/*****************************************************************************
* block.c: Data blocks management functions
*****************************************************************************
- * Copyright (C) 2003-2004 the VideoLAN team
+ * Copyright (C) 2003-2004 VLC authors and VideoLAN
* Copyright (C) 2007-2009 Rémi Denis-Courmont
*
* Authors: Laurent Aimar <fenrir@videolan.org>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
*
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
*****************************************************************************/
/*****************************************************************************
# include "config.h"
#endif
-#include <vlc_common.h>
#include <sys/stat.h>
#include <assert.h>
-#include "vlc_block.h"
+#include <errno.h>
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+#include <fcntl.h>
+
+#include <vlc_common.h>
+#include <vlc_block.h>
+#include <vlc_fs.h>
/**
* @section Block handling functions.
*/
-/**
- * Internal state for heap block.
- */
-struct block_sys_t
-{
- block_t self;
- size_t i_allocated_buffer;
- uint8_t p_allocated_buffer[];
-};
-
#ifndef NDEBUG
static void BlockNoRelease( block_t *b )
{
fprintf( stderr, "block %p has no release callback! This is a bug!\n", b );
abort();
}
+
+static void block_Check (block_t *block)
+{
+ while (block != NULL)
+ {
+ unsigned char *start = block->p_start;
+ unsigned char *end = block->p_start + block->i_size;
+ unsigned char *bufstart = block->p_buffer;
+ unsigned char *bufend = block->p_buffer + block->i_buffer;
+
+ assert (block->pf_release != BlockNoRelease);
+ assert (start <= end);
+ assert (bufstart <= bufend);
+ assert (bufstart >= start);
+ assert (bufend <= end);
+
+ block = block->p_next;
+ }
+}
+
+static void block_Invalidate (block_t *block)
+{
+ block->p_next = NULL;
+ block_Check (block);
+ block->pf_release = BlockNoRelease;
+}
+#else
+# define block_Check(b) ((void)(b))
+# define block_Invalidate(b) ((void)(b))
#endif
void block_Init( block_t *restrict b, void *buf, size_t size )
{
/* Fill all fields to their default */
b->p_next = NULL;
+ b->p_buffer = buf;
+ b->i_buffer = size;
+ b->p_start = buf;
+ b->i_size = size;
b->i_flags = 0;
+ b->i_nb_samples = 0;
b->i_pts =
b->i_dts = VLC_TS_INVALID;
b->i_length = 0;
- b->i_rate = 0;
- b->p_buffer = buf;
- b->i_buffer = size;
#ifndef NDEBUG
b->pf_release = BlockNoRelease;
#endif
}
-static void BlockRelease( block_t *p_block )
+static void block_generic_Release (block_t *block)
{
- free( p_block );
+ /* That is always true for blocks allocated with block_Alloc(). */
+ assert (block->p_start == (unsigned char *)(block + 1));
+ block_Invalidate (block);
+ free (block);
}
static void BlockMetaCopy( block_t *restrict out, const block_t *in )
{
+ out->p_next = in->p_next;
+ out->i_nb_samples = in->i_nb_samples;
out->i_dts = in->i_dts;
out->i_pts = in->i_pts;
out->i_flags = in->i_flags;
out->i_length = in->i_length;
- out->i_rate = in->i_rate;
- out->i_samples = in->i_samples;
}
-/* Memory alignment */
+/* Memory alignment (must be a multiple of sizeof(void*) and a power of two) */
#define BLOCK_ALIGN 16
-/* Initial size of reserved header and footer */
-#define BLOCK_PADDING_SIZE 32
+/* Initial reserved header and footer size (must be multiple of alignment) */
+#define BLOCK_PADDING 32
/* Maximum size of reserved footer before we release with realloc() */
#define BLOCK_WASTE_SIZE 2048
-block_t *block_Alloc( size_t i_size )
