ircd: Preliminary AIO experimental stub on linux platforms.

charybdis/charybdis.cc

@@ -121,6 +121,7 @@ try
 	sigs.add(SIGTERM);
 	sigs.add(SIGUSR1);
 	sigs.add(SIGUSR2);
+	sigs.add(SIGIO);
 	sigs.async_wait(sigfd_handler);
 
 	// Because we registered signal handlers with the io_context, ios->run()
@@ -211,6 +212,7 @@ catch(const std::exception &e)
 	return false;
 }
 
+static void handle_io();
 static void handle_usr2();
 static void handle_usr1();
 static void handle_quit();
@@ -240,6 +242,7 @@ sigfd_handler(const boost::system::error_code &ec,
 
 	switch(signum)
 	{
+		case SIGIO:    handle_io();             break;
 		case SIGUSR1:  handle_usr1();           break;
 		case SIGUSR2:  handle_usr2();           break;
 		case SIGINT:   handle_interruption();   break;
@@ -288,6 +291,17 @@ catch(const std::exception &e)
 	ircd::log::error("SIGUSR2 handler: %s", e.what());
 }
 
+void
+handle_io()
+try
+{
+	ircd::fs::notify();
+}
+catch(const std::exception &e)
+{
+	ircd::log::error("SIGIO handler: %s", e.what());
+}
+
 void
 handle_hangup()
 try

configure.ac

@@ -438,6 +438,9 @@ RB_CHK_SYSHEADER([winsock2.h], [WINSOCK2_H])
 RB_CHK_SYSHEADER([ws2tcpip.h], [WS2TCPIP_H])
 RB_CHK_SYSHEADER([iphlpapi.h], [IPHLPAPI_H])
 
+dnl linux platform
+RB_CHK_SYSHEADER([aio.h], [AIO_H])
+
 dnl experimental
 RB_CHK_SYSHEADER([experimental/string_view], [EXPERIMENTAL_STRING_VIEW])
 RB_CHK_SYSHEADER([experimental/optional], [EXPERIMENTAL_OPTIONAL])
@@ -499,6 +502,16 @@ AM_COND_IF(INTERIX,
 ],[])
 
 
+AM_COND_IF(LINUX,
+[
+	AC_ARG_ENABLE(aio,
+	AC_HELP_STRING([--enable-aio], [Enable AIO support on Linux platforms]),
+	[
+		IRCD_DEFINE(USE_AIO, [1], [Define to 1 if you want AIO support on linux])
+		LIBS="$LIBS -rt"
+	],[])
+],[])
+
 
 dnl ***************************************************************************
 dnl Installation Layout

include/ircd/fs.h

@@ -45,6 +45,9 @@
 /// during IOs.
 namespace ircd::fs
 {
+	struct aio;
+	struct init;
+
 	IRCD_EXCEPTION(ircd::error, error)
 	IRCD_EXCEPTION(error, filesystem_error)
 
@@ -101,11 +104,13 @@ namespace ircd::fs
 	bool overwrite(const std::string &name, const const_raw_buffer &buf);
 	bool overwrite(const string_view &name, const const_raw_buffer &buf);
 
-	struct init;
+	void notify();
 }
 
 struct ircd::fs::init
 {
+	std::unique_ptr<fs::aio> aio;
+
 	init();
 	~init() noexcept;
 };

ircd/fs.cc

@@ -26,6 +26,10 @@
 #include <boost/filesystem.hpp>
 #include <ircd/asio.h>
 
+#ifdef IRCD_USE_AIO
+	#include <RB_INC_AIO_H
+#endif
+
 namespace ircd::fs
 {
 	using namespace boost::filesystem;
@@ -54,6 +58,16 @@ ircd::fs::paths
 	{ "db",                DBPATH        },
 }};
 
+ircd::fs::init::init()
+:aio{std::make_unique<fs::aio>()}
+{
+}
+
+ircd::fs::init::~init()
+noexcept
+{
+}
+
 bool
 ircd::fs::write(const std::string &path,
                 const const_raw_buffer &buf)
@@ -89,72 +103,6 @@ ircd::fs::append(const std::string &path,
 	return true;
 }
 
