1#include <assert.h>
2#include <stdio.h>
3#include <stdlib.h>
4#include <string.h>
5#include <unistd.h>
6#include <uv.h>
7
8uv_loop_t *loop;
9uv_pipe_t queue;
10
11typedef struct {
12    uv_write_t req;
13    uv_buf_t buf;
14} write_req_t;
15
16void free_write_req(uv_write_t *req) {
17    write_req_t *wr = (write_req_t*) req;
18    free(wr->buf.base);
19    free(wr);
20}
21
22void alloc_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) {
23  buf->base = malloc(suggested_size);
24  buf->len = suggested_size;
25}
26
27void echo_write(uv_write_t *req, int status) {
28    if (status) {
29        fprintf(stderr, "Write error %s\n", uv_err_name(status));
30    }
31    free_write_req(req);
32}
33
34void echo_read(uv_stream_t *client, ssize_t nread, const uv_buf_t *buf) {
35    if (nread > 0) {
36        write_req_t *req = (write_req_t*) malloc(sizeof(write_req_t));
37        req->buf = uv_buf_init(buf->base, nread);
38        uv_write((uv_write_t*) req, client, &req->buf, 1, echo_write);
39        return;
40    }
41
42    if (nread < 0) {
43        if (nread != UV_EOF)
44            fprintf(stderr, "Read error %s\n", uv_err_name(nread));
45        uv_close((uv_handle_t*) client, NULL);
46    }
47
48    free(buf->base);
49}
50
51void on_new_connection(uv_stream_t *q, ssize_t nread, const uv_buf_t *buf) {
52    if (nread < 0) {
53        if (nread != UV_EOF)
54            fprintf(stderr, "Read error %s\n", uv_err_name(nread));
55        uv_close((uv_handle_t*) q, NULL);
56        return;
57    }
58
59    uv_pipe_t *pipe = (uv_pipe_t*) q;
60    if (!uv_pipe_pending_count(pipe)) {
61        fprintf(stderr, "No pending count\n");
62        return;
63    }
64
65    uv_handle_type pending = uv_pipe_pending_type(pipe);
66    assert(pending == UV_TCP);
67
68    uv_tcp_t *client = (uv_tcp_t*) malloc(sizeof(uv_tcp_t));
69    uv_tcp_init(loop, client);
70    if (uv_accept(q, (uv_stream_t*) client) == 0) {
71        uv_os_fd_t fd;
72        uv_fileno((const uv_handle_t*) client, &fd);
73        fprintf(stderr, "Worker %d: Accepted fd %d\n", getpid(), fd);
74        uv_read_start((uv_stream_t*) client, alloc_buffer, echo_read);
75    }
76    else {
77        uv_close((uv_handle_t*) client, NULL);
78    }
79}
80
81int main() {
82    loop = uv_default_loop();
83
84    uv_pipe_init(loop, &queue, 1 /* ipc */);
85    uv_pipe_open(&queue, 0);
86    uv_read_start((uv_stream_t*)&queue, alloc_buffer, on_new_connection);
87    return uv_run(loop, UV_RUN_DEFAULT);
88}
89