Draft changes to the io_uring prototype

Package.swift

@@ -48,4 +48,4 @@ let package = Package(
       dependencies: ["SystemPackage"],
       cSettings: cSettings,
       swiftSettings: swiftSettings),
-  ])
+  ])

Sources/CSystem/include/CSystemLinux.h

@@ -21,5 +21,6 @@
 #include <pthread.h>
 #include <sched.h>
 #include <unistd.h>
+#include "io_uring.h"
 #endif
 

Sources/CSystem/include/io_uring.h

@@ -0,0 +1,61 @@
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/uio.h>
+
+#include <signal.h>
+#include <linux/io_uring.h>
+
+#ifndef SWIFT_IORING_C_WRAPPER
+#define SWIFT_IORING_C_WRAPPER
+
+#ifdef __alpha__
+/*
+ * alpha is the only exception, all other architectures
+ * have common numbers for new system calls.
+ */
+# ifndef __NR_io_uring_setup
+#  define __NR_io_uring_setup		535
+# endif
+# ifndef __NR_io_uring_enter
+#  define __NR_io_uring_enter		536
+# endif
+# ifndef __NR_io_uring_register
+#  define __NR_io_uring_register	537
+# endif
+#else /* !__alpha__ */
+# ifndef __NR_io_uring_setup
+#  define __NR_io_uring_setup		425
+# endif
+# ifndef __NR_io_uring_enter
+#  define __NR_io_uring_enter		426
+# endif
+# ifndef __NR_io_uring_register
+#  define __NR_io_uring_register	427
+# endif
+#endif
+
+int io_uring_register(int fd, unsigned int opcode, void *arg,
+		      unsigned int nr_args)
+{
+	return syscall(__NR_io_uring_register, fd, opcode, arg, nr_args);
+}
+
+int io_uring_setup(unsigned int entries, struct io_uring_params *p)
+{
+	return syscall(__NR_io_uring_setup, entries, p);
+}
+
+int io_uring_enter2(int fd, unsigned int to_submit, unsigned int min_complete,
+		   unsigned int flags, void *args, size_t sz)
+{
+	return syscall(__NR_io_uring_enter, fd, to_submit, min_complete,
+			flags, args, _NSIG / 8);
+}
+
+int io_uring_enter(int fd, unsigned int to_submit, unsigned int min_complete,
+		   unsigned int flags, sigset_t *sig)
+{
+	return io_uring_enter2(fd, to_submit, min_complete, flags, sig, _NSIG / 8);
+}
+
+#endif

Sources/System/IOCompletion.swift

@@ -0,0 +1,56 @@
+@_implementationOnly import CSystem
+
+public struct IOCompletion: ~Copyable {
+    let rawValue: io_uring_cqe
+}
+
+extension IOCompletion {
+    public struct Flags: OptionSet, Hashable, Codable {
+        public let rawValue: UInt32
+
+        public init(rawValue: UInt32) {
+            self.rawValue = rawValue
+        }
+
+        public static let allocatedBuffer = Flags(rawValue: 1 << 0)
+        public static let moreCompletions = Flags(rawValue: 1 << 1)
+        public static let socketNotEmpty = Flags(rawValue: 1 << 2)
+        public static let isNotificationEvent = Flags(rawValue: 1 << 3)
+    }
+}
+
+extension IOCompletion {
+    public var userData: UInt64 { //TODO: naming?
+        get {
+            rawValue.user_data
+        }
+    }
+
+    public var userPointer: UnsafeRawPointer? {
+        get {
+            UnsafeRawPointer(bitPattern: UInt(rawValue.user_data))
+        }
+    }
+
+    public var result: Int32 {
+        get {
+            rawValue.res
+        }
+    }
+
+    public var flags: IOCompletion.Flags {
+        get {
+            Flags(rawValue: rawValue.flags & 0x0000FFFF)
+        }
+    }
+
+    public var bufferIndex: UInt16? {
+        get {
+            if self.flags.contains(.allocatedBuffer) {
+                return UInt16(rawValue.flags >> 16)
+            } else {
+                return nil
+            }
+        }
+    }
+}