From c6a29e1c3bc41d6cdf7fa8a0400e3afd05ee06b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Ludwig?= <sludwig@rejectedsoftware.com>
Date: Wed, 23 Jan 2019 15:19:29 +0100
Subject: [PATCH] Make createChannel safe and add Channel.bufferFill.

---
 source/vibe/core/channel.d | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/source/vibe/core/channel.d b/source/vibe/core/channel.d
index b699811..6995c28 100644
--- a/source/vibe/core/channel.d
+++ b/source/vibe/core/channel.d
@@ -54,6 +54,14 @@ struct Channel(T, size_t buffer_size = 100) {
 	/// ditto
 	@property bool empty() shared { return m_impl.empty; }
 
+	/** Returns the current count of items in the buffer.
+
+		This function is useful for diagnostic purposes.
+	*/
+	@property size_t bufferFill() { return m_impl.bufferFill; }
+	/// ditto
+	@property size_t bufferFill() shared { return m_impl.bufferFill; }
+
 	/** Closes the channel.
 
 		A closed channel does not accept any new items enqueued using `put` and
@@ -121,7 +129,7 @@ private final class ChannelImpl(T, size_t buffer_size) {
 	}
 
 	this()
-	shared {
+	shared @trusted {
 		m_mutex = cast(shared)new Mutex;
 		m_condition = cast(shared)new TaskCondition(cast(Mutex)m_mutex);
 	}
@@ -134,6 +142,14 @@ private final class ChannelImpl(T, size_t buffer_size) {
 		}
 	}
 
+	@property size_t bufferFill()
+	shared {
+		synchronized (m_mutex) {
+			auto thisus = () @trusted { return cast(ChannelImpl)this; } ();
+			return thisus.m_items.length;
+		}
+	}
+
 	void close()
 	shared {
 		synchronized (m_mutex) {
@@ -221,7 +237,7 @@ private final class ChannelImpl(T, size_t buffer_size) {
 	}
 }
 
-unittest { // test basic operation and non-copyable struct compatiblity
+@safe unittest { // test basic operation and non-copyable struct compatiblity
 	static struct S {
 		int i;
 		@disable this(this);
@@ -250,7 +266,7 @@ unittest { // test basic operation and non-copyable struct compatiblity
 	assert(!ch.tryConsumeOne(v));
 }
 
-unittest { // make sure shared(Channel!T) can also be used
+@safe unittest { // make sure shared(Channel!T) can also be used
 	shared ch = createChannel!int;
 	ch.put(1);
 	assert(!ch.empty);