github.com/epfl-dcsl/gotee@v0.0.0-20200909122901-014b35f5e5e9/src/gnet/sock_linux.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package gnet
     6  
     7  import (
     8  	"runtime"
     9  	"syscall"
    10  )
    11  
    12  func maxListenerBacklog() int {
    13  	//TODO @aghosn, quick fix for debugging.
    14  	if runtime.IsEnclave() {
    15  		return 128
    16  	}
    17  	fd, err := open("/proc/sys/net/core/somaxconn")
    18  	if err != nil {
    19  		return syscall.SOMAXCONN
    20  	}
    21  	defer fd.close()
    22  	l, ok := fd.readLine()
    23  	if !ok {
    24  		return syscall.SOMAXCONN
    25  	}
    26  	f := getFields(l)
    27  	n, _, ok := dtoi(f[0])
    28  	if n == 0 || !ok {
    29  		return syscall.SOMAXCONN
    30  	}
    31  	// Linux stores the backlog in a uint16.
    32  	// Truncate number to avoid wrapping.
    33  	// See issue 5030.
    34  	if n > 1<<16-1 {
    35  		n = 1<<16 - 1
    36  	}
    37  	return n
    38  }