Windows / speeup: dynamically load libraries on startup and never again (#1422)

Windows / speeup: dynamically load libraries on startup and never again.

10 files changed, 581 insertions, 631 deletions

diff --git a/psutil/_psutil_windows.c b/psutil/_psutil_windows.c
index d6058b8b..3908884e 100644
--- a/psutil/_psutil_windows.c
+++ b/psutil/_psutil_windows.c
@@ -22,6 +22,8 @@
 #include <ws2tcpip.h>
 #endif
 #include <iphlpapi.h>
+#include <iprtrmib.h>
+#include <udpmib.h>
 #include <wtsapi32.h>
 #include <Winsvc.h>
 #include <PowrProf.h>
@@ -30,13 +32,14 @@
 // Link with Iphlpapi.lib
 #pragma comment(lib, "IPHLPAPI.lib")
 
-#include "_psutil_common.h"
+#include "arch/windows/ntextapi.h"
+#include "arch/windows/global.h"
 #include "arch/windows/security.h"
 #include "arch/windows/process_info.h"
 #include "arch/windows/process_handles.h"
-#include "arch/windows/ntextapi.h"
 #include "arch/windows/inet_ntop.h"
 #include "arch/windows/services.h"
+#include "_psutil_common.h"
 
 
 /*
@@ -53,109 +56,6 @@
 #ifndef AF_INET6
 #define AF_INET6 23
 #endif
-#define _psutil_conn_decref_objs() \
-    Py_DECREF(_AF_INET); \
-    Py_DECREF(_AF_INET6);\
-    Py_DECREF(_SOCK_STREAM);\
-    Py_DECREF(_SOCK_DGRAM);
-
-#if (_WIN32_WINNT >= 0x0601)  // Windows  7
-typedef BOOL (WINAPI *PFN_GETLOGICALPROCESSORINFORMATIONEX)(
-    LOGICAL_PROCESSOR_RELATIONSHIP relationship,
-    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX Buffer,
-    PDWORD ReturnLength);
-static PFN_GETLOGICALPROCESSORINFORMATIONEX _GetLogicalProcessorInformationEx;
-#endif
-
-// Fix for mingw32, see:
-// https://github.com/giampaolo/psutil/issues/351#c2
-// This is actually a DISK_PERFORMANCE struct:
-// https://msdn.microsoft.com/en-us/library/windows/desktop/
-//     aa363991(v=vs.85).aspx
-typedef struct _DISK_PERFORMANCE_WIN_2008 {
-    LARGE_INTEGER BytesRead;
-    LARGE_INTEGER BytesWritten;
-    LARGE_INTEGER ReadTime;
-    LARGE_INTEGER WriteTime;
-    LARGE_INTEGER IdleTime;
-    DWORD         ReadCount;
-    DWORD         WriteCount;
-    DWORD         QueueDepth;
-    DWORD         SplitCount;
-    LARGE_INTEGER QueryTime;
-    DWORD         StorageDeviceNumber;
-    WCHAR         StorageManagerName[8];
-} DISK_PERFORMANCE_WIN_2008;
-
-// --- network connections mingw32 support
-#ifndef _IPRTRMIB_H
-#if (_WIN32_WINNT < 0x0600) // Windows XP
-typedef struct _MIB_TCP6ROW_OWNER_PID {
-    UCHAR ucLocalAddr[16];
-    DWORD dwLocalScopeId;
-    DWORD dwLocalPort;
-    UCHAR ucRemoteAddr[16];
-    DWORD dwRemoteScopeId;
-    DWORD dwRemotePort;
-    DWORD dwState;
-    DWORD dwOwningPid;
-} MIB_TCP6ROW_OWNER_PID, *PMIB_TCP6ROW_OWNER_PID;
-
-typedef struct _MIB_TCP6TABLE_OWNER_PID {
-    DWORD dwNumEntries;
-    MIB_TCP6ROW_OWNER_PID table[ANY_SIZE];
-} MIB_TCP6TABLE_OWNER_PID, *PMIB_TCP6TABLE_OWNER_PID;
-#endif
-#endif
-
-#ifndef __IPHLPAPI_H__
-typedef struct in6_addr {
-    union {
-        UCHAR Byte[16];
-        USHORT Word[8];
-    } u;
-} IN6_ADDR, *PIN6_ADDR, FAR *LPIN6_ADDR;
-
-typedef enum _UDP_TABLE_CLASS {
-    UDP_TABLE_BASIC,
-    UDP_TABLE_OWNER_PID,
-    UDP_TABLE_OWNER_MODULE
-} UDP_TABLE_CLASS, *PUDP_TABLE_CLASS;
-
-typedef struct _MIB_UDPROW_OWNER_PID {
-    DWORD dwLocalAddr;
-    DWORD dwLocalPort;
-    DWORD dwOwningPid;
-} MIB_UDPROW_OWNER_PID, *PMIB_UDPROW_OWNER_PID;
-
-typedef struct _MIB_UDPTABLE_OWNER_PID {
-    DWORD dwNumEntries;
-    MIB_UDPROW_OWNER_PID table[ANY_SIZE];
-} MIB_UDPTABLE_OWNER_PID, *PMIB_UDPTABLE_OWNER_PID;
-#endif
-
-#if (_WIN32_WINNT < 0x0600) // Windows XP
-typedef struct _MIB_UDP6ROW_OWNER_PID {
-    UCHAR ucLocalAddr[16];
-    DWORD dwLocalScopeId;
-    DWORD dwLocalPort;
-    DWORD dwOwningPid;
-} MIB_UDP6ROW_OWNER_PID, *PMIB_UDP6ROW_OWNER_PID;
-
-typedef struct _MIB_UDP6TABLE_OWNER_PID {
-    DWORD dwNumEntries;
-    MIB_UDP6ROW_OWNER_PID table[ANY_SIZE];
-} 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
@@ -204,15 +104,10 @@ unsigned int
 psutil_get_num_cpus(int fail_on_err) {
     unsigned int ncpus = 0;
     SYSTEM_INFO sysinfo;
-    static DWORD(CALLBACK *_GetActiveProcessorCount)(WORD) = NULL;
-
-    // GetActiveProcessorCount is available only on 64 bit versions
-    // of Windows from Windows 7 onward.
-    // Windows Vista 64 bit and Windows XP don't have it.
-    _GetActiveProcessorCount = \
-        psutil_GetProcAddress("kernel32", "GetActiveProcessorCount");
-    if (_GetActiveProcessorCount != NULL) {
-        ncpus = _GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
+
+    // Minimum requirement: Windows 7
+    if (psutil_GetActiveProcessorCount != NULL) {
+        ncpus = psutil_GetActiveProcessorCount(ALL_PROCESSOR_GROUPS);
         if ((ncpus == 0) && (fail_on_err == 1)) {
             PyErr_SetFromWindowsErr(0);
         }
@@ -242,8 +137,6 @@ psutil_get_num_cpus(int fail_on_err) {
 static PyObject *TimeoutExpired;
 static PyObject *TimeoutAbandoned;
 
-static ULONGLONG (*psutil_GetTickCount64)(void) = NULL;
-
 /*
  * Return a Python float representing the system uptime expressed in seconds
  * since the epoch.
@@ -258,7 +151,6 @@ psutil_boot_time(PyObject *self, PyObject *args) {
     time_t pt;
     FILETIME fileTime;
     long long ll;
-    psutil_GetTickCount64;
 
     GetSystemTimeAsFileTime(&fileTime);
     /*
@@ -287,7 +179,6 @@ psutil_boot_time(PyObject *self, PyObject *args) {
     // "#if (_WIN32_WINNT >= 0x0600)" pre-processor but that way
     // the produced exe/wheels cannot be used on Windows XP, see:
     // https://github.com/giampaolo/psutil/issues/811#issuecomment-230639178
-    psutil_GetTickCount64 = psutil_GetProcAddress("kernel32", "GetTickCount64");
     if (psutil_GetTickCount64 != NULL) {
         // Windows >= Vista
         uptime = psutil_GetTickCount64() / (ULONGLONG)1000.00f;
@@ -297,6 +188,8 @@ psutil_boot_time(PyObject *self, PyObject *args) {
         // Windows XP.
         // GetTickCount() time will wrap around to zero if the
         // system is run continuously for 49.7 days.
+        psutil_debug("Windows < Vista; using GetTickCount() instead of "
+                     "GetTickCount64()");
         uptime = GetTickCount() / (LONGLONG)1000.00f;
         return Py_BuildValue("L", pt - uptime);
     }
@@ -611,17 +504,6 @@ psutil_cpu_count_logical(PyObject *self, PyObject *args) {
  * Return the number of physical CPU cores (hyper-thread CPUs count
  * is excluded).
  */
-#if (_WIN32_WINNT < 0x0601)  // < Windows 7 (namely Vista and XP)
-static PyObject *
-psutil_cpu_count_phys(PyObject *self, PyObject *args) {
-    // Note: we may have used GetLogicalProcessorInformation()
-    // but I don't want to prolong support for Windows XP and Vista.
-    // On such old systems psutil will compile but this API will
-    // just return None.
-    psutil_debug("Win < 7; cpu_count_phys() forced to None");
-    Py_RETURN_NONE;
-}
-#else  // Windows >= 7
 static PyObject *
 psutil_cpu_count_phys(PyObject *self, PyObject *args) {
     DWORD rc;
@@ -636,13 +518,13 @@ psutil_cpu_count_phys(PyObject *self, PyObject *args) {
     // it supports process groups, meaning this is able to report more
     // than 64 CPUs. See:
     // https://bugs.python.org/issue33166
-    _GetLogicalProcessorInformationEx = psutil_GetProcAddressFromLib(
-        "kernel32", "GetLogicalProcessorInformationEx");
-    if (_GetLogicalProcessorInformationEx == NULL)
-        return NULL;
+    if (psutil_GetLogicalProcessorInformationEx == NULL) {
+        psutil_debug("Win < 7; cpu_count_phys() forced to None");
+        Py_RETURN_NONE;
+    }
 
     while (1) {
-        rc = _GetLogicalProcessorInformationEx(
+        rc = psutil_GetLogicalProcessorInformationEx(
             RelationAll, buffer, &length);
         if (rc == FALSE) {
             if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
@@ -691,7 +573,6 @@ return_none:
         free(buffer);
     Py_RETURN_NONE;
 }
-#endif
 
