posix: use WSAPoll on win32

src/CMakeLists.txt

@@ -89,8 +89,12 @@ check_function_exists(getloadavg GIT_RAND_GETLOADAVG)
 
 # poll
 
-check_symbol_exists(poll poll.h GIT_IO_POLL)
-check_symbol_exists(select sys/select.h GIT_IO_SELECT)
+if(WIN32)
+	set(GIT_IO_WSAPOLL 1)
+else()
+	check_symbol_exists(poll poll.h GIT_IO_POLL)
+	check_symbol_exists(select sys/select.h GIT_IO_SELECT)
+endif()
 
 # determine architecture of the machine
 

src/util/git2_features.h.in

@@ -62,6 +62,7 @@
 #cmakedefine GIT_RAND_GETLOADAVG 1
 
 #cmakedefine GIT_IO_POLL 1
+#cmakedefine GIT_IO_WSAPOLL 1
 #cmakedefine GIT_IO_SELECT 1
 
 #endif

src/util/posix.h

@@ -198,6 +198,9 @@ extern const char *p_gai_strerror(int ret);
 #ifdef GIT_IO_POLL
 # include <poll.h>
 # define p_poll poll
+#elif GIT_IO_WSAPOLL
+# include <winsock2.h>
+# define p_poll WSAPoll
 #else
 # define POLLIN  0x01
 # define POLLPRI 0x02