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 from __future__ import print_function
  24 import os
  25 import sys
  26 import argparse
  27 # This is for timeout support. Use the recommended way of import.
  28 # We do timeouts because when doing, execution testing, we have a habit
  29 # of finding variants that infinite loop
  30 if os.name == 'posix' and sys.version_info[0] < 3:
  31   import subprocess32 as subprocess
  32 else:
  33   import subprocess
  34 parser = argparse.ArgumentParser()
  35
  36 parser.add_argument('--skipstart', type=int, default=0)
  37 parser.add_argument('--skipend', type=int, default=(1 << 32))
  38 parser.add_argument('--countstart', type=int, default=0)
  39 parser.add_argument('--countend', type=int, default=(1 << 32))
  40 parser.add_argument('--timeout', type=int, default=None)
  41 # Use shell support if you need to use complex shell expressions in your command
  42 parser.add_argument('--shell', type=bool, default=False)
  43 parser.add_argument('command', nargs='+')
  44
  45 args = parser.parse_args()
  46
  47 start = args.skipstart
  48 end = args.skipend
  49
  50 print("Bisect of Skip starting!")
  51 print("Start: %d" % start)
  52 print("End: %d" % end)
  53
  54 last = None
  55 while start != end and start != end-1:
  56     count = start + (end - start)//2
  57     print("Visiting Skip: %d with (Start, End) = (%d,%d)" % (count, start, end))
  58     cmd = [x % {'skip':count, 'count':-1} for x in args.command]
  59     print(cmd)
  60     try:
  61         result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
  62         if result == 0:
  63            print("    PASSES! Setting end to count")
  64            end = count
  65         else:
  66            print("    FAILS! Setting start to count")
  67            start = count
  68     except:
  69         print(" TIMEOUT, setting end to count")
  70         end = count
  71 firstcount = start
  72 print("Last good skip: %d" % start)
  73 start = args.countstart
  74 end = args.countend
  75 print("Bisect of Count starting!")
  76 print("Start: %d" % start)
  77 print("End: %d" % end)
  78 while start != end and start != end-1:
  79     count = start + (end - start)//2
  80     print("Visiting Count: %d with (Start, End) = (%d,%d)" % (count, start, end))
  81     cmd = [x % {'count':count, 'skip':firstcount } for x in args.command]
  82     print(cmd)
  83     try:
  84         result = subprocess.call(cmd, shell=args.shell, timeout=args.timeout)
  85         if result == 0:
  86            print("    PASSES! Setting start to count")
  87            start = count
  88         else:
  89            print("    FAILS! Setting end to count")
  90            end = count
  91     except:
  92         print(" TIMEOUT, setting start to count")
  93         start = count
  94
  95 print("Last good count: %d" % start)