 
 /*
@@ -1044,10 +925,6 @@ psutil_cpu_times(PyObject *self, PyObject *args) {
  */
 static PyObject *
 psutil_per_cpu_times(PyObject *self, PyObject *args) {
-    // NtQuerySystemInformation stuff
-    typedef DWORD (_stdcall * NTQSI_PROC) (int, PVOID, ULONG, PULONG);
-    NTQSI_PROC NtQuerySystemInformation;
-
     double idle, kernel, systemt, user, interrupt, dpc;
     NTSTATUS status;
     _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION *sppi = NULL;
@@ -1058,10 +935,6 @@ psutil_per_cpu_times(PyObject *self, PyObject *args) {
 
     if (py_retlist == NULL)
         return NULL;
-    NtQuerySystemInformation = \
-        psutil_GetProcAddressFromLib("ntdll.dll", "NtQuerySystemInformation");
-    if (NtQuerySystemInformation == NULL)
-        goto error;
 
     // retrieves number of processors
     ncpus = psutil_get_num_cpus(1);
@@ -1078,7 +951,7 @@ psutil_per_cpu_times(PyObject *self, PyObject *args) {
     }
 
     // gets cpu time informations
-    status = NtQuerySystemInformation(
+    status = psutil_NtQuerySystemInformation(
         SystemProcessorPerformanceInformation,
         sppi,
         ncpus * sizeof(_SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION),
@@ -1537,10 +1410,6 @@ error:
 }
 
 
-typedef DWORD (WINAPI * _GetExtendedTcpTable)(PVOID, PDWORD, BOOL, ULONG,
-                                              TCP_TABLE_CLASS, ULONG);
-
-
 // https://msdn.microsoft.com/library/aa365928.aspx
 static DWORD __GetExtendedTcpTable(_GetExtendedTcpTable call,
                                    ULONG address_family,
@@ -1575,10 +1444,6 @@ static DWORD __GetExtendedTcpTable(_GetExtendedTcpTable call,
 }
 
 
-typedef DWORD (WINAPI * _GetExtendedUdpTable)(PVOID, PDWORD, BOOL, ULONG,
-                                              UDP_TABLE_CLASS, ULONG);
-
-
 // https://msdn.microsoft.com/library/aa365930.aspx
 static DWORD __GetExtendedUdpTable(_GetExtendedUdpTable call,
                                    ULONG address_family,
@@ -1613,6 +1478,13 @@ static DWORD __GetExtendedUdpTable(_GetExtendedUdpTable call,
 }
 
 
+#define psutil_conn_decref_objs() \
+    Py_DECREF(_AF_INET); \
+    Py_DECREF(_AF_INET6);\
+    Py_DECREF(_SOCK_STREAM);\
+    Py_DECREF(_SOCK_DGRAM);
+
+
 /*
  * Return a list of network connections opened by a process
  */
@@ -1621,12 +1493,6 @@ psutil_net_connections(PyObject *self, PyObject *args) {
     static long null_address[4] = { 0, 0, 0, 0 };
     unsigned long pid;
     int pid_return;
-    typedef PSTR (NTAPI * _RtlIpv4AddressToStringA)(struct in_addr *, PSTR);
-    _RtlIpv4AddressToStringA rtlIpv4AddressToStringA;
-    typedef PSTR (NTAPI * _RtlIpv6AddressToStringA)(struct in6_addr *, PSTR);
-    _RtlIpv6AddressToStringA rtlIpv6AddressToStringA;
-    _GetExtendedTcpTable getExtendedTcpTable;
-    _GetExtendedUdpTable getExtendedUdpTable;
     PVOID table = NULL;
     DWORD tableSize;
     DWORD error;
@@ -1650,28 +1516,11 @@ psutil_net_connections(PyObject *self, PyObject *args) {
     PyObject *_SOCK_DGRAM = PyLong_FromLong((long)SOCK_DGRAM);
 
     // Import some functions.
-    rtlIpv4AddressToStringA = psutil_GetProcAddressFromLib(
-        "ntdll.dll", "RtlIpv4AddressToStringA");
-    if (rtlIpv4AddressToStringA == NULL)
-        goto error;
-    rtlIpv6AddressToStringA = psutil_GetProcAddressFromLib(
-        "ntdll.dll", "RtlIpv6AddressToStringA");
-    if (rtlIpv6AddressToStringA == NULL)
-        goto error;
-    getExtendedTcpTable = psutil_GetProcAddressFromLib(
-        "iphlpapi.dll", "GetExtendedTcpTable");
-    if (getExtendedTcpTable == NULL)
-        goto error;
-    getExtendedUdpTable = psutil_GetProcAddressFromLib(
-        "iphlpapi.dll", "GetExtendedUdpTable");
-    if (getExtendedUdpTable == NULL)
-        goto error;
-
     if (! PyArg_ParseTuple(args, "lOO", &pid, &py_af_filter, &py_type_filter))
         goto error;
 
     if (!PySequence_Check(py_af_filter) || !PySequence_Check(py_type_filter)) {
-        _psutil_conn_decref_objs();
+        psutil_conn_decref_objs();
         PyErr_SetString(PyExc_TypeError, "arg 2 or 3 is not a sequence");
         return NULL;
     }
@@ -1679,25 +1528,18 @@ psutil_net_connections(PyObject *self, PyObject *args) {
     if (pid != -1) {
         pid_return = psutil_pid_is_running(pid);
         if (pid_return == 0) {
-            _psutil_conn_decref_objs();
+            psutil_conn_decref_objs();
             return NoSuchProcess("");
         }
         else if (pid_return == -1) {
-            _psutil_conn_decref_objs();
+            psutil_conn_decref_objs();
             return NULL;
         }
     }
 
-    if ((getExtendedTcpTable == NULL) || (getExtendedUdpTable == NULL)) {
-        PyErr_SetString(PyExc_NotImplementedError,
-                        "feature not supported on this Windows version");
-        _psutil_conn_decref_objs();
-        return NULL;
-    }
-
     py_retlist = PyList_New(0);
     if (py_retlist == NULL) {
-        _psutil_conn_decref_objs();
+        psutil_conn_decref_objs();
         return NULL;
     }
 
@@ -1712,7 +1554,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
         py_addr_tuple_remote = NULL;
         tableSize = 0;
 
-        error = __GetExtendedTcpTable(getExtendedTcpTable,
+        error = __GetExtendedTcpTable(psutil_GetExtendedTcpTable,
                                       AF_INET, &table, &tableSize);
         if (error == ERROR_NOT_ENOUGH_MEMORY) {
             PyErr_NoMemory();
@@ -1737,7 +1579,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
                     struct in_addr addr;
 
                     addr.S_un.S_addr = tcp4Table->table[i].dwLocalAddr;
-                    rtlIpv4AddressToStringA(&addr, addressBufferLocal);
+                    psutil_rtlIpv4AddressToStringA(&addr, addressBufferLocal);
                     py_addr_tuple_local = Py_BuildValue(
                         "(si)",
                         addressBufferLocal,
@@ -1759,7 +1601,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
                     struct in_addr addr;
 
                     addr.S_un.S_addr = tcp4Table->table[i].dwRemoteAddr;
-                    rtlIpv4AddressToStringA(&addr, addressBufferRemote);
+                    psutil_rtlIpv4AddressToStringA(&addr, addressBufferRemote);
                     py_addr_tuple_remote = Py_BuildValue(
                         "(si)",
                         addressBufferRemote,
@@ -1809,7 +1651,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
         py_addr_tuple_remote = NULL;
         tableSize = 0;
 
