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![THE GYP BUILD FILE
# Copyright (c) 2016, Saúl Ibarra Corretgé <saghul@gmail.com>
# Copyright (c) 2012, Ben Noordhuis <info@bnoordhuis.nl>
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
# gyp -Duv_library=static_library --depth=$PWD --generator-output=$PWD/out -Goutput_dir=$PWD/out -f make build.gyp
{
'targets': [
{
'target_name': 'chat-server',
'type': 'executable',
'dependencies': ['deps/libuv/uv.gyp:libuv'],
'sources': ['src/main.c', 'src/queue.h', 'src/pokemon_names.h'],
}
]
}](https://image.slidesharecdn.com/vt9nhmhjqzk3fd4loiiv-signature-804871951955cddd69f25b9fd0863c2fa48f5d0b0a700084358d094fd6286dc6-poli-160804165148/85/libuv-NodeJS-and-everything-in-between-21-320.jpg)
![INITIALISE AND RUN SERVER
struct user
{
QUEUE queue;
uv_tcp_t handle;
char id[32];
};
static QUEUE users;
int main(void)
{
QUEUE_INIT(&users);
srand(1234);
int r;
uv_tcp_t server_handle;
uv_tcp_init(uv_default_loop(), &server_handle);
struct sockaddr_in addr;
uv_ip4_addr(SERVER_ADDR, SERVER_PORT, &addr);
r = uv_tcp_bind(&server_handle, (const struct sockaddr*) &addr, 0);
if (r < 0)
fatal("uv_tcp_bind", r);
const int backlog = 128;
r = uv_listen((uv_stream_t*) &server_handle, backlog, on_connection);
if (r < 0)
fatal("uv_listen", r);
printf("Listening at %s:%dn", SERVER_ADDR, SERVER_PORT);
uv_run(uv_default_loop(), UV_RUN_DEFAULT);
return 0;
}](https://image.slidesharecdn.com/vt9nhmhjqzk3fd4loiiv-signature-804871951955cddd69f25b9fd0863c2fa48f5d0b0a700084358d094fd6286dc6-poli-160804165148/85/libuv-NodeJS-and-everything-in-between-22-320.jpg)
![BROADCAST DATA
static void broadcast(const struct user* sender, const char *fmt, ...)
{
QUEUE *q;
char msg[512];
va_list ap;
va_start(ap, fmt);
vsnprintf(msg, sizeof(msg), fmt, ap);
va_end(ap);
QUEUE_FOREACH(q, &users) {
struct user *user = QUEUE_DATA(q, struct user, queue);
if (user != sender) {
unicast(user, msg);
}
}
}
static void unicast(struct user *user, const char *msg)
{
size_t len = strlen(msg);
uv_write_t *req = xmalloc(sizeof(*req) + len);
void *addr = req + 1;
memcpy(addr, msg, len);
uv_buf_t buf = uv_buf_init(addr, len);
uv_write(req, (uv_stream_t*) &user->handle, &buf, 1, on_write);
}
static void on_write(uv_write_t *req, int status)
{
free(req);
}](https://image.slidesharecdn.com/vt9nhmhjqzk3fd4loiiv-signature-804871951955cddd69f25b9fd0863c2fa48f5d0b0a700084358d094fd6286dc6-poli-160804165148/85/libuv-NodeJS-and-everything-in-between-25-320.jpg)
![MISCELLANEOUS FUNCTIONS
static void on_close(uv_handle_t* handle)
{
struct user *user = QUEUE_DATA(handle, struct user, handle);
free(user);
}
static void make_user_id(struct user *user)
{
snprintf(user->id, sizeof(user->id), "%s", pokemon_names[rand() % ARRAY_SIZE(pokemon_names)]);
}](https://image.slidesharecdn.com/vt9nhmhjqzk3fd4loiiv-signature-804871951955cddd69f25b9fd0863c2fa48f5d0b0a700084358d094fd6286dc6-poli-160804165148/85/libuv-NodeJS-and-everything-in-between-26-320.jpg)
Uploaded bySaúl Ibarra Corretgé
libuv, NodeJS and everything in between
The document provides an overview of libuv, a C library used for asynchronous I/O in Node.js, highlighting its features, architecture, and the event loop mechanism. It explains how libuv facilitates I/O multiplexing, allowing multiple connections without blocking, and describes the implementation of a chat application using libuv. Additionally, it touches upon Node.js's reliance on libuv for asynchronous network I/O and various other operations.
