Addresses #1321

Reopens ticket.
Cannot get handles (from _get_osfhandle) to work with ReadFile or WriteFile

git-svn-id: file:///svn/toku/tokudb.1032b@8373 c7de825b-a66e-492c-adef-691d508d4ae1

windows/files.c

@@ -4,36 +4,27 @@
 #include <unistd.h>
 #include <windows.h>
 
+// Note: pread and pwrite are not thread safe on the same fildes as they
+// rely on the file offset
+
 int64_t
 pread(int fildes, void *buf, size_t nbyte, int64_t offset) {
-    long     handle;
-    OVERLAPPED win_offset = {0}; 
-    handle =  _get_osfhandle(fildes);
-    win_offset.Offset     = offset % (1LL<<32LL);
-    win_offset.OffsetHigh = offset / (1LL<<32LL);
-
-    DWORD bytes_read;
-    int64_t r = ReadFile(&handle, buf, nbyte, &bytes_read, &win_offset);
-    if (!r) r = GetLastError();
-    else    r = bytes_read;
-
+    int64_t r = _lseeki64(fildes, offset, SEEK_SET);
+    if (r>=0) {
+        assert(r==offset);
+        r = read(fildes, buf, nbyte);
+    }
     // printf("%s: %d %p %u %I64d %I64d\n", __FUNCTION__, fildes, buf, nbyte, offset, r); fflush(stdout);
     return r;
 }
 
 int64_t
 pwrite(int fildes, const void *buf, size_t nbyte, int64_t offset) {
-    long     handle;
-    OVERLAPPED win_offset = {0}; 
-    handle =  _get_osfhandle(fildes);
-    win_offset.Offset     = offset % (1LL<<32LL);
-    win_offset.OffsetHigh = offset / (1LL<<32LL);
-
-    DWORD bytes_written;
-    int64_t r = WriteFile(&handle, buf, nbyte, &bytes_written, &win_offset);
-    if (!r) r = GetLastError();
-    else    r = bytes_written;
-
+    int64_t r = _lseeki64(fildes, offset, SEEK_SET);
+    if (r>=0) {
+        assert(r==offset);
+        r = write(fildes, buf, nbyte);
+    }
     // printf("%s: %d %p %u %I64d %I64d\n", __FUNCTION__, fildes, buf, nbyte, offset, r); fflush(stdout);
     return r;
 }