[vlc-devel] [PATCH] udp: remove redundant thread
Rémi Denis-Courmont
remi at remlab.net
Wed Oct 19 12:02:50 CEST 2016
The I/O thread has been made redundant by the prefetch filter.
Remove it and simplify accordingly.
---
modules/access/udp.c | 180 +++++++++++++++------------------------------------
1 file changed, 51 insertions(+), 129 deletions(-)
diff --git a/modules/access/udp.c b/modules/access/udp.c
index eb2dbc4..ced4f8e 100644
--- a/modules/access/udp.c
+++ b/modules/access/udp.c
@@ -43,11 +43,9 @@
#include <vlc_network.h>
#include <vlc_block.h>
#include <vlc_interrupt.h>
-#include <vlc_atomic.h>
#ifdef HAVE_POLL
# include <poll.h>
#endif
-#include <fcntl.h>
/*****************************************************************************
* Module descriptor
@@ -66,7 +64,7 @@ vlc_module_begin ()
set_subcategory( SUBCAT_INPUT_ACCESS )
add_obsolete_integer( "server-port" ) /* since 2.0.0 */
- add_integer( "udp-buffer", 0x400000, BUFFER_TEXT, BUFFER_LONGTEXT, true )
+ add_obsolete_integer( "udp-buffer" ) /* since 3.0.0 */
add_integer( "udp-timeout", -1, TIMEOUT_TEXT, NULL, true )
set_capability( "access", 0 )
@@ -80,11 +78,6 @@ struct access_sys_t
int fd;
int timeout;
size_t mtu;
- size_t fifo_size;
- block_fifo_t *fifo;
- vlc_sem_t semaphore;
- vlc_thread_t thread;
- atomic_bool timeout_reached;
};
/*****************************************************************************
@@ -92,7 +85,6 @@ struct access_sys_t
*****************************************************************************/
static block_t *BlockUDP( access_t *, bool * );
static int Control( access_t *, int, va_list );
-static void* ThreadRead( void *data );
/*****************************************************************************
* Open: open the socket
@@ -170,45 +162,17 @@ static int Open( vlc_object_t *p_this )
if( sys->fd == -1 )
{
msg_Err( p_access, "cannot open socket" );
- goto error;
- }
-
- /* Revert to blocking I/O */
-#ifndef _WIN32
- fcntl(sys->fd, F_SETFL, fcntl(sys->fd, F_GETFL) & ~O_NONBLOCK);
-#else
- ioctlsocket(sys->fd, FIONBIO, &(unsigned long){ 0 });
-#endif
-
- /* FIXME: There are no particular reasons to create a FIFO and thread here.
- * Those are just working around bugs in the stream cache. */
- sys->fifo = block_FifoNew();
- if( unlikely( sys->fifo == NULL ) )
- {
- net_Close( sys->fd );
- goto error;
+error:
+ free( sys );
+ return VLC_EGENERIC;
}
sys->mtu = 7 * 188;
- sys->fifo_size = var_InheritInteger( p_access, "udp-buffer");
- vlc_sem_init( &sys->semaphore, 0 );
sys->timeout = var_InheritInteger( p_access, "udp-timeout");
- atomic_init(&sys->timeout_reached, false);
if( sys->timeout > 0)
sys->timeout *= 1000;
- if( vlc_clone( &sys->thread, ThreadRead, p_access,
- VLC_THREAD_PRIORITY_INPUT ) )
- {
- vlc_sem_destroy( &sys->semaphore );
- block_FifoRelease( sys->fifo );
- net_Close( sys->fd );
-error:
- free( sys );
- return VLC_EGENERIC;
- }
-
return VLC_SUCCESS;
}
@@ -220,10 +184,6 @@ static void Close( vlc_object_t *p_this )
access_t *p_access = (access_t*)p_this;
access_sys_t *sys = p_access->p_sys;
- vlc_cancel( sys->thread );
- vlc_join( sys->thread, NULL );
- vlc_sem_destroy( &sys->semaphore );
- block_FifoRelease( sys->fifo );
net_Close( sys->fd );
free( sys );
}
@@ -261,102 +221,64 @@ static int Control( access_t *p_access, int i_query, va_list args )
/*****************************************************************************
* BlockUDP:
*****************************************************************************/
-static block_t *BlockUDP( access_t *p_access, bool *restrict eof )
+static block_t *BlockUDP(access_t *access, bool *restrict eof)
{
- access_sys_t *sys = p_access->p_sys;
- block_t *block;
+ access_sys_t *sys = access->p_sys;
- if (atomic_load(&sys->timeout_reached)) {
- *eof = true;
+ block_t *pkt = block_Alloc(sys->mtu);
+ if (unlikely(pkt == NULL))
+ { /* OOM - dequeue and discard one packet */
+ char dummy;
+ recv(sys->fd, &dummy, 1, 0);
return NULL;
}
- vlc_sem_wait_i11e(&sys->semaphore);
- vlc_fifo_Lock(sys->fifo);
-
- block = vlc_fifo_DequeueUnlocked(sys->fifo);
- vlc_fifo_Unlock(sys->fifo);
-
- return block;
-}
-
-/*****************************************************************************
- * ThreadRead: Pull packets from socket as soon as possible.
