path: root/internal/debug/trace.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/>.

//+build go1.5

package debug

import (
    "errors"
    "os"
    "runtime/trace"

    "github.com/ethereum/go-ethereum/log"
)

// StartGoTrace turns on tracing, writing to the given file.
func (h *HandlerT) StartGoTrace(file string) error {
    h.mu.Lock()
    defer h.mu.Unlock()
    if h.traceW != nil {
        return errors.New("trace already in progress")
    }
    f, err := os.Create(expandHome(file))
    if err != nil {
        return err
    }
    if err := trace.Start(f); err != nil {
        f.Close()
        return err
    }
    h.traceW = f
    h.traceFile = file
    log.Info("Go tracing started", "dump", h.traceFile)
    return nil
}

// StopTrace stops an ongoing trace.
func (h *HandlerT) StopGoTrace() error {
    h.mu.Lock()
    defer h.mu.Unlock()
    trace.Stop()
    if h.traceW == nil {
        return errors.New("trace not in progress")
    }
    log.Info("Done writing Go trace", "dump", h.traceFile)
    h.traceW.Close()
    h.traceW = nil
    h.traceFile = ""
    return nil
}