From 921b59c467ac78ef2a770ad1bb3e61fbef51bd09 Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Mon, 17 Jan 2022 14:12:11 -0600
Subject: [PATCH] Add API to wake a waiting thread in LiWaitForNextVideoFrame()

---
 src/Limelight.h           |  1 +
 src/LinkedBlockingQueue.c | 16 +++++++++++++++-
 src/LinkedBlockingQueue.h |  3 +++
 src/VideoDepacketizer.c   |  4 ++++
 4 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/Limelight.h b/src/Limelight.h
index b3cd6e8..f24454e 100644
--- a/src/Limelight.h
+++ b/src/Limelight.h
@@ -651,6 +651,7 @@ typedef void* VIDEO_FRAME_HANDLE;
 bool LiWaitForNextVideoFrame(VIDEO_FRAME_HANDLE* frameHandle, PDECODE_UNIT* decodeUnit);
 bool LiPollNextVideoFrame(VIDEO_FRAME_HANDLE* frameHandle, PDECODE_UNIT* decodeUnit);
 bool LiPeekNextVideoFrame(PDECODE_UNIT* decodeUnit);
+void LiWakeWaitForVideoFrame(void);
 void LiCompleteVideoFrame(VIDEO_FRAME_HANDLE handle, int drStatus);
 
 #ifdef __cplusplus
diff --git a/src/LinkedBlockingQueue.c b/src/LinkedBlockingQueue.c
index 1551425..5d7f9a7 100644
--- a/src/LinkedBlockingQueue.c
+++ b/src/LinkedBlockingQueue.c
@@ -71,6 +71,13 @@ void LbqSignalQueueDrain(PLINKED_BLOCKING_QUEUE queueHead) {
     PltSignalConditionVariable(&queueHead->cond);
 }
 
+void LbqSignalQueueUserWake(PLINKED_BLOCKING_QUEUE queueHead) {
+    PltLockMutex(&queueHead->mutex);
+    queueHead->pendingUserWake = true;
+    PltUnlockMutex(&queueHead->mutex);
+    PltSignalConditionVariable(&queueHead->cond);
+}
+
 int LbqGetItemCount(PLINKED_BLOCKING_QUEUE queueHead) {
     return queueHead->currentSize;
 }
@@ -196,7 +203,7 @@ int LbqWaitForQueueElement(PLINKED_BLOCKING_QUEUE queueHead, void** data) {
     PltLockMutex(&queueHead->mutex);
 
     // Wait for a waking condition: either data available or rundown
-    while (queueHead->head == NULL && !queueHead->draining && !queueHead->shutdown) {
+    while (queueHead->head == NULL && !queueHead->draining && !queueHead->shutdown && !queueHead->pendingUserWake) {
         PltWaitForConditionVariable(&queueHead->cond, &queueHead->mutex);
     }
 
@@ -206,6 +213,13 @@ int LbqWaitForQueueElement(PLINKED_BLOCKING_QUEUE queueHead, void** data) {
         return LBQ_INTERRUPTED;
     }
 
+    // If this is a user requested wake, process it now
+    if (queueHead->pendingUserWake) {
+        queueHead->pendingUserWake = false;
+        PltUnlockMutex(&queueHead->mutex);
+        return LBQ_USER_WAKE;
+    }
+
     // If we're draining, only abort if we have no data available
     if (queueHead->draining && queueHead->head == NULL) {
         PltUnlockMutex(&queueHead->mutex);
diff --git a/src/LinkedBlockingQueue.h b/src/LinkedBlockingQueue.h
index 5f58802..426f43d 100644
--- a/src/LinkedBlockingQueue.h
+++ b/src/LinkedBlockingQueue.h
@@ -7,6 +7,7 @@
 #define LBQ_INTERRUPTED 1
 #define LBQ_BOUND_EXCEEDED 2
 #define LBQ_NO_ELEMENT 3
+#define LBQ_USER_WAKE 4
 
 typedef struct _LINKED_BLOCKING_QUEUE_ENTRY {
     struct _LINKED_BLOCKING_QUEUE_ENTRY* flink;
@@ -24,6 +25,7 @@ typedef struct _LINKED_BLOCKING_QUEUE {
     int lifetimeSize;
     bool shutdown;
     bool draining;
+    bool pendingUserWake;
 } LINKED_BLOCKING_QUEUE, *PLINKED_BLOCKING_QUEUE;
 
 int LbqInitializeLinkedBlockingQueue(PLINKED_BLOCKING_QUEUE queueHead, int sizeBound);
@@ -35,4 +37,5 @@ PLINKED_BLOCKING_QUEUE_ENTRY LbqDestroyLinkedBlockingQueue(PLINKED_BLOCKING_QUEU
 PLINKED_BLOCKING_QUEUE_ENTRY LbqFlushQueueItems(PLINKED_BLOCKING_QUEUE queueHead);
 void LbqSignalQueueShutdown(PLINKED_BLOCKING_QUEUE queueHead);
 void LbqSignalQueueDrain(PLINKED_BLOCKING_QUEUE queueHead);
+void LbqSignalQueueUserWake(PLINKED_BLOCKING_QUEUE queueHead);
 int LbqGetItemCount(PLINKED_BLOCKING_QUEUE queueHead);
diff --git a/src/VideoDepacketizer.c b/src/VideoDepacketizer.c
index 36727cf..8087084 100644
--- a/src/VideoDepacketizer.c
+++ b/src/VideoDepacketizer.c
@@ -221,6 +221,10 @@ bool LiPeekNextVideoFrame(PDECODE_UNIT* decodeUnit) {
     return true;
 }
 
+void LiWakeWaitForVideoFrame(void) {
+    LbqSignalQueueUserWake(&decodeUnitQueue);
+}
+
 // Cleanup a decode unit by freeing the buffer chain and the holder
 void LiCompleteVideoFrame(VIDEO_FRAME_HANDLE handle, int drStatus) {
     PQUEUED_DECODE_UNIT qdu = handle;