From 0d52cc97e477c03de6b3b998603fac6dc6d7ad44 Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Sun, 19 Jan 2020 21:32:22 +0200
Subject: [PATCH] sync: make new_mutex() and new_waitgroup() return &Mutex and
 &Waitgroup

---
 examples/news_fetcher.v          | 8 ++------
 vlib/clipboard/clipboard_linux.v | 4 ++--
 vlib/sync/sync_nix.v             | 5 ++---
 vlib/sync/sync_windows.v         | 6 +++---
 vlib/sync/waitgroup.v            | 9 +++------
 5 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/examples/news_fetcher.v b/examples/news_fetcher.v
index 4807a5dd7d..982062148c 100644
--- a/examples/news_fetcher.v
+++ b/examples/news_fetcher.v
@@ -63,15 +63,11 @@ fn main() {
 		}
 		ids = tmp
 	}
-	wg := sync.new_waitgroup()
-	mtx := sync.new_mutex()
 	mut fetcher := &Fetcher{
 		ids: ids
-		mu: 0
-		wg: 0
+		mu: sync.new_mutex()
+		wg: sync.new_waitgroup()
 	}
-	fetcher.mu = &mtx
-	fetcher.wg = &wg
 	fetcher.wg.add(ids.len)
 	for i := 0; i < nr_threads; i++ {
 		go fetcher.fetch()
diff --git a/vlib/clipboard/clipboard_linux.v b/vlib/clipboard/clipboard_linux.v
index b2f791a94a..d20a1416d3 100644
--- a/vlib/clipboard/clipboard_linux.v
+++ b/vlib/clipboard/clipboard_linux.v
@@ -103,7 +103,7 @@ pub struct Clipboard {
 	selection Atom //the selection atom
 	window Window
 	atoms []Atom
-	mutex sync.Mutex
+	mutex &sync.Mutex
 	text string // text data sent or received
 	got_text bool // used to confirm that we have got the text
 	is_owner bool // to save selection owner state
@@ -137,7 +137,7 @@ fn new_x11_clipboard(selection atom_type) &Clipboard {
 
 	if display == C.NULL {
 		println("ERROR: No X Server running. Clipboard cannot be used.")
-		return &Clipboard{ display: 0 }
+		return &Clipboard{ display: 0 mutex: sync.new_mutex() }
 	}
 
 	mut cb := &Clipboard{
diff --git a/vlib/sync/sync_nix.v b/vlib/sync/sync_nix.v
index 3d225a55a5..930d3f7e6b 100644
--- a/vlib/sync/sync_nix.v
+++ b/vlib/sync/sync_nix.v
@@ -16,9 +16,8 @@ pub struct Mutex {
 	mutex C.pthread_mutex_t
 }
 
-pub fn new_mutex() Mutex {
-	m := Mutex{
-	}
+pub fn new_mutex() &Mutex {
+	m := &Mutex{}
 	C.pthread_mutex_init(&m.mutex, C.NULL)
 	return m
 }
diff --git a/vlib/sync/sync_windows.v b/vlib/sync/sync_windows.v
index 74aa807960..1a766fab80 100644
--- a/vlib/sync/sync_windows.v
+++ b/vlib/sync/sync_windows.v
@@ -39,8 +39,8 @@ const (
 	WAIT_FAILED        = 0xFFFFFFFF
 )
 
-pub fn new_mutex() Mutex {
-	sm := Mutex{}
+pub fn new_mutex() &Mutex {
+	sm := &Mutex{}
 	unsafe {
 		mut m := sm		
 		m.mx = C.CreateMutex(0, false, 0)
@@ -48,8 +48,8 @@ pub fn new_mutex() Mutex {
 			m.state = .broken // handle broken and mutex state are broken
 			return sm
 		}		
-		return sm
 	}
+	return sm
 }
 
 pub fn (m mut Mutex) lock() {
diff --git a/vlib/sync/waitgroup.v b/vlib/sync/waitgroup.v
index f7a624db72..dcc45b08fd 100644
--- a/vlib/sync/waitgroup.v
+++ b/vlib/sync/waitgroup.v
@@ -5,15 +5,12 @@ module sync
 // [init_with=new_waitgroup] // TODO: implement support for init_with struct attribute, and disallow WaitGroup{} from outside the sync.new_waitgroup() function.
 pub struct WaitGroup {
 mut:
-	mu     Mutex
+	mu     &Mutex = &Mutex(0)
 	active int
 }
 
-pub fn new_waitgroup() WaitGroup {
-	mut w := WaitGroup{
-	}
-	w.mu = sync.new_mutex()
-	return w
+pub fn new_waitgroup() &WaitGroup {
+	return &WaitGroup{mu: sync.new_mutex() }
 }
 
 pub fn (wg mut WaitGroup) add(delta int) {