fdtrack: temporary hack for tracking file descriptor usage

Package fdtrack logs statistics about open file descriptors.
This should help identify the source of #1549.

15 files changed, 314 insertions, 7 deletions

diff --git a/Godeps/_workspace/src/github.com/huin/goupnp/httpu/httpu.go b/Godeps/_workspace/src/github.com/huin/goupnp/httpu/httpu.go
index 862c3def4..3f4606af0 100644
--- a/Godeps/_workspace/src/github.com/huin/goupnp/httpu/httpu.go
+++ b/Godeps/_workspace/src/github.com/huin/goupnp/httpu/httpu.go
@@ -9,6 +9,8 @@ import (
 	"net/http"
 	"sync"
 	"time"
+
+	"github.com/ethereum/go-ethereum/fdtrack"
 )
 
 // HTTPUClient is a client for dealing with HTTPU (HTTP over UDP). Its typical
@@ -25,6 +27,7 @@ func NewHTTPUClient() (*HTTPUClient, error) {
 	if err != nil {
 		return nil, err
 	}
+	fdtrack.Open("upnp")
 	return &HTTPUClient{conn: conn}, nil
 }
 
@@ -33,6 +36,7 @@ func NewHTTPUClient() (*HTTPUClient, error) {
 func (httpu *HTTPUClient) Close() error {
 	httpu.connLock.Lock()
 	defer httpu.connLock.Unlock()
+	fdtrack.Close("upnp")
 	return httpu.conn.Close()
 }
 
diff --git a/Godeps/_workspace/src/github.com/huin/goupnp/soap/soap.go b/Godeps/_workspace/src/github.com/huin/goupnp/soap/soap.go
index 815610734..786ce6fa8 100644
--- a/Godeps/_workspace/src/github.com/huin/goupnp/soap/soap.go
+++ b/Godeps/_workspace/src/github.com/huin/goupnp/soap/soap.go
@@ -7,9 +7,12 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"net/url"
 	"reflect"
+
+	"github.com/ethereum/go-ethereum/fdtrack"
 )
 
 const (
@@ -26,6 +29,17 @@ type SOAPClient struct {
 func NewSOAPClient(endpointURL url.URL) *SOAPClient {
 	return &SOAPClient{
 		EndpointURL: endpointURL,
+		HTTPClient: http.Client{
+			Transport: &http.Transport{
+				Dial: func(network, addr string) (net.Conn, error) {
+					c, err := net.Dial(network, addr)
+					if c != nil {
+						c = fdtrack.WrapConn("upnp", c)
+					}
+					return c, err
+				},
+			},
+		},
 	}
 }
 
diff --git a/Godeps/_workspace/src/github.com/jackpal/go-nat-pmp/natpmp.go b/Godeps/_workspace/src/github.com/jackpal/go-nat-pmp/natpmp.go
index 8ce4e8342..b165c784e 100644
--- a/Godeps/_workspace/src/github.com/jackpal/go-nat-pmp/natpmp.go
+++ b/Godeps/_workspace/src/github.com/jackpal/go-nat-pmp/natpmp.go
@@ -5,6 +5,8 @@ import (
 	"log"
 	"net"
 	"time"
+
+	"github.com/ethereum/go-ethereum/fdtrack"
 )
 
 // Implement the NAT-PMP protocol, typically supported by Apple routers and open source
@@ -102,6 +104,8 @@ func (n *Client) rpc(msg []byte, resultSize int) (result []byte, err error) {
 	if err != nil {
 		return
 	}
+	fdtrack.Open("natpmp")
+	defer fdtrack.Close("natpmp")
 	defer conn.Close()
 
 	result = make([]byte, resultSize)
diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/storage/file_storage.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/storage/file_storage.go
index 46cc9d070..6d44f74b3 100644
--- a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/storage/file_storage.go
+++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/storage/file_storage.go
@@ -18,6 +18,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/syndtr/goleveldb/leveldb/util"
 )
 