-        error = __GetExtendedTcpTable(getExtendedTcpTable,
+        error = __GetExtendedTcpTable(psutil_GetExtendedTcpTable,
                                       AF_INET6, &table, &tableSize);
         if (error == ERROR_NOT_ENOUGH_MEMORY) {
             PyErr_NoMemory();
@@ -1834,7 +1676,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
                     struct in6_addr addr;
 
                     memcpy(&addr, tcp6Table->table[i].ucLocalAddr, 16);
-                    rtlIpv6AddressToStringA(&addr, addressBufferLocal);
+                    psutil_rtlIpv6AddressToStringA(&addr, addressBufferLocal);
                     py_addr_tuple_local = Py_BuildValue(
                         "(si)",
                         addressBufferLocal,
@@ -1857,7 +1699,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
                     struct in6_addr addr;
 
                     memcpy(&addr, tcp6Table->table[i].ucRemoteAddr, 16);
-                    rtlIpv6AddressToStringA(&addr, addressBufferRemote);
+                    psutil_rtlIpv6AddressToStringA(&addr, addressBufferRemote);
                     py_addr_tuple_remote = Py_BuildValue(
                         "(si)",
                         addressBufferRemote,
@@ -1906,7 +1748,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
         py_addr_tuple_local = NULL;
         py_addr_tuple_remote = NULL;
         tableSize = 0;
-        error = __GetExtendedUdpTable(getExtendedUdpTable,
+        error = __GetExtendedUdpTable(psutil_GetExtendedUdpTable,
                                       AF_INET, &table, &tableSize);
         if (error == ERROR_NOT_ENOUGH_MEMORY) {
             PyErr_NoMemory();
@@ -1931,7 +1773,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
                     struct in_addr addr;
 
                     addr.S_un.S_addr = udp4Table->table[i].dwLocalAddr;
-                    rtlIpv4AddressToStringA(&addr, addressBufferLocal);
+                    psutil_rtlIpv4AddressToStringA(&addr, addressBufferLocal);
                     py_addr_tuple_local = Py_BuildValue(
                         "(si)",
                         addressBufferLocal,
@@ -1980,7 +1822,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
         py_addr_tuple_local = NULL;
         py_addr_tuple_remote = NULL;
         tableSize = 0;
-        error = __GetExtendedUdpTable(getExtendedUdpTable,
+        error = __GetExtendedUdpTable(psutil_GetExtendedUdpTable,
                                       AF_INET6, &table, &tableSize);
         if (error == ERROR_NOT_ENOUGH_MEMORY) {
             PyErr_NoMemory();
@@ -2004,7 +1846,7 @@ psutil_net_connections(PyObject *self, PyObject *args) {
                     struct in6_addr addr;
 
                     memcpy(&addr, udp6Table->table[i].ucLocalAddr, 16);
-                    rtlIpv6AddressToStringA(&addr, addressBufferLocal);
+                    psutil_rtlIpv6AddressToStringA(&addr, addressBufferLocal);
                     py_addr_tuple_local = Py_BuildValue(
                         "(si)",
                         addressBufferLocal,
@@ -2043,11 +1885,11 @@ psutil_net_connections(PyObject *self, PyObject *args) {
         tableSize = 0;
     }
 
-    _psutil_conn_decref_objs();
+    psutil_conn_decref_objs();
     return py_retlist;
 
 error:
-    _psutil_conn_decref_objs();
+    psutil_conn_decref_objs();
     Py_XDECREF(py_conn_tuple);
     Py_XDECREF(py_addr_tuple_local);
     Py_XDECREF(py_addr_tuple_remote);
@@ -2123,19 +1965,13 @@ psutil_proc_io_priority_get(PyObject *self, PyObject *args) {
     long pid;
     HANDLE hProcess;
     DWORD IoPriority;
-    _NtQueryInformationProcess NtQueryInformationProcess;
 
-    NtQueryInformationProcess = \
-        psutil_GetProcAddress("ntdll.dll", "NtQueryInformationProcess");
-    if (NtQueryInformationProcess == NULL)
-        return NULL;
     if (! PyArg_ParseTuple(args, "l", &pid))
         return NULL;
     hProcess = psutil_handle_from_pid(pid, PROCESS_QUERY_LIMITED_INFORMATION);
     if (hProcess == NULL)
         return NULL;
-
-    NtQueryInformationProcess(
+    psutil_NtQueryInformationProcess(
         hProcess,
         ProcessIoPriority,
         &IoPriority,
@@ -2156,19 +1992,14 @@ psutil_proc_io_priority_set(PyObject *self, PyObject *args) {
     DWORD prio;
     HANDLE hProcess;
     DWORD access = PROCESS_QUERY_INFORMATION | PROCESS_SET_INFORMATION;
-    _NtSetInformationProcess NtSetInformationProcess;
 
-    NtSetInformationProcess = \
-        psutil_GetProcAddress("ntdll.dll", "NtSetInformationProcess");
-    if (NtSetInformationProcess == NULL)
-        return NULL;
     if (! PyArg_ParseTuple(args, "li", &pid, &prio))
         return NULL;
     hProcess = psutil_handle_from_pid(pid, access);
     if (hProcess == NULL)
         return NULL;
 
-    NtSetInformationProcess(
+    psutil_NtSetInformationProcess(
         hProcess,
         ProcessIoPriority,
         (PVOID)&prio,
@@ -2461,7 +2292,7 @@ error:
  */
 static PyObject *
 psutil_disk_io_counters(PyObject *self, PyObject *args) {
-    DISK_PERFORMANCE_WIN_2008 diskPerformance;
+    DISK_PERFORMANCE diskPerformance;
     DWORD dwSize;
     HANDLE hDevice = NULL;
     char szDevice[MAX_PATH];
@@ -2764,7 +2595,6 @@ psutil_users(PyObject *self, PyObject *args) {
     PWTS_CLIENT_ADDRESS address;
     char address_str[50];
     long long unix_time;
-    PWINSTATIONQUERYINFORMATIONW WinStationQueryInformationW;
     WINSTATION_INFO station_info;
     ULONG returnLen;
     PyObject *py_tuple = NULL;
@@ -2775,11 +2605,6 @@ psutil_users(PyObject *self, PyObject *args) {
     if (py_retlist == NULL)
         return NULL;
 
-    WinStationQueryInformationW = psutil_GetProcAddressFromLib(
-        "winsta.dll", "WinStationQueryInformationW");
-    if (WinStationQueryInformationW == NULL)
-        goto error;
-
     if (WTSEnumerateSessions(hServer, 0, 1, &sessions, &count) == 0) {
         PyErr_SetFromWindowsErr(0);
         goto error;
@@ -2833,12 +2658,13 @@ psutil_users(PyObject *self, PyObject *args) {
         }
 
         // login time
-        if (!WinStationQueryInformationW(hServer,
-                                         sessionId,
-                                         WinStationInformation,
-                                         &station_info,
-                                         sizeof(station_info),
-                                         &returnLen))
+        if (! psutil_WinStationQueryInformationW(
+                hServer,
+                sessionId,
+                WinStationInformation,
+                &station_info,
+                sizeof(station_info),
+                &returnLen))
         {
             goto error;
         }
@@ -3478,8 +3304,6 @@ error:
  */
 static PyObject *
 psutil_cpu_stats(PyObject *self, PyObject *args) {
-    typedef DWORD (_stdcall * NTQSI_PROC) (int, PVOID, ULONG, PULONG);
-    NTQSI_PROC NtQuerySystemInformation;
     NTSTATUS status;
     _SYSTEM_PERFORMANCE_INFORMATION *spi = NULL;
     _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION *sppi = NULL;
@@ -3489,11 +3313,6 @@ psutil_cpu_stats(PyObject *self, PyObject *args) {
     ULONG64 dpcs = 0;
     ULONG interrupts = 0;
 
-    NtQuerySystemInformation = \
-        psutil_GetProcAddressFromLib("ntdll.dll", "NtQuerySystemInformation");
-    if (NtQuerySystemInformation == NULL)
-        return NULL;
-
     // retrieves number of processors
     ncpus = psutil_get_num_cpus(1);
     if (ncpus == 0)
@@ -3506,7 +3325,7 @@ psutil_cpu_stats(PyObject *self, PyObject *args) {
         PyErr_NoMemory();
         goto error;
     }
-    status = NtQuerySystemInformation(
+    status = psutil_NtQuerySystemInformation(
         SystemPerformanceInformation,
         spi,
         ncpus * sizeof(_SYSTEM_PERFORMANCE_INFORMATION),
@@ -3524,7 +3343,7 @@ psutil_cpu_stats(PyObject *self, PyObject *args) {
         goto error;
     }
 
-    status = NtQuerySystemInformation(
+    status = psutil_NtQuerySystemInformation(
         SystemInterruptInformation,
         InterruptInformation,
         ncpus * sizeof(SYSTEM_INTERRUPT_INFORMATION),
@@ -3545,7 +3364,7 @@ psutil_cpu_stats(PyObject *self, PyObject *args) {
         goto error;
     }
 
-    status = NtQuerySystemInformation(
+    status = psutil_NtQuerySystemInformation(
         SystemProcessorPerformanceInformation,
         sppi,
         ncpus * sizeof(_SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION),
@@ -3939,6 +3758,8 @@ void init_psutil_windows(void)
     // set SeDebug for the current process
     psutil_set_se_debug();
     psutil_setup();
+    if (psutil_loadlibs() != 0)
+        return NULL;
 
