[vlc-devel] [PATCH 1/3] [RFC] chromecast: use a dummy UDP socket to notify the receiving thread of pending work
Steve Lhomme
robux4 at videolabs.io
Thu Apr 28 14:33:42 CEST 2016
--
In some cases we will need to send STOP or SEEK messages from some threads
that have been interrupted, resulting in TLS not sending the data. So now
we send messages from the receiving thread.
If net_Socket() was public we wouldn't need to tie this dummy socket to
localhost:0.
---
modules/stream_out/chromecast/chromecast.h | 3 +
modules/stream_out/chromecast/chromecast_ctrl.cpp | 133 +++++++++++++++-------
2 files changed, 93 insertions(+), 43 deletions(-)
diff --git a/modules/stream_out/chromecast/chromecast.h b/modules/stream_out/chromecast/chromecast.h
index 3b13c4a..0700bd6 100644
--- a/modules/stream_out/chromecast/chromecast.h
+++ b/modules/stream_out/chromecast/chromecast.h
@@ -102,6 +102,7 @@ private:
receiver_state receiverState;
int i_sock_fd;
+ int i_send_ready_fd;
vlc_tls_creds_t *p_creds;
vlc_tls_t *p_tls;
@@ -147,6 +148,8 @@ private:
void processMessage(const castchannel::CastMessage &msg);
+ void notifySendRequest();
+
int sendMessage(const castchannel::CastMessage &msg);
void buildMessage(const std::string & namespace_,
diff --git a/modules/stream_out/chromecast/chromecast_ctrl.cpp b/modules/stream_out/chromecast/chromecast_ctrl.cpp
index 4a1d6d4..11b0681 100644
--- a/modules/stream_out/chromecast/chromecast_ctrl.cpp
+++ b/modules/stream_out/chromecast/chromecast_ctrl.cpp
@@ -37,6 +37,7 @@
#ifdef HAVE_POLL
# include <poll.h>
#endif
+#include <vlc_network.h>
#include "../../misc/webservices/json.h"
@@ -98,6 +99,7 @@ intf_sys_t::intf_sys_t(vlc_object_t * const p_this, int port, std::string device
, targetIP(device_addr)
, receiverState(RECEIVER_IDLE)
, i_sock_fd(-1)
+ , i_send_ready_fd(-1)
, p_creds(NULL)
, p_tls(NULL)
, conn_status(CHROMECAST_DISCONNECTED)
@@ -142,6 +144,9 @@ intf_sys_t::~intf_sys_t()
disconnectChromecast();
+ if ( i_send_ready_fd != -1 )
+ net_Close( i_send_ready_fd );
+
vlc_cond_destroy(&loadCommandCond);
vlc_mutex_destroy(&lock);
}
@@ -242,19 +247,21 @@ void intf_sys_t::disconnectChromecast()
*/
// Use here only C linkage and POD types as this function is a cancelation point.
extern "C" int recvPacket(vlc_object_t *p_module, bool &b_msgReceived,
- uint32_t &i_payloadSize, int i_sock_fd, vlc_tls_t *p_tls,
+ uint32_t &i_payloadSize, int i_sock_fd, int i_send_fd, vlc_tls_t *p_tls,
unsigned *pi_received, uint8_t *p_data, bool *pb_pingTimeout,
int *pi_wait_delay, int *pi_wait_retries)
{
- struct pollfd ufd[1];
+ struct pollfd ufd[2];
ufd[0].fd = i_sock_fd;
ufd[0].events = POLLIN;
+ ufd[1].fd = i_send_fd;
+ ufd[1].events = POLLRDNORM | POLLHUP | POLLERR;
/* The Chromecast normally sends a PING command every 5 seconds or so.
* If we do not receive one after 6 seconds, we send a PING.
* If after this PING, we do not receive a PONG, then we consider the
* connection as dead. */
- if (poll(ufd, 1, *pi_wait_delay) == 0)
+ if (poll(ufd, 2, *pi_wait_delay) == 0)
{
if (*pb_pingTimeout)
{
@@ -282,37 +289,54 @@ extern "C" int recvPacket(vlc_object_t *p_module, bool &b_msgReceived,
*pi_wait_retries = PING_WAIT_RETRIES;
}
- int i_ret;
-
- /* Packet structure:
- * +------------------------------------+------------------------------+
- * | Payload size (uint32_t big endian) | Payload data |
- * +------------------------------------+------------------------------+ */
- while (*pi_received < PACKET_HEADER_LEN)
+ int i_ret = 0;
+ if ( ufd[0].revents & POLLIN )
{
- // We receive the header.
- i_ret = tls_Recv(p_tls, p_data + *pi_received, PACKET_HEADER_LEN - *pi_received);
- if (i_ret <= 0)
- return i_ret;
- *pi_received += i_ret;
- }
+ /* we have received stuff */
- // We receive the payload.
+ /* Packet structure:
+ * +------------------------------------+------------------------------+
+ * | Payload size (uint32_t big endian) | Payload data |
+ * +------------------------------------+------------------------------+ */
+ while (*pi_received < PACKET_HEADER_LEN)
+ {
+ // We receive the header.