@@ -369,6 +370,8 @@ func (fw fileWrap) Close() error {
 	err := fw.File.Close()
 	if err != nil {
 		f.fs.log(fmt.Sprintf("close %s.%d: %v", f.Type(), f.Num(), err))
+	} else {
+		fdtrack.Close("leveldb")
 	}
 	return err
 }
@@ -400,6 +403,7 @@ func (f *file) Open() (Reader, error) {
 		return nil, err
 	}
 ok:
+	fdtrack.Open("leveldb")
 	f.open = true
 	f.fs.open++
 	return fileWrap{of, f}, nil
@@ -418,6 +422,7 @@ func (f *file) Create() (Writer, error) {
 	if err != nil {
 		return nil, err
 	}
+	fdtrack.Open("leveldb")
 	f.open = true
 	f.fs.open++
 	return fileWrap{of, f}, nil
diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index 68a2c79e2..9dc37f3a8 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -38,6 +38,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/ethdb"
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/metrics"
@@ -528,6 +529,9 @@ func startEth(ctx *cli.Context, eth *eth.Ethereum) {
 	// Start Ethereum itself
 	utils.StartEthereum(eth)
 
+	// Start logging file descriptor stats.
+	fdtrack.Start()
+
 	am := eth.AccountManager()
 	account := ctx.GlobalString(utils.UnlockedAccountFlag.Name)
 	accounts := strings.Split(account, " ")
diff --git a/fdtrack/fdtrack.go b/fdtrack/fdtrack.go
new file mode 100644
index 000000000..2f5ab57f4
--- /dev/null
+++ b/fdtrack/fdtrack.go
@@ -0,0 +1,112 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package fdtrack logs statistics about open file descriptors.
+package fdtrack
+
+import (
+	"fmt"
+	"net"
+	"sort"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/logger/glog"
+)
+
+var (
+	mutex sync.Mutex
+	all   = make(map[string]int)
+)
+
+func Open(desc string) {
+	mutex.Lock()
+	all[desc] += 1
+	mutex.Unlock()
+}
+
+func Close(desc string) {
+	mutex.Lock()
+	defer mutex.Unlock()
+	if c, ok := all[desc]; ok {
+		if c == 1 {
+			delete(all, desc)
+		} else {
+			all[desc]--
+		}
+	}
+}
+
+func WrapListener(desc string, l net.Listener) net.Listener {
+	Open(desc)
+	return &wrappedListener{l, desc}
+}
+
+type wrappedListener struct {
+	net.Listener
+	desc string
+}
+
+func (w *wrappedListener) Accept() (net.Conn, error) {
+	c, err := w.Listener.Accept()
+	if err == nil {
+		c = WrapConn(w.desc, c)
+	}
+	return c, err
+}
+
+func (w *wrappedListener) Close() error {
+	err := w.Listener.Close()
+	if err == nil {
+		Close(w.desc)
+	}
+	return err
+}
+
+func WrapConn(desc string, conn net.Conn) net.Conn {
+	Open(desc)
+	return &wrappedConn{conn, desc}
+}
+
+type wrappedConn struct {
+	net.Conn
+	desc string
+}
+
+func (w *wrappedConn) Close() error {
+	err := w.Conn.Close()
+	if err == nil {
+		Close(w.desc)
+	}
+	return err
+}
+
+func Start() {
+	go func() {
+		for range time.Tick(15 * time.Second) {
+			mutex.Lock()
+			var sum, tracked = 0, []string{}
+			for what, n := range all {
+				sum += n
+				tracked = append(tracked, fmt.Sprintf("%s:%d", what, n))
+			}
+			mutex.Unlock()
+			used, _ := fdusage()
+			sort.Strings(tracked)
+			glog.Infof("fd usage %d/%d, tracked %d %v", used, fdlimit(), sum, tracked)
+		}
+	}()
+}
diff --git a/fdtrack/fdusage.go b/fdtrack/fdusage.go
new file mode 100644
index 000000000..689625a8f
--- /dev/null
+++ b/fdtrack/fdusage.go
@@ -0,0 +1,29 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build !linux,!darwin
+
+package fdtrack
+
+import "errors"
+
+func fdlimit() int {
+	return 0
+}
+
+func fdusage() (int, error) {
+	return 0, errors.New("not implemented")
+}
diff --git a/fdtrack/fdusage_darwin.go b/fdtrack/fdusage_darwin.go
new file mode 100644
index 000000000..04a3a9baf
--- /dev/null
+++ b/fdtrack/fdusage_darwin.go
@@ -0,0 +1,72 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build darwin
+
+package fdtrack
+
+import (
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// #cgo CFLAGS: -lproc
+// #include <libproc.h>
+// #include <stdlib.h>
+import "C"
+
+func fdlimit() int {
+	var nofile syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &nofile); err != nil {
+		return 0
+	}
+	return int(nofile.Cur)
+}
+
+func fdusage() (int, error) {
+	pid := C.int(os.Getpid())
+	// Query for a rough estimate on the amout of data that
+	// proc_pidinfo will return.
+	rlen, err := C.proc_pidinfo(pid, C.PROC_PIDLISTFDS, 0, nil, 0)
+	if rlen <= 0 {
+		return 0, err
+	}
+	// Load the list of file descriptors. We don't actually care about
+	// the content, only about the size. Since the number of fds can
+	// change while we're reading them, the loop enlarges the buffer
+	// until proc_pidinfo says the result fitted.
+	var buf unsafe.Pointer
+	defer func() {
+		if buf != nil {
+			C.free(buf)
+		}
+	}()
+	for buflen := rlen; ; buflen *= 2 {
+		buf, err = C.reallocf(buf, C.size_t(buflen))
+		if buf == nil {
+			return 0, err
+		}
+		rlen, err = C.proc_pidinfo(pid, C.PROC_PIDLISTFDS, 0, buf, buflen)
+		if rlen <= 0 {
+			return 0, err
+		} else if rlen == buflen {
+			continue
+		}
+		return int(rlen / C.PROC_PIDLISTFD_SIZE), nil
+	}
+	panic("unreachable")
+}
diff --git a/fdtrack/fdusage_linux.go b/fdtrack/fdusage_linux.go
new file mode 100644
index 000000000..d9a856a0c
--- /dev/null
+++ b/fdtrack/fdusage_linux.go
@@ -0,0 +1,53 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build linux
+
+package fdtrack
+
+import (
+	"io"
+	"os"
+	"syscall"
+)
+
+func fdlimit() int {
+	var nofile syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &nofile); err != nil {
+		return 0
+	}
+	return int(nofile.Cur)
+}
+
+func fdusage() (int, error) {
+	f, err := os.Open("/proc/self/fd")
+	if err != nil {
+		return 0, err
+	}
+	defer f.Close()
+	const batchSize = 100
+	n := 0
+	for {
+		list, err := f.Readdirnames(batchSize)
+		n += len(list)
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return 0, err
+		}
+	}
+	return n, nil
+}
diff --git a/p2p/dial.go b/p2p/dial.go
index 0fd3a4cf5..8b210bacd 100644
--- a/p2p/dial.go
+++ b/p2p/dial.go
@@ -23,6 +23,7 @@ import (
 	"net"
 	"time"
 
