]> git.sesse.net Git - vlc/blobdiff - src/misc/block.c
macosx: Add a missing PL_LOCK in the wizard.
[vlc] / src / misc / block.c
index 3a3ccbfadffb698fe7c61f58a7c70427674f86a6..a757e3cf2d487753602ca57282b3e905d2940095 100644 (file)
@@ -1,8 +1,8 @@
 /*****************************************************************************
  * block.c: Data blocks management functions
  *****************************************************************************
- * Copyright (C) 2003 VideoLAN
- * $Id: block.c,v 1.5 2003/11/22 14:42:47 fenrir Exp $
+ * Copyright (C) 2003-2004 the VideoLAN team
+ * $Id$
  *
  * Authors: Laurent Aimar <fenrir@videolan.org>
  *
  *
  * 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., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  *****************************************************************************/
 
 /*****************************************************************************
  * Preamble
  *****************************************************************************/
-#include <stdlib.h>
-#include <stdarg.h>
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
 
-#include <vlc/vlc.h>
+#include <vlc_common.h>
+#include <sys/stat.h>
 #include "vlc_block.h"
 
+/*****************************************************************************
+ * Block functions.
+ *****************************************************************************/
 /* private */
 struct block_sys_t
 {
-    vlc_mutex_t lock;
-
-    uint8_t     *p_allocated_buffer;
-    int         i_allocated_buffer;
-
-    vlc_bool_t  b_modify;       /* has it been put in modified state */
-    int         i_duplicated;   /* how many times has the content been
-                                 * duplicated */
-
+    block_t     self;
+    size_t      i_allocated_buffer;
+    uint8_t     p_allocated_buffer[0];
 };
 
-static void BlockRelease( block_t *p_block )
+#ifndef NDEBUG
+static void BlockNoRelease( block_t *b )
 {
-    vlc_mutex_lock( &p_block->p_sys->lock );
-
-    p_block->p_sys->i_duplicated--;
-    if( p_block->p_sys->i_duplicated < 0 )
-    {
-        vlc_mutex_unlock( &p_block->p_sys->lock );
-        vlc_mutex_destroy( &p_block->p_sys->lock );
-        free( p_block->p_sys->p_allocated_buffer );
-        free( p_block->p_sys );
-        free( p_block );
-
-        return;
-    }
-
-    vlc_mutex_unlock( &p_block->p_sys->lock );
-    free( p_block );
+    fprintf( stderr, "block %p has no release callback! This is a bug!\n", b );
+    abort();
 }
+#endif
 
-static block_t *__BlockDupContent( block_t *p_block )
+void block_Init( block_t *restrict b, void *buf, size_t size )
 {
-    block_t *p_dup;
-
-    p_dup = block_New( p_block->p_manager, p_block->i_buffer );
-    memcpy( p_dup->p_buffer, p_block->p_buffer, p_block->i_buffer );
-    p_dup->b_frame_display = p_block->b_frame_display;
-    p_dup->b_frame_start   = p_block->b_frame_start;
-    p_dup->i_pts           = p_block->i_pts;
-    p_dup->i_dts           = p_block->i_dts;
-    p_dup->b_discontinuity = p_block->b_discontinuity;
-
-    return p_dup;
+    /* Fill all fields to their default */
+    b->p_next = b->p_prev = NULL;
+    b->i_flags = 0;
+    b->i_pts = b->i_dts = b->i_length = 0;
+    b->i_rate = 0;
+    b->p_buffer = buf;
+    b->i_buffer = size;
+#ifndef NDEBUG
+    b->pf_release = BlockNoRelease;
+#endif
 }
 
-static block_t *BlockModify( block_t *p_block, vlc_bool_t b_will_modify )
+static void BlockRelease( block_t *p_block )
 {
-    block_t *p_mod = p_block;   /* by default */
-
-    vlc_mutex_lock( &p_block->p_sys->lock );
-
-    if( p_block->p_sys->b_modify == b_will_modify )
-    {
-        vlc_mutex_unlock( &p_block->p_sys->lock );
-        return p_block;
-    }
-
-    if( p_block->p_sys->i_duplicated == 0 )
-    {
-        p_block->p_sys->b_modify = b_will_modify;
-        vlc_mutex_unlock( &p_block->p_sys->lock );
-        return p_block;
-    }
-
-    /* FIXME we could avoid that
-     * we just need to create a new p_sys with new mem FIXME */
-    p_mod = __BlockDupContent( p_block );
-    vlc_mutex_unlock( &p_block->p_sys->lock );
+    free( p_block );
+}
 