+block_t *block_Alloc (size_t size)
{
- /* We do only one malloc
- * TODO: bench if doing 2 malloc but keeping a pool of buffer is better
- * TODO: use memalign
- * 16 -> align on 16
- * 2 * BLOCK_PADDING_SIZE -> pre + post padding
- */
- const size_t i_alloc = i_size + 2 * BLOCK_PADDING_SIZE + BLOCK_ALIGN;
- block_sys_t *p_sys = malloc( sizeof( *p_sys ) + i_alloc );
-
- if( p_sys == NULL )
+ /* 2 * BLOCK_PADDING: pre + post padding */
+ const size_t alloc = sizeof (block_t) + BLOCK_ALIGN + (2 * BLOCK_PADDING)
+ + size;
+ if (unlikely(alloc <= size))
return NULL;
- /* Fill opaque data */
- p_sys->i_allocated_buffer = i_alloc;
-
- block_Init( &p_sys->self, p_sys->p_allocated_buffer + BLOCK_PADDING_SIZE
- + BLOCK_ALIGN
- - ((uintptr_t)p_sys->p_allocated_buffer % BLOCK_ALIGN),
- i_size );
- p_sys->self.pf_release = BlockRelease;
+ block_t *b = malloc (alloc);
+ if (unlikely(b == NULL))
+ return NULL;
- return &p_sys->self;
+ block_Init (b, b + 1, alloc - sizeof (*b));
+ static_assert ((BLOCK_PADDING % BLOCK_ALIGN) == 0,
+ "BLOCK_PADDING must be a multiple of BLOCK_ALIGN");
+ b->p_buffer += BLOCK_PADDING + BLOCK_ALIGN - 1;
+ b->p_buffer = (void *)(((uintptr_t)b->p_buffer) & ~(BLOCK_ALIGN - 1));
+ b->i_buffer = size;
+ b->pf_release = block_generic_Release;
+ return b;
}
block_t *block_Realloc( block_t *p_block, ssize_t i_prebody, size_t i_body )
{
- block_sys_t *p_sys = (block_sys_t *)p_block;
size_t requested = i_prebody + i_body;
+ block_Check( p_block );
+
/* Corner case: empty block requested */
if( i_prebody <= 0 && i_body <= (size_t)(-i_prebody) )
{
return NULL;
}
- if( p_block->pf_release != BlockRelease )
- {
- /* Special case when pf_release if overloaded
- * TODO if used one day, then implement it in a smarter way */
- block_t *p_dup = block_Duplicate( p_block );
- block_Release( p_block );
- if( !p_dup )
- return NULL;
-
- p_block = p_dup;
- p_sys = (block_sys_t *)p_block;
- }
-
- uint8_t *p_start = p_sys->p_allocated_buffer;
- uint8_t *p_end = p_sys->p_allocated_buffer + p_sys->i_allocated_buffer;
-
- assert( p_block->p_buffer + p_block->i_buffer <= p_end );
- assert( p_block->p_buffer >= p_start );
+ assert( p_block->p_start <= p_block->p_buffer );
+ assert( p_block->p_start + p_block->i_size
+ >= p_block->p_buffer + p_block->i_buffer );
/* Corner case: the current payload is discarded completely */
if( i_prebody <= 0 && p_block->i_buffer <= (size_t)-i_prebody )
p_block->i_buffer = 0; /* discard current payload */
if( p_block->i_buffer == 0 )
{
- size_t available = p_end - p_start;
-
- if( requested <= available )
+ if( requested <= p_block->i_size )
{ /* Enough room: recycle buffer */
- size_t extra = available - requested;
+ size_t extra = p_block->i_size - requested;
- p_block->p_buffer = p_start + (extra / 2);
+ p_block->p_buffer = p_block->p_start + (extra / 2);
p_block->i_buffer = requested;
return p_block;
}
if( p_block->i_buffer > i_body )
p_block->i_buffer = i_body;
+ uint8_t *p_start = p_block->p_start;
+ uint8_t *p_end = p_start + p_block->i_size;
+
/* Second, reallocate the buffer if we lack space. This is done now to
* minimize the payload size for memory copy. */
assert( i_prebody >= 0 );
if( (size_t)(p_block->p_buffer - p_start) < (size_t)i_prebody
- || (size_t)(p_end - p_block->p_buffer) < p_block->i_buffer + i_body )
+ || (size_t)(p_end - p_block->p_buffer) < i_body )
{
- /* FIXME: this is really dumb, we should use realloc() */
block_t *p_rea = block_Alloc( requested );
if( p_rea )
{