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/p2p/discover"
@@ -212,6 +213,7 @@ func (t *dialTask) Do(srv *Server) {
 		glog.V(logger.Detail).Infof("dial error: %v", err)
 		return
 	}
+	fd = fdtrack.WrapConn("p2p", fd)
 	mfd := newMeteredConn(fd, false)
 
 	srv.setupConn(mfd, t.flags, t.dest)
diff --git a/p2p/discover/udp.go b/p2p/discover/udp.go
index 4e6ecaf23..d7ca9000d 100644
--- a/p2p/discover/udp.go
+++ b/p2p/discover/udp.go
@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/p2p/nat"
@@ -197,6 +198,7 @@ func ListenUDP(priv *ecdsa.PrivateKey, laddr string, natm nat.Interface, nodeDBP
 	if err != nil {
 		return nil, err
 	}
+	fdtrack.Open("p2p")
 	conn, err := net.ListenUDP("udp", addr)
 	if err != nil {
 		return nil, err
@@ -234,6 +236,7 @@ func newUDP(priv *ecdsa.PrivateKey, c conn, natm nat.Interface, nodeDBPath strin
 
 func (t *udp) close() {
 	close(t.closing)
+	fdtrack.Close("p2p")
 	t.conn.Close()
 	// TODO: wait for the loops to end.
 }
diff --git a/p2p/metrics.go b/p2p/metrics.go
index f98cac274..8ee4ed04b 100644
--- a/p2p/metrics.go
+++ b/p2p/metrics.go
@@ -34,7 +34,7 @@ var (
 // meteredConn is a wrapper around a network TCP connection that meters both the
 // inbound and outbound network traffic.
 type meteredConn struct {
-	*net.TCPConn // Network connection to wrap with metering
+	net.Conn
 }
 