-    BlockRelease( p_block );
+/* Memory alignment */
+#define BLOCK_ALIGN        16
+/* Initial size of reserved header and footer */
+#define BLOCK_PADDING_SIZE 32
+/* Maximum size of reserved footer before we release with realloc() */
+#define BLOCK_WASTE_SIZE   2048
 
-    return p_mod;
+block_t *block_Alloc( size_t i_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 )
+        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;
+
+    return &p_sys->self;
 }
 
-static block_t *BlockDuplicate( block_t *p_block )
+block_t *block_Realloc( block_t *p_block, ssize_t i_prebody, size_t i_body )
 {
-    block_t *p_dup;
+    block_sys_t *p_sys = (block_sys_t *)p_block;
+    ssize_t i_buffer_size = i_prebody + i_body;
 
-    vlc_mutex_lock( &p_block->p_sys->lock );
-    if( !p_block->p_sys->b_modify )
+    if( i_buffer_size <= 0 )
     {
-        p_block->p_sys->i_duplicated++;
-        vlc_mutex_unlock( &p_block->p_sys->lock );
-        p_dup = block_NewEmpty();
-        memcpy( p_dup, p_block, sizeof( block_t ) );
-        p_dup->p_next = NULL;
-        return p_dup;
+        block_Release( p_block );
+        return NULL;
     }
-    p_dup = __BlockDupContent( p_block );
-    vlc_mutex_unlock( &p_block->p_sys->lock );
-
-    return p_dup;
-}
 
-static block_t *BlockRealloc( block_t *p_block, int i_prebody, int i_body )
-{
+    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;
+    }
 
-    vlc_mutex_lock( &p_block->p_sys->lock );
-    if( i_prebody < 0 || p_block->p_buffer - i_prebody >
-        p_block->p_sys->p_allocated_buffer )
+    /* Adjust reserved header if there is enough room */
+    if( p_block->p_buffer - i_prebody > p_sys->p_allocated_buffer &&
+        p_block->p_buffer - i_prebody < p_sys->p_allocated_buffer +
+        p_sys->i_allocated_buffer )
     {
         p_block->p_buffer -= i_prebody;
         p_block->i_buffer += i_prebody;
         i_prebody = 0;
     }
-    if( i_body < 0 ||
-        p_block->p_buffer + i_body < p_block->p_sys->p_allocated_buffer +
-        p_block->p_sys->i_allocated_buffer )
+
+    /* Adjust payload size if there is enough room */
+    if( p_block->p_buffer + i_body < p_sys->p_allocated_buffer +
+        p_sys->i_allocated_buffer )
     {
-        p_block->i_buffer = i_body;
+        p_block->i_buffer = i_buffer_size;
         i_body = 0;
     }
-    vlc_mutex_unlock( &p_block->p_sys->lock );
 
-    if( i_prebody > 0 )
+    /* Not enough room, reallocate the buffer */
+    if( i_body > 0 || i_prebody > 0 )
     {
-        block_t *p_rea = block_New( p_block->p_manager, i_prebody + i_body );
+        /* FIXME: this is really dumb, we should use realloc() */
+        block_t *p_rea = block_New( NULL, i_buffer_size );
+
+        if( p_rea )
+        {
+            p_rea->i_dts     = p_block->i_dts;
+            p_rea->i_pts     = p_block->i_pts;
+            p_rea->i_flags   = p_block->i_flags;
+            p_rea->i_length  = p_block->i_length;
+            p_rea->i_rate    = p_block->i_rate;
+            p_rea->i_samples = p_block->i_samples;
+
+            memcpy( p_rea->p_buffer + i_prebody, p_block->p_buffer,
+                    __MIN( p_block->i_buffer, p_rea->i_buffer - i_prebody ) );
+        }
 
