intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 71 insertions, 0 deletions

diff --git a/util/system/flock.cpp b/util/system/flock.cpp
new file mode 100644
index 0000000000..fe88fecaff
--- /dev/null
+++ b/util/system/flock.cpp
@@ -0,0 +1,71 @@
+#include "flock.h"
+
+#ifndef _unix_
+
+    #include <util/generic/utility.h>
+
+    #include "winint.h"
+    #include <io.h>
+    #include <errno.h>
+
+    #ifdef __cplusplus
+extern "C" {
+    #endif
+
+    int flock(int fd, int op) {
+        return Flock((HANDLE)_get_osfhandle(fd), op);
+    }
+
+    int Flock(void* hdl, int op) {
+        errno = 0;
+
+        if (hdl == INVALID_HANDLE_VALUE) {
+            errno = EBADF;
+            return -1;
+        }
+
+        DWORD low = 1, high = 0;
+        OVERLAPPED io;
+
+        Zero(io);
+
+        UnlockFileEx(hdl, 0, low, high, &io);
+
+        switch (op & ~LOCK_NB) {
+            case LOCK_EX:
+            case LOCK_SH: {
+                auto mode = ((op & ~LOCK_NB) == LOCK_EX) ? LOCKFILE_EXCLUSIVE_LOCK : 0;
+                if (op & LOCK_NB) {
+                    if (LockFileEx(hdl, mode | LOCKFILE_FAIL_IMMEDIATELY, 0, low, high, &io)) {
+                        return 0;
+                    } else if (GetLastError() == ERROR_LOCK_VIOLATION) {
+                        ClearLastSystemError();
+                        errno = EWOULDBLOCK;
+                        return -1;
+                    }
+                } else {
+                    if (LockFileEx(hdl, mode, 0, low, high, &io)) {
+                        return 0;
+                    }
+                }
+                break;
+            }
+            case LOCK_UN:
+                return 0;
+                break;
+            default:
+                break;
+        }
+        errno = EINVAL;
+        return -1;
+    }
+
+    int fsync(int fd) {
+        return _commit(fd);
+    }
+
+    #ifdef __cplusplus
+}
+    #endif
+
+#endif