Userspace: Add simple AudioServer and LibAudio

userspace/programs/AudioServer/main.cpp

@@ -0,0 +1,184 @@
+#include "AudioServer.h"
+
+#include <LibAudio/Audio.h>
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+static int open_server_fd()
+{
+	struct stat st;
+	if (stat(LibAudio::s_audio_server_socket.data(), &st) != -1)
+		unlink(LibAudio::s_audio_server_socket.data());
+
+	int server_fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (server_fd == -1)
+	{
+		dwarnln("failed to create server socket: {}", strerror(errno));
+		return -1;
+	}
+
+	sockaddr_un server_addr;
+	server_addr.sun_family = AF_UNIX;
+	strcpy(server_addr.sun_path, LibAudio::s_audio_server_socket.data());
+	if (bind(server_fd, (sockaddr*)&server_addr, sizeof(server_addr)) == -1)
+	{
+		dwarnln("failed to bind server socket: {}", strerror(errno));
+		return -1;
+	}
+
+	if (chmod(LibAudio::s_audio_server_socket.data(), 0777) == -1)
+	{
+		dwarnln("failed to set server socket permissions: {}", strerror(errno));
+		return -1;
+	}
+
+	if (listen(server_fd, SOMAXCONN) == -1)
+	{
+		dwarnln("failed to make server socket listening: {}", strerror(errno));
+		return -1;
+	}
+
+	return server_fd;
+}
+
+static uint64_t get_current_ms()
+{
+	timespec ts;
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
+}
+
+int main()
+{
+	constexpr int non_terminating_signals[] {
+		SIGCONT,
+		SIGSTOP,
+		SIGTSTP,
+		SIGTTIN,
+		SIGTTOU,
+	};
+	for (int sig = _SIGMIN; sig <= _SIGMAX; sig++)
+		signal(sig, exit);
+	for (int sig : non_terminating_signals)
+		signal(sig, SIG_DFL);
+
+	const int audio_device_fd = open("/dev/audio0", O_RDWR | O_NONBLOCK);
+	if (audio_device_fd == -1)
+	{
+		dwarnln("failed to open audio device: {}", strerror(errno));
+		return 1;
+	}
+
+	auto* audio_server = new AudioServer(audio_device_fd);
+	if (audio_server == nullptr)
+	{
+		dwarnln("Failed to allocate AudioServer: {}", strerror(errno));
+		return 1;
+	}
+
+	const int server_fd = open_server_fd();
+	if (server_fd == -1)
+		return 1;
+
+	struct ClientInfo
+	{
+		int fd;
+	};
+
+	BAN::Vector<ClientInfo> clients;
+
+	dprintln("AudioServer started");
+
+	constexpr uint64_t update_interval_ms = 100;
+	uint64_t next_update_ms = get_current_ms() + update_interval_ms;
+
+	for (;;)
+	{
+		fd_set fds;
+		FD_ZERO(&fds);
+		FD_SET(server_fd, &fds);
+
+		int max_fd = server_fd;
+		for (const auto& client : clients)
+		{
+			max_fd = BAN::Math::max(max_fd, client.fd);
+			FD_SET(client.fd, &fds);
+		}
+
+		const uint64_t current_ms = get_current_ms();
+		if (current_ms >= next_update_ms)
+		{
+			audio_server->update();
+			next_update_ms = current_ms + update_interval_ms;
+		}
+
+		const uint64_t timeout_ms = next_update_ms - current_ms;
+
+		timeval timeout {
+			.tv_sec = static_cast<time_t>(timeout_ms / 1000),
+			.tv_usec = static_cast<suseconds_t>((timeout_ms % 1000) * 1000)
+		};
+		if (select(max_fd + 1, &fds, nullptr, nullptr, &timeout) == -1)
+		{
+			dwarnln("select: {}", strerror(errno));
+			break;
+		}
+
+		if (FD_ISSET(server_fd, &fds))
+		{
+			const int client_fd = accept(server_fd, nullptr, nullptr);
+			if (client_fd == -1)
+			{
+				dwarnln("accept: {}", strerror(errno));
+				continue;
+			}
+
+			if (auto ret = clients.emplace_back(client_fd); ret.is_error())
+			{
+				dwarnln("Failed to add client: {}", ret.error());
+				close(client_fd);
+				continue;
+			}
+
+			if (auto ret = audio_server->on_new_client(client_fd); ret.is_error())
+			{
+				dwarnln("Failed to initialize client: {}", ret.error());
+				clients.pop_back();
+				close(client_fd);
+				continue;
+			}
+		}
+
+		for (size_t i = 0; i < clients.size(); i++)
+		{
+			auto& client = clients[i];
+			if (!FD_ISSET(client.fd, &fds))
+				continue;
+
+			long smo_key;
+			const ssize_t nrecv = recv(client.fd, &smo_key, sizeof(smo_key), 0);
+
+			if (nrecv < static_cast<ssize_t>(sizeof(smo_key)) || !audio_server->on_client_packet(client.fd, smo_key))
+			{
+				if (nrecv == 0)
+					;
+				else if (nrecv < 0)
+					dwarnln("recv: {}", strerror(errno));
+				else if (nrecv < static_cast<ssize_t>(sizeof(smo_key)))
+					dwarnln("client sent only {} bytes, {} expected", nrecv, sizeof(smo_key));
+
+				audio_server->on_client_disconnect(client.fd);
+				close(client.fd);
+				clients.remove(i--);
+				continue;
+			}
+		}
+	}
+}