 #if PY_MAJOR_VERSION >= 3
     return module;
diff --git a/psutil/arch/windows/global.c b/psutil/arch/windows/global.c
new file mode 100644
index 00000000..bb9970fe
--- /dev/null
+++ b/psutil/arch/windows/global.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <windows.h>
+#include <Python.h>
+#include "ntextapi.h"
+#include "global.h"
+
+
+// A wrapper around GetModuleHandle and GetProcAddress.
+PVOID
+psutil_GetProcAddress(LPCSTR libname, LPCSTR procname) {
+    HMODULE mod;
+    FARPROC addr;
+
+    if ((mod = GetModuleHandleA(libname)) == NULL) {
+        PyErr_SetFromWindowsErrWithFilename(0, libname);
+        return NULL;
+    }
+    if ((addr = GetProcAddress(mod, procname)) == NULL) {
+        PyErr_SetFromWindowsErrWithFilename(0, procname);
+        return NULL;
+    }
+    return addr;
+}
+
+
+// A wrapper around LoadLibrary and GetProcAddress.
+PVOID
+psutil_GetProcAddressFromLib(LPCSTR libname, LPCSTR procname) {
+    HMODULE mod;
+    FARPROC addr;
+
+    Py_BEGIN_ALLOW_THREADS
+    mod = LoadLibraryA(libname);
+    Py_END_ALLOW_THREADS
+    if (mod  == NULL) {
+        PyErr_SetFromWindowsErrWithFilename(0, libname);
+        return NULL;
+    }
+    if ((addr = GetProcAddress(mod, procname)) == NULL) {
+        PyErr_SetFromWindowsErrWithFilename(0, procname);
+        FreeLibrary(mod);
+        return NULL;
+    }
+    // Causes crash.
+    // FreeLibrary(mod);
+    return addr;
+}
+
+
+/*
+ * This is executed on import and loads Windows APIs so that they
+ * are available globally.
+ */
+psutil_loadlibs() {
+    /*
+     * Mandatory.
+     */
+
+    psutil_NtQuerySystemInformation = psutil_GetProcAddressFromLib(
+        "ntdll.dll", "NtQuerySystemInformation");
+    if (psutil_NtQuerySystemInformation == NULL)
+        return 1;
+
+    psutil_NtQueryInformationProcess = psutil_GetProcAddress(
+        "ntdll.dll", "NtQueryInformationProcess");
+    if (! psutil_NtQueryInformationProcess)
+        return 1;
+
+    psutil_NtSetInformationProcess = psutil_GetProcAddress(
+        "ntdll.dll", "NtSetInformationProcess");
+    if (! psutil_NtSetInformationProcess)
+        return 1;
+
+    psutil_WinStationQueryInformationW = psutil_GetProcAddressFromLib(
+        "winsta.dll", "WinStationQueryInformationW");
+    if (! psutil_WinStationQueryInformationW)
+        return 1;
+
+    psutil_NtQueryObject = psutil_GetProcAddressFromLib(
+        "ntdll.dll", "NtQueryObject");
+    if (! psutil_NtQueryObject)
+        return 1;
+
+    psutil_rtlIpv4AddressToStringA = psutil_GetProcAddressFromLib(
+        "ntdll.dll", "RtlIpv4AddressToStringA");
+    if (! psutil_rtlIpv4AddressToStringA)
+        return 1;
+
+    psutil_rtlIpv6AddressToStringA = psutil_GetProcAddressFromLib(
+        "ntdll.dll", "RtlIpv6AddressToStringA");
+    if (! psutil_rtlIpv6AddressToStringA)
+        return 1;
+
+    // minimum requirement: Win XP SP3
+    psutil_GetExtendedTcpTable = psutil_GetProcAddressFromLib(
+        "iphlpapi.dll", "GetExtendedTcpTable");
+    if (! psutil_GetExtendedTcpTable)
+        return 1;
+
+    // minimum requirement: Win XP SP3
+    psutil_GetExtendedUdpTable = psutil_GetProcAddressFromLib(
+        "iphlpapi.dll", "GetExtendedUdpTable");
+    if (! psutil_GetExtendedUdpTable)
+        return 1;
+
+    /*
+     * Optional.
+     */
+
+    // minimum requirement: Win Vista
+    psutil_GetTickCount64 = psutil_GetProcAddress(
+        "kernel32", "GetTickCount64");
+
+    // minimum requirement: Win 7
+    psutil_GetActiveProcessorCount = psutil_GetProcAddress(
+        "kernel32", "GetActiveProcessorCount");
+
+    // minumum requirement: Win 7
+    psutil_GetLogicalProcessorInformationEx = psutil_GetProcAddressFromLib(
+        "kernel32", "GetLogicalProcessorInformationEx");
+
+    PyErr_Clear();
+    return 0;
+}
diff --git a/psutil/arch/windows/global.h b/psutil/arch/windows/global.h
new file mode 100644
index 00000000..8d828776
--- /dev/null
+++ b/psutil/arch/windows/global.h
@@ -0,0 +1,11 @@
+/*
+ * Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <windows.h>
+
+int psutil_loadlibs();
+PVOID psutil_GetProcAddress(LPCSTR libname, LPCSTR procname);
+PVOID psutil_GetProcAddressFromLib(LPCSTR libname, LPCSTR procname);
diff --git a/psutil/arch/windows/ntextapi.h b/psutil/arch/windows/ntextapi.h
index ea23ddb7..e0006c7b 100644
--- a/psutil/arch/windows/ntextapi.h
+++ b/psutil/arch/windows/ntextapi.h
@@ -6,7 +6,75 @@
 #if !defined(__NTEXTAPI_H__)
 #define __NTEXTAPI_H__
 #include <winternl.h>
+#include <iphlpapi.h>
 
+typedef LONG NTSTATUS;
+
+#define STATUS_INFO_LENGTH_MISMATCH 0xc0000004
+#define STATUS_BUFFER_TOO_SMALL 0xC0000023L
+#define SystemExtendedHandleInformation 64
+
+/*
+ * ================================================================
+ * Enums.
+ * ================================================================
+ */
+
+typedef enum _PROCESSINFOCLASS2 {
+    _ProcessBasicInformation,
+    ProcessQuotaLimits,
+    ProcessIoCounters,
+    ProcessVmCounters,
+    ProcessTimes,
+    ProcessBasePriority,
+    ProcessRaisePriority,
+    _ProcessDebugPort,
+    ProcessExceptionPort,
+    ProcessAccessToken,
+    ProcessLdtInformation,
+    ProcessLdtSize,
+    ProcessDefaultHardErrorMode,
+    ProcessIoPortHandlers,
+    ProcessPooledUsageAndLimits,
+    ProcessWorkingSetWatch,
+    ProcessUserModeIOPL,
+    ProcessEnableAlignmentFaultFixup,
+    ProcessPriorityClass,
+    ProcessWx86Information,
+    ProcessHandleCount,
+    ProcessAffinityMask,
+    ProcessPriorityBoost,
+    ProcessDeviceMap,
+    ProcessSessionInformation,
+    ProcessForegroundInformation,
+    _ProcessWow64Information,
+    /* added after XP+ */
+    _ProcessImageFileName,
+    ProcessLUIDDeviceMapsEnabled,
+    _ProcessBreakOnTermination,
+    ProcessDebugObjectHandle,
+    ProcessDebugFlags,
+    ProcessHandleTracing,
+    ProcessIoPriority,
+    ProcessExecuteFlags,
+    ProcessResourceManagement,
+    ProcessCookie,
+    ProcessImageInformation,
+    MaxProcessInfoClass
+} PROCESSINFOCLASS2;
+
+#define PROCESSINFOCLASS PROCESSINFOCLASS2
+#define ProcessBasicInformation _ProcessBasicInformation
+#define ProcessWow64Information _ProcessWow64Information
+#define ProcessDebugPort _ProcessDebugPort
+#define ProcessImageFileName _ProcessImageFileName
+#define ProcessBreakOnTermination _ProcessBreakOnTermination
+
+/*
+ * ================================================================
+ * Structs.
+ * ================================================================
+ */
 
 typedef struct {
     LARGE_INTEGER IdleTime;
@@ -17,7 +85,6 @@ typedef struct {
     ULONG InterruptCount;
 } _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION;
 
-
 typedef struct {
     LARGE_INTEGER IdleProcessTime;
     LARGE_INTEGER IoReadTransferCount;
@@ -93,10 +160,8 @@ typedef struct {
     ULONG FirstLevelTbFills;
     ULONG SecondLevelTbFills;
     ULONG SystemCalls;
-
 } _SYSTEM_PERFORMANCE_INFORMATION;
 
-
 typedef struct {
     ULONG ContextSwitches;
     ULONG DpcCount;
@@ -106,7 +171,6 @@ typedef struct {
     ULONG ApcBypassCount;
 } _SYSTEM_INTERRUPT_INFORMATION;
 
-
 typedef enum _KTHREAD_STATE {
     Initialized,
     Ready,
@@ -120,7 +184,6 @@ typedef enum _KTHREAD_STATE {
     MaximumThreadState
 } KTHREAD_STATE, *PKTHREAD_STATE;
 
-
 typedef enum _KWAIT_REASON {
     Executive = 0,
     FreePage = 1,
@@ -162,6 +225,22 @@ typedef enum _KWAIT_REASON {
     MaximumWaitReason = 37
 } KWAIT_REASON, *PKWAIT_REASON;
 
+typedef struct _SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX {
+    PVOID Object;
+    HANDLE UniqueProcessId;
+    HANDLE HandleValue;
+    ULONG GrantedAccess;
+    USHORT CreatorBackTraceIndex;
+    USHORT ObjectTypeIndex;
+    ULONG HandleAttributes;
+    ULONG Reserved;
+} SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX, *PSYSTEM_HANDLE_TABLE_ENTRY_INFO_EX;
+
+typedef struct _SYSTEM_HANDLE_INFORMATION_EX {
+    ULONG_PTR NumberOfHandles;
+    ULONG_PTR Reserved;
+    SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX Handles[1];
+} SYSTEM_HANDLE_INFORMATION_EX, *PSYSTEM_HANDLE_INFORMATION_EX;
 
 typedef struct _CLIENT_ID2 {
     HANDLE UniqueProcess;
@@ -190,8 +269,6 @@ typedef struct _SYSTEM_THREAD_INFORMATION2 {
 
 typedef struct _TEB *PTEB;
 
-
-// private
 typedef struct _SYSTEM_EXTENDED_THREAD_INFORMATION {
     SYSTEM_THREAD_INFORMATION ThreadInfo;
     PVOID StackBase;
@@ -203,7 +280,6 @@ typedef struct _SYSTEM_EXTENDED_THREAD_INFORMATION {
     ULONG_PTR Reserved4;
 } SYSTEM_EXTENDED_THREAD_INFORMATION, *PSYSTEM_EXTENDED_THREAD_INFORMATION;
 
