windows: add definition of getpid and getcwd

getcwd - is used in lib/util.c. getcwd is deprecated on Windows but has
_getcwd which is defined in <direct.h>:
https://msdn.microsoft.com/en-us/library/sf98bd4y(v=vs.120).aspx

getpid - is used in several files (i.e. lib/vlog.c). getpid
is also and deprecated and _getpid should be used:
https://msdn.microsoft.com/en-us/library/t2y34y40(v=vs.120).aspx
The problem using _getpid is that the definition is in <process.h>.
A file called process.h also exists in the lib folder. This will mess up
includes.
An option would be to use a wrapper like we use for lib/string.h(.in) but
that would mean to also add it to the automake chain.
A simple solution would be to map it to GetCurrentProcessId
https://msdn.microsoft.com/en-us/library/windows/desktop/ms683180(v=vs.85).aspx

_getpid uses GetCurrentProcessId behind the scenes, casting the result
is not required.

Signed-off-by: Alin Gabriel Serdean <aserdean@cloudbasesolutions.com>
Co-authored-by: Ben Pfaff <blp@ovn.org>
Signed-off-by: Ben Pfaff <blp@ovn.org>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/windows/unistd.h b/include/windows/unistd.h
index 8629f7e11..2e9f0aef1 100644
--- a/include/windows/unistd.h
+++ b/include/windows/unistd.h
@@ -18,8 +18,11 @@
 
 #define WIN32_LEAN_AND_MEAN
 #include <windows.h>
+#include <direct.h>
+#include <windefs.h>
 
 #define fsync _commit
+#define getcwd _getcwd
 
 /* Standard file descriptors.  */
 #define STDIN_FILENO    0   /* Standard input.  */
@@ -33,6 +36,15 @@
 #define _SC_NPROCESSORS_ONLN            0x2
 #define _SC_PHYS_PAGES                  0x4
 
+
+static __inline pid_t getpid(void)
+{
+    /* Since _getpid: https://msdn.microsoft.com/en-us/library/t2y34y40.aspx
+     * uses GetCurrentProcessId behind the scenes it is safe to assume no
+     * casting is required */
+    return GetCurrentProcessId();
+}
+
 __inline int GetNumLogicalProcessors(void)
 {
     SYSTEM_INFO info_temp;