tools/rb/find_leakers.py

   1 #!/usr/bin/python
   2 #
   3 # This Source Code Form is subject to the terms of the Mozilla Public
   4 # License, v. 2.0. If a copy of the MPL was not distributed with this
   5 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
   6
   7 # This script processes a `refcount' log, and finds out if any object leaked.
   8 # It simply goes through the log, finds `AddRef' or `Ctor' lines, and then
   9 # sees if they `Release' or `Dtor'. If not, it reports them as leaks.
  10 # Please see README file in the same directory.
  11
  12 import sys
  13
  14 import six
  15
  16
  17 def print_output(allocation, obj_to_class):
  18     """Formats and prints output."""
  19     items = []
  20     for (
  21         obj,
  22         count,
  23     ) in six.iteritems(allocation):
  24         # Adding items to a list, so we can sort them.
  25         items.append((obj, count))
  26     # Sorting by count.
  27     items.sort(key=lambda item: item[1])
  28
  29     for (
  30         obj,
  31         count,
  32     ) in items:
  33         print(
  34             "{obj} ({count}) @ {class_name}".format(
  35                 obj=obj, count=count, class_name=obj_to_class[obj]
  36             )
  37         )
  38
  39
  40 def process_log(log_lines):
  41     """Process through the log lines, and print out the result.
  42
  43     @param log_lines: List of strings.
  44     """
  45     allocation = {}
  46     class_count = {}
  47     obj_to_class = {}
  48
  49     for log_line in log_lines:
  50         if not log_line.startswith("<"):
  51             continue
  52
  53         (
  54             class_name,
  55             obj,
  56             ignore,
  57             operation,
  58             count,
  59         ) = log_line.strip("\r\n").split(
  60             " "
  61         )[:5]
  62
  63         # for AddRef/Release `count' is the refcount,
  64         # for Ctor/Dtor it's the size.
  65
  66         if (operation == "AddRef" and count == "1") or operation == "Ctor":
  67             # Examples:
  68             #     <nsStringBuffer> 0x01AFD3B8 1 AddRef 1
  69             #     <PStreamNotifyParent> 0x08880BD0 8 Ctor (20)
  70             class_count[class_name] = class_count.setdefault(class_name, 0) + 1
  71             allocation[obj] = class_count[class_name]
  72             obj_to_class[obj] = class_name
  73
  74         elif (operation == "Release" and count == "0") or operation == "Dtor":
  75             # Examples:
  76             #     <nsStringBuffer> 0x01AFD3B8 1 Release 0
  77             #     <PStreamNotifyParent> 0x08880BD0 8 Dtor (20)
  78             if obj not in allocation:
  79                 print(
  80                     "An object was released that wasn't allocated!",
  81                 )
  82                 print(obj, "@", class_name)
  83             else:
  84                 allocation.pop(obj)
  85             obj_to_class.pop(obj)
  86
  87     # Printing out the result.
  88     print_output(allocation, obj_to_class)
  89
  90
  91 def print_usage():
  92     print("")
  93     print("Usage: find-leakers.py [log-file]")
  94     print("")
  95     print("If `log-file' provided, it will read that as the input log.")
  96     print("Else, it will read the stdin as the input log.")
  97     print("")
  98
  99
 100 def main():
 101     """Main method of the script."""
 102     if len(sys.argv) == 1:
 103         # Reading log from stdin.
 104         process_log(sys.stdin.readlines())
 105     elif len(sys.argv) == 2:
 106         # Reading log from file.
 107         with open(sys.argv[1], "r") as log_file:
 108             log_lines = log_file.readlines()
 109         process_log(log_lines)
 110     else:
 111         print("ERROR: Invalid number of arguments")
 112         print_usage()
 113
 114
 115 if __name__ == "__main__":
 116     main()