+ i_ret = tls_Recv(p_tls, p_data + *pi_received, PACKET_HEADER_LEN - *pi_received);
+ if (i_ret <= 0)
+ return i_ret;
+ *pi_received += i_ret;
+ }
- // Get the size of the payload
- i_payloadSize = U32_AT( p_data );
- const uint32_t i_maxPayloadSize = PACKET_MAX_LEN - PACKET_HEADER_LEN;
+ // We receive the payload.
- if (i_payloadSize > i_maxPayloadSize)
- {
- // Error case: the packet sent by the Chromecast is too long: we drop it.
- msg_Err( p_module, "Packet too long: droping its data");
+ // Get the size of the payload
+ i_payloadSize = U32_AT( p_data );
+ const uint32_t i_maxPayloadSize = PACKET_MAX_LEN - PACKET_HEADER_LEN;
- uint32_t i_size = i_payloadSize - (*pi_received - PACKET_HEADER_LEN);
- if (i_size > i_maxPayloadSize)
- i_size = i_maxPayloadSize;
+ if (i_payloadSize > i_maxPayloadSize)
+ {
+ // Error case: the packet sent by the Chromecast is too long: we drop it.
+ msg_Err( p_module, "Packet too long: droping its data");
+
+ uint32_t i_size = i_payloadSize - (*pi_received - PACKET_HEADER_LEN);
+ if (i_size > i_maxPayloadSize)
+ i_size = i_maxPayloadSize;
+
+ i_ret = tls_Recv(p_tls, p_data + PACKET_HEADER_LEN, i_size);
+ if (i_ret <= 0)
+ return i_ret;
+ *pi_received += i_ret;
+
+ if (*pi_received < i_payloadSize + PACKET_HEADER_LEN)
+ return i_ret;
- i_ret = tls_Recv(p_tls, p_data + PACKET_HEADER_LEN, i_size);
+ *pi_received = 0;
+ return -1;
+ }
+
+ // Normal case
+ i_ret = tls_Recv(p_tls, p_data + *pi_received,
+ i_payloadSize - (*pi_received - PACKET_HEADER_LEN));
if (i_ret <= 0)
return i_ret;
*pi_received += i_ret;
@@ -320,23 +344,15 @@ extern "C" int recvPacket(vlc_object_t *p_module, bool &b_msgReceived,
if (*pi_received < i_payloadSize + PACKET_HEADER_LEN)
return i_ret;
+ assert(*pi_received == i_payloadSize + PACKET_HEADER_LEN);
*pi_received = 0;
- return -1;
+ b_msgReceived = true;
}
- // Normal case
- i_ret = tls_Recv(p_tls, p_data + *pi_received,
- i_payloadSize - (*pi_received - PACKET_HEADER_LEN));
- if (i_ret <= 0)
- return i_ret;
- *pi_received += i_ret;
-
- if (*pi_received < i_payloadSize + PACKET_HEADER_LEN)
- return i_ret;
+ if ( ufd[1].revents )
+ /* we have stuff to send */
+ i_ret = 1;
- assert(*pi_received == i_payloadSize + PACKET_HEADER_LEN);
- *pi_received = 0;
- b_msgReceived = true;
return i_ret;
}
@@ -863,13 +879,35 @@ bool intf_sys_t::handleMessages()
bool b_msgReceived = false;
uint32_t i_payloadSize = 0;
- int i_ret = recvPacket( p_module, b_msgReceived, i_payloadSize, i_sock_fd,
+
+ int canc = vlc_savecancel();
+ // Not cancellation-safe part.
+
+ vlc_mutex_lock(&lock);
+
+ /* dummy socket that we close to unblock the receiver, so we can send data */
+ /* net_Socket( p_module, AF_INET, SOCK_DGRAM, IPPROTO_UDP ); */
+ i_send_ready_fd = net_ConnectUDP( p_module, "localhost", 0, 0 );
+ if (i_send_ready_fd == -1)
+ msg_Err( p_module, "can't create the internal communication" );
+ vlc_mutex_unlock(&lock);
+ vlc_restorecancel(canc);
+
+ int i_ret = recvPacket( p_module, b_msgReceived, i_payloadSize, i_sock_fd, i_send_ready_fd,
p_tls, &i_received, p_packet, &b_pingTimeout,
&i_waitdelay, &i_retries);
- int canc = vlc_savecancel();
+ canc = vlc_savecancel();
// Not cancellation-safe part.
+ vlc_mutex_lock(&lock);
+ if ( i_send_ready_fd != -1 )
+ {
+ net_Close( i_send_ready_fd );
+ i_send_ready_fd = -1;
+ }
+ vlc_mutex_unlock(&lock);
+
#if defined(_WIN32)
if ((i_ret < 0 && WSAGetLastError() != WSAEWOULDBLOCK) || (i_ret == 0))
#else
@@ -898,3 +936,12 @@ bool intf_sys_t::handleMessages()
vlc_mutex_locker locker(&lock);
return conn_status != CHROMECAST_CONNECTION_DEAD;
}
+
+void intf_sys_t::notifySendRequest()
+{
+ if ( i_send_ready_fd != -1 )
+ {
+ net_Close( i_send_ready_fd );
+ i_send_ready_fd = -1;
+ }
+}
--
2.7.0
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