-        memcpy( &p_rea->p_buffer[i_prebody], p_block->p_buffer,
-                p_block->i_buffer );
+        block_Release( p_block );
 
         return p_rea;
     }
 
-    if( i_body > 0 )
+    /* We have a very large reserved footer now? Release some of it. */
+    if ((p_sys->p_allocated_buffer + p_sys->i_allocated_buffer) -
+        (p_block->p_buffer + p_block->i_buffer) > BLOCK_WASTE_SIZE)
     {
-        int i_start;
-        block_t *p_rea = BlockModify( p_block, VLC_TRUE );
+        const size_t news = p_block->i_buffer + 2 * BLOCK_PADDING_SIZE + 16;
+        block_sys_t *newb = realloc (p_sys, sizeof (*p_sys) + news);
 
-        i_start = p_rea->p_buffer - p_rea->p_sys->p_allocated_buffer;
-
-        p_rea->p_sys->i_allocated_buffer += i_body - p_rea->i_buffer;
-        p_rea->p_sys->p_allocated_buffer =
-            realloc( p_rea->p_sys->p_allocated_buffer,
-                     p_rea->p_sys->i_allocated_buffer );
-
-        p_rea->p_buffer = &p_rea->p_sys->p_allocated_buffer[i_start];
-        p_rea->i_buffer = i_body;
-
-        return p_rea;
+        if (newb != NULL)
+        {
+            p_sys = newb;
+            p_sys->i_allocated_buffer = news;
+            p_block = &p_sys->self;
+            p_block->p_buffer = p_sys->p_allocated_buffer + BLOCK_PADDING_SIZE
+                + BLOCK_ALIGN
+                - ((uintptr_t)p_sys->p_allocated_buffer % BLOCK_ALIGN);
+        }
     }
 
     return p_block;
 }
 
-/*****************************************************************************
- * Standard block management
- *
- *****************************************************************************/
-/* to be used by other block management */
-block_t *block_NewEmpty( void )
-{
-    block_t *p_block;
-
-    p_block = malloc( sizeof( block_t ) );
-    memset( p_block, 0, sizeof( block_t ) );
+#ifdef HAVE_MMAP
+# include <sys/mman.h>
 
-    p_block->p_next         = NULL;
-    p_block->b_frame_display= VLC_TRUE;
-    p_block->b_frame_start  = VLC_FALSE;
-    p_block->i_pts          = 0;
-    p_block->i_dts          = 0;
-    p_block->i_length       = 0;
-
-    p_block->b_discontinuity= VLC_FALSE;
-
-    p_block->i_buffer       = 0;
-    p_block->p_buffer       = NULL;
+typedef struct block_mmap_t
+{
+    block_t     self;
+    void       *base_addr;
+    size_t      length;
+} block_mmap_t;
 
-    p_block->pf_release     = NULL;
-    p_block->pf_duplicate   = NULL;
-    p_block->pf_modify      = NULL;
-    p_block->pf_realloc     = NULL;
+static void block_mmap_Release (block_t *block)
+{
+    block_mmap_t *p_sys = (block_mmap_t *)block;
 
-    p_block->p_manager      = NULL;
-    p_block->p_sys = NULL;
-    return p_block;
+    munmap (p_sys->base_addr, p_sys->length);
+    free (p_sys);
 }
 
-block_t *__block_New( vlc_object_t *p_obj, int i_size )
+/**
+ * Creates a block from a virtual address memory mapping (mmap).
+ * This is provided by LibVLC so that mmap blocks can safely be deallocated
+ * even after the allocating plugin has been unloaded from memory.
+ *
+ * @param addr base address of the mapping (as returned by mmap)
+ * @param length length (bytes) of the mapping (as passed to mmap)
+ * @return NULL if addr is MAP_FAILED, or an error occurred (in the later
+ * case, munmap(addr, length) is invoked before returning).
+ */
+block_t *block_mmap_Alloc (void *addr, size_t length)
 {
-    block_t     *p_block;
-    block_sys_t *p_sys;
+    if (addr == MAP_FAILED)
+        return NULL;
 
-    p_block = block_NewEmpty();
-
-    p_block->i_buffer       = i_size;
-    if( i_size > 0 )
+    block_mmap_t *block = malloc (sizeof (*block));
+    if (block == NULL)
     {
-        p_block->p_buffer   = malloc( i_size );
+        munmap (addr, length);
+        return NULL;
     }
 
-    p_block->pf_release     = BlockRelease;
-    p_block->pf_duplicate   = BlockDuplicate;
-    p_block->pf_modify      = BlockModify;
-    p_block->pf_realloc     = BlockRealloc;
-
-    /* that should be ok (no comunication between multiple p_vlc) */
-    p_block->p_manager      = VLC_OBJECT( p_obj->p_vlc );
+    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;
+}
+#else
+block_t *block_mmap_Alloc (void *addr, size_t length)
+{
+    (void)addr; (void)length; return NULL;
+}
+#endif
 
