svn commit: r1534102 - in /subversion/trunk: build.conf subversion/libsvn_subr/sysinfo.c

[rh...@apache.org]

Author: rhuijben
Date: Mon Oct 21 11:30:06 2013
New Revision: 1534102

URL: http://svn.apache.org/r1534102
Log:
On Windows: stop linking against a system DLL that is not used by most
processes, to avoid a slight performance penalty on loading libsvn_subr
that is only needed for 'svn --version --verbose'.

As this dll is usually not loaded and not needed except for debugging,
we don't want to pay the system (and especially virusscanner) overhead
of always loading this dll.

* build.conf
  (libsvn_subr): Remove psapi.lib.

* subversion/libsvn_subr/sysinfo.c
  (FNENUMPROCESSMODULES): Fix definition to match system header.
  (enum_loaded_modules): Obtain EnumProcessModules dynamically.

Modified:
    subversion/trunk/build.conf
    subversion/trunk/subversion/libsvn_subr/sysinfo.c

Modified: subversion/trunk/build.conf
URL: http://svn.apache.org/viewvc/subversion/trunk/build.conf?rev=1534102&r1=1534101&r2=1534102&view=diff
==============================================================================
--- subversion/trunk/build.conf (original)
+++ subversion/trunk/build.conf Mon Oct 21 11:30:06 2013
@@ -357,7 +357,7 @@ install = fsmod-lib
 path = subversion/libsvn_subr
 libs = aprutil apriconv apr xml zlib apr_memcache sqlite magic intl
 msvc-libs = kernel32.lib advapi32.lib shfolder.lib ole32.lib
-            crypt32.lib version.lib psapi.lib
+            crypt32.lib version.lib
 msvc-export = 
         svn_auth.h svn_base64.h svn_cache_config.h svn_checksum.h svn_cmdline.h
         svn_compat.h svn_config.h svn_ctype.h svn_dirent_uri.h svn_dso.h 

Modified: subversion/trunk/subversion/libsvn_subr/sysinfo.c
URL: http://svn.apache.org/viewvc/subversion/trunk/subversion/libsvn_subr/sysinfo.c?rev=1534102&r1=1534101&r2=1534102&view=diff
==============================================================================
--- subversion/trunk/subversion/libsvn_subr/sysinfo.c (original)
+++ subversion/trunk/subversion/libsvn_subr/sysinfo.c Mon Oct 21 11:30:06 2013
@@ -546,7 +546,7 @@ linux_release_name(apr_pool_t *pool)
 
 #ifdef WIN32
 typedef DWORD (WINAPI *FNGETNATIVESYSTEMINFO)(LPSYSTEM_INFO);
-typedef BOOL (WINAPI *FNENUMPROCESSMODULES) (HANDLE, HMODULE, DWORD, LPDWORD);
+typedef BOOL (WINAPI *FNENUMPROCESSMODULES) (HANDLE, HMODULE*, DWORD, LPDWORD);
 
 /* Get system and version info, and try to tell the difference
    between the native system type and the runtime environment of the
@@ -763,16 +763,36 @@ win32_release_name(apr_pool_t *pool)
 static HMODULE *
 enum_loaded_modules(apr_pool_t *pool)
 {
+  HMODULE psapi_dll = 0;
   HANDLE current = GetCurrentProcess();
   HMODULE dummy[1];
   HMODULE *handles;
   DWORD size;
+  FNENUMPROCESSMODULES EnumProcessModules_;
 
-  if (!EnumProcessModules(current, dummy, sizeof(dummy), &size))
+  psapi_dll = GetModuleHandleA("psapi.dll");
+
+  if (!psapi_dll)
+    {
+      /* Load and never unload, just like static linking */
+      psapi_dll = LoadLibraryA("psapi.dll");
+    }
+
+  if (!psapi_dll)
+      return NULL;
+
+  EnumProcessModules_ = (FNENUMPROCESSMODULES)
+                              GetProcAddress(psapi_dll, "EnumProcessModules");
+
+  /* Before Windows XP psapi was an optional module */
+  if (! EnumProcessModules_)
+    return NULL;
+
+  if (!EnumProcessModules_(current, dummy, sizeof(dummy), &size))
     return NULL;
 
   handles = apr_palloc(pool, size + sizeof *handles);
-  if (!EnumProcessModules(current, handles, size, &size))
+  if (! EnumProcessModules_(current, handles, size, &size))
     return NULL;
   handles[size / sizeof *handles] = NULL;
   return handles;

Re: svn commit: r1534102 - in /subversion/trunk: build.conf subversion/libsvn_subr/sysinfo.c

[Ivan Zhakov <iv...@visualsvn.com>]

On 21 October 2013 15:30,  <rh...@apache.org> wrote:
> Author: rhuijben
> Date: Mon Oct 21 11:30:06 2013
> New Revision: 1534102
>
> URL: http://svn.apache.org/r1534102
> Log:
> On Windows: stop linking against a system DLL that is not used by most
> processes, to avoid a slight performance penalty on loading libsvn_subr
> that is only needed for 'svn --version --verbose'.
>
> As this dll is usually not loaded and not needed except for debugging,
> we don't want to pay the system (and especially virusscanner) overhead
> of always loading this dll.
>
May be it's worth to remove #include <psapi.h> to prevent accidental
usage of psapi functions directly?


-- 
Ivan Zhakov
CTO | VisualSVN | http://www.visualsvn.com