1 files changed, 82 insertions, 0 deletions
diff --git a/v_windows/v/vlib/os/filelock/lib_nix.c.v b/v_windows/v/vlib/os/filelock/lib_nix.c.v
new file mode 100644
index 0000000..1af9916
--- /dev/null
+++ b/v_windows/v/vlib/os/filelock/lib_nix.c.v
@@ -0,0 +1,82 @@
+module filelock
+
+import time
+
+#include <sys/file.h>
+
+fn C.unlink(&char) int
+fn C.open(&char, int, int) int
+fn C.flock(int, int) int
+
+[unsafe]
+pub fn (mut l FileLock) unlink() {
+	if l.fd != -1 {
+		C.close(l.fd)
+		l.fd = -1
+	}
+	C.unlink(&char(l.name.str))
+}
+
+pub fn (mut l FileLock) acquire() ?bool {
+	if l.fd != -1 {
+		// lock already acquired by this instance
+		return false
+	}
+	fd := open_lockfile(l.name)
+	if fd == -1 {
+		return error('cannot create lock file $l.name')
+	}
+	if C.flock(fd, C.LOCK_EX) == -1 {
+		C.close(fd)
+		return error('cannot lock')
+	}
+	l.fd = fd
+	return true
+}
+
+pub fn (mut l FileLock) release() bool {
+	if l.fd != -1 {
+		unsafe {
+			l.unlink()
+		}
+		return true
+	}
+	return false
+}
+
+pub fn (mut l FileLock) wait_acquire(s int) ?bool {
+	fin := time.now().add(s)
+	for time.now() < fin {
+		if l.try_acquire() {
+			return true
+		}
+		C.usleep(1000)
+	}
+	return false
+}
+
+fn open_lockfile(f string) int {
+	mut fd := C.open(&char(f.str), C.O_CREAT, 0o644)
+	if fd == -1 {
+		// if stat is too old delete lockfile
+		fd = C.open(&char(f.str), C.O_RDONLY, 0)
+	}
+	return fd
+}
+
+pub fn (mut l FileLock) try_acquire() bool {
+	if l.fd != -1 {
+		return true
+	}
+	fd := open_lockfile('$l.name')
+	if fd != -1 {
+		err := C.flock(fd, C.LOCK_EX | C.LOCK_NB)
+		if err == -1 {
+			C.close(fd)
+			return false
+		}
+		l.fd = fd
+		return true
+	}
+	return false
+}