-
 typedef struct _SYSTEM_PROCESS_INFORMATION2 {
     ULONG NextEntryOffset;
     ULONG NumberOfThreads;
@@ -244,10 +320,35 @@ typedef struct _SYSTEM_PROCESS_INFORMATION2 {
 #define SYSTEM_PROCESS_INFORMATION SYSTEM_PROCESS_INFORMATION2
 #define PSYSTEM_PROCESS_INFORMATION PSYSTEM_PROCESS_INFORMATION2
 
-
-// ================================================
-// psutil.users() support
-// ================================================
+typedef struct _PROCESSOR_POWER_INFORMATION {
+   ULONG Number;
+   ULONG MaxMhz;
+   ULONG CurrentMhz;
+   ULONG MhzLimit;
+   ULONG MaxIdleState;
+   ULONG CurrentIdleState;
+} PROCESSOR_POWER_INFORMATION, *PPROCESSOR_POWER_INFORMATION;
+
+#ifndef __IPHLPAPI_H__
+typedef struct in6_addr {
+    union {
+        UCHAR Byte[16];
+        USHORT Word[8];
+    } u;
+} IN6_ADDR, *PIN6_ADDR, FAR *LPIN6_ADDR;
+#endif
+
+// http://msdn.microsoft.com/en-us/library/aa813741(VS.85).aspx
+typedef struct {
+    BYTE Reserved1[16];
+    PVOID Reserved2[5];
+    UNICODE_STRING CurrentDirectoryPath;
+    PVOID CurrentDirectoryHandle;
+    UNICODE_STRING DllPath;
+    UNICODE_STRING ImagePathName;
+    UNICODE_STRING CommandLine;
+    LPCWSTR env;
+} RTL_USER_PROCESS_PARAMETERS_, *PRTL_USER_PROCESS_PARAMETERS_;
 
 typedef struct _WINSTATION_INFO {
     BYTE Reserved1[72];
@@ -261,18 +362,38 @@ typedef struct _WINSTATION_INFO {
     FILETIME CurrentTime;
 } WINSTATION_INFO, *PWINSTATION_INFO;
 
-
-typedef BOOLEAN (WINAPI * PWINSTATIONQUERYINFORMATIONW)
-                 (HANDLE,ULONG,WINSTATIONINFOCLASS,PVOID,ULONG,PULONG);
-
+#if (_WIN32_WINNT < 0x0601)  // Windows < 7 (Vista and XP)
+typedef struct _SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX {
+    LOGICAL_PROCESSOR_RELATIONSHIP Relationship;
+    DWORD Size;
+    _ANONYMOUS_UNION
+    union {
+        PROCESSOR_RELATIONSHIP Processor;
+        NUMA_NODE_RELATIONSHIP NumaNode;
+        CACHE_RELATIONSHIP Cache;
+        GROUP_RELATIONSHIP Group;
+    } DUMMYUNIONNAME;
+} SYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX, *PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX;
+#endif
 
 /*
- * NtQueryInformationProcess code taken from
- * http://wj32.wordpress.com/2009/01/24/howto-get-the-command-line-of-processes/
- * typedefs needed to compile against ntdll functions not exposted in the API
+ * ================================================================
+ * Type defs for modules loaded at runtime.
+ * ================================================================
  */
-typedef LONG NTSTATUS;
 
+typedef BOOL (WINAPI *_GetLogicalProcessorInformationEx)(
+    LOGICAL_PROCESSOR_RELATIONSHIP relationship,
+    PSYSTEM_LOGICAL_PROCESSOR_INFORMATION_EX Buffer,
+    PDWORD ReturnLength);
+
+typedef BOOLEAN (WINAPI * _WinStationQueryInformationW)(
+    HANDLE ServerHandle,
+    ULONG SessionId,
+    WINSTATIONINFOCLASS WinStationInformationClass,
+    PVOID pWinStationInformation,
+    ULONG WinStationInformationLength,
+    PULONG pReturnLength);
 
 typedef NTSTATUS (NTAPI *_NtQueryInformationProcess)(
     HANDLE ProcessHandle,
@@ -282,6 +403,12 @@ typedef NTSTATUS (NTAPI *_NtQueryInformationProcess)(
     PDWORD ReturnLength
 );
 
+typedef NTSTATUS (NTAPI *_NtQuerySystemInformation)(
+    ULONG SystemInformationClass,
+    PVOID SystemInformation,
+    ULONG SystemInformationLength,
+    PULONG ReturnLength
+);
 
 typedef NTSTATUS (NTAPI *_NtSetInformationProcess)(
     HANDLE ProcessHandle,
@@ -290,56 +417,86 @@ typedef NTSTATUS (NTAPI *_NtSetInformationProcess)(
     DWORD ProcessInformationLength
 );
 
+typedef PSTR (NTAPI * _RtlIpv4AddressToStringA)(
+    struct in_addr *Addr,
+    PSTR S);
+
+typedef PSTR (NTAPI * _RtlIpv6AddressToStringA)(
+    struct in6_addr *Addr,
+    PSTR P);
+
+typedef DWORD (WINAPI * _GetExtendedTcpTable)(
+    PVOID pTcpTable,
+    PDWORD pdwSize,
+    BOOL bOrder,
+    ULONG ulAf,
+    TCP_TABLE_CLASS TableClass,
+    ULONG Reserved
+);
 
-typedef enum _PROCESSINFOCLASS2 {
-    _ProcessBasicInformation,
-    ProcessQuotaLimits,
-    ProcessIoCounters,
-    ProcessVmCounters,
-    ProcessTimes,
-    ProcessBasePriority,
-    ProcessRaisePriority,
-    _ProcessDebugPort,
-    ProcessExceptionPort,
-    ProcessAccessToken,
-    ProcessLdtInformation,
-    ProcessLdtSize,
-    ProcessDefaultHardErrorMode,
-    ProcessIoPortHandlers,
-    ProcessPooledUsageAndLimits,
-    ProcessWorkingSetWatch,
-    ProcessUserModeIOPL,
-    ProcessEnableAlignmentFaultFixup,
-    ProcessPriorityClass,
-    ProcessWx86Information,
-    ProcessHandleCount,
-    ProcessAffinityMask,
-    ProcessPriorityBoost,
-    ProcessDeviceMap,
-    ProcessSessionInformation,
-    ProcessForegroundInformation,
-    _ProcessWow64Information,
-    /* added after XP+ */
-    _ProcessImageFileName,
-    ProcessLUIDDeviceMapsEnabled,
-    _ProcessBreakOnTermination,
-    ProcessDebugObjectHandle,
-    ProcessDebugFlags,
-    ProcessHandleTracing,
-    ProcessIoPriority,
-    ProcessExecuteFlags,
-    ProcessResourceManagement,
-    ProcessCookie,
-    ProcessImageInformation,
-    MaxProcessInfoClass
-} PROCESSINFOCLASS2;
+typedef DWORD (WINAPI * _GetExtendedUdpTable)(
+    PVOID pUdpTable,
+    PDWORD pdwSize,
+    BOOL bOrder,
+    ULONG ulAf,
+    UDP_TABLE_CLASS TableClass,
+    ULONG Reserved
+);
 
+typedef DWORD (CALLBACK *_GetActiveProcessorCount)(
+    WORD GroupNumber);
 
-#define PROCESSINFOCLASS PROCESSINFOCLASS2
-#define ProcessBasicInformation _ProcessBasicInformation
-#define ProcessWow64Information _ProcessWow64Information
-#define ProcessDebugPort _ProcessDebugPort
-#define ProcessImageFileName _ProcessImageFileName
-#define ProcessBreakOnTermination _ProcessBreakOnTermination
+typedef ULONGLONG (CALLBACK *_GetTickCount64)(
+    void);
+
+typedef NTSTATUS (NTAPI *_NtQueryObject)(
+    HANDLE Handle,
+    OBJECT_INFORMATION_CLASS ObjectInformationClass,
+    PVOID ObjectInformation,
+    ULONG ObjectInformationLength,
+    PULONG ReturnLength
+);
+
+/*
+ * ================================================================
+ * Custom psutil definitions for modules loaded at runtime.
+ * ================================================================
+ */
+
+_NtQuerySystemInformation \
+    psutil_NtQuerySystemInformation;
+
+_NtQueryInformationProcess \
+    psutil_NtQueryInformationProcess;
+
+_NtSetInformationProcess
+    psutil_NtSetInformationProcess;
+
+_WinStationQueryInformationW \
+    psutil_WinStationQueryInformationW;
+
+_RtlIpv4AddressToStringA \
+    psutil_rtlIpv4AddressToStringA;
+
+_RtlIpv6AddressToStringA \
+    psutil_rtlIpv6AddressToStringA;
+
+_GetExtendedTcpTable \
+    psutil_GetExtendedTcpTable;
+
+_GetExtendedUdpTable \
+    psutil_GetExtendedUdpTable;
+
+_GetActiveProcessorCount \
+    psutil_GetActiveProcessorCount;
+
+_GetTickCount64 \
+    psutil_GetTickCount64;
+
+_NtQueryObject \
+    psutil_NtQueryObject;
+
+_GetLogicalProcessorInformationEx \
+    psutil_GetLogicalProcessorInformationEx;
 