-    p_block->p_sys = p_sys = malloc( sizeof( block_sys_t ) );
-    vlc_mutex_init( p_obj, &p_sys->lock );
-    p_sys->p_allocated_buffer = p_block->p_buffer;
-    p_sys->i_allocated_buffer = p_block->i_buffer;
-    p_sys->i_duplicated = 0;
-    p_sys->b_modify = VLC_TRUE;
 
-    return p_block;
+#ifdef WIN32
+static
+ssize_t pread (int fd, void *buf, size_t count, off_t offset)
+{
+    HANDLE handle = (HANDLE)(intptr_t)_get_osfhandle (fd);
+    if (handle == INVALID_HANDLE_VALUE)
+        return -1;
+
+    OVERLAPPED olap = { .Offset = offset, .OffsetHigh = (offset >> 32), };
+    DWORD written;
+    /* This braindead API will override the file pointer even if we specify
+     * an explicit read offset... So do not expect this to mix well with
+     * regular read() calls. */
+    if (ReadFile (handle, buf, count, &written, &olap))
+        return written;
+    return -1;
 }
+#endif
 
-void block_ChainAppend( block_t **pp_list, block_t *p_block )
+/**
+ * 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.
+ *
+ * @param fd file descriptor to load from
+ * @return a new block with the file content at p_buffer, and file length at
+ * i_buffer (release it with block_Release()), or NULL upon error (see errno).
+ */
+block_t *block_File (int fd)
 {
-
-    if( *pp_list == NULL )
+    size_t length;
+    struct stat st;
+
+    /* First, get the file size */
+    if (fstat (fd, &st))
+        return NULL;
+
+    /* st_size is meaningful for regular files, shared memory and typed memory.
+     * It's also meaning for symlinks, but that's not possible with fstat().
+     * In other cases, it's undefined, and we should really not go further. */
+#ifndef S_TYPEISSHM
+# define S_TYPEISSHM( buf ) (0)
+#endif
+    if (S_ISDIR (st.st_mode))
     {
-        *pp_list = p_block;
+        errno = EISDIR;
+        return NULL;
     }
-    else
+    if (!S_ISREG (st.st_mode) && !S_TYPEISSHM (&st))
     {
-        block_t *p = *pp_list;
-
-        while( p->p_next )
-        {
-            p = p->p_next;
-        }
-        p->p_next = p_block;
+        errno = ESPIPE;
+        return NULL;
     }
-}
 
-void block_ChainRelease( block_t *p_block )
-{
-    while( p_block )
+    /* Prevent an integer overflow in mmap() and malloc() */
+    if (st.st_size >= SIZE_MAX)
     {
-        block_t *p_next;
-        p_next = p_block->p_next;
-        p_block->pf_release( p_block );
-        p_block = p_next;
+        errno = ENOMEM;
+        return NULL;
     }
-}
+    length = (size_t)st.st_size;
 
-int block_ChainExtract( block_t *p_list, void *p_data, int i_max )
-{
-    block_t *b;
-    int     i_total = 0;
-    uint8_t *p = p_data;
-
-    for( b = p_list; b != NULL; b = b->p_next )
+#ifdef HAVE_MMAP
+    if (length > 0)
     {
-        int i_copy;
+        void *addr;
 
-        i_copy = __MIN( i_max, b->i_buffer );
-        if( i_copy > 0 )
-        {
-            memcpy( p, b->p_buffer, i_copy );
-            i_max   -= i_copy;
-            i_total += i_copy;
-            p       += i_copy;
-
-            if( i_max == 0 )
-            {
-                return i_total;
-            }
-        }
+        addr = mmap (NULL, length, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
+        if (addr != MAP_FAILED)
+            return block_mmap_Alloc (addr, length);
     }
-    return i_total;
-}
+#endif
 
-block_t *block_ChainGather( block_t *p_list )
-{
-    int     i_total = 0;
-    block_t *b, *g;
+    /* If mmap() is not implemented by the OS _or_ the filesystem... */
+    block_t *block = block_Alloc (length);
+    if (block == NULL)
+        return NULL;
 
-    