;
printf ("Init context.\n");
ret = ipc_context_init (&ctx);
if (ret != 0) {
printf ("Cannot init context.\n");
return 1;
}
printf ("Connect to a 'pong' service.\n");
ret = ipc_connect_service (ctx, &servicefd, SERVICE, SERVICE_LEN);
if (ret != 0) {
return err(ctx, "Cannot connect to a service.");
}
printf ("Let's schedule a message.\n");
ret = ipc_schedule (ctx, servicefd, "hello, plz bounce me", 21);
if (ret != 0) {
return err(ctx, "Cannot schedule a message.");
}
printf ("Let's set the timer to one second.\n");
ipc_context_timer (ctx, 1000);
printf ("Let's loop over events.\n");
char should_continue = 1;
size_t count = 0;
while(should_continue) {
size = MAX_MSG_SIZE;
ret = ipc_wait_event (ctx, &event_type, &index, &originfd, message, &size);
if (ret != 0) {
return err(ctx, "Error while waiting for an event.");
}
printf ("EVENT %lu\t", count++);
switch ((enum event_types) event_type) {
case ERROR: return err(ctx, "Error.");
case EXTERNAL: return err(ctx, "External (shouldn't happen).");
case SWITCH_RX: return err(ctx, "Switch RX (shouldn't happen).");
case SWITCH_TX: return err(ctx, "Switch TX (shouldn't happen).");
case CONNECTION: return err(ctx, "Connection (shouldn't happen).");
case DISCONNECTION: return err(ctx, "Disconnection (shouldn't happen).");
case TIMER: { printf ("TIMER.\n"); break; }
case MESSAGE_TX: { printf ("A message has been sent.\n"); break; }
case MESSAGE_RX: {
if (size == 0) {
printf ("No message returned.\n");
printf ("Deinit context\n");
ipc_context_deinit (&ctx);
return 1;
}
message[size] = '\0';
printf ("Response (size %lu): %s.\n", size, message);
// We received the response, quitting.
should_continue = 0;
break;
}
}
}
printf ("Deinit context\n");
ipc_context_deinit (&ctx);
printf ("Context freed.\n");
return 0;
}

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c/pongd.c Normal file
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#include <stdio.h>
#include <stdlib.h>
#include <libipc.h>
#define SERVICE "pong"
#define SERVICE_LEN 4
#define MAX_MSG_SIZE 10000
int err(void *ctx, char *msg) {
printf("error: %s\n", msg);
printf("Free context\n");
ipc_context_deinit (&ctx);
return 1;
}
int main(int argc, char**argv) {
int ret = 0;
int servicefd = 0;
char message[MAX_MSG_SIZE];
size_t size = MAX_MSG_SIZE;
char event_type;
size_t index = 0;
int originfd = 0;
void *ctx = NULL;
int max_count = 0;
if (argc > 1) {
max_count = atoi(argv[1]);
printf ("Wait for %d timer events.\n", max_count);
}
printf ("Init context.\n");
ret = ipc_context_init (&ctx);
if (ret != 0) {
printf ("Cannot init context.\n");
return 1;
}
printf ("Create a 'pong' service.\n");
ret = ipc_service_init (ctx, &servicefd, SERVICE, SERVICE_LEN);
if (ret != 0) {
return err (ctx, "Cannot create a service.");
}
printf ("Set the timer to two seconds.\n");
ipc_context_timer (ctx, 2000);
printf ("Loop over events.\n");
char should_continue = 1;
size_t count = 0;
size_t count_timer = 0;
while(should_continue) {
size = MAX_MSG_SIZE;
ret = ipc_wait_event (ctx, &event_type, &index, &originfd, message, &size);
if (ret != 0) {
return err (ctx, "Error while waiting for an event.");
}
if ((enum event_types) event_type != TIMER) {
printf ("EVENT %lu\t", count++);
}
switch ((enum event_types) event_type) {
case ERROR: return err(ctx, "Error.");
case EXTERNAL: return err(ctx, "External (shouldn't happen).");
case SWITCH_RX: return err(ctx, "Switch RX (shouldn't happen).");
case SWITCH_TX: return err(ctx, "Switch TX (shouldn't happen).");
case CONNECTION: { printf ("New connection.\n"); break; }
case DISCONNECTION: { printf ("User disconnected.\n"); break; }
case TIMER: {
printf ("\rTIMER (%lu).", count_timer++);
fflush(stdout);
if (max_count && count_timer >= (size_t) max_count) {
printf ("waited for %lu timer events: quitting\n", count_timer);
should_continue = 0;
}
break;
}
case MESSAGE_TX: {
printf ("Message sent.\n");
break;
}
case MESSAGE_RX: {
if (size == 0) {
return err(ctx, "Error: no message returned.");
}
else {
message[size+1] = '\0';
printf ("Message received (size %lu): %s.\n", size, message);
printf ("Scheduling this message.\n");
ret = ipc_schedule (ctx, originfd, message, size);
if (ret != 0) {
return err(ctx, "Cannot schedule a message.");
}
}
break;
}
}
}
printf ("Deinit context\n");
ipc_context_deinit (&ctx);
printf ("Context freed.\n");
return 0;
}