From 6caff0b105186a1252d41474807194d86d38f7a5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Ludwig?= <sludwig@rejectedsoftware.com>
Date: Sat, 27 Oct 2018 00:42:06 +0200
Subject: [PATCH 1/2] Fix synchronization and shutdown issues in TaskPool.

- terminate() would hang if called from a worker thread because it would attempt to self-join
- the handleWorkerTasks could miss signal emits, resulting in a hanging task queue or a missed termination signal
---
 source/vibe/core/taskpool.d | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/source/vibe/core/taskpool.d b/source/vibe/core/taskpool.d
index 736f770..87b0c32 100644
--- a/source/vibe/core/taskpool.d
+++ b/source/vibe/core/taskpool.d
@@ -71,7 +71,6 @@ shared final class TaskPool {
 		m_state.lock.term = true;
 		m_signal.emit();
 
-		auto ec = m_signal.emitCount;
 		while (true) {
 			WorkerThread th;
 			with (m_state.lock)
@@ -81,6 +80,9 @@ shared final class TaskPool {
 				}
 			if (!th) break;
 
+			if (th is Thread.getThis())
+				continue;
+
 			() @trusted {
 				try th.join();
 				catch (Exception e) {
@@ -271,9 +273,8 @@ private final class WorkerThread : Thread {
 
 		logDebug("worker thread enter");
 		TaskFuncInfo taskfunc;
-		while(true){
-			auto emit_count = m_pool.m_signal.emitCount;
-
+		auto emit_count = m_pool.m_signal.emitCount;
+		while(true) {
 			with (m_pool.m_state.lock) {
 				logDebug("worker thread check");
 
@@ -282,7 +283,7 @@ private final class WorkerThread : Thread {
 				if (m_queue.consume(taskfunc)) {
 					logDebug("worker thread got specific task");
 				} else if (queue.consume(taskfunc)) {
-					logDebug("worker thread got specific task");
+					logDebug("worker thread got unspecific task");
 				}
 			}
 

From 439437436403fcb5399b2c0bcfcf37cfa8b16af3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=B6nke=20Ludwig?= <sludwig@rejectedsoftware.com>
Date: Sat, 27 Oct 2018 00:43:26 +0200
Subject: [PATCH 2/2] Fix race-condition in test case.

The wait() call without arguments could miss the initial emit(), if called too late, which could easily happen on VMs with less predictable timing.
---
 tests/issue-58-task-already-scheduled.d | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tests/issue-58-task-already-scheduled.d b/tests/issue-58-task-already-scheduled.d
index 80cc9f6..9325252 100644
--- a/tests/issue-58-task-already-scheduled.d
+++ b/tests/issue-58-task-already-scheduled.d
@@ -38,7 +38,7 @@ void main()
 
 void worker()
 {
-	ev.wait();
+	ev.wait(0);
 	ev.emit();
 	setTimer(dur!"seconds"(1), {
 		auto c = atomicOp!"+="(counter, 1);