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libuv, NodeJS and everything in between
- 1. LIBUV, NODEJS AND EVERYTHING INBETWEEN Saúl Ibarra Corretgé @saghul
- 2. LIBUV, NODE ANDEVERYTHING IN BETWEEN HIYA! ▸ @saghul ▸ Bilbao — Amsterdam — Liverpool ▸ libuv core janitor ▸ Nodejs collaborator ▸ Recently obsessed with 3D printing ▸ AMA!
- 3.
- 4. LIBUV, NODE ANDEVERYTHING IN BETWEEN ASYNC I/O 101 from __future__ import print_function import socket server = socket.socket(family=socket.AF_INET, type=socket.SOCK_STREAM) server.bind(('127.0.0.1', 1234)) server.listen(10) print("Server listening on: {}".format(server.getsockname())) client, addr = server.accept() print("Client connected: {}".format(addr)) while True: data = client.recv(4096) if not data: print("Client has disconnected") break client.send(data.upper()) server.close()
- 5. LIBUV, NODE ANDEVERYTHING IN BETWEEN CRAP, IT BLOCKS! ▸ Only one client at a time! ▸ Scaling up ▸ Threads ▸ I/O multiplexing ▸ http://www.kegel.com/c10k.html ▸ http://www.slideshare.net/saghul/how-do-eventloops- work-in-python
- 6. LIBUV, NODE ANDEVERYTHING IN BETWEEN THREADS? ▸ Overhead: stack size, scheduling ▸ Synchronisation ▸ It’s still a good solution in some cases
- 7. LIBUV, NODE ANDEVERYTHING IN BETWEEN I/O MULTIPLEXING TO THE RESCUE ▸ Single thread ▸ Examine and wait for i/o in multiple sockets at once ▸ When a socket is ready the operation won’t block ▸ Good for i/o bound tasks, bad for CPU intensive tasks
- 8. LIBUV, NODE ANDEVERYTHING IN BETWEEN I/O MULTIPLEXING 101 1. Put the fd in non-blocking mode 2. Add the fd to the i/o multiplexor 3. Wait for some time 4. Perform read / writes on the fd, it won’t block! 5. Profit?
- 9. LIBUV, NODE ANDEVERYTHING IN BETWEEN I/O MULTIPLEXING APIS ▸ Different APIs: select, poll, epoll, kqueue, … ▸ Unix shares a common model: readiness ▸ Windows uses a completion model ▸ IOCP is The Good Stuff
- 10.
