Fix option -p 1, support -p auto

base/client.jl

@@ -270,7 +270,7 @@ let reqarg = Set(UTF8String["--home", "-H",
  # load ~/.julia_history file
  history_file = bool(opts.historyfile)
  # add processors
- if opts.nprocs > 1
+ if opts.nprocs > 0
  addprocs(opts.nprocs)
  end
  # load processes from machine file

doc/manual/getting-started.rst

@@ -115,7 +115,8 @@ those available for the ``perl`` and ``ruby`` programs::
  -J, --sysimage <file> Start up with the given system image file
  -C, --cpu-target <target> Limit usage of cpu features up to <target>
 
- -p, --procs <n> Run n local processes
+ -p, --procs {N|auto} Integer value N launches N additional local worker processes
+ 'auto' launches as many workers as the number of local cores
  --machinefile <file> Run processes on hosts listed in <file>
 
  -i Force isinteractive() to be true

ui/repl.c

@@ -56,7 +56,8 @@ static const char opts[] =
  " -J, --sysimage <file> Start up with the given system image file\n"
  " -C, --cpu-target <target> Limit usage of cpu features up to <target>\n\n"
 
- " -p, --procs <n> Run n local processes\n"
+ " -p, --procs {N|auto} Integer value N launches N additional local worker processes\n"
+ " 'auto' launches as many workers as the number of local cores\n"
  " --machinefile <file> Run processes on hosts listed in <file>\n\n"
 
  " -i Force isinteractive() to be true\n"
@@ -186,9 +187,14 @@ void parse_opts(int *argcp, char ***argvp)
  break;
  case 'p': // procs
  errno = 0;
- jl_options.nprocs = strtol(optarg, &endptr, 10);
- if (errno != 0 || optarg == endptr || *endptr != 0 || jl_options.nprocs < 1)
- jl_errorf("julia: -p,--procs=<n> must be an integer >= 1\n");
+ if (!strcmp(optarg,"auto")) {
+ jl_options.nprocs = jl_cpu_cores();
+ }
+ else {
+ jl_options.nprocs = strtol(optarg, &endptr, 10);
+ if (errno != 0 || optarg == endptr || *endptr != 0 || jl_options.nprocs < 1)
+ jl_errorf("julia: -p,--procs=<n> must be an integer >= 1\n");
+ }
  break;
  case opt_machinefile:
  jl_options.machinefile = strdup(optarg);