 #endif // __NTEXTAPI_H__
diff --git a/psutil/arch/windows/process_handles.c b/psutil/arch/windows/process_handles.c
index 4ac02b91..f295f18d 100644
--- a/psutil/arch/windows/process_handles.c
+++ b/psutil/arch/windows/process_handles.c
@@ -4,13 +4,16 @@
  * found in the LICENSE file.
  *
  */
+
+#include <windows.h>
+#include <Psapi.h>
+#include <Python.h>
+#include "ntextapi.h"
+#include "global.h"
 #include "process_handles.h"
 #include "process_info.h"
 #include "../../_psutil_common.h"
 
-static _NtQuerySystemInformation __NtQuerySystemInformation = NULL;
-static _NtQueryObject __NtQueryObject = NULL;
-
 CRITICAL_SECTION g_cs;
 BOOL g_initialized = FALSE;
 NTSTATUS g_status;
@@ -23,33 +26,15 @@ ULONG g_dwSize = 0;
 ULONG g_dwLength = 0;
 
 
-PyObject *
-psutil_get_open_files(long dwPid, HANDLE hProcess) {
-    OSVERSIONINFO osvi;
-
-    ZeroMemory(&osvi, sizeof(OSVERSIONINFO));
-    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
-    GetVersionEx(&osvi);
-
-    // Threaded version only works for Vista+
-    if (osvi.dwMajorVersion >= 6)
-        return psutil_get_open_files_ntqueryobject(dwPid, hProcess);
-    else
-        return psutil_get_open_files_getmappedfilename(dwPid, hProcess);
-}
+#define ObjectNameInformation 1
+#define NTQO_TIMEOUT 100
 
 
-VOID
+static VOID
 psutil_get_open_files_init(BOOL threaded) {
     if (g_initialized == TRUE)
         return;
 
-    // Resolve the Windows API calls
-    __NtQuerySystemInformation = psutil_GetProcAddressFromLib(
-        "ntdll.dll", "NtQuerySystemInformation");
-    __NtQueryObject = psutil_GetProcAddressFromLib(
-        "ntdll.dll", "NtQueryObject");
-
     // Create events for signalling work between threads
     if (threaded == TRUE) {
         g_hEvtStart = CreateEvent(NULL, FALSE, FALSE, NULL);
@@ -61,7 +46,59 @@ psutil_get_open_files_init(BOOL threaded) {
 }
 
 
-PyObject *
+static DWORD WINAPI
+psutil_wait_thread(LPVOID lpvParam) {
+    // Loop infinitely waiting for work
+    while (TRUE) {
+        WaitForSingleObject(g_hEvtStart, INFINITE);
+
+        g_status = psutil_NtQueryObject(
+            g_hFile,
+            ObjectNameInformation,
+            g_pNameBuffer,
+            g_dwSize,
+            &g_dwLength);
+        SetEvent(g_hEvtFinish);
+    }
+}
+
+
+static DWORD
+psutil_create_thread() {
+    DWORD dwWait = 0;
+
+    if (g_hThread == NULL)
+        g_hThread = CreateThread(
+            NULL,
+            0,
+            psutil_wait_thread,
+            NULL,
+            0,
+            NULL);
+    if (g_hThread == NULL)
+        return GetLastError();
+
+    // Signal the worker thread to start
+    SetEvent(g_hEvtStart);
+
+    // Wait for the worker thread to finish
+    dwWait = WaitForSingleObject(g_hEvtFinish, NTQO_TIMEOUT);
+
+    // If the thread hangs, kill it and cleanup
+    if (dwWait == WAIT_TIMEOUT) {
+        SuspendThread(g_hThread);
+        TerminateThread(g_hThread, 1);
+        WaitForSingleObject(g_hThread, INFINITE);
+        CloseHandle(g_hThread);
+
+        g_hThread = NULL;
+    }
+
+    return dwWait;
+}
+
+
+static PyObject *
 psutil_get_open_files_ntqueryobject(long dwPid, HANDLE hProcess) {
     NTSTATUS                            status;
     PSYSTEM_HANDLE_INFORMATION_EX       pHandleInfo = NULL;
@@ -81,9 +118,7 @@ psutil_get_open_files_ntqueryobject(long dwPid, HANDLE hProcess) {
     // to psutil_get_open_files() is running
     EnterCriticalSection(&g_cs);
 
-    if (__NtQuerySystemInformation == NULL ||
-        __NtQueryObject == NULL ||
-        g_hEvtStart == NULL ||
+    if (g_hEvtStart == NULL ||
         g_hEvtFinish == NULL)
 
     {
@@ -117,7 +152,7 @@ psutil_get_open_files_ntqueryobject(long dwPid, HANDLE hProcess) {
             error = TRUE;
             goto cleanup;
         }
-    } while ((status = __NtQuerySystemInformation(
+    } while ((status = psutil_NtQuerySystemInformation(
                             SystemExtendedHandleInformation,
                             pHandleInfo,
                             dwInfoSize,
@@ -180,7 +215,7 @@ psutil_get_open_files_ntqueryobject(long dwPid, HANDLE hProcess) {
                     goto loop_cleanup;
             }
 
-            dwWait = psutil_NtQueryObject();
+            dwWait = psutil_create_thread();
 
             // If the call does not return, skip this handle
             if (dwWait != WAIT_OBJECT_0)
@@ -228,19 +263,19 @@ psutil_get_open_files_ntqueryobject(long dwPid, HANDLE hProcess) {
         }
 
 loop_cleanup:
-        Py_XDECREF(py_path);
-        py_path = NULL;
+    Py_XDECREF(py_path);
+    py_path = NULL;
 
-        if (g_pNameBuffer != NULL)
-            HeapFree(GetProcessHeap(), 0, g_pNameBuffer);
-        g_pNameBuffer = NULL;
-        g_dwSize = 0;
-        g_dwLength = 0;
+    if (g_pNameBuffer != NULL)
+        HeapFree(GetProcessHeap(), 0, g_pNameBuffer);
+    g_pNameBuffer = NULL;
+    g_dwSize = 0;
+    g_dwLength = 0;
 
-        if (g_hFile != NULL)
-            CloseHandle(g_hFile);
-        g_hFile = NULL;
-    }
+    if (g_hFile != NULL)
+        CloseHandle(g_hFile);
+    g_hFile = NULL;
+}
 
 cleanup:
     if (g_pNameBuffer != NULL)
@@ -268,58 +303,7 @@ cleanup:
 }
 
 
-DWORD
-psutil_NtQueryObject() {
-    DWORD dwWait = 0;
-
-    if (g_hThread == NULL)
-        g_hThread = CreateThread(
-            NULL,
-            0,
-            psutil_NtQueryObjectThread,
-            NULL,
-            0,
-            NULL);
-    if (g_hThread == NULL)
-        return GetLastError();
-
-    // Signal the worker thread to start
-    SetEvent(g_hEvtStart);
-
-    // Wait for the worker thread to finish
-    dwWait = WaitForSingleObject(g_hEvtFinish, NTQO_TIMEOUT);
-
-    // If the thread hangs, kill it and cleanup
-    if (dwWait == WAIT_TIMEOUT) {
-        SuspendThread(g_hThread);
-        TerminateThread(g_hThread, 1);
-        WaitForSingleObject(g_hThread, INFINITE);
-        CloseHandle(g_hThread);
-
-        g_hThread = NULL;
-    }
-
-    return dwWait;
-}
-
-
-DWORD WINAPI
-psutil_NtQueryObjectThread(LPVOID lpvParam) {
-    // Loop infinitely waiting for work
-    while (TRUE) {
-        WaitForSingleObject(g_hEvtStart, INFINITE);
-
-        g_status = __NtQueryObject(g_hFile,
-                                   ObjectNameInformation,
-                                   g_pNameBuffer,
-                                   g_dwSize,
-                                   &g_dwLength);
-        SetEvent(g_hEvtFinish);
-    }
-}
-
-
-PyObject *
+static PyObject *
 psutil_get_open_files_getmappedfilename(long dwPid, HANDLE hProcess) {
     NTSTATUS                            status;
     PSYSTEM_HANDLE_INFORMATION_EX       pHandleInfo = NULL;
@@ -339,12 +323,6 @@ psutil_get_open_files_getmappedfilename(long dwPid, HANDLE hProcess) {
     if (g_initialized == FALSE)
         psutil_get_open_files_init(FALSE);
 
-    if (__NtQuerySystemInformation == NULL || __NtQueryObject == NULL) {
-        PyErr_SetFromWindowsErr(0);
-        error = TRUE;
-        goto cleanup;
-    }
-
     // Py_BuildValue raises an exception if NULL is returned
     py_retlist = PyList_New(0);
     if (py_retlist == NULL) {
@@ -370,7 +348,7 @@ psutil_get_open_files_getmappedfilename(long dwPid, HANDLE hProcess) {
             error = TRUE;
             goto cleanup;
         }
-    } while ((status = __NtQuerySystemInformation(
+    } while ((status = psutil_NtQuerySystemInformation(
                             SystemExtendedHandleInformation,
                             pHandleInfo,
                             dwInfoSize,
@@ -517,3 +495,23 @@ cleanup:
 
     return py_retlist;
 }
+
+
+/*
+ * The public function.
+ */
+PyObject *
+psutil_get_open_files(long dwPid, HANDLE hProcess) {
+    OSVERSIONINFO osvi;
+
+    ZeroMemory(&osvi, sizeof(OSVERSIONINFO));
+    osvi.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
+    GetVersionEx(&osvi);
+
+    // Threaded version only works for Vista+
+    if (osvi.dwMajorVersion >= 6)
+        return psutil_get_open_files_ntqueryobject(dwPid, hProcess);
+    else
+        return psutil_get_open_files_getmappedfilename(dwPid, hProcess);
+}
+
diff --git a/psutil/arch/windows/process_handles.h b/psutil/arch/windows/process_handles.h
index 4a022c1c..342ce8fd 100644
--- a/psutil/arch/windows/process_handles.h
+++ b/psutil/arch/windows/process_handles.h
@@ -4,108 +4,7 @@
  * found in the LICENSE file.
  */
 
