Add high resolution to nmsleep wrapper on windows.

Makefile.am

@@ -24,7 +24,7 @@ bin_SCRIPTS	= $(top_srcdir)/*.cl
 cgminer_LDFLAGS	= $(PTHREAD_FLAGS)
 cgminer_LDADD	= $(DLOPEN_FLAGS) @LIBCURL_LIBS@ @JANSSON_LIBS@ @PTHREAD_LIBS@ \
 		  @OPENCL_LIBS@ @NCURSES_LIBS@ @PDCURSES_LIBS@ @WS2_LIBS@ \
-		  @UDEV_LIBS@ @LIBUSB_LIBS@ \
+		  @UDEV_LIBS@ @LIBUSB_LIBS@ @MM_LIBS@ \
 		  @MATH_LIBS@ lib/libgnu.a ccan/libccan.a
 
 if HAVE_WINDOWS

configure.ac

@@ -65,6 +65,7 @@ PTHREAD_FLAGS="-lpthread"
 DLOPEN_FLAGS="-ldl"
 OPENCL_LIBS="-lOpenCL"
 WS2_LIBS=""
+MM_LIBS=""
 MATH_LIBS="-lm"
 
 case $target in
@@ -85,6 +86,7 @@ case $target in
     PTHREAD_FLAGS=""
     DLOPEN_FLAGS=""
     WS2_LIBS="-lws2_32"
+    MM_LIBS="-lwinmm"
     AC_DEFINE([_WIN32_WINNT], [0x0501], "WinNT version for XP+ support")
     ;;
   powerpc-*-darwin*)
@@ -493,6 +495,7 @@ AC_SUBST(PTHREAD_LIBS)
 AC_SUBST(NCURSES_LIBS)
 AC_SUBST(PDCURSES_LIBS)
 AC_SUBST(WS2_LIBS)
+AC_SUBST(MM_LIBS)
 AC_SUBST(MATH_LIBS)
 AC_SUBST(UDEV_LIBS)
 AC_SUBST(YASM_FMT)

util.c

@@ -30,6 +30,7 @@
 # include <netinet/tcp.h>
 # include <netdb.h>
 #else
+# include <windows.h>
 # include <winsock2.h>
 # include <ws2tcpip.h>
 #endif
@@ -825,6 +826,9 @@ void nmsleep(unsigned int msecs)
 	int ret;
 	ldiv_t d;
 
+#ifdef WIN32
+	timeBeginPeriod(1);
+#endif
 	d = ldiv(msecs, 1000);
 	tleft.tv_sec = d.quot;
 	tleft.tv_nsec = d.rem * 1000000;
@@ -833,6 +837,9 @@ void nmsleep(unsigned int msecs)
 		twait.tv_nsec = tleft.tv_nsec;
 		ret = nanosleep(&twait, &tleft);
 	} while (ret == -1 && errno == EINTR);
+#ifdef WIN32
+	timeEndPeriod(1);
+#endif
 }
 
 /* Returns the microseconds difference between end and start times as a double */