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

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;
+}

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);