Use real system default value of FD_SETSIZE instead of guessing

src/include/platform.h

@@ -63,24 +63,14 @@
 /* Some platforms (FreeBSD, Solaris, W32) allow to override
    default FD_SETSIZE by defining it before including
    headers. */
-#if defined(_WIN32) && !defined(__CYGWIN__)
-/* Default FD_SETSIZE value for WinSock */
-#define MHD_SYS_DEFAULT_FD_SETSIZE 64
-#elif defined(__sun) && defined(_LP64)
-/* Default FD_SETSIZE value for 64bit Solaris since version 7
-   and SunOS since version 2.7 */
-#define MHD_SYS_DEFAULT_FD_SETSIZE 65536
-#else  /* all other platforms */
-/* Default FD_SETSIZE value for most platforms */
-#define MHD_SYS_DEFAULT_FD_SETSIZE 1024
-#endif /* all other platforms */
+#define _MHD_SYS_DEFAULT_FD_SETSIZE get_system_fdsetsize_value()
 #elif defined(_WIN32) && !defined(__CYGWIN__)
 /* Platform with WinSock and without overridden FD_SETSIZE */
 #define FD_SETSIZE 2048 /* Override default small value */
-#define MHD_SYS_DEFAULT_FD_SETSIZE 64
-#else
-/* Use system default value */
-#define MHD_SYS_DEFAULT_FD_SETSIZE FD_SETSIZE
+#define _MHD_SYS_DEFAULT_FD_SETSIZE get_system_fdsetsize_value()
+#else /* !FD_SETSIZE && !WinSock*/
+#define _MHD_SYS_DEFAULT_FD_SETSIZE FD_SETSIZE
+#define _MHD_FD_SETSIZE_IS_DEFAULT 1
 #endif /* FD_SETSIZE */
 
 #define _XOPEN_SOURCE_EXTENDED  1

src/microhttpd/Makefile.am

@@ -64,6 +64,7 @@ libmicrohttpd_la_SOURCES = \
   memorypool.c memorypool.h \
   mhd_mono_clock.c mhd_mono_clock.h \
   mhd_limits.h mhd_byteorder.h \
+  sysfdsetsize.c sysfdsetsize.h \
   response.c response.h
 libmicrohttpd_la_CPPFLAGS = \
   $(AM_CPPFLAGS) $(MHD_LIB_CPPFLAGS) \

src/microhttpd/daemon.c

@@ -52,6 +52,10 @@
 #include <sys/sendfile.h>
 #endif
 
+#ifndef _MHD_FD_SETSIZE_IS_DEFAULT
+#include "sysfdsetsize.h"
+#endif /* !_MHD_FD_SETSIZE_IS_DEFAULT */
+
 #ifdef _WIN32
 #ifndef WIN32_LEAN_AND_MEAN
 #define WIN32_LEAN_AND_MEAN 1
@@ -677,7 +681,7 @@ MHD_get_fdset (struct MHD_Daemon *daemon,
 {
   return MHD_get_fdset2(daemon, read_fd_set,
       write_fd_set, except_fd_set,
-      max_fd, MHD_SYS_DEFAULT_FD_SETSIZE);
+      max_fd, _MHD_SYS_DEFAULT_FD_SETSIZE);
 }
 
 /**

w32/common/libmicrohttpd-files.vcxproj

@@ -14,6 +14,7 @@
     <ClCompile Include="$(MhdSrc)microhttpd\reason_phrase.c" />
     <ClCompile Include="$(MhdSrc)microhttpd\response.c" />
     <ClCompile Include="$(MhdSrc)microhttpd\tsearch.c" />
+    <ClCompile Include="$(MhdSrc)microhttpd\sysfdsetsize.c" />
     <ClCompile Include="$(MhdSrc)platform\w32functions.c" />
   </ItemGroup>
   <ItemGroup>
@@ -32,6 +33,7 @@
     <ClInclude Include="$(MhdSrc)microhttpd\mhd_mono_clock.h" />
     <ClInclude Include="$(MhdSrc)microhttpd\response.h" />
     <ClInclude Include="$(MhdSrc)microhttpd\tsearch.h" />
+    <ClInclude Include="$(MhdSrc)microhttpd\sysfdsetsize.h" />
     <ClInclude Include="$(MhdW32Common)MHD_config.h" />
   </ItemGroup>
   <ItemGroup>

w32/common/libmicrohttpd-filters.vcxproj

@@ -22,6 +22,29 @@
       <Extensions>in</Extensions>
     </Filter>
   </ItemGroup>
+  <ItemGroup>
+    <ClInclude Include="$(MhdSrc)include\autoinit_funcs.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="$(MhdSrc)include\microhttpd.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="$(MhdSrc)include\platform.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="$(MhdSrc)include\platform_interface.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="$(MhdSrc)include\w32functions.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClInclude Include="$(MhdW32Common)MHD_config.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
+    <ClCompile Include="$(MhdSrc)platform\w32functions.c">
+      <Filter>Source Files\platform_interface</Filter>
+    </ClCompile>
+  </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(MhdSrc)microhttpd\base64.c">
       <Filter>Source Files</Filter>
@@ -56,17 +79,12 @@
     <ClCompile Include="$(MhdSrc)microhttpd\response.c">
       <Filter>Source Files</Filter>
     </ClCompile>
-    <ClCompile Include="$(MhdSrc)platform\w32functions.c">
-      <Filter>Source Files\platform_interface</Filter>
-    </ClCompile>
     <ClCompile Include="$(MhdSrc)microhttpd\tsearch.c">
       <Filter>Source Files</Filter>
     </ClCompile>
     <ClCompile Include="$(MhdSrc)microhttpd\mhd_mono_clock.c">
       <Filter>Source Files</Filter>
     </ClCompile>
-  </ItemGroup>
-  <ItemGroup>
     <ClInclude Include="$(MhdSrc)microhttpd\base64.h">
       <Filter>Source Files</Filter>
     </ClInclude>
@@ -85,27 +103,9 @@
     <ClInclude Include="$(MhdSrc)microhttpd\response.h">
       <Filter>Source Files</Filter>
     </ClInclude>
-    <ClInclude Include="$(MhdSrc)include\microhttpd.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
-    <ClInclude Include="$(MhdSrc)include\platform.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
-    <ClInclude Include="$(MhdSrc)include\platform_interface.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
-    <ClInclude Include="$(MhdSrc)include\w32functions.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
-    <ClInclude Include="$(MhdW32Common)MHD_config.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="$(MhdSrc)microhttpd\tsearch.h">
       <Filter>Source Files</Filter>
     </ClInclude>
-    <ClInclude Include="$(MhdSrc)include\autoinit_funcs.h">
-      <Filter>Header Files</Filter>
-    </ClInclude>
     <ClInclude Include="$(MhdSrc)microhttpd\mhd_limits.h">
       <Filter>Source Files</Filter>
     </ClInclude>
@@ -115,6 +115,12 @@
     <ClInclude Include="$(MhdSrc)microhttpd\mhd_mono_clock.h">
       <Filter>Source Files</Filter>
     </ClInclude>
+    <ClInclude Include="$(MhdSrc)microhttpd\sysfdsetsize.h">
+      <Filter>Source Files</Filter>
+    </ClInclude>
+    <ClCompile Include="$(MhdSrc)microhttpd\sysfdsetsize.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="$(MhdW32Common)microhttpd_dll_res_vc.rc">