path: root/internal/debug/flags.go

// Copyright 2016 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 debug

import (
    "fmt"
    "net/http"
    _ "net/http/pprof"
    "runtime"

    "github.com/codegangsta/cli"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
)

var (
    verbosityFlag = cli.GenericFlag{
        Name:  "verbosity",
        Usage: "Logging verbosity: 0=silent, 1=error, 2=warn, 3=info, 4=core, 5=debug, 6=detail",
        Value: glog.GetVerbosity(),
    }
    vmoduleFlag = cli.GenericFlag{
        Name:  "vmodule",
        Usage: "Per-module verbosity: comma-separated list of <pattern>=<level> (e.g. eth/*=6,p2p=5)",
        Value: glog.GetVModule(),
    }
    backtraceAtFlag = cli.GenericFlag{
        Name:  "backtrace",
        Usage: "Request a stack trace at a specific logging statement (e.g. \"block.go:271\")",
        Value: glog.GetTraceLocation(),
    }
    pprofFlag = cli.BoolFlag{
        Name:  "pprof",
        Usage: "Enable the pprof HTTP server",
    }
    pprofPortFlag = cli.IntFlag{
        Name:  "pprofport",
        Usage: "pprof HTTP server listening port",
        Value: 6060,
    }
    memprofilerateFlag = cli.IntFlag{
        Name:  "memprofilerate",
        Usage: "Turn on memory profiling with the given rate",
        Value: runtime.MemProfileRate,
    }
    blockprofilerateFlag = cli.IntFlag{
        Name:  "blockprofilerate",
        Usage: "Turn on block profiling with the given rate",
    }
    cpuprofileFlag = cli.StringFlag{
        Name:  "cpuprofile",
        Usage: "Write CPU profile to the given file",
    }
    traceFlag = cli.StringFlag{
        Name:  "trace",
        Usage: "Write execution trace to the given file",
    }
)

// Flags holds all command-line flags required for debugging.
var Flags = []cli.Flag{
    verbosityFlag, vmoduleFlag, backtraceAtFlag,
    pprofFlag, pprofPortFlag,
    memprofilerateFlag, blockprofilerateFlag, cpuprofileFlag, traceFlag,
}

// Setup initializes profiling and logging based on the CLI flags.
// It should be called as early as possible in the program.
func Setup(ctx *cli.Context) error {
    // logging
    glog.CopyStandardLogTo("INFO")
    glog.SetToStderr(true)

    // profiling, tracing
    runtime.MemProfileRate = ctx.GlobalInt(memprofilerateFlag.Name)
    Handler.SetBlockProfileRate(ctx.GlobalInt(blockprofilerateFlag.Name))
    if traceFile := ctx.GlobalString(traceFlag.Name); traceFile != "" {
        if err := Handler.StartGoTrace(traceFile); err != nil {
            return err
        }
    }
    if cpuFile := ctx.GlobalString(cpuprofileFlag.Name); cpuFile != "" {
        if err := Handler.StartCPUProfile(cpuFile); err != nil {
            return err
        }
    }

    // pprof server
    if ctx.GlobalBool(pprofFlag.Name) {
        address := fmt.Sprintf("127.0.0.1:%d", ctx.GlobalInt(pprofPortFlag.Name))
        go func() {
            glog.V(logger.Info).Infof("starting pprof server at http://%s/debug/pprof", address)
            glog.Errorln(http.ListenAndServe(address, nil))
        }()
    }
    return nil
}

// Exit stops all running profiles, flushing their output to the
// respective file.
func Exit() {
    Handler.StopCPUProfile()
    Handler.StopGoTrace()
}