code: public static int getNumCores() {
          class CpuFilter implements FileFilter {
              @Override
              public boolean accept(File pathname) {
                  return Pattern.matches("cpu[0-9]", pathname.getName());
              }
          }
  
          if (sCoreNum == 0) {
              try {
                  // Get directory containing CPU info
                  File dir = new File("/sys/devices/system/cpu/");
                  // Filter to only list the devices we care about
                  File[] files = dir.listFiles(new CpuFilter());
                  // Return the number of cores (virtual CPU devices)
                  sCoreNum = files.length;
              } catch (Exception e) {
                  Log.e(TAG, "getNumCores exception", e);
                  sCoreNum = 1;
              }
          }
          return sCoreNum;
      }
docs: Get cpu core number
  
  @return int cpu core number