memcpy( p_rea->p_buffer, p_block->p_buffer, p_block->i_buffer );
}
block_Release( p_block );
+ if( p_rea == NULL )
+ return NULL;
p_block = p_rea;
}
else
* XXX it might not preserve the alignment of p_buffer */
if( p_end - (p_block->p_buffer + i_body) > BLOCK_WASTE_SIZE )
{
- const ptrdiff_t i_prebody = p_block->p_buffer - p_start;
- const size_t i_new = requested + 1 * BLOCK_PADDING_SIZE;
- block_sys_t *p_new = realloc( p_sys, sizeof (*p_sys) + i_new );
-
- if( p_new != NULL )
+ block_t *p_rea = block_Alloc( requested );
+ if( p_rea )
{
- p_sys = p_new;
- p_sys->i_allocated_buffer = i_new;
- p_block = &p_sys->self;
- p_block->p_buffer = &p_sys->p_allocated_buffer[i_prebody];
+ BlockMetaCopy( p_rea, p_block );
+ p_rea->p_buffer += i_prebody;
+ p_rea->i_buffer -= i_prebody;
+ memcpy( p_rea->p_buffer, p_block->p_buffer, p_block->i_buffer );
+ block_Release( p_block );
+ p_block = p_rea;
}
}
}
-typedef struct
-{
- block_t self;
- void *mem;
-} block_heap_t;
-
-static void block_heap_Release (block_t *self)
+static void block_heap_Release (block_t *block)
{
- block_heap_t *block = (block_heap_t *)self;
-
- free (block->mem);
+ block_Invalidate (block);
+ free (block->p_start);
free (block);
}
* When block_Release() is called, VLC will free() the specified pointer.
*
* @param ptr base address of the heap allocation (will be free()'d)
- * @param addr base address of the useful buffer data
- * @param length bytes length of the useful buffer datan
+ * @param length bytes length of the heap allocation
* @return NULL in case of error (ptr free()'d in that case), or a valid
* block_t pointer.
*/
-block_t *block_heap_Alloc (void *ptr, void *addr, size_t length)
+block_t *block_heap_Alloc (void *addr, size_t length)
{
- block_heap_t *block = malloc (sizeof (*block));
+ block_t *block = malloc (sizeof (*block));
if (block == NULL)
{
free (addr);
return NULL;
}
- block_Init (&block->self, (uint8_t *)addr, length);
- block->self.pf_release = block_heap_Release;
- block->mem = ptr;
- return &block->self;
+ block_Init (block, addr, length);
+ block->pf_release = block_heap_Release;
+ return block;
}
#ifdef HAVE_MMAP
# include <sys/mman.h>
-typedef struct block_mmap_t
-{
- block_t self;
- void *base_addr;
- size_t length;
-} block_mmap_t;
-
static void block_mmap_Release (block_t *block)
{
- block_mmap_t *p_sys = (block_mmap_t *)block;
-
- munmap (p_sys->base_addr, p_sys->length);
- free (p_sys);
+ block_Invalidate (block);
+ munmap (block->p_start, block->i_size);
+ free (block);
}
/**
if (addr == MAP_FAILED)
return NULL;
- block_mmap_t *block = malloc (sizeof (*block));
+ block_t *block = malloc (sizeof (*block));
if (block == NULL)
{
munmap (addr, length);
return NULL;
}
- block_Init (&block->self, (uint8_t *)addr, length);
- block->self.pf_release = block_mmap_Release;
- block->base_addr = addr;
- block->length = length;
- return &block->self;
+ block_Init (block, addr, length);
+ block->pf_release = block_mmap_Release;
+ return block;
}
#else
block_t *block_mmap_Alloc (void *addr, size_t length)
#ifdef WIN32
-#ifdef UNDER_CE
-#define _get_osfhandle(a) ((long) (a))
-#endif
+# include <io.h>
static
ssize_t pread (int fd, void *buf, size_t count, off_t offset)
#endif
/**
- * Loads a file into a block of memory. If possible a private file mapping is
- * created. Otherwise, the file is read normally. On 32-bits platforms, this
- * function will not work for very large files, due to memory space
- * constraints. Cancellation point.
