[core] Protecting RCV buffer access (#1335)

Together with #1333 fixes #486
Haivision · Jun 11, 2020 · 903e023 · 903e023
1 parent e03dbc6
commit 903e023
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Showing 2 changed files with 9 additions and 4 deletions.
diff --git a/srtcore/core.cpp b/srtcore/core.cpp
@@ -6918,7 +6918,9 @@ int CUDT::receiveMessage(char* data, int len, SRT_MSGCTRL& w_mctrl, int by_excep
     if (m_bBroken || m_bClosing)
     {
         HLOGC(mglog.Debug, log << CONID() << "receiveMessage: CONNECTION BROKEN - reading from recv buffer just for formality");
+        enterCS(m_RcvBufferLock);
         int res       = m_pRcvBuffer->readMsg(data, len);
+        leaveCS(m_RcvBufferLock);
         w_mctrl.srctime = 0;
 
         // Kick TsbPd thread to schedule next wakeup (if running)
@@ -6956,8 +6958,9 @@ int CUDT::receiveMessage(char* data, int len, SRT_MSGCTRL& w_mctrl, int by_excep
     if (!m_bSynRecving)
     {
         HLOGC(dlog.Debug, log << CONID() << "receiveMessage: BEGIN ASYNC MODE. Going to extract payload size=" << len);
-
-        int res = m_pRcvBuffer->readMsg(data, len, (w_mctrl), seqdistance);
+        enterCS(m_RcvBufferLock);
+        const int res = m_pRcvBuffer->readMsg(data, len, (w_mctrl), seqdistance);
+        leaveCS(m_RcvBufferLock);
         HLOGC(dlog.Debug, log << CONID() << "AFTER readMsg: (NON-BLOCKING) result=" << res);
 
         if (res == 0)
@@ -7020,7 +7023,7 @@ int CUDT::receiveMessage(char* data, int len, SRT_MSGCTRL& w_mctrl, int by_excep
     {
         steady_clock::time_point tstime SRT_ATR_UNUSED;
         int32_t seqno;
-        if (stillConnected() && !timeout && (!m_pRcvBuffer->isRcvDataReady((tstime), (seqno), seqdistance)))
+        if (stillConnected() && !timeout && !m_pRcvBuffer->isRcvDataReady((tstime), (seqno), seqdistance))
         {
             /* Kick TsbPd thread to schedule next wakeup (if running) */
             if (m_bTsbPd)
@@ -7073,7 +7076,9 @@ int CUDT::receiveMessage(char* data, int len, SRT_MSGCTRL& w_mctrl, int by_excep
                 << " NMSG " << m_pRcvBuffer->getRcvMsgNum());
                 */
 
+        enterCS(m_RcvBufferLock);
         res = m_pRcvBuffer->readMsg((data), len, (w_mctrl), seqdistance);
+        leaveCS(m_RcvBufferLock);
         HLOGC(dlog.Debug, log << CONID() << "AFTER readMsg: (BLOCKING) result=" << res);
 
         if (m_bBroken || m_bClosing)

diff --git a/srtcore/core.h b/srtcore/core.h
@@ -1647,7 +1647,7 @@ class CUDT
     srt::sync::Mutex m_RecvDataLock;             // lock associated to m_RecvDataCond
 
     srt::sync::Mutex m_SendLock;                 // used to synchronize "send" call
-    srt::sync::Mutex m_RecvLock;                 // used to synchronize "recv" call
+    srt::sync::Mutex m_RecvLock;                 // used to synchronize "recv" call, protects TSBPD drift updates (CRcvBuffer::isRcvDataReady())
     srt::sync::Mutex m_RcvLossLock;              // Protects the receiver loss list (access: CRcvQueue::worker, CUDT::tsbpd)
     srt::sync::Mutex m_StatsLock;                // used to synchronize access to trace statistics