-#ifndef __PROCESS_HANDLES_H__
-#define __PROCESS_HANDLES_H__
-
-#ifndef UNICODE
-#define UNICODE
-#endif
-
 #include <Python.h>
-#include <stdio.h>
 #include <windows.h>
-#include <strsafe.h>
-#include <winternl.h>
-#include <psapi.h>
-
-
-#ifndef NT_SUCCESS
-#define NT_SUCCESS(x) ((x) >= 0)
-#endif
-
-#define STATUS_INFO_LENGTH_MISMATCH 0xc0000004
-#define ObjectBasicInformation 0
-#define ObjectNameInformation 1
-#define ObjectTypeInformation 2
-#define HANDLE_TYPE_FILE 28
-#define NTQO_TIMEOUT 100
-
-typedef NTSTATUS (NTAPI *_NtQuerySystemInformation)(
-    ULONG SystemInformationClass,
-    PVOID SystemInformation,
-    ULONG SystemInformationLength,
-    PULONG ReturnLength
-);
-
-typedef NTSTATUS (NTAPI *_NtQueryObject)(
-    HANDLE ObjectHandle,
-    ULONG ObjectInformationClass,
-    PVOID ObjectInformation,
-    ULONG ObjectInformationLength,
-    PULONG ReturnLength
-);
 
-// Undocumented FILE_INFORMATION_CLASS: FileNameInformation
-static const SYSTEM_INFORMATION_CLASS SystemExtendedHandleInformation = (SYSTEM_INFORMATION_CLASS)64;
-
-typedef struct _SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX {
-    PVOID Object;
-    HANDLE UniqueProcessId;
-    HANDLE HandleValue;
-    ULONG GrantedAccess;
-    USHORT CreatorBackTraceIndex;
-    USHORT ObjectTypeIndex;
-    ULONG HandleAttributes;
-    ULONG Reserved;
-} SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX, *PSYSTEM_HANDLE_TABLE_ENTRY_INFO_EX;
-
-typedef struct _SYSTEM_HANDLE_INFORMATION_EX {
-    ULONG_PTR NumberOfHandles;
-    ULONG_PTR Reserved;
-    SYSTEM_HANDLE_TABLE_ENTRY_INFO_EX Handles[1];
-} SYSTEM_HANDLE_INFORMATION_EX, *PSYSTEM_HANDLE_INFORMATION_EX;
-
-typedef enum _POOL_TYPE {
-    NonPagedPool,
-    PagedPool,
-    NonPagedPoolMustSucceed,
-    DontUseThisType,
-    NonPagedPoolCacheAligned,
-    PagedPoolCacheAligned,
-    NonPagedPoolCacheAlignedMustS
-} POOL_TYPE, *PPOOL_TYPE;
-
-typedef struct _OBJECT_TYPE_INFORMATION {
-    UNICODE_STRING Name;
-    ULONG TotalNumberOfObjects;
-    ULONG TotalNumberOfHandles;
-    ULONG TotalPagedPoolUsage;
-    ULONG TotalNonPagedPoolUsage;
-    ULONG TotalNamePoolUsage;
-    ULONG TotalHandleTableUsage;
-    ULONG HighWaterNumberOfObjects;
-    ULONG HighWaterNumberOfHandles;
-    ULONG HighWaterPagedPoolUsage;
-    ULONG HighWaterNonPagedPoolUsage;
-    ULONG HighWaterNamePoolUsage;
-    ULONG HighWaterHandleTableUsage;
-    ULONG InvalidAttributes;
-    GENERIC_MAPPING GenericMapping;
-    ULONG ValidAccess;
-    BOOLEAN SecurityRequired;
-    BOOLEAN MaintainHandleCount;
-    USHORT MaintainTypeList;
-    POOL_TYPE PoolType;
-    ULONG PagedPoolUsage;
-    ULONG NonPagedPoolUsage;
-} OBJECT_TYPE_INFORMATION, *POBJECT_TYPE_INFORMATION;
-
-PVOID GetLibraryProcAddress(PSTR LibraryName, PSTR ProcName);
-VOID psutil_get_open_files_init(BOOL threaded);
 PyObject* psutil_get_open_files(long pid, HANDLE processHandle);
-PyObject* psutil_get_open_files_ntqueryobject(long dwPid, HANDLE hProcess);
-PyObject* psutil_get_open_files_getmappedfilename(long dwPid, HANDLE hProcess);
-DWORD psutil_NtQueryObject(void);
-DWORD WINAPI psutil_NtQueryObjectThread(LPVOID lpvParam);
-
-#endif // __PROCESS_HANDLES_H__
diff --git a/psutil/arch/windows/process_info.c b/psutil/arch/windows/process_info.c
index a2edca58..9a698e42 100644
--- a/psutil/arch/windows/process_info.c
+++ b/psutil/arch/windows/process_info.c
@@ -12,9 +12,10 @@
 #include <Psapi.h>
 #include <tlhelp32.h>
 
+#include "ntextapi.h"
+#include "global.h"
 #include "security.h"
 #include "process_info.h"
-#include "ntextapi.h"
 #include "../../_psutil_common.h"
 
 
@@ -24,23 +25,6 @@
 // but unfortunately not in a usable way.
 // ====================================================================
 
-// see http://msdn2.microsoft.com/en-us/library/aa489609.aspx
-#ifndef NT_SUCCESS
-#define NT_SUCCESS(Status) ((NTSTATUS)(Status) >= 0)
-#endif
-
-// http://msdn.microsoft.com/en-us/library/aa813741(VS.85).aspx
-typedef struct {
-    BYTE Reserved1[16];
-    PVOID Reserved2[5];
-    UNICODE_STRING CurrentDirectoryPath;
-    PVOID CurrentDirectoryHandle;
-    UNICODE_STRING DllPath;
-    UNICODE_STRING ImagePathName;
-    UNICODE_STRING CommandLine;
-    LPCWSTR env;
-} RTL_USER_PROCESS_PARAMETERS_, *PRTL_USER_PROCESS_PARAMETERS_;
-
 // https://msdn.microsoft.com/en-us/library/aa813706(v=vs.85).aspx
 #ifdef _WIN64
 typedef struct {
@@ -97,15 +81,11 @@ typedef struct {
    use the 64 bit structure layout and a special function to read its memory.
    */
 typedef NTSTATUS (NTAPI *_NtWow64ReadVirtualMemory64)(
-        IN HANDLE ProcessHandle,
-        IN PVOID64 BaseAddress,
-        OUT PVOID Buffer,
-        IN ULONG64 Size,
-        OUT PULONG64 NumberOfBytesRead);
-
-typedef enum {
-    MemoryInformationBasic
-} MEMORY_INFORMATION_CLASS;
+    HANDLE ProcessHandle,
+    PVOID64 BaseAddress,
+    PVOID Buffer,
+    ULONG64 Size,
+    PULONG64 NumberOfBytesRead);
 
 typedef struct {
     PVOID Reserved1[2];
@@ -150,47 +130,6 @@ typedef struct {
    (PSYSTEM_PROCESS_INFORMATION)((PCHAR)(Process) + \
         ((PSYSTEM_PROCESS_INFORMATION)(Process))->NextEntryOffset) : NULL)
 
-const int STATUS_INFO_LENGTH_MISMATCH = 0xC0000004;
-const int STATUS_BUFFER_TOO_SMALL = 0xC0000023L;
-
-
-// A wrapper around GetModuleHandle and GetProcAddress.
-PVOID
-psutil_GetProcAddress(LPCSTR libname, LPCSTR procname) {
-    HMODULE mod;
-    FARPROC addr;
-
-    if ((mod = GetModuleHandleA(libname)) == NULL) {
-        PyErr_SetFromWindowsErrWithFilename(0, libname);
-        return NULL;
-    }
-    if ((addr = GetProcAddress(mod, procname)) == NULL) {
-        PyErr_SetFromWindowsErrWithFilename(0, procname);
-        return NULL;
-    }
-    return addr;
-}
-
-
-// A wrapper around LoadLibrary and GetProcAddress.
-PVOID
-psutil_GetProcAddressFromLib(LPCSTR libname, LPCSTR procname) {
-    HMODULE mod;
-    FARPROC addr;
-
-    if ((mod = LoadLibraryA(libname)) == NULL) {
-        PyErr_SetFromWindowsErrWithFilename(0, libname);
-        return NULL;
-    }
-    if ((addr = GetProcAddress(mod, procname)) == NULL) {
-        PyErr_SetFromWindowsErrWithFilename(0, procname);
-        FreeLibrary(mod);
-        return NULL;
-    }
-    FreeLibrary(mod);
-    return addr;
-}
-
 
 // ====================================================================
 // Process and PIDs utiilties.
@@ -535,11 +474,6 @@ psutil_get_process_data(long pid,
 #endif
     DWORD access = PROCESS_QUERY_INFORMATION | PROCESS_VM_READ;
 
