1 #include <inttypes.h> 2 #include <stdio.h> 3 #include <stdlib.h> 4 #include <string.h> 5 #include <uv.h> 6 7 uv_loop_t *loop; 8 9 struct child_worker { 10 uv_process_t req; 11 uv_process_options_t options; 12 uv_pipe_t pipe; 13 } *workers; 14 15 int round_robin_counter; 16 int child_worker_count; 17 18 uv_buf_t dummy_buf; 19 char worker_path[500]; 20 21 void close_process_handle(uv_process_t *req, int64_t exit_status, int term_signal) { 22 fprintf(stderr, "Process exited with status %" PRId64 ", signal %d\n", exit_status, term_signal); 23 uv_close((uv_handle_t*) req, NULL); 24 } 25 26 void alloc_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf) { 27 buf->base = malloc(suggested_size); 28 buf->len = suggested_size; 29 } 30 31 void on_new_connection(uv_stream_t *server, int status) { 32 if (status == -1) { 33 // error! 34 return; 35 } 36 37 uv_tcp_t *client = (uv_tcp_t*) malloc(sizeof(uv_tcp_t)); 38 uv_tcp_init(loop, client); 39 if (uv_accept(server, (uv_stream_t*) client) == 0) { 40 uv_write_t *write_req = (uv_write_t*) malloc(sizeof(uv_write_t)); 41 dummy_buf = uv_buf_init("a", 1); 42 struct child_worker *worker = &workers[round_robin_counter]; 43 uv_write2(write_req, (uv_stream_t*) &worker->pipe, &dummy_buf, 1, (uv_stream_t*) client, NULL); 44 round_robin_counter = (round_robin_counter + 1) % child_worker_count; 45 } 46 else { 47 uv_close((uv_handle_t*) client, NULL); 48 } 49 } 50 51 void setup_workers() { 52 size_t path_size = 500; 53 uv_exepath(worker_path, &path_size); 54 strcpy(worker_path + (strlen(worker_path) - strlen("multi-echo-server")), "worker"); 55 fprintf(stderr, "Worker path: %s\n", worker_path); 56 57 char* args[2]; 58 args[0] = worker_path; 59 args[1] = NULL; 60 61 round_robin_counter = 0; 62 63 // ... 64 65 // launch same number of workers as number of CPUs 66 uv_cpu_info_t *info; 67 int cpu_count; 68 uv_cpu_info(&info, &cpu_count); 69 uv_free_cpu_info(info, cpu_count); 70 71 child_worker_count = cpu_count; 72 73 workers = calloc(cpu_count, sizeof(struct child_worker)); 74 while (cpu_count--) { 75 struct child_worker *worker = &workers[cpu_count]; 76 uv_pipe_init(loop, &worker->pipe, 1); 77 78 uv_stdio_container_t child_stdio[3]; 79 child_stdio[0].flags = UV_CREATE_PIPE | UV_READABLE_PIPE; 80 child_stdio[0].data.stream = (uv_stream_t*) &worker->pipe; 81 child_stdio[1].flags = UV_IGNORE; 82 child_stdio[2].flags = UV_INHERIT_FD; 83 child_stdio[2].data.fd = 2; 84 85 worker->options.stdio = child_stdio; 86 worker->options.stdio_count = 3; 87 88 worker->options.exit_cb = close_process_handle; 89 worker->options.file = args[0]; 90 worker->options.args = args; 91 92 uv_spawn(loop, &worker->req, &worker->options); 93 fprintf(stderr, "Started worker %d\n", worker->req.pid); 94 } 95 } 96 97 int main() { 98 loop = uv_default_loop(); 99 100 setup_workers(); 101 102 uv_tcp_t server; 103 uv_tcp_init(loop, &server); 104 105 struct sockaddr_in bind_addr; 106 uv_ip4_addr("0.0.0.0", 7000, &bind_addr); 107 uv_tcp_bind(&server, (const struct sockaddr *)&bind_addr, 0); 108 int r; 109 if ((r = uv_listen((uv_stream_t*) &server, 128, on_new_connection))) { 110 fprintf(stderr, "Listen error %s\n", uv_err_name(r)); 111 return 2; 112 } 113 return uv_run(loop, UV_RUN_DEFAULT); 114 } 115