typos (mainmatter#55)

* Add missing of

* change tense of spawn

* ignored to ignoring

* add need

Author: c-git

book/src/07_threads/00_intro.md

@@ -12,4 +12,4 @@ We'll have the opportunity to touch most of Rust's core concurrency features, in
 - Shared state, using `Arc`, `Mutex` and `RwLock`
 - `Send` and `Sync`, the traits that encode Rust's concurrency guarantees
 
-We'll also discuss various design patterns for multithreaded systems and some their trade-offs.
+We'll also discuss various design patterns for multithreaded systems and some of their trade-offs.

book/src/07_threads/11_locks.md

@@ -74,7 +74,7 @@ struct TicketStore {
 ```
 
 This approach is more efficient, but it has a downside: `TicketStore` has to become **aware** of the multithreaded
-nature of the system; up until now, `TicketStore` has been blissfully ignored the existence of threads.\
+nature of the system; up until now, `TicketStore` has been blissfully ignoring the existence of threads.\
 Let's go for it anyway.
 
 ## Who holds the lock?

book/src/07_threads/13_without_channels.md

@@ -48,7 +48,7 @@ If we remove the channels, we need to introduce (another) lock to synchronize ac
 
 If we use a `Mutex`, then it makes no sense to use an additional `RwLock` for each ticket: the `Mutex` will
 already serialize access to the entire store, so we wouldn't be able to read tickets in parallel anyway.\
-If we use a `RwLock`, instead, we can read tickets in parallel. We just to pause all reads while inserting
+If we use a `RwLock`, instead, we can read tickets in parallel. We just need to pause all reads while inserting
 or removing a ticket.
 
 Let's go down this path and see where it leads us.

exercises/07_threads/01_threads/src/lib.rs

@@ -8,7 +8,7 @@
 // You _could_ pass this test by just returning `v.iter().sum()`,
 // but that would defeat the purpose of the exercise.
 //
-// Hint: you won't be able to get the spawn threads to _borrow_
+// Hint: you won't be able to get the spawned threads to _borrow_
 // slices of the vector directly. You'll need to allocate new
 // vectors for each half of the original vector. We'll see why
 // this is necessary in the next exercise.