Fix IsProcessRunning on Windows (#335)

IsProcessRunning on Windows would only consider if we could get a handle to a process.  It is possible to get a handle to a process even if it is terminated in Windows.  To actually know if the process is running, a further call to GetExitCodeProces is required.  Addressing this issue ensures that the ZenServerState::Sweep method doesn't keep terminated processes in the state table.

1 files changed, 12 insertions, 1 deletions

diff --git a/src/zencore/thread.cpp b/src/zencore/thread.cpp
index 67a0878d0..a44c0ee90 100644
--- a/src/zencore/thread.cpp
+++ b/src/zencore/thread.cpp
@@ -1065,9 +1065,20 @@ IsProcessRunning(int pid)
 		ThrowSystemError(Error, fmt::format("failed to open process with pid {}", pid));
 	}
 
+	bool  bStillActive = true;
+	DWORD ExitCode	   = 0;
+	if (0 != GetExitCodeProcess(hProc, &ExitCode))
+	{
+		bStillActive = ExitCode == STILL_ACTIVE;
+	}
+	else
+	{
+		ZEN_WARN("Unable to get exit code from handle for process '{}', treating the process as active", pid);
+	}
+
 	CloseHandle(hProc);
 
-	return true;
+	return bStillActive;
 #elif ZEN_PLATFORM_LINUX || ZEN_PLATFORM_MAC
 	return (kill(pid_t(pid), 0) == 0);
 #endif