Re: [libvirt] [PATCH v1 2/2] command: Change virCommandAddEnv so it replaces existing environment variables.

On Mon, Sep 24, 2012 at 02:07:36PM -0600, Eric Blake wrote: > On 09/24/2012 01:53 PM, Richard W.M. Jones wrote: > >>>> + /* Search for the name in the existing environment. */ >>>> + namelen = strcspn(env, "="); >>> >>> Would 'strchr(env, '=') - env' be any more efficient? But that's a >>> micro-optimization, probably not worth worrying about. >> >> I guess I trust glibc or gcc to have these string primitives >> optimized better than I could. > > Ah, but glibc is open source, so we can check for ourselves:

> That is, you are definitely wasting time pre-computing the reject table, > compared to doing a strchr() for the one rejection.

Possibly, if we weren't just about to spend 100000 cycles doing a fork. Now, a project to rewrite all Python utilities in Linux in a compiled high-level language like OCaml, there's something I could get behind :-)

Unfortunately this patch does not fix the bug, but it now fails in a different, and stranger way: libvir: error : libvirtd quit during handshake: Input/output error In this code: if ((rv = saferead(cmd->handshakeNotify[0], &c, sizeof(c))) != sizeof(c)) { if (rv < 0) virReportSystemError(errno, "%s", _("Unable to wait on parent process")); else virReportSystemError(EIO, "%s", _("libvirtd quit during handshake")); return -1; }