- *****************************************************************************/
-static void* ThreadRead( void *data )
-{
- access_t *access = data;
- access_sys_t *sys = access->p_sys;
-
- for(;;)
- {
- block_t *pkt = block_Alloc(sys->mtu);
- if (unlikely(pkt == NULL))
- { /* OOM - dequeue and discard one packet */
- char dummy;
- recv(sys->fd, &dummy, 1, 0);
- continue;
- }
-
- struct iovec iov = {
- .iov_base = pkt->p_buffer,
- .iov_len = sys->mtu,
- };
- struct msghdr msg = {
- .msg_iov = &iov,
- .msg_iovlen = 1,
+ struct iovec iov = {
+ .iov_base = pkt->p_buffer,
+ .iov_len = sys->mtu,
+ };
+ struct msghdr msg = {
+ .msg_iov = &iov,
+ .msg_iovlen = 1,
#ifdef __linux__
- .msg_flags = MSG_TRUNC,
+ .msg_flags = MSG_TRUNC,
#endif
- };
- ssize_t len;
+ };
- block_cleanup_push(pkt);
- do
- {
- int poll_return=0;
- struct pollfd ufd[1];
- ufd[0].fd = sys->fd;
- ufd[0].events = POLLIN;
-
- while ((poll_return = poll(ufd, 1, sys->timeout)) < 0); /* cancellation point */
- if (unlikely( poll_return == 0))
- {
- msg_Err( access, "Timeout on receiving, timeout %d seconds", sys->timeout/1000 );
- atomic_store(&sys->timeout_reached, true);
- len=0;
- break;
- }
- len = recvmsg(sys->fd, &msg, 0);
- }
- while (len == -1);
- vlc_cleanup_pop();
+ struct pollfd ufd[1];
-#ifdef MSG_TRUNC
- if (msg.msg_flags & MSG_TRUNC)
- {
- msg_Err(access, "%zd bytes packet truncated (MTU was %zu)",
- len, sys->mtu);
- pkt->i_flags |= BLOCK_FLAG_CORRUPTED;
- sys->mtu = len;
- }
- else
-#endif
- pkt->i_buffer = len;
+ ufd[0].fd = sys->fd;
+ ufd[0].events = POLLIN;
- vlc_fifo_Lock(sys->fifo);
- /* Discard old buffers on overflow */
- while (vlc_fifo_GetBytes(sys->fifo) + len > sys->fifo_size)
- {
- int canc = vlc_savecancel();
- block_Release(vlc_fifo_DequeueUnlocked(sys->fifo));
- vlc_restorecancel(canc);
- }
+ switch (vlc_poll_i11e(ufd, 1, sys->timeout))
+ {
+ case 0:
+ msg_Err(access, "receive time-out");
+ *eof = true;
+ /* fall through */
+ case -1:
+ goto skip;
+ }
+
+ ssize_t len = recvmsg(sys->fd, &msg, 0);
+ if (len < 0)
+ {
+skip:
+ block_Release(pkt);
+ return NULL;
+ }
- vlc_fifo_QueueUnlocked(sys->fifo, pkt);
- vlc_fifo_Unlock(sys->fifo);
- vlc_sem_post(&sys->semaphore);
+#ifdef MSG_TRUNC
+ if (msg.msg_flags & MSG_TRUNC)
+ {
+ msg_Err(access, "%zd bytes packet truncated (MTU was %zu)",
+ len, sys->mtu);
+ pkt->i_flags |= BLOCK_FLAG_CORRUPTED;
+ sys->mtu = len;
}
+ else
+#endif
+ pkt->i_buffer = len;
- return NULL;
+ return pkt;
}
--
2.9.3
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