yhirose
bef278e0d2
Samples that did not compile or run as shown: - res.user_data.get<T>() inside a generic lambda needs the `template` keyword; use explicit parameter types (tour 09, cookbook s15). - listen() on a Unix domain socket fails with port 0 (tour 09, s22). - "*.dev.local" is not a NO_PROXY pattern (c16). - ssl_backend_error() holds a verify result, not an ERR_get_error() value, after a verification failure; decode each with the matching OpenSSL function (c18). - The content provider's `length` is everything that remains, so the sample read the whole file in one call (s05). Statements corrected: - Client keep-alive is off by default; c14 is rewritten around set_keep_alive(true). - Mounted files are looked up before GET handlers (tour 04, s04). - Params keep insertion order, and to_string(Error::Connection) reads "Could not establish connection" (tour 02). - A chunked provider ends with sink.done(), and post_routing_handler runs before the response is sent (tour 09). - Timeouts surface as Error::Read; Error::Timeout comes from the stream API (c17). The max timeout cuts off the wait for the response only (c13). The progress callback needs Content-Length (c11). - Encoding selection follows q-values, then Brotli, gzip, Zstd (s08), and the client compresses with the first of those it was built with (c15). - stop() cuts a provider-driven response short (s19); a rejected content_reader already gets 400 or 413 (s07); user_data values must be copyable (s12); Client accepts a client certificate too (t04); on_message() is the fallback for every unhandled event and 204/403/404 end reconnection (e04); the pong timeout takes two to three intervals and ends a waiting read() (w02). In the LLM app tutorial, an uncaught exception does not crash the server, so say what it does instead. Drop the server and client timeout settings whose stated purpose, covering inference and download time, they do not serve: those timeouts bound a single socket wait. Update the llama.cpp server layout in chapter 7.
1.9 KiB
title, order, status
| title | order | status |
|---|---|---|
| S19. Shut Down Gracefully | 38 | draft |
To stop the server, call Server::stop(). It's safe to call even while requests are in flight, so you can wire it to SIGINT or SIGTERM for a graceful shutdown.
Basic usage
httplib::Server svr;
svr.Get("/", [](const auto &, auto &res) { res.set_content("ok", "text/plain"); });
std::thread t([&] { svr.listen("0.0.0.0", 8080); });
// wait for input on the main thread, or whatever
std::cin.get();
svr.stop();
t.join();
listen() blocks, so the typical pattern is: run the server on a background thread and call stop() from the main thread. After stop(), listen() returns and you can join().
Shut down on a signal
Here's how to stop the server on SIGINT (Ctrl+C) or SIGTERM.
#include <csignal>
httplib::Server svr;
// global so the signal handler can reach it
httplib::Server *g_svr = nullptr;
int main() {
svr.Get("/", [](const auto &, auto &res) { res.set_content("ok", "text/plain"); });
g_svr = &svr;
std::signal(SIGINT, [](int) { if (g_svr) g_svr->stop(); });
std::signal(SIGTERM, [](int) { if (g_svr) g_svr->stop(); });
svr.listen("0.0.0.0", 8080);
std::cout << "server stopped" << std::endl;
}
stop() is thread-safe and signal-safe — you can call it from a signal handler. Even when listen() is running on the main thread, the signal pulls it out cleanly.
What happens to in-flight requests
When you call stop(), new connections are refused, but handlers that are already running are allowed to finish. A response still being sent by a content provider (a streaming response, for example) is cut short, though. Once all workers drain, listen() returns. That's what makes it graceful.
Warning: There's a wait between calling
stop()andlisten()returning — it's the time in-flight requests take to finish. To enforce a timeout, you'll need to add your own shutdown timer in application code.