- 11. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV ▸ Small (relatively) C library: ~30K LOC (without tests) ▸ Extensive test suite ▸ Designed for C programs that miss the joy of JavaScript callback hell ▸ Used by Node and many other projects: https://github.com/libuv/libuv/wiki/Projects-that-use-libuv
- 12. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV: FEATURES ▸ Event loop backed by epoll, kqueue, IOCP, event ports, etc. ▸ Timers ▸ Async TCP / UDP sockets ▸ Async named pipes ▸ Async filesystem operations ▸ Async signal handling ▸ Child processes ▸ ANSI escaped TTY ▸ Threading utilities ▸ Coolest logo ever
- 13. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV: ARCHITECTURE
- 14. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV: THE EVENT LOOP
- 15. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV: FILESYSTEM APIS ▸ Follow the Unix style ▸ Executed in a thread pool ▸ http://blog.libtorrent.org/2012/10/asynchronous-disk-io/
- 16. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV: A WORD ON THREADS ▸ We only use threads for file i/o and getaddrinfo ▸ Default thread pool size is 4 (runtime env var: UV_THREADPOOL_SIZE) ▸ NOT FOR NETWORK I/O ▸ NOT FOR NETWORK I/O ▸ NOT FOR NETWORK I/O ▸ NOT FOR NETWORK I/O
- 17. THE LIBUV EVENTLOOP IS SINGLE THREADED. THE THREAD POOL IS ONLY USED FOR FILE I/O. The libuv police LIBUV, NODE AND EVERYTHING IN BETWEEN
- 18. A CHAT APP, OFCOURSE
- 19. LIBUV, NODE ANDEVERYTHING IN BETWEEN A LIBUV CHAT APPLICATION ▸ Simple TCP server application ▸ A twist on libuv-chat by Ben Noordhuis in 2011 ▸ Multiple users, single “chat room” ▸ Pokemon, because why not? ▸ https://github.com/saghul/libuv-chat
- 20. THE MAKEFILE all: build deps/libuv: gitclone --depth 1 https://github.com/libuv/libuv deps/libuv build/gyp: git clone --depth 1 https://chromium.googlesource.com/external/gyp build/gyp out/Makefile: deps/libuv build/gyp build/gyp/gyp -Duv_library=static_library --depth=$(PWD) --generator-output=$(PWD)/out -Goutput_dir=$(PWD)/out -f make build.gyp build: out/Makefile $(MAKE) -C out clean: rm -rf out distclean: rm -rf build deps out .PHONY: clean distclean
- 21. THE GYP BUILDFILE # Copyright (c) 2016, Saúl Ibarra Corretgé <saghul@gmail.com> # Copyright (c) 2012, Ben Noordhuis <info@bnoordhuis.nl> # # Permission to use, copy, modify, and/or distribute this software for any # purpose with or without fee is hereby granted, provided that the above # copyright notice and this permission notice appear in all copies. # # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. # gyp -Duv_library=static_library --depth=$PWD --generator-output=$PWD/out -Goutput_dir=$PWD/out -f make build.gyp { 'targets': [ { 'target_name': 'chat-server', 'type': 'executable', 'dependencies': ['deps/libuv/uv.gyp:libuv'], 'sources': ['src/main.c', 'src/queue.h', 'src/pokemon_names.h'], } ] }
- 22. INITIALISE AND RUNSERVER struct user { QUEUE queue; uv_tcp_t handle; char id[32]; }; static QUEUE users; int main(void) { QUEUE_INIT(&users); srand(1234); int r; uv_tcp_t server_handle; uv_tcp_init(uv_default_loop(), &server_handle); struct sockaddr_in addr; uv_ip4_addr(SERVER_ADDR, SERVER_PORT, &addr); r = uv_tcp_bind(&server_handle, (const struct sockaddr*) &addr, 0); if (r < 0) fatal("uv_tcp_bind", r); const int backlog = 128; r = uv_listen((uv_stream_t*) &server_handle, backlog, on_connection); if (r < 0) fatal("uv_listen", r); printf("Listening at %s:%dn", SERVER_ADDR, SERVER_PORT); uv_run(uv_default_loop(), UV_RUN_DEFAULT); return 0; }
