cleanups and add PROCESS_CREATION_FLAGS

Author: matu3ba

lib/std/child_process.zig

@@ -1128,12 +1128,12 @@ pub const ChildProcess = struct {
     }
 };
 
-const PortPipeReturn = if (builtin.os.tag == .windows) [2]windows.HANDLE else [2]os.fd_t;
+const PortPipeT = if (builtin.os.tag == .windows) [2]windows.HANDLE else [2]os.fd_t;
 
 /// Portable pipe creation without handle inheritance
-pub inline fn portablePipe() !PortPipeReturn {
+pub inline fn portablePipe() !PortPipeT {
     // TODO think how to offer user an interface to lpSecurityDescriptor
-    var pipe_new: PortPipeReturn = undefined;
+    var pipe_new: PortPipeT = undefined;
     if (builtin.os.tag == .windows) {
         const saAttr = windows.SECURITY_ATTRIBUTES{
             .nLength = @sizeOf(windows.SECURITY_ATTRIBUTES),

lib/std/os/windows.zig

@@ -1576,6 +1576,45 @@ pub fn GetEnvironmentVariableW(lpName: LPWSTR, lpBuffer: [*]u16, nSize: DWORD) G
     return rc;
 }
 
+// zig fmt: off
+pub const PROCESS_CREATION_FLAGS = enum(u32) {
+    // <- gap here ->
+    DEBUG_PROCESS                       = 0x0000_0001,
+    DEBUG_ONLY_THIS_PROCESS             = 0x0000_0002,
+    CREATE_SUSPENDED                    = 0x0000_0004,
+    DETACHED_PROCESS                    = 0x0000_0008,
+    CREATE_NEW_CONSOLE                  = 0x0000_0010,
+    NORMAL_PRIORITY_CLASS               = 0x0000_0020,
+    IDLE_PRIORITY_CLASS                 = 0x0000_0040,
+    HIGH_PRIORITY_CLASS                 = 0x0000_0080,
+    REALTIME_PRIORITY_CLASS             = 0x0000_0100,
+    CREATE_NEW_PROCESS_GROUP            = 0x0000_0200,
+    CREATE_UNICODE_ENVIRONMENT          = 0x0000_0400,
+    CREATE_SEPARATE_WOW_VDM             = 0x0000_0800,
+    CREATE_SHARED_WOW_VDM               = 0x0000_1000,
+    CREATE_FORCEDOS                     = 0x0000_2000,
+    BELOW_NORMAL_PRIORITY_CLASS         = 0x0000_4000,
+    ABOVE_NORMAL_PRIORITY_CLASS         = 0x0000_8000,
+    INHERIT_PARENT_AFFINITY             = 0x0001_0000,
+    INHERIT_CALLER_PRIORITY             = 0x0002_0000,
+    CREATE_PROTECTED_PROCESS            = 0x0004_0000,
+    EXTENDED_STARTUPINFO_PRESENT        = 0x0008_0000,
+    PROCESS_MODE_BACKGROUND_BEGIN       = 0x0010_0000,
+    PROCESS_MODE_BACKGROUND_END         = 0x0020_0000,
+    CREATE_SECURE_PROCESS               = 0x0040_0000,
+    // <- gap here ->
+    CREATE_BREAKAWAY_FROM_JOB           = 0x0100_0000,
+    CREATE_PRESERVE_CODE_AUTHZ_LEVEL    = 0x0200_0000,
+    CREATE_DEFAULT_ERROR_MODE           = 0x0400_0000,
+    CREATE_NO_WINDOW                    = 0x0800_0000,
+    PROFILE_USER                        = 0x1000_0000,
+    PROFILE_KERNEL                      = 0x2000_0000,
+    PROFILE_SERVER                      = 0x4000_0000,
+    CREATE_IGNORE_SYSTEM_DEFAULT        = 0x8000_0000,
+    _,
+};
+// zig fmt: on
+
 pub const CreateProcessError = error{
     FileNotFound,
     AccessDenied,
@@ -2919,8 +2958,6 @@ pub const COORD = extern struct {
     Y: SHORT,
 };
 
-pub const CREATE_UNICODE_ENVIRONMENT = 1024;
-
 pub const TLS_OUT_OF_INDEXES = 4294967295;
 pub const IMAGE_TLS_DIRECTORY = extern struct {
     StartAddressOfRawData: usize,

test/standalone/childprocess_extrapipe/parent.zig

@@ -32,6 +32,10 @@ pub fn main() !void {
     // enabling of file inheritance directly before and closing directly after spawn
     // less time to leak => better
     {
+        // Besides being faster to spawn, posix_spawn enables to close pipe[pipe_wr]
+        // within the child before it is closed from Kernel after execv.
+        // Note, that posix_spawn is executed in the child, so it does not allow
+        // to minimize the leaking time of the parent's handle side.
         if (os.hasPosixSpawn) child_proc.posix_actions = try os.posix_spawn.Actions.init();
         defer if (os.hasPosixSpawn) child_proc.posix_actions.?.deinit();
         if (os.hasPosixSpawn) try child_proc.posix_actions.?.close(pipe[pipe_wr]);
@@ -42,7 +46,7 @@ pub fn main() !void {
         try child_proc.spawn();
     }
 
-    // windows does have inheritance disabled on default, but we check to be sure
+    // check that inheritance was disabled for the handle the whole time
     if (builtin.target.os.tag == .windows) {
         var handle_flags: windows.DWORD = undefined;
         try windows.GetHandleInformation(pipe[pipe_wr], &handle_flags);