AIX: implement num_ctx_switches (#1164)

* small changes

* AIX: implement num_ctx_switches

1 files changed, 42 insertions, 2 deletions

diff --git a/psutil/_psutil_aix.c b/psutil/_psutil_aix.c
index 8ffc8f47..0834726d 100644
--- a/psutil/_psutil_aix.c
+++ b/psutil/_psutil_aix.c
@@ -4,16 +4,16 @@
  * All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
- /*
+ */
 
 /*
  * AIX support is experimental at this time.
  * The following functions and methods are unsupported on the AIX platform:
  * - psutil.Process.memory_maps
- * - psutil.Process.num_ctx_switches
  *
  * Known limitations:
  * - psutil.Process.io_counters read count is always 0
+ * - psutil.Process.threads may not be available on older AIX versions
  * - reading basic process info may fail or return incorrect values when
  *   process is starting (see IBM APAR IV58499 - fixed in newer AIX versions)
  * - sockets and pipes may not be counted in num_fds (fixed in newer AIX
@@ -49,6 +49,7 @@
 
 #include "arch/aix/ifaddrs.h"
 #include "arch/aix/net_connections.h"
+#include "arch/aix/common.h"
 #include "_psutil_common.h"
 #include "_psutil_posix.h"
 
@@ -308,6 +309,43 @@ psutil_proc_cred(PyObject *self, PyObject *args) {
 
 
 /*
+ * Return process voluntary and involuntary context switches as a Python tuple.
+ */
+static PyObject *
+psutil_proc_num_ctx_switches(PyObject *self, PyObject *args) {
+    PyObject *py_tuple = NULL;
+    pid32_t requested_pid;
+    pid32_t pid = 0;
+    int np = 0;
+    struct procentry64 *processes = (struct procentry64 *)NULL;
+    struct procentry64 *p;
+
+    if (! PyArg_ParseTuple(args, "i", &requested_pid))
+        return NULL;
+
+    processes = psutil_read_process_table(&np);
+    if (!processes)
+        return NULL;
+
+    /* Loop through processes */
+    for (p = processes; np > 0; np--, p++) {
+        pid = p->pi_pid;
+        if (requested_pid != pid)
+            continue;
+        py_tuple = Py_BuildValue("LL",
+            (long long) p->pi_ru.ru_nvcsw,    /* voluntary context switches */
+            (long long) p->pi_ru.ru_nivcsw);  /* involuntary */
+        free(processes);
+        return py_tuple;
+    }
+
+    /* finished iteration without finding requested pid */
+    free(processes);
+    return NoSuchProcess();
+}
+
+
+/*
  * Return users currently connected on the system.
  */
 static PyObject *
@@ -833,6 +871,8 @@ PsutilMethods[] =
 #endif
     {"proc_io_counters", psutil_proc_io_counters, METH_VARARGS,
      "Get process I/O counters."},
+    {"proc_num_ctx_switches", psutil_proc_num_ctx_switches, METH_VARARGS,
+     "Get process I/O counters."},
 
     // --- system-related functions
     {"users", psutil_users, METH_VARARGS,