-ircd::fs::init::init()
-{
-	#if 0
-	struct aioinit aio {0};
-	aio.aio_threads = 0;
-	aio.aio_num = 64;
-	aio.aio_idle_time = 0;
-	aio_init(&aio);
-	#endif
-}
-
-ircd::fs::init::~init()
-noexcept
-{
-}
-
-#if 0 //_WIN32
-namespace ircd::fs
-{
-
-
-}
-
-/// Reads the file at path into a string; yields your ircd::ctx.
-///
-std::string
-ircd::fs::read(const std::string &path)
-{
-	const int fd
-	{
-		syscall(::open, path.c_str(), O_CLOEXEC, O_RDONLY)
-	};
-
-	const unwind close{[&fd]
-	{
-		syscall(::close, fd);
-	}};
-
-	struct stat stat;
-	syscall(::fstat, fd, &stat);
-	const auto &size{stat.st_size};
-
-	std::string ret(size, char{});
-	const mutable_buffer buf
-	{
-		const_cast<char *>(ret.data()), ret.size()
-	};
-
-	struct aiocb cb
-	{
-		fd, 0, data(buf), size(buf), 0
-	};
-
-	syscall(::aio_read, &cb);
-
-	struct aiocb cbs[]
-	{
-		&cb
-	};
-
-	syscall(::aio_suspend, &cbs, sizeof(cbs) / sizeof(aiocb), nullptr);
-
-	ret.resize(read);
-	return ret;
-}
-#else
 std::string
 ircd::fs::read(const std::string &path)
 {
@@ -164,7 +112,6 @@ ircd::fs::read(const std::string &path)
 	std::istream_iterator<char> e{};
 	return std::string{b, e};
 }
-#endif
 
 ircd::string_view
 ircd::fs::read(const string_view &path,
@@ -336,3 +283,120 @@ catch(const std::out_of_range &e)
 {
 	return nullptr;
 }
+
+///////////////////////////////////////////////////////////////////////////////
+//
+// linux aio
+//
+
+namespace ircd::fs
+{
+	ctx::ctx *waiter;
+}
+
+void
+ircd::fs::notify()
+{
+	if(waiter)
+		notify(*waiter);
+}
+
+#ifndef IRCD_USE_AIO
+
+struct ircd::fs::aio
+{
+	aio() {}
+	~aio() noexcept {}
+};
+
+#else
+
+struct ircd::fs::aio
+{
+	aioinit init {0};
+
+	std::string read(const std::string &path);
+
+	aio();
+	~aio() noexcept;
+};
+
+ircd::fs::aio::aio()
+{
+	init.aio_threads = 0;
+	init.aio_num = 64;
+	init.aio_idle_time = 0;
+	aio_init(&init);
+
+	auto test{[this]
+	{
+		const auto got{this->read("/etc/passwd")};
+		std::cout << "got: " << got << std::endl;
+	}};
+
+	ircd::context
+	{
+		"aiotest", context::POST | context::DETACH, test
+	};
+}
+
+ircd::fs::aio::~aio()
+noexcept
+{
+}
+
+/// Reads the file at path into a string; yields your ircd::ctx.
+///
+std::string
+ircd::fs::aio::read(const std::string &path)
+{
+	const auto fd
+	{
+		syscall(::open, path.c_str(), O_CLOEXEC, O_RDONLY)
+	};
+
+	const unwind close{[&fd]
+	{
+		syscall(::close, fd);
+	}};
+
+	struct stat stat;
+	syscall(::fstat, fd, &stat);
+	const auto &size{stat.st_size};
+
+	std::string ret(size, char{});
+	const mutable_buffer buf
+	{
+		const_cast<char *>(ret.data()), ret.size()
+	};
+
+	struct aiocb cb {0};
+	cb.aio_fildes = fd;
+	cb.aio_offset = 0;
+	cb.aio_buf = buffer::data(buf);
+	cb.aio_nbytes = buffer::size(buf);
+	cb.aio_reqprio = 0;
+	cb.aio_sigevent.sigev_notify = SIGEV_SIGNAL;
+	cb.aio_sigevent.sigev_signo = SIGIO;
+	cb.aio_sigevent.sigev_value.sival_ptr = nullptr;
+
+	syscall(::aio_read, &cb);
+
+	waiter = ctx::current;
+	int errval; do
+	{
+		ctx::wait();
+	}
+	while((errval = ::aio_error(&cb)) == EINPROGRESS);
+
+	const ssize_t bytes
+	{
+		syscall(::aio_return, &cb)
+	};
+
+	assert(bytes >= 0);
+	ret.resize(size_t(bytes));
+	return ret;
+}
+
+#endif