1 files changed, 116 insertions, 0 deletions
diff --git a/vere/pkg/vere/platform/windows/daemon.c b/vere/pkg/vere/platform/windows/daemon.c
new file mode 100644
index 0000000..e08b945
--- /dev/null
+++ b/vere/pkg/vere/platform/windows/daemon.c
@@ -0,0 +1,116 @@
+#include "noun.h"
+#include "vere.h"
+
+/* _dup_std_handle(): creates an inheritable duplicate of a standard handle.
+*/
+static BOOL
+_dup_std_handle(HANDLE* new_u, DWORD typ_u)
+{
+  DWORD dum_u;
+  HANDLE han_u = GetStdHandle(typ_u);
+  BOOL con_u = GetConsoleMode(han_u, &dum_u);
+  if ( con_u ) {
+    han_u = (HANDLE)_get_osfhandle(c3_open(c3_dev_null, O_RDWR, 0));
+  }
+
+  if ( !DuplicateHandle(GetCurrentProcess(), han_u, GetCurrentProcess(), new_u, 0, TRUE, DUPLICATE_SAME_ACCESS) ) {
+    fprintf(stderr, "vere: DuplicateHandle(%lu): %lu\r\n", typ_u, GetLastError());
+    exit(1);
+  }
+
+  return con_u;
+}
+
+/* _on_boot_completed_cb: invoked when the ship has finished booting.
+*/
+static void _on_boot_completed_cb() {
+  HANDLE hin_u = GetStdHandle(STD_INPUT_HANDLE);
+  SetEvent(hin_u);
+  CloseHandle(hin_u);
+}
+
+/* u3_daemon_init(): platform-specific daemon mode initialization.
+*/
+void
+u3_daemon_init()
+{
+  //  detect if this process is the child daemon process
+  //
+  if ( ResetEvent(GetStdHandle(STD_INPUT_HANDLE)) ) {
+    u3_Host.bot_f = _on_boot_completed_cb;
+    return;
+  }
+
+  STARTUPINFOW psi_u;
+  ZeroMemory(&psi_u, sizeof(psi_u));
+  psi_u.cb = sizeof(psi_u);
+  psi_u.dwFlags = STARTF_USESTDHANDLES;
+
+  //  duplicate standard output and error handles for the child process,
+  //  replacing any raw console handles with handles to /dev/null
+  //  print a warning if raw console output detected
+  //
+  //  On Windows, console handles become invalid once the console is
+  //  detached. This will cause urbit terminal output to fail. libuv
+  //  provides no way of changing the handle of an open uv_pipe_handle,
+  //  and Windows has no equivalent of dup2() for handles, so I cannot
+  //  substitute a /dev/null handle once the terminal is initialized.
+  //  It is possible to create an anonymous pipe and have the child
+  //  process take over its drain end after it signals that the ship
+  //  has booted, but -d is intended for background operation anyway
+  //  and does not seem to warrant the added complexity.
+  //
+  if ( _dup_std_handle(&psi_u.hStdOutput, STD_OUTPUT_HANDLE) |
+       _dup_std_handle(&psi_u.hStdError,  STD_ERROR_HANDLE) )
+  {
+    fprintf(stderr, "vere: -d used from a Windows console without redirection\r\n"
+                    "      no output from the daemon process will be visible\r\n");
+    fflush(stderr);
+  }
+
+  //  create an event for the child process to signal
+  //  the parent that the ship has finished booting
+  //  pass the handle as "stdin" (otherwise unused with -d)
+  //
+  SECURITY_ATTRIBUTES sa_u = {sizeof (SECURITY_ATTRIBUTES), NULL, TRUE};
+  if ( !(psi_u.hStdInput = CreateEvent(&sa_u, TRUE, FALSE, NULL)) ) {
+    fprintf(stderr, "vere: CreateEvent: %lu\r\n", GetLastError());
+    exit(1);
+  }
+
+  //  create the child process with the same command line as parent
+  //  it will start, re-parse the command line, and call u3_daemon_init
+  //
+  PROCESS_INFORMATION ppi_u;
+  if ( !CreateProcessW(NULL, _wcsdup(GetCommandLineW()), NULL, NULL, TRUE, DETACHED_PROCESS, NULL, NULL, &psi_u, &ppi_u) ) {
+    fprintf(stderr, "vere: CreateProcess: %lu\r\n", GetLastError());
+    exit(1);
+  }
+
+  CloseHandle(ppi_u.hThread);
+
+  //  wait for the child process to exit or to signal the event
+  //
+  DWORD exi_u;
+  HANDLE han_u[2] = {ppi_u.hProcess, psi_u.hStdInput};
+  switch ( WaitForMultipleObjects(2, han_u, FALSE, INFINITE) ) {
+  case WAIT_OBJECT_0:
+    //  the child process exited prematurely, propagate its exit code
+    //
+    if ( GetExitCodeProcess(ppi_u.hProcess, &exi_u) ) {
+      exit(exi_u);
+    }
+
+    fprintf(stderr, "vere: GetExitCodeProcess: %lu\r\n", GetLastError());
+    exit(1);
+
+  case WAIT_OBJECT_0 + 1:
+    //  the child process has finished booting, exit normally
+    //
+    exit(0);
+
+  default:
+    fprintf(stderr, "vere: WaitForMultipleObjects: %lu\r\n", GetLastError());
+    exit(1);
+  }
+}