windows: add some C comments

2 files changed, 18 insertions, 2 deletions

diff --git a/psutil/_psutil_windows.c b/psutil/_psutil_windows.c
index 670be24c..7e6792db 100644
--- a/psutil/_psutil_windows.c
+++ b/psutil/_psutil_windows.c
@@ -2691,6 +2691,19 @@ psutil_proc_num_handles(PyObject *self, PyObject *args)
 }
 
 
+/*
+ * Get various process information by using NtQuerySystemInformation.
+ * We use this as a fallback when faster functions fail with access
+ * denied. This is slower because it iterates over all processes.
+ * Returned tuple includes the following process info:
+ *
+ * - num_threads
+ * - ctx_switches
+ * - num_handles (fallback)
+ * - user/kernel times (fallback)
+ * - create time (fallback)
+ * - io counters (fallback)
+ */
 static PyObject *
 psutil_proc_info(PyObject *self, PyObject *args)
 {
@@ -3395,4 +3408,4 @@ void init_psutil_windows(void)
 #if PY_MAJOR_VERSION >= 3
     return module;
 #endif
-}
\ No newline at end of file
+}
diff --git a/psutil/arch/windows/process_info.c b/psutil/arch/windows/process_info.c
index ad272bff..a59cce47 100644
--- a/psutil/arch/windows/process_info.c
+++ b/psutil/arch/windows/process_info.c
@@ -357,7 +357,10 @@ const int STATUS_BUFFER_TOO_SMALL = 0xC0000023L;
 
 /*
  * Given a process PID and a PSYSTEM_PROCESS_INFORMATION structure
- * fills the structure with process information.
+ * fills the structure with various process information by using
+ * NtQuerySystemInformation.
+ * We use this as a fallback when faster functions fail with access
+ * denied. This is slower because it iterates over all processes.
  * On success return 1, else 0 with Python exception already set.
  */
 int