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1 #!/usr/bin/env python | 1 #!/usr/bin/env python |
2 # Copyright (c) 2012 The Chromium Authors. All rights reserved. | 2 # Copyright (c) 2012 The Chromium Authors. All rights reserved. |
3 # Use of this source code is governed by a BSD-style license that can be | 3 # Use of this source code is governed by a BSD-style license that can be |
4 # found in the LICENSE file. | 4 # found in the LICENSE file. |
5 | 5 |
6 """Waits for the go signal and replaces itself with the command to be run. | 6 """Executes with the command to be run and optionally waits for the go signal. |
7 | 7 |
8 Not meant to be used directly, only meant to be used by trace_inputs.py. | 8 Not meant to be used directly, only meant to be used by trace_inputs.py. |
| 9 |
| 10 This script is used by the tracer as a signal for the log parser that the child |
| 11 process is the process we care about. It is especially important on kernel based |
| 12 tracer because we want it to trace the relevant process tree. |
9 """ | 13 """ |
10 | 14 |
11 import os | |
12 import subprocess | 15 import subprocess |
13 import sys | 16 import sys |
14 | 17 |
15 | 18 |
16 def main(): | 19 def main(): |
17 signal = 'Go!' | |
18 value = sys.stdin.read(len(signal)) | |
19 assert value == signal | |
20 sys.stdin.close() | |
21 # Replace the executable with an absolute path to make it easier to grok. | |
22 cmd = sys.argv[1:] | 20 cmd = sys.argv[1:] |
23 cmd[0] = os.path.abspath(cmd[0]) | 21 if sys.argv[1] == '--wait': |
24 if cmd[0].endswith('.py'): | 22 cmd = cmd[1:] |
25 cmd.insert(0, sys.executable) | 23 signal = 'Go!' |
26 p = subprocess.Popen(cmd) | 24 value = sys.stdin.read(len(signal)) |
27 #print 'Child pid: %d' % p.pid | 25 assert value == signal |
28 p.wait() | 26 sys.stdin.close() |
29 return p.returncode | 27 |
| 28 # The reason os.execve() is not used is that we don't want the modules |
| 29 # imported here to influence the executable being traced, so we need a fresh |
| 30 # pid and need to fork. |
| 31 return subprocess.call(cmd) |
30 | 32 |
31 | 33 |
32 if __name__ == '__main__': | 34 if __name__ == '__main__': |
33 sys.exit(main()) | 35 sys.exit(main()) |
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