On Tue, 13 Nov 2012 23:42:08 +0100, Yakov Galka <ybungalobill@gmail.com> wrote:
[...]Now, consider the following execution order: A1, B1, A2, B2, A3, B3. The result is that the write-end of the pipe of b.exe is inherited by a.exe too (i.e. 'leaked' into a.exe). b.exe exits, closing its write-end of the pipe. However, a.exe still holds (indefinitely) the write-end of b's pipe! Result: thread B will hang until the unrelated process a.exe exits (and perhaps all the children that a.exe created in its own turn).
On Windows create_pipe() creates non-inheritable handles for the pipe. They only become inheritable when an initializer like bind_stdout is used. Do you think this solves the problem you outlined? On POSIX one could use initializers like close_fds or close_fds_if to explicitly close file descriptors for child processes. Then no "leak" should be possible either. I don't know whether that would be enough to turn Boost.Process into a thread-safe library (I didn't think about thread-safety yet). But then your example could be worth adding to the FAQ? Boris
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