[vlc-devel] [PATCH v3] udp: pull and buffer received packets in udp access module
Rémi Denis-Courmont
remi at remlab.net
Sun Aug 18 20:58:41 CEST 2013
Le dimanche 18 août 2013 10:24:50 Tzu-Jung Lee a écrit :
> Signed-off-by: Tzu-Jung Lee <tjlee at ambarella.com>
> ---
> Revised acoording to Rémi's comments
>
> modules/access/udp.c | 93
> ++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 75
> insertions(+), 18 deletions(-)
>
> diff --git a/modules/access/udp.c b/modules/access/udp.c
> index 6613ebe..a6e4424 100644
> --- a/modules/access/udp.c
> +++ b/modules/access/udp.c
> @@ -40,6 +40,7 @@
> #include <vlc_plugin.h>
> #include <vlc_access.h>
> #include <vlc_network.h>
> +#include <vlc_block.h>
>
> #define MTU 65535
>
> @@ -49,6 +50,9 @@
> static int Open ( vlc_object_t * );
> static void Close( vlc_object_t * );
>
> +#define BUFFER_TEXT N_("Receive buffer")
> +#define BUFFER_LONGTEXT N_("UDP receive buffer size (bytes)" )
> +
> vlc_module_begin ()
> set_shortname( N_("UDP" ) )
> set_description( N_("UDP input") )
> @@ -56,6 +60,7 @@ 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
> )
>
> set_capability( "access", 0 )
> add_shortcut( "udp", "udpstream", "udp4", "udp6" )
> @@ -63,11 +68,22 @@ vlc_module_begin ()
> set_callbacks( Open, Close )
> vlc_module_end ()
>
> +struct access_sys_t
> +{
> + int i_fd;
> + int i_fifo_size;
> +
> + block_fifo_t *p_fifo;
> +
> + vlc_thread_t thread;
> +};
> +
> /**************************************************************************
> *** * Local prototypes
>
> ***************************************************************************
> **/ static block_t *BlockUDP( access_t * );
> static int Control( access_t *, int, va_list );
> +static void* ThreadRead( void *data );
>
> /**************************************************************************
> *** * Open: open the socket
> @@ -75,12 +91,18 @@ static int Control( access_t *, int, va_list );
> static int Open( vlc_object_t *p_this )
> {
> access_t *p_access = (access_t*)p_this;
> + access_sys_t *p_sys;
>
> char *psz_name = strdup( p_access->psz_location );
> char *psz_parser;
> const char *psz_server_addr, *psz_bind_addr = "";
> int i_bind_port = 1234, i_server_port = 0;
> - int fd;
> + int i_fd;
> +
> + if( !( p_sys = malloc ( sizeof( *p_sys ) ) ) )
unlikely(). Please split malloc() and test.
> + return VLC_ENOMEM;
> +
> + p_access->p_sys = p_sys;
>
> /* Set up p_access */
> access_InitFields( p_access );
> @@ -128,15 +150,30 @@ static int Open( vlc_object_t *p_this )
> msg_Dbg( p_access, "opening server=%s:%d local=%s:%d",
> psz_server_addr, i_server_port, psz_bind_addr, i_bind_port );
>
> - fd = net_OpenDgram( p_access, psz_bind_addr, i_bind_port,
> - psz_server_addr, i_server_port, IPPROTO_UDP );
> + i_fd = net_OpenDgram( p_access, psz_bind_addr, i_bind_port,
> + psz_server_addr, i_server_port, IPPROTO_UDP );
> free (psz_name);
> - if( fd == -1 )
> + if( i_fd == -1 )
> {
> msg_Err( p_access, "cannot open socket" );
> + net_Close (i_fd);
> + free (p_sys);
> + return VLC_EGENERIC;
> + }
> +
> + p_sys->i_fd = i_fd;
> + p_sys->p_fifo = block_FifoNew();
Missing -unlikely- error case.
> + p_sys->i_fifo_size = var_InheritInteger(p_access, "udp-buffer");
> +
> + if( vlc_clone( &p_sys->thread, ThreadRead, p_access,
> + VLC_THREAD_PRIORITY_HIGHEST ) )
> + {
> + msg_Err( p_access, "cannot spawn UDP access thread" );
> + block_FifoRelease( p_sys->p_fifo );
> + net_Close (i_fd);
> + free (p_sys);
> return VLC_EGENERIC;
> }
> - p_access->p_sys = (void *)(intptr_t)fd;
>
> return VLC_SUCCESS;
> }
> @@ -147,8 +184,11 @@ static int Open( vlc_object_t *p_this )
> static void Close( vlc_object_t *p_this )
> {
> access_t *p_access = (access_t*)p_this;
> + access_sys_t *p_sys = p_access->p_sys;
>
You need to join the thread before you destroy the FIFO.
> - net_Close( (intptr_t)p_access->p_sys );
> + block_FifoRelease( p_sys->p_fifo );
> + net_Close( p_sys->i_fd );
> + free (p_sys);
> }
>
> /**************************************************************************
> *** @@ -198,20 +238,37 @@ static int Control( access_t *p_access, int
> i_query, va_list args )
> ***************************************************************************
> **/ static block_t *BlockUDP( access_t *p_access )
> {
> - int fd = (intptr_t)p_access->p_sys;
> + access_sys_t *p_sys = p_access->p_sys;
>
> - /* Read data */
> - block_t *p_block = block_Alloc( MTU );
> - if( unlikely(p_block == NULL) )
> - return NULL;
> + return block_FifoGet( p_sys->p_fifo );
> +}
> +/**************************************************************************
> *** + * ThreadRead: Pull packets from socket as soon as possible.
> +
> ***************************************************************************
> **/ +static void* ThreadRead( void *data )
> +{
> + access_t *p_access = (access_t*)data;
> + access_sys_t *p_sys = p_access->p_sys;
> + int i_fifo_size = p_sys->i_fifo_size;
>
> - ssize_t len = net_Read( p_access, fd, NULL,
> - p_block->p_buffer, MTU, false );
> - if( len < 0 )
> + for (;;)
> {
> - block_Release( p_block );
> - return NULL;
> - }
> + block_FifoPace(p_sys->p_fifo, SIZE_MAX, i_fifo_size);
>
> - return block_Realloc( p_block, 0, len );
> + block_t *p_pk = block_Alloc( MTU );
> + if( unlikely(p_pk == NULL) )
> + return NULL;
> +
> + ssize_t len = net_Read( p_access, p_sys->i_fd, NULL,
> + p_pk->p_buffer, MTU, false );
> + if( len <= 0 )
> + {
> + block_Release( p_pk );
> + return NULL;
This will still break streaming on recoverable ICMP errors.
> + }
> +
> + p_pk = block_Realloc( p_pk, 0, len );
> + block_FifoPut( p_sys->p_fifo, p_pk );
> + }
> + return NULL;
> }
--
Rémi Denis-Courmont
http://www.remlab.net/
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