utils/bisect-skip-count

   1 #!/usr/bin/env python
   2 # This script is used to bisect skip and count arguments for --debug-counter.
   3 # It is similar to bisect, except it understands how to increase skip and decrease count
   4 #
   5 # Typical usage:
   6 #
   7 # bisect-skip-count bisect-command.sh "%(skip)d" "%(count)d" 2>&1 | tee bisect.out
   8 #
   9 # bisect-command.sh is something like this:
  10 # #! /bin/bash
  11 #
  12 # skip=$1
  13 # count=$2
  14 #
  15 # opt -debug-counter=my-counter-skip=${skip},my-counter-count=${count}
  16 # ... Test output of opt and exit zero for pass, non-zero for fail
  17 #
  18 # Examine bisect.out to look for "Last good skip" and "Last good
  19 # count" to find the values of the counter that produce a passing
  20 # result.  Incrementing the last good count by one or decrementing the
  21 # last good skip by one should produce a failure.
  22 #
  23 import os
  24 import sys
  25 import argparse
  26 # This is for timeout support. Use the recommended way of import.
  27 # We do timeouts because when doing, execution testing, we have a habit
  28 # of finding variants that infinite loop
  29 if os.name == 'posix' and sys.version_info[0] < 3:
  30   import subprocess32 as subprocess
  31 else:
  32   import subprocess
  33 parser = argparse.ArgumentParser()
  34
  35 parser.add_argument('--skipstart', type=int, default=0)
  36 parser.add_argument('--skipend', type=int, default=(1 << 32))
  37 parser.add_argument('--countstart', type=int, default=0)
  38 parser.add_argument('--countend', type=int, default=(1 << 32))
  39 parser.add_argument('--timeout', type=int, default=None)
  40 # Use shell support if you need to use complex shell expressions in your command
  41 parser.add_argument('--shell', type=bool, default=False)
  42 parser.add_argument('command', nargs='+')
  43
  44 args = parser.parse_args()
  45
  46 start = args.skipstart
  47 end = args.skipend
  48
  49 print("Bisect of Skip starting!")
  50 print("Start: %d" % start)
  51 print("End: %d" % end)
  52
  53 last = None
  54 while start != end and start != end-1:
  55     count = start + (end - start)/2
  56     print("Visiting Skip: %d with (Start, End) = (%d,%d)" % (count, start, end))
  57     cmd = [x % {'skip':count, 'count':-1} for x in args.command]
  58     print cmd
  59     try:
  60         result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
  61         if result == 0:
  62            print("    PASSES! Setting end to count")
  63            end = count
  64         else:
  65            print("    FAILS! Setting start to count")
  66            start = count
  67     except:
  68         print(" TIMEOUT, setting end to count")
  69         end = count
  70 firstcount = start
  71 print("Last good skip: %d" % start)
  72 start = args.countstart
  73 end = args.countend
  74 print("Bisect of Count starting!")
  75 print("Start: %d" % start)
  76 print("End: %d" % end)
  77 while start != end and start != end-1:
  78     count = start + (end - start)/2
  79     print("Visiting Count: %d with (Start, End) = (%d,%d)" % (count, start, end))
  80     cmd = [x % {'count':count, 'skip':firstcount } for x in args.command]
  81     print cmd
  82     try:
  83         result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
  84         if result == 0:
  85            print("    PASSES! Setting start to count")
  86            start = count
  87         else:
  88            print("    FAILS! Setting end to count")
  89            end = count
  90     except:
  91         print(" TIMEOUT, setting start to count")
  92         start = count
  93
  94 print("Last good count: %d" % start)