mongoose/examples/multi-threaded/main.c
2022-08-25 17:00:47 -03:00

103 lines
3.6 KiB
C

// Copyright (c) 2020 Cesanta Software Limited
// All rights reserved
//
// Multithreading example.
// For each incoming request, we spawn a separate thread, that sleeps for
// some time to simulate long processing time, produces an output and
// hands over that output to the request handler function.
//
#include "mongoose.h"
static void start_thread(void (*f)(void *), void *p) {
#ifdef _WIN32
_beginthread((void(__cdecl *)(void *)) f, 0, p);
#else
#define closesocket(x) close(x)
#include <pthread.h>
pthread_t thread_id = (pthread_t) 0;
pthread_attr_t attr;
(void) pthread_attr_init(&attr);
(void) pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
pthread_create(&thread_id, &attr, (void *(*) (void *) ) f, p);
pthread_attr_destroy(&attr);
#endif
}
struct userdata {
int sock; // Paired socket, worker thread owns it
struct mg_str
body; // data to be processed
};
static void thread_function(void *param) {
struct userdata *p = (struct userdata *) param;
sleep(2); // Simulate long execution
// Respond, wakeup event manager
if (p->body.len)
send(p->sock, p->body.ptr, p->body.len, 0); // if there is a body, echo it
else
send(p->sock, "hi", 2, 0); // otherwise just respond "hi"
close(p->sock); // Close the connection
free((void *) p->body.ptr); // free body
free(p); // free userdata
}
static void link_conns(struct mg_connection *c1, struct mg_connection *c2) {
c1->fn_data = c2;
c2->fn_data = c1;
}
static void unlink_conns(struct mg_connection *c1, struct mg_connection *c2) {
c1->fn_data = c2->fn_data = NULL;
}
// Pipe event handler
static void pcb(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
struct mg_connection *parent = (struct mg_connection *) fn_data;
MG_INFO(("%lu %p %d %p", c->id, c->fd, ev, parent));
if (parent == NULL) { // If parent connection closed, close too
c->is_closing = 1;
} else if (ev == MG_EV_READ) { // Got data from the worker thread
mg_http_reply(parent, 200, "Host: foo.com\r\n", "%.*s\n", c->recv.len,
c->recv.buf); // Respond!
c->recv.len = 0; // Tell Mongoose we've consumed data
} else if (ev == MG_EV_OPEN) {
link_conns(c, parent);
} else if (ev == MG_EV_CLOSE) {
unlink_conns(c, parent);
}
}
// HTTP request callback
static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) {
if (ev == MG_EV_HTTP_MSG) {
struct mg_http_message *hm = (struct mg_http_message *) ev_data;
if (mg_http_match_uri(hm, "/fast")) {
// Single-threaded code path, for performance comparison
// The /fast URI responds immediately
mg_http_reply(c, 200, "Host: foo.com\r\n", "hi\n");
} else {
// Multithreading code path
struct userdata *data = calloc(1, sizeof(*data)); // worker will free it
// parse headers or use request body, duplicate data and pass it to worker
// thread
data->body = mg_strdup(hm->body); // worker will free it
data->sock = mg_mkpipe(c->mgr, pcb, c, true); // Create pipe
start_thread(thread_function, data); // Start thread and pass data
}
} else if (ev == MG_EV_CLOSE) {
if (c->fn_data != NULL) unlink_conns(c, c->fn_data);
}
}
int main(void) {
struct mg_mgr mgr;
mg_mgr_init(&mgr);
mg_log_set(MG_LL_DEBUG); // Set debug log level
mg_http_listen(&mgr, "http://localhost:8000", fn, NULL); // Create listener
for (;;) mg_mgr_poll(&mgr, 1000); // Event loop
mg_mgr_free(&mgr); // Cleanup
return 0;
}