cafe-grader-judge-scripts

Commit r109:f75d1acc9cdd public

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Description:
fixed bug in dir_init teardown (wrong log filename)
Commit status:
[Not Reviewed]
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r109:f75d1acc9cdd - - 1 file changed: 6 inserted, 2 deleted

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@@ -1,109 +1,113
1 require 'ftools'
1 require 'ftools'
2
2
3 # DirInit::Manager handles directory initialization and clean-up when
3 # DirInit::Manager handles directory initialization and clean-up when
4 # there are many concurrent processes that wants to modify the
4 # there are many concurrent processes that wants to modify the
5 # directory in the same way.
5 # directory in the same way.
6 #
6 #
7 # An example usage is when each process wants to copy some temporary
7 # An example usage is when each process wants to copy some temporary
8 # files to the directory and delete these files after finishing its
8 # files to the directory and delete these files after finishing its
9 # job. Problems may occur when the first process delete the files
9 # job. Problems may occur when the first process delete the files
10 # while the second process is still using the files.
10 # while the second process is still using the files.
11 #
11 #
12 # This library maintain a reference counter on the processes using the
12 # This library maintain a reference counter on the processes using the
13 # directory. It locks the dir to manage critical section when
13 # directory. It locks the dir to manage critical section when
14 # updating the reference counter.
14 # updating the reference counter.
15
15
16 module DirInit
16 module DirInit
17
17
18 class Manager
18 class Manager
19
19
20 def initialize(dir_name, usage_filename='.usage_counter')
20 def initialize(dir_name, usage_filename='.usage_counter')
21 @dir_name = dir_name
21 @dir_name = dir_name
22 @usage_filename = usage_filename
22 @usage_filename = usage_filename
23 end
23 end
24
24
25 + def lock_filename
26 + return @dir_name + '/lockfile'
27 + end
28 +
25 # Check if someone has initialized the dir. If not, call block.
29 # Check if someone has initialized the dir. If not, call block.
26
30
27 def setup # :yields: block
31 def setup # :yields: block
28 - dir = File.new(@dir_name + '/lockfile',"w+")
32 + dir = File.new(lock_filename,"w+")
29 dir.flock(File::LOCK_EX)
33 dir.flock(File::LOCK_EX)
30 begin
34 begin
31 counter_filename = get_counter_filename
35 counter_filename = get_counter_filename
32 if File.exist? counter_filename
36 if File.exist? counter_filename
33 # someone is here
37 # someone is here
34 f = File.new(counter_filename,"r+")
38 f = File.new(counter_filename,"r+")
35 counter = f.read.to_i
39 counter = f.read.to_i
36 f.seek(0)
40 f.seek(0)
37 f.write("#{counter+1}\n")
41 f.write("#{counter+1}\n")
38 f.close
42 f.close
39 else
43 else
40 # i'm the first, create the counter file
44 # i'm the first, create the counter file
41 counter = 0
45 counter = 0
42 f = File.new(counter_filename,"w")
46 f = File.new(counter_filename,"w")
43 f.write("1\n")
47 f.write("1\n")
44 f.close
48 f.close
45 end
49 end
46
50
47 # if no one is here
51 # if no one is here
48 if counter == 0
52 if counter == 0
49 if block_given?
53 if block_given?
50 yield
54 yield
51 end
55 end
52 end
56 end
53
57
54 rescue
58 rescue
55 raise
59 raise
56
60
57 ensure
61 ensure
58 # make sure it unlock the directory
62 # make sure it unlock the directory
59 dir.flock(File::LOCK_UN)
63 dir.flock(File::LOCK_UN)
60 dir.close
64 dir.close
61 end
65 end
62 end
66 end
63
67
64 # Check if I am the last one using the dir. If true, call block.
68 # Check if I am the last one using the dir. If true, call block.
65
69
66 def teardown
70 def teardown
67 - dir = File.new(@dir_name)
71 + dir = File.new(lock_filename)
68 dir.flock(File::LOCK_EX)
72 dir.flock(File::LOCK_EX)
69 begin
73 begin
70 counter_filename = get_counter_filename
74 counter_filename = get_counter_filename
71 if File.exist? counter_filename
75 if File.exist? counter_filename
72 # someone is here
76 # someone is here
73 f = File.new(counter_filename,"r+")
77 f = File.new(counter_filename,"r+")
74 counter = f.read.to_i
78 counter = f.read.to_i
75 f.seek(0)
79 f.seek(0)
76 f.write("#{counter-1}\n")
80 f.write("#{counter-1}\n")
77 f.close
81 f.close
78
82
79 if counter == 1
83 if counter == 1
80 # i'm the last one
84 # i'm the last one
81
85
82 File.delete(counter_filename)
86 File.delete(counter_filename)
83 if block_given?
87 if block_given?
84 yield
88 yield
85 end
89 end
86 end
90 end
87 else
91 else
88 # This is BAD
92 # This is BAD
89 raise "Error: reference count missing"
93 raise "Error: reference count missing"
90 end
94 end
91
95
92 rescue
96 rescue
93 raise
97 raise
94
98
95 ensure
99 ensure
96 # make sure it unlock the directory
100 # make sure it unlock the directory
97 dir.flock(File::LOCK_UN)
101 dir.flock(File::LOCK_UN)
98 dir.close
102 dir.close
99 end
103 end
100 end
104 end
101
105
102 protected
106 protected
103
107
104 def get_counter_filename
108 def get_counter_filename
105 return File.join(@dir_name,@usage_filename)
109 return File.join(@dir_name,@usage_filename)
106 end
110 end
107
111
108 end
112 end
109 end
113 end
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