Windows: Fixed `WIFEXITED` and `WIFSIGNALED` stubs. The `WIFEXITED` and `WIFSIGNALED` macros were incorrectly checking if the exit code was not -1 to determine if the process exited or was signaled. However, -1 is a valid return code on Windows, so when logic like `CHECK(WIFEXITED(status)|| WIFSIGNALED(status))` was used, it would end up aborting the process accidentally.
For `WIFEXITED`, we simply return `true` because all error codes on Windows indicate the process exited (if the process instead failed to spawn, then `os::spawn()` would return `None()` instead of an exit code). For `WIFIGNALED`, we simply return `false` for similar reasons. We assume the process did not exit due to a signal, as that is not an expected scenario on Windows. Review: https://reviews.apache.org/r/65840/ Project: http://git-wip-us.apache.org/repos/asf/mesos/repo Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/ca357e95 Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/ca357e95 Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/ca357e95 Branch: refs/heads/master Commit: ca357e95f62604329dcb57076af10a86e8c25a41 Parents: 5ca0f58 Author: Akash Gupta <akash-gu...@hotmail.com> Authored: Tue Mar 6 13:11:19 2018 -0800 Committer: Andrew Schwartzmeyer <and...@schwartzmeyer.com> Committed: Tue Mar 6 13:41:49 2018 -0800 ---------------------------------------------------------------------- 3rdparty/stout/include/stout/windows.hpp | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/mesos/blob/ca357e95/3rdparty/stout/include/stout/windows.hpp ---------------------------------------------------------------------- diff --git a/3rdparty/stout/include/stout/windows.hpp b/3rdparty/stout/include/stout/windows.hpp index 8f7817a..1bfcdf4 100644 --- a/3rdparty/stout/include/stout/windows.hpp +++ b/3rdparty/stout/include/stout/windows.hpp @@ -364,10 +364,13 @@ inline const char* strsignal(int signum) #define SIGPIPE 100 -// `os::system` returns -1 if the processor cannot be started -// therefore any return value indicates the process has been started +// On Windows, the exit code, unlike Linux, is simply a 32 bit unsigned integer +// with no special encoding. Since the `status` value from `waitpid` returns a +// 32 bit integer, we can't use it to determine if the process exited normally, +// because all the possibilities could be valid exit codes. So, we assume that +// if we get an exit code, the process exited normally. #ifndef WIFEXITED -#define WIFEXITED(x) ((x) != -1) +#define WIFEXITED(x) true #endif // WIFEXITED // Returns the exit status of the child. @@ -376,8 +379,12 @@ inline const char* strsignal(int signum) #define WEXITSTATUS(x) static_cast<DWORD>(x) #endif // WEXITSTATUS +// A signaled Windows process always exits with status code 3, but it's +// impossible to distinguish that from a process that exits normally with +// status code 3. Since signals aren't really used on Windows, we will +// assume that the process is not signaled. #ifndef WIFSIGNALED -#define WIFSIGNALED(x) ((x) != -1) +#define WIFSIGNALED(x) false #endif // WIFSIGNALED // Specifies that `::waitpid` should return immediately rather than
