import uring-sys and iou

Those crates are moving in a fairly slow pace, while uring moves fast.
As much as I fully understand that the maintainers have other
commitments, this is harming us a bit.

Importing this inside glommio is, actually a way to avoid a fork in my
view: I consider this temporary and would encourage anyone that is
sending code that touches iou and uring-sys to make a bona fide effort
to upstream them. But by having them as a buffer here, we can detach
our lifetimes.

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "glommio/liburing"]
+	path = glommio/liburing
+	url = git://git.kernel.dk/liburing

glommio/Cargo.toml

@@ -17,11 +17,10 @@ readme = "../README.md"
 log = "0.4"
 concurrent-queue = "1.1.2"
 futures-lite = "1.11.1"
-libc = "0.2.73"
+libc = "0.2.77"
 socket2 = { version = "0.3.18", features = ["unix", "reuseport"] }
-iou = { path = "../../iou" }
-uring-sys = { path = "../../uring-sys" }
 nix = "0.19.0"
+bitflags = "1.2.0"
 bitmaps = "2.1.0"
 typenum = "1.12"
 scoped-tls = "1.0.0"
@@ -42,6 +41,9 @@ futures = "0.3.5"
 fastrand = "1.4.0"
 tokio = { version = "0.3.5", default-features = false, features = ["rt", "macros", "rt-multi-thread", "net", "io-util", "time"] }
 
+[build-dependencies]
+cc = "1.0.47"
+
 [features]
 bench = []
 

glommio/README.uring_sys_iou.md

@@ -0,0 +1,15 @@
+This crate includes imported code for
+[uring-sys](https://github.com/ringbahn/uring-sys) and
+[iou](https://github.com/ringbahn/iou)
+from the ringbahn project.
+
+It is my intention that those imports are temporary and I don't
+mean this as a hard fork. On the other hand those crates haven't been
+as actively maintained as we would like. They are very central for
+what we do, as uring evolves very rapidly, so I have decided to
+soft fork them.
+
+Every patch that touches code in those directories should make at
+least a good faith effort to merge the code back into iou and uring-sys.
+Hopefully with time they will, at their own pace, have all the code
+that we need in which case we can revert back to using them externally.

glommio/build.rs

@@ -0,0 +1,49 @@
+use std::env;
+use std::fs;
+use std::path::*;
+use std::process::Command;
+
+use cc::Build;
+
+fn main() {
+    let project = PathBuf::from(env::var("CARGO_MANIFEST_DIR").unwrap())
+        .canonicalize()
+        .unwrap();
+    let liburing = project.join("liburing");
+
+    // Run the configure script in OUT_DIR to get `compat.h`
+    let configured_include = configure(&liburing);
+
+    let src = liburing.join("src");
+
+    // liburing
+    Build::new()
+        .file(src.join("setup.c"))
+        .file(src.join("queue.c"))
+        .file(src.join("syscall.c"))
+        .file(src.join("register.c"))
+        .include(src.join("include"))
+        .include(&configured_include)
+        .extra_warnings(false)
+        .compile("uring");
+
+    // (our additional, linkable C bindings)
+    Build::new()
+        .file(project.join("rusturing.c"))
+        .include(src.join("include"))
+        .include(&configured_include)
+        .compile("rusturing");
+}
+
+fn configure(liburing: &Path) -> PathBuf {
+    let out_dir = PathBuf::from(env::var("OUT_DIR").unwrap())
+        .canonicalize()
+        .unwrap();
+    fs::copy(liburing.join("configure"), out_dir.join("configure")).unwrap();
+    fs::create_dir_all(out_dir.join("src/include/liburing")).unwrap();
+    Command::new("./configure")
+        .current_dir(&out_dir)
+        .output()
+        .expect("configure script failed");
+    out_dir.join("src/include")
+}