// The ``runtime.GetCPUCount`` function tries to detect the number of CPUs on
// the current machine.
func GetCPUCount() (count int) {
// On BSD systems, it should be possible to use ``sysctl -n hw.ncpu`` to
// figure this out.
if (Platform == "darwin") || (Platform == "freebsd") {
output, err := command.GetOutput(
[]string{"/usr/sbin/sysctl", "-n", "hw.ncpu"},
)
if err != nil {
return 1
}
count, err = strconv.Atoi(strings.TrimSpace(output))
if err != nil {
return 1
}
// Linux systems provide introspection via ``/proc/cpuinfo``.
} else if Platform == "linux" {
output, err := command.GetOutput([]string{"/bin/cat", "/proc/cpuinfo"})
if err != nil {
return 1
}
for _, line := range strings.Split(output, "\n") {
if strings.HasPrefix(line, "processor") {
count += 1
}
}
}
// For unknown platforms, we assume that there's just a single processor.
if count == 0 {
return 1
}
return count
}
// Try and figure out the number of CPUs on the current machine
func GetCPUCount() (count int) {
if (Platform == "darwin") || (Platform == "freebsd") {
output, err := command.GetOutput([]string{"/usr/sbin/sysctl", "-n", "hw.ncpu"})
if err != nil {
return 1
}
count, err = strconv.Atoi(strings.TrimSpace(output))
if err != nil {
return 1
}
} else if Platform == "linux" {
output, err := command.GetOutput([]string{"/bin/cat", "/proc/cpuinfo"})
if err != nil {
return 1
}
for _, line := range strings.Split(output, "\n", 0) {
if strings.HasPrefix(line, "processor") {
count += 1
}
}
}
if count == 0 {
return 1
}
return count
}
func TestCPUCount(t *testing.T) {
cpus := GetCPUCount()
output, err := command.GetOutput(
[]string{
os.Getenv("AMPIFY_ROOT") + "/environ/local/bin/python",
"-c",
"import multiprocessing; print multiprocessing.cpu_count()"})
if err != nil {
t.Errorf("Couldn't call Python:\n%v", err)
return
}
expected, err := strconv.Atoi(strings.TrimSpace(output))
if err != nil {
t.Errorf("Couldn't parse the output from Python:\n%v", err)
return
}
if cpus != expected {
t.Errorf("Got mis-matched CPU Counts: %d vs. %d", cpus, expected)
}
}