Merge pull request #80 from yuk1ty/section-10_2

10.2: `nix::fcntl::flock()` を使って `Cargo.toml` に排他ロックを掛け、10秒sleepするプログラム

Author: yuk1ty

Cargo.lock

@@ -8,13 +8,18 @@ edition = "2018"
 
 [dependencies]
 lib = { path = "../lib" }
+nix = "0.20.0"
 notify = "4.0.16"
 memmap2 = "0.2.2"
 
 [[bin]]
 name = "10_1"
 path = "src/10_1/main.rs"
 
+[[bin]]
+name = "10_2"
+path = "src/10_2/main.rs"
+
 [[bin]]
 name = "10_3"
 path = "src/10_3/main.rs"

chapter10/Cargo.toml

@@ -0,0 +1,22 @@
+use std::{thread, time};
+
+use nix::{fcntl, sys};
+
+fn main() -> nix::Result<()> {
+    let fd = fcntl::open(
+        "Cargo.toml",
+        fcntl::OFlag::O_RDONLY,
+        sys::stat::Mode::empty(),
+    )?;
+
+    println!("try locking...");
+    fcntl::flock(fd, fcntl::FlockArg::LockExclusive)?;
+    println!("locked!");
+
+    thread::sleep(time::Duration::from_secs(10));
+
+    fcntl::flock(fd, fcntl::FlockArg::Unlock)?;
+    println!("unlock");
+
+    Ok(())
+}