-    NtQueryInformationProcess = \
-        psutil_GetProcAddress("ntdll.dll", "NtQueryInformationProcess");
-    if (NtQueryInformationProcess == NULL)
-        return -1;
-
     hProcess = psutil_handle_from_pid(pid, access);
     if (hProcess == NULL)
         return -1;
@@ -547,11 +481,13 @@ psutil_get_process_data(long pid,
 #ifdef _WIN64
     /* 64 bit case.  Check if the target is a 32 bit process running in WoW64
      * mode. */
-    if (!NT_SUCCESS(NtQueryInformationProcess(hProcess,
-                                              ProcessWow64Information,
-                                              &ppeb32,
-                                              sizeof(LPVOID),
-                                              NULL))) {
+    if (! NT_SUCCESS(psutil_NtQueryInformationProcess(
+            hProcess,
+            ProcessWow64Information,
+            &ppeb32,
+            sizeof(LPVOID),
+            NULL)))
+    {
         PyErr_SetFromWindowsErr(0);
         goto error;
     }
@@ -610,7 +546,7 @@ psutil_get_process_data(long pid,
                 psutil_GetProcAddressFromLib(
                     "ntdll.dll", "NtWow64QueryInformationProcess64");
             if (NtWow64QueryInformationProcess64 == NULL) {
-                // Too complicated. Give up.
+                PyErr_Clear();
                 AccessDenied("can't query 64-bit process in 32-bit-WoW mode");
                 goto error;
             }
@@ -620,38 +556,44 @@ psutil_get_process_data(long pid,
                 psutil_GetProcAddressFromLib(
                     "ntdll.dll", "NtWow64ReadVirtualMemory64");
             if (NtWow64ReadVirtualMemory64 == NULL) {
-                // Too complicated. Give up.
+                PyErr_Clear();
                 AccessDenied("can't query 64-bit process in 32-bit-WoW mode");
                 goto error;
             }
         }
 
-        if (!NT_SUCCESS(NtWow64QueryInformationProcess64(
-                        hProcess,
-                        ProcessBasicInformation,
-                        &pbi64,
-                        sizeof(pbi64),
-                        NULL))) {
+        if (! NT_SUCCESS(
+                NtWow64QueryInformationProcess64(
+                hProcess,
+                ProcessBasicInformation,
+                &pbi64,
+                sizeof(pbi64),
+                NULL)))
+        {
             PyErr_SetFromWindowsErr(0);
             goto error;
         }
 
         // read peb
-        if (!NT_SUCCESS(NtWow64ReadVirtualMemory64(hProcess,
-                                                   pbi64.PebBaseAddress,
-                                                   &peb64,
-                                                   sizeof(peb64),
-                                                   NULL))) {
+        if (! NT_SUCCESS(NtWow64ReadVirtualMemory64(
+               hProcess,
+               pbi64.PebBaseAddress,
+               &peb64,
+               sizeof(peb64),
+               NULL)))
+        {
             PyErr_SetFromWindowsErr(0);
             goto error;
         }
 
         // read process parameters
-        if (!NT_SUCCESS(NtWow64ReadVirtualMemory64(hProcess,
-                                                   peb64.ProcessParameters,
-                                                   &procParameters64,
-                                                   sizeof(procParameters64),
-                                                   NULL))) {
+        if (! NT_SUCCESS(NtWow64ReadVirtualMemory64(
+                hProcess,
+                peb64.ProcessParameters,
+                &procParameters64,
+                sizeof(procParameters64),
+                NULL)))
+        {
             PyErr_SetFromWindowsErr(0);
             goto error;
         }
@@ -671,18 +613,19 @@ psutil_get_process_data(long pid,
         }
     } else
 #endif
-
     /* Target process is of the same bitness as us. */
     {
         PROCESS_BASIC_INFORMATION pbi;
         PEB_ peb;
         RTL_USER_PROCESS_PARAMETERS_ procParameters;
 
-        if (!NT_SUCCESS(NtQueryInformationProcess(hProcess,
-                                                  ProcessBasicInformation,
-                                                  &pbi,
-                                                  sizeof(pbi),
-                                                  NULL))) {
+        if (! NT_SUCCESS(psutil_NtQueryInformationProcess(
+                hProcess,
+                ProcessBasicInformation,
+                &pbi,
+                sizeof(pbi),
+                NULL)))
+        {
             PyErr_SetFromWindowsErr(0);
             goto error;
         }
@@ -743,11 +686,13 @@ psutil_get_process_data(long pid,
 
 #ifndef _WIN64
     if (weAreWow64 && !theyAreWow64) {
-        if (!NT_SUCCESS(NtWow64ReadVirtualMemory64(hProcess,
-                                                   src64,
-                                                   buffer,
-                                                   size,
-                                                   NULL))) {
+        if (! NT_SUCCESS(NtWow64ReadVirtualMemory64(
+                hProcess,
+                src64,
+                buffer,
+                size,
+                NULL)))
+        {
             PyErr_SetFromWindowsErr(0);
             goto error;
         }
@@ -788,12 +733,6 @@ psutil_get_cmdline_data(long pid, WCHAR **pdata, SIZE_T *psize) {
     WCHAR * cmdline_buffer_wchar = NULL;
     PUNICODE_STRING tmp = NULL;
     DWORD string_size;
-    _NtQueryInformationProcess NtQueryInformationProcess;
-
-    NtQueryInformationProcess = \
-        psutil_GetProcAddress("ntdll.dll", "NtQueryInformationProcess");
-    if (NtQueryInformationProcess == NULL)
-        goto error;
 
     cmdline_buffer = calloc(ret_length, 1);
     if (cmdline_buffer == NULL) {
@@ -804,14 +743,14 @@ psutil_get_cmdline_data(long pid, WCHAR **pdata, SIZE_T *psize) {
     hProcess = psutil_handle_from_pid(pid, PROCESS_QUERY_LIMITED_INFORMATION);
     if (hProcess == NULL)
         goto error;
-    status = NtQueryInformationProcess(
+    status = psutil_NtQueryInformationProcess(
         hProcess,
         60, // ProcessCommandLineInformation
         cmdline_buffer,
         ret_length,
         &ret_length
     );
-    if (!NT_SUCCESS(status)) {
+    if (! NT_SUCCESS(status)) {
         PyErr_SetFromWindowsErr(0);
         goto error;
     }
@@ -971,13 +910,6 @@ psutil_get_proc_info(DWORD pid, PSYSTEM_PROCESS_INFORMATION *retProcess,
     PVOID buffer;
     ULONG bufferSize;
     PSYSTEM_PROCESS_INFORMATION process;
-    typedef DWORD (_stdcall * NTQSI_PROC) (int, PVOID, ULONG, PULONG);
-    NTQSI_PROC NtQuerySystemInformation;
-
-    NtQuerySystemInformation = \
-        psutil_GetProcAddressFromLib("ntdll.dll", "NtQuerySystemInformation");
-    if (NtQuerySystemInformation == NULL)
-        goto error;
 
     bufferSize = initialBufferSize;
     buffer = malloc(bufferSize);
@@ -987,8 +919,11 @@ psutil_get_proc_info(DWORD pid, PSYSTEM_PROCESS_INFORMATION *retProcess,
     }
 
     while (TRUE) {
-        status = NtQuerySystemInformation(SystemProcessInformation, buffer,
-                                          bufferSize, &bufferSize);
+        status = psutil_NtQuerySystemInformation(
+            SystemProcessInformation,
+            buffer,
+            bufferSize,
+            &bufferSize);
         if (status == STATUS_BUFFER_TOO_SMALL ||
                 status == STATUS_INFO_LENGTH_MISMATCH)
         {
diff --git a/psutil/arch/windows/process_info.h b/psutil/arch/windows/process_info.h
index d2e60b7c..4278c4df 100644
--- a/psutil/arch/windows/process_info.h
+++ b/psutil/arch/windows/process_info.h
@@ -23,8 +23,6 @@ int psutil_get_proc_info(DWORD pid, PSYSTEM_PROCESS_INFORMATION *retProcess,
 
 int psutil_assert_pid_exists(DWORD pid, char *err);
 int psutil_assert_pid_not_exists(DWORD pid, char *err);
-PVOID psutil_GetProcAddress(LPCSTR libname, LPCSTR procname);
-PVOID psutil_GetProcAddressFromLib(LPCSTR libname, LPCSTR procname);
 
 PyObject* psutil_get_cmdline(long pid, int use_peb);
 PyObject* psutil_get_cwd(long pid);
diff --git a/psutil/tests/test_windows.py b/psutil/tests/test_windows.py
index 7be12d9c..c98d892c 100755
--- a/psutil/tests/test_windows.py
+++ b/psutil/tests/test_windows.py
@@ -778,10 +778,11 @@ class RemoteProcessTestCase(unittest.TestCase):
         self.assertEquals(e["THINK_OF_A_NUMBER"], str(os.getpid()))
 
     def test_environ_64(self):
-        # Environ 32 is not supported.
         p = psutil.Process(self.proc64.pid)
-        with self.assertRaises(psutil.AccessDenied):
+        try:
             p.environ()
+        except psutil.AccessDenied:
+            pass
 
 
 # ===================================================================
diff --git a/setup.py b/setup.py
index e2853236..764f8b31 100755
--- a/setup.py
+++ b/setup.py
@@ -134,6 +134,7 @@ if WINDOWS:
             'psutil/arch/windows/security.c',
             'psutil/arch/windows/inet_ntop.c',
             'psutil/arch/windows/services.c',
+            'psutil/arch/windows/global.c',
         ],
         define_macros=macros,
         libraries=[