termux-packages/x11-packages/qemu-system-x86_64/qemu-2.12.1_lockf_implementation.h.patch

diff -uNr qemu-2.12.1/lockf_implementation.h qemu-2.12.1.mod/lockf_implementation.h
--- qemu-2.12.1/lockf_implementation.h	1970-01-01 03:00:00.000000000 +0300
+++ qemu-2.12.1.mod/lockf_implementation.h	2018-09-17 16:27:47.010729227 +0300
@@ -0,0 +1,56 @@
+#ifndef LOCKF_IMPLEMENTATION_H
+#define LOCKF_IMPLEMENTATION_H
+
+//
+// lockf() implementation from GNU Libc
+//
+
+static int lockf (int fd, int cmd, off_t len)
+{
+  struct flock fl;
+
+  memset ((char *) &fl, '\0', sizeof (fl));
+
+  /* lockf is always relative to the current file position.  */
+  fl.l_whence = SEEK_CUR;
+  fl.l_start = 0;
+  fl.l_len = len;
+
+  switch (cmd)
+    {
+    case F_TEST:
+      /* Test the lock: return 0 if FD is unlocked or locked by this process;
+     return -1, set errno to EACCES, if another process holds the lock.  */
+      fl.l_type = F_RDLCK;
+      if (fcntl (fd, F_GETLK, &fl) < 0)
+    return -1;
+      if (fl.l_type == F_UNLCK || fl.l_pid == getpid ())
+    return 0;
+      errno = EACCES;
+      return -1;
+
+    case F_ULOCK:
+      fl.l_type = F_UNLCK;
+      cmd = F_SETLK;
+      break;
+    case F_LOCK:
+      fl.l_type = F_WRLCK;
+      cmd = F_SETLKW;
+      break;
+    case F_TLOCK:
+      fl.l_type = F_WRLCK;
+      cmd = F_SETLK;
+      break;
+
+    default:
+      errno = EINVAL;
+      return -1;
+    }
+
+  /* lockf() is a cancellation point but so is fcntl() if F_SETLKW is
+     used.  Therefore we don't have to care about cancellation here,
+     the fcntl() function will take care of it.  */
+  return fcntl (fd, cmd, &fl);
+}
+
+#endif