If the code is performance sensitive, then you want to use a Buffer, and you‘ll need to serialize access. Otherwise each log line write will be a sys call - but depending on your use case that may be acceptable.
> On Jul 21, 2019, at 1:17 PM, Ian Lance Taylor <i...@golang.org> wrote: > > On Sun, Jul 21, 2019 at 7:11 AM dev null <dev.null.dum...@gmail.com > <mailto:dev.null.dum...@gmail.com>> wrote: >> >> Hi folks, >> I have a program that has a function that appends data to the file - like a >> log appender appending to a file. >> I open the file in append only mode >> >> logFileWriter, err := os.OpenFile(file, os.O_CREATE|os.O_WRONLY|os.O_APPEND, >> 0755) >> >> and then there is a function to write to the file, which has simple code >> >> logFileWriter.Write(logLine) >> >> In the overall program, there are multiple go routines that will call this >> function to append log lines. My understanding is that there is need to >> protect this function using mutex because eventually at the syscall level >> they would be serialized anyway. its not possible that partial writes will >> happen (ignore crashes of the computer in the middle of writes etc. because >> mutex won't help anyway there). > > I'm guessing that you meant to write "there is no need to protect". > > To the best of my knowledge, that is correct. Go will in effect be > handing off synchronization to the kernel, and a Unix-like kernel > should never interleave writes to a file opened in append mode. > (Assuming your file is not mounted over NFS or some other varieties of > networked file system.) (I should add that I'm only asserting this > for Unix-like kernels, I'm not sure about Windows.) > > Ian > > -- > You received this message because you are subscribed to the Google Groups > "golang-nuts" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to golang-nuts+unsubscr...@googlegroups.com > <mailto:golang-nuts+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/golang-nuts/CAOyqgcWNBvX96faRA1kfbfudQ7q1PkB6dGHLm%2B2Y%3DmP76dAV8w%40mail.gmail.com > > <https://groups.google.com/d/msgid/golang-nuts/CAOyqgcWNBvX96faRA1kfbfudQ7q1PkB6dGHLm%2B2Y%3DmP76dAV8w%40mail.gmail.com>. -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/E88C3EED-E2B9-4B31-96B0-F6E5DE7D0D24%40ix.netcom.com.