+ * Loads a file into a block of memory through a file descriptor.
+ * If possible a private file mapping is created. Otherwise, the file is read
+ * normally. This function is a cancellation point.
+ *
+ * @note On 32-bits platforms,
+ * this function will not work for very large files,
+ * due to memory space constraints.
*
* @param fd file descriptor to load from
* @return a new block with the file content at p_buffer, and file length at
return block;
}
+/**
+ * Loads a file into a block of memory from the file path.
+ * See also block_File().
+ */
+block_t *block_FilePath (const char *path)
+{
+ int fd = vlc_open (path, O_RDONLY);
+ if (fd == -1)
+ return NULL;
+
+ block_t *block = block_File (fd);
+ close (fd);
+ return block;
+}
+
/**
* @section Thread-safe block queue functions
*/
void block_FifoEmpty( block_fifo_t *p_fifo )
{
- block_t *b;
+ block_t *block;
vlc_mutex_lock( &p_fifo->lock );
- for( b = p_fifo->p_first; b != NULL; )
+ block = p_fifo->p_first;
+ if (block != NULL)
{
- block_t *p_next;
-
- p_next = b->p_next;
- block_Release( b );
- b = p_next;
+ p_fifo->i_depth = p_fifo->i_size = 0;
+ p_fifo->p_first = NULL;
+ p_fifo->pp_last = &p_fifo->p_first;
}
-
- p_fifo->i_depth = p_fifo->i_size = 0;
- p_fifo->p_first = NULL;
- p_fifo->pp_last = &p_fifo->p_first;
vlc_cond_broadcast( &p_fifo->wait_room );
vlc_mutex_unlock( &p_fifo->lock );
+
+ while (block != NULL)
+ {
+ block_t *buf;
+
+ buf = block->p_next;
+ block_Release (block);
+ block = buf;
+ }
}
/**
* Immediately queue one block at the end of a FIFO.
* @param fifo queue
* @param block head of a block list to queue (may be NULL)
+ * @return total number of bytes appended to the queue
*/
size_t block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
{
- size_t i_size = 0;
- vlc_mutex_lock( &p_fifo->lock );
+ size_t i_size = 0, i_depth = 0;
+ block_t *p_last;
- while (p_block != NULL)
+ if (p_block == NULL)
+ return 0;
+ for (p_last = p_block; ; p_last = p_last->p_next)
{
- i_size += p_block->i_buffer;
-
- *p_fifo->pp_last = p_block;
- p_fifo->pp_last = &p_block->p_next;
- p_fifo->i_depth++;
- p_fifo->i_size += p_block->i_buffer;
-
- p_block = p_block->p_next;
+ i_size += p_last->i_buffer;
+ i_depth++;
+ if (!p_last->p_next)
+ break;
}
- /* We queued one block: wake up one read-waiting thread */
+ vlc_mutex_lock (&p_fifo->lock);
+ *p_fifo->pp_last = p_block;
+ p_fifo->pp_last = &p_last->p_next;
+ p_fifo->i_depth += i_depth;
+ p_fifo->i_size += i_size;
+ /* We queued at least one block: wake up one read-waiting thread */
vlc_cond_signal( &p_fifo->wait );
vlc_mutex_unlock( &p_fifo->lock );
vlc_mutex_unlock( &p_fifo->lock );
}
+/**
+ * Dequeue the first block from the FIFO. If necessary, wait until there is
+ * one block in the queue. This function is (always) cancellation point.
+ *
+ * @return a valid block, or NULL if block_FifoWake() was called.
+ */
block_t *block_FifoGet( block_fifo_t *p_fifo )
{
block_t *b;
return b;
}
+/**
+ * Peeks the first block in the FIFO.
+ * If necessary, wait until there is one block.
+ * This function is (always) a cancellation point.
+ *
+ * @warning This function leaves the block in the FIFO.
+ * You need to protect against concurrent threads who could dequeue the block.
+ * Preferrably, there should be only one thread reading from the FIFO.
+ *
+ * @return a valid block.
+ */
block_t *block_FifoShow( block_fifo_t *p_fifo )
{
block_t *b;
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