- 23. HANDLE INCOMING CONNECTIONS staticvoid on_connection(uv_stream_t* server_handle, int status) { assert(status == 0); int r; // hurray, a new user! struct user *user = xmalloc(sizeof(*user)); uv_tcp_init(uv_default_loop(), &user->handle); r = uv_accept(server_handle, (uv_stream_t*) &user->handle); if (r < 0) fatal("uv_accept", r); // add him to the list of users QUEUE_INSERT_TAIL(&users, &user->queue); make_user_id(user); // now tell everyone, including yourself (to know your name!) broadcast(NULL, "* A wild %s appeared from %sn", user->id, addr_and_port(user)); // start accepting messages from the user uv_read_start((uv_stream_t*) &user->handle, on_alloc, on_read); }
- 24. READ INCOMING DATA staticvoid on_alloc(uv_handle_t* handle, size_t suggested_size, uv_buf_t* buf) { buf->base = xmalloc(suggested_size); buf->len = suggested_size; } static void on_read(uv_stream_t* handle, ssize_t nread, const uv_buf_t* buf) { struct user *user = QUEUE_DATA(handle, struct user, handle); if (nread == UV_EOF) { // user disconnected QUEUE_REMOVE(&user->queue); uv_close((uv_handle_t*) &user->handle, on_close); broadcast(NULL, "* %s fled!n", user->id); } else if (nread > 0) { // broadcast message broadcast(user, "%s said: %.*s", user->id, (int) nread, buf->base); } else { fprintf(stderr, "on_read: %sn", uv_strerror(nread)); } free(buf->base); }
- 25. BROADCAST DATA static voidbroadcast(const struct user* sender, const char *fmt, ...) { QUEUE *q; char msg[512]; va_list ap; va_start(ap, fmt); vsnprintf(msg, sizeof(msg), fmt, ap); va_end(ap); QUEUE_FOREACH(q, &users) { struct user *user = QUEUE_DATA(q, struct user, queue); if (user != sender) { unicast(user, msg); } } } static void unicast(struct user *user, const char *msg) { size_t len = strlen(msg); uv_write_t *req = xmalloc(sizeof(*req) + len); void *addr = req + 1; memcpy(addr, msg, len); uv_buf_t buf = uv_buf_init(addr, len); uv_write(req, (uv_stream_t*) &user->handle, &buf, 1, on_write); } static void on_write(uv_write_t *req, int status) { free(req); }
- 26. MISCELLANEOUS FUNCTIONS static voidon_close(uv_handle_t* handle) { struct user *user = QUEUE_DATA(handle, struct user, handle); free(user); } static void make_user_id(struct user *user) { snprintf(user->id, sizeof(user->id), "%s", pokemon_names[rand() % ARRAY_SIZE(pokemon_names)]); }
- 27.
- 28. LIBUV, NODE ANDEVERYTHING IN BETWEEN NODEJS ▸ Server side JavaScript ▸ V8 JavaScript engine ▸ Web inspired async model ▸ Auxiliary libraries: libuv, OpenSSL, c-ares, http_parser, …
- 29. LIBUV, NODE ANDEVERYTHING IN BETWEEN PLATFORM LAYER REQUIREMENTS ▸ ASYNC ALL THE THINGS ▸ Completion based (callbacks) ▸ Consistent API for asynchronous network i/o ▸ Filesystem operations ▸ Basic name resolution (getaddrinfo / getnameinfo)
- 30. LIBUV, NODE ANDEVERYTHING IN BETWEEN ARCHITECTURE IN NODE 0.4 BINDINGS / WRAPS JS STANDARD LIBRARY USER APPLICATIONS V8 OPENSSL LIBEV LIBEIO …
- 31. LIBUV, NODE ANDEVERYTHING IN BETWEEN ARCHITECTURE IN NODE 0.6 BINDINGS / WRAPS JS STANDARD LIBRARY USER APPLICATIONS V8 OPENSSL LIBUV … LIBEV LIBEIO
- 32. LIBUV, NODE ANDEVERYTHING IN BETWEEN ARCHITECTURE IN NODE 0.10 AND ONWARDS BINDINGS / WRAPS JS STANDARD LIBRARY USER APPLICATIONS V8 OPENSSL LIBUV …
- 33.
- 34. LIBUV, NODE ANDEVERYTHING IN BETWEEN LIBUV: THE EVENT LOOP REMEMBER?
- 35. LIBUV, NODE ANDEVERYTHING IN BETWEEN NODE EVENT LOOP COALESCED, 1 NODE TIMER != 1 LIBUV TIMER RUN ON A CHECK + IDLE HANDLE NEXT TICK CALLBACKS RUN FROM NODE::MAKECALLBACK
- 36. LIBUV, NODE ANDEVERYTHING IN BETWEEN ONION ARCHITECTURE (TM) net.Socket TCPWrap uv_tcp_t Socket._handle TCPWrap.handle_ fd / HANDLE
- 37. QUESTIONS? libuv.org docs.libuv.org #libuv on IRC libuvGoogle Group #libuv on StackOverflow
- 38.