#941: cpu frequency - windows implementation

psutil/__init__.py

@@ -181,7 +181,7 @@
     "pid_exists", "pids", "process_iter", "wait_procs",             # proc
     "virtual_memory", "swap_memory",                                # memory
     "cpu_times", "cpu_percent", "cpu_times_percent", "cpu_count",   # cpu
-    "cpu_stats", "cpu_freq",
+    "cpu_stats",  # "cpu_freq",
     "net_io_counters", "net_connections", "net_if_addrs",           # network
     "net_if_stats",
     "disk_io_counters", "disk_partitions", "disk_usage",            # disk
@@ -1869,6 +1869,8 @@ def cpu_freq():
         """
         return _psplatform.cpu_freq()
 
+    __all__.append("cpu_freq")
+
 
 # =====================================================================
 # --- system memory related functions

psutil/_psutil_windows.c

@@ -24,6 +24,7 @@
 #include <iphlpapi.h>
 #include <wtsapi32.h>
 #include <Winsvc.h>
+#include <PowrProf.h>
 
 // Link with Iphlpapi.lib
 #pragma comment(lib, "IPHLPAPI.lib")
@@ -145,6 +146,16 @@ typedef struct _MIB_UDP6TABLE_OWNER_PID {
 } MIB_UDP6TABLE_OWNER_PID, *PMIB_UDP6TABLE_OWNER_PID;
 #endif
 
+typedef struct _PROCESSOR_POWER_INFORMATION {
+   ULONG Number;
+   ULONG MaxMhz;
+   ULONG CurrentMhz;
+   ULONG MhzLimit;
+   ULONG MaxIdleState;
+   ULONG CurrentIdleState;
+} PROCESSOR_POWER_INFORMATION, *PPROCESSOR_POWER_INFORMATION;
+
+
 PIP_ADAPTER_ADDRESSES
 psutil_get_nic_addresses() {
     // allocate a 15 KB buffer to start with
@@ -3391,6 +3402,60 @@ psutil_cpu_stats(PyObject *self, PyObject *args) {
 }
 
 
+/*
+ * Return CPU frequency.
+ */
+static PyObject *
+psutil_cpu_freq(PyObject *self, PyObject *args) {
+    PROCESSOR_POWER_INFORMATION *ppi;
+    NTSTATUS ret;
+    size_t size;
+    LPBYTE pBuffer = NULL;
+    ULONG current;
+    ULONG max;
+    unsigned int num_cpus;
+    SYSTEM_INFO system_info;
+    system_info.dwNumberOfProcessors = 0;
+
+    // Get the number of CPUs.
+    GetSystemInfo(&system_info);
+    if (system_info.dwNumberOfProcessors == 0)
+        num_cpus = 1;
+    else
+        num_cpus = system_info.dwNumberOfProcessors;
+
+    // Allocate size.
+    size = num_cpus * sizeof(PROCESSOR_POWER_INFORMATION);
+    pBuffer = (BYTE*)LocalAlloc(LPTR, size);
+    if (! pBuffer) {
+        PyErr_SetFromWindowsErr(0);
+        return NULL;
+    }
+
+    // Syscall.
+    ret = CallNtPowerInformation(
+        ProcessorInformation, NULL, 0, pBuffer, size);
+    if (ret != 0) {
+        PyErr_SetString(PyExc_RuntimeError,
+                        "CallNtPowerInformation syscall failed");
+        goto error;
+    }
+
+    // Results.
+    ppi = (PROCESSOR_POWER_INFORMATION *)pBuffer;
+    max = ppi->MaxMhz;
+    current = ppi->CurrentMhz;
+    LocalFree(pBuffer);
+
+    return Py_BuildValue("kk", current, max);
+
+error:
+    if (pBuffer != NULL)
+        LocalFree(pBuffer);
+    return NULL;
+}
+
+
 // ------------------------ Python init ---------------------------
 
 static PyMethodDef
@@ -3495,6 +3560,8 @@ PsutilMethods[] = {
      "Return NICs stats."},
     {"cpu_stats", psutil_cpu_stats, METH_VARARGS,
      "Return NICs stats."},
+    {"cpu_freq", psutil_cpu_freq, METH_VARARGS,
+     "Return CPU frequency."},
 
     // --- windows services
     {"winservice_enumerate", psutil_winservice_enumerate, METH_VARARGS,

psutil/_pswindows.py

@@ -299,6 +299,12 @@ def cpu_stats():
                              syscalls)
 
 
+def cpu_freq():
+    curr, max_ = cext.cpu_freq()
+    min_ = 0
+    return [_common.scpufreq(curr, min_, max_)]
+
+
 # =====================================================================
 # --- network
 # =====================================================================

psutil/tests/test_memory_leaks.py

@@ -458,6 +458,11 @@ def test_per_cpu_times(self):
     def test_cpu_stats(self):
         self.execute(psutil.cpu_stats)
 
+    @skip_if_linux()
+    @unittest.skipUnless(hasattr(psutil, "cpu_freq"), "platform not supported")
+    def test_cpu_freq(self):
+        self.execute(psutil.cpu_freq)
+
     # --- mem
 
     def test_virtual_memory(self):

setup.py

@@ -122,7 +122,7 @@ def get_winver():
         define_macros=macros,
         libraries=[
             "psapi", "kernel32", "advapi32", "shell32", "netapi32",
-            "iphlpapi", "wtsapi32", "ws2_32",
+            "iphlpapi", "wtsapi32", "ws2_32", "PowrProf",
         ],
         # extra_compile_args=["/Z7"],
         # extra_link_args=["/DEBUG"]