 // newMeteredConn creates a new metered connection, also bumping the ingress or
@@ -45,13 +45,13 @@ func newMeteredConn(conn net.Conn, ingress bool) net.Conn {
 	} else {
 		egressConnectMeter.Mark(1)
 	}
-	return &meteredConn{conn.(*net.TCPConn)}
+	return &meteredConn{conn}
 }
 
 // Read delegates a network read to the underlying connection, bumping the ingress
 // traffic meter along the way.
 func (c *meteredConn) Read(b []byte) (n int, err error) {
-	n, err = c.TCPConn.Read(b)
+	n, err = c.Conn.Read(b)
 	ingressTrafficMeter.Mark(int64(n))
 	return
 }
@@ -59,7 +59,7 @@ func (c *meteredConn) Read(b []byte) (n int, err error) {
 // Write delegates a network write to the underlying connection, bumping the
 // egress traffic meter along the way.
 func (c *meteredConn) Write(b []byte) (n int, err error) {
-	n, err = c.TCPConn.Write(b)
+	n, err = c.Conn.Write(b)
 	egressTrafficMeter.Mark(int64(n))
 	return
 }
diff --git a/p2p/server.go b/p2p/server.go
index ba83c5503..7351a2654 100644
--- a/p2p/server.go
+++ b/p2p/server.go
@@ -25,6 +25,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/p2p/discover"
@@ -372,7 +373,7 @@ func (srv *Server) startListening() error {
 	}
 	laddr := listener.Addr().(*net.TCPAddr)
 	srv.ListenAddr = laddr.String()
-	srv.listener = listener
+	srv.listener = fdtrack.WrapListener("p2p", listener)
 	srv.loopWG.Add(1)
 	go srv.listenLoop()
 	// Map the TCP listening port if NAT is configured.
diff --git a/rpc/comms/http.go b/rpc/comms/http.go
index c165aa27e..c08b744a1 100644
--- a/rpc/comms/http.go
+++ b/rpc/comms/http.go
@@ -29,6 +29,7 @@ import (
 	"io"
 	"io/ioutil"
 
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/rpc/codec"
@@ -177,6 +178,7 @@ func listenHTTP(addr string, h http.Handler) (*stopServer, error) {
 	if err != nil {
 		return nil, err
 	}
+	l = fdtrack.WrapListener("rpc", l)
 	s := &stopServer{l: l, idle: make(map[net.Conn]struct{})}
 	s.Server = &http.Server{
 		Addr:         addr,
diff --git a/rpc/comms/ipc_unix.go b/rpc/comms/ipc_unix.go
index aff90cfaa..432bf93b5 100644
--- a/rpc/comms/ipc_unix.go
+++ b/rpc/comms/ipc_unix.go
@@ -22,6 +22,7 @@ import (
 	"net"
 	"os"
 
+	"github.com/ethereum/go-ethereum/fdtrack"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/rpc/codec"
@@ -50,15 +51,16 @@ func (self *ipcClient) reconnect() error {
 func startIpc(cfg IpcConfig, codec codec.Codec, api shared.EthereumApi) error {
 	os.Remove(cfg.Endpoint) // in case it still exists from a previous run
 
-	l, err := net.ListenUnix("unix", &net.UnixAddr{Name: cfg.Endpoint, Net: "unix"})
+	l, err := net.Listen("unix", cfg.Endpoint)
 	if err != nil {
 		return err
 	}
+	l = fdtrack.WrapListener("ipc", l)
 	os.Chmod(cfg.Endpoint, 0600)
 
 	go func() {
 		for {
-			conn, err := l.AcceptUnix()
+			conn, err := l.Accept()
 			if err != nil {
 				glog.V(logger.Error).Infof("Error accepting ipc connection - %v\n", err)
 				continue