Added chapter9 PD code

chapter9/Cargo.lock

@@ -0,0 +1,5 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "chapter9"
+version = "0.1.0"

chapter9/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "chapter9"
+version = "0.1.0"
+authors = ["peshwar9"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+[[bin]]
+name = "message-passing"
+path = "src/message-passing.rs"
+
+[[bin]]
+name = "shared-state"
+path = "src/shared-state.rs"
+
+[dependencies]

chapter9/dirnames.txt

@@ -0,0 +1,6 @@
+/Users/<username>/rust/project1
+/Users/<username>/rust/project2
+/Users/<username>/rust/project3
+/Users/<username>/rust/project4
+/Users/<username>/rust/project5
+

chapter9/src/message-passing.rs

@@ -0,0 +1,27 @@
+use std::sync::mpsc;
+use std::thread;
+
+fn main() {
+    let (transmitter1, receiver) = mpsc::channel();
+
+    let transmitter2 = mpsc::Sender::clone(&transmitter1);
+
+    thread::spawn(move || {
+        let num_vec: Vec<String> = vec!["One".into(), "two".into(), "three".into(), "four".into()];
+        for num in num_vec {
+            transmitter1.send(num).unwrap();
+        }
+    });
+
+    thread::spawn(move || {
+        let num_vec: Vec<String> =
+            vec!["Five".into(), "Six".into(), "Seven".into(), "eight".into()];
+        for num in num_vec {
+            transmitter2.send(num).unwrap();
+        }
+    });
+
+    for received_val in receiver {
+        println!("Received from thread: {}", received_val);
+    }
+}

chapter9/src/shared-state.rs

@@ -0,0 +1,76 @@
+use std::ffi::OsStr;
+use std::fs;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+use std::path::PathBuf;
+use std::sync::{Arc, Mutex};
+use std::thread;
+
+#[derive(Debug)]
+pub struct SrcStats {
+    pub number_of_files: u32,
+    pub loc: u32,
+    pub comments: u32,
+    pub blanks: u32,
+}
+
+fn main() {
+    let src_stats = SrcStats {
+        number_of_files: 0,
+        loc: 0,
+        comments: 0,
+        blanks: 0,
+    };
+    let stats_counter = Arc::new(Mutex::new(src_stats));
+
+    let mut dir_list = File::open("./dirnames.txt").unwrap();
+    let reader = BufReader::new(&mut dir_list);
+    let dir_lines: Vec<_> = reader.lines().collect();
+
+    let mut child_handles = vec![];
+    for dir in dir_lines {
+        let dir = dir.unwrap();
+        let src_stats = Arc::clone(&stats_counter);
+
+        let handle = thread::spawn(move || {
+            let mut dir_entries = vec![PathBuf::from(dir)];
+            let mut file_entries = vec![];
+            while let Some(entry) = dir_entries.pop() {
+                for inner_entry in fs::read_dir(&entry).unwrap() {
+                    if let Ok(entry) = inner_entry {
+                        if entry.path().is_dir() {
+                            dir_entries.push(entry.path());
+                        } else {
+                            if entry.path().extension() == Some(OsStr::new("rs")) {
+                                println!("File name processed is {:?}", entry);
+                                file_entries.push(entry);
+                            }
+                        }
+                    }
+                }
+            }
+            for file in file_entries {
+                let file_contents = fs::read_to_string(&file.path()).unwrap();
+
+                let mut stats_pointer = src_stats.lock().unwrap();
+                for line in file_contents.lines() {
+                    if line.len() == 0 {
+                        stats_pointer.blanks += 1;
+                    } else if line.starts_with("//") {
+                        stats_pointer.comments += 1;
+                    } else {
+                        stats_pointer.loc += 1;
+                    }
+                }
+
+                stats_pointer.number_of_files += 1;
+            }
+        });
+        child_handles.push(handle);
+    }
+
+    for handle in child_handles {
+        handle.join().unwrap();
+    }
+    println!("Source stats: {:?}", stats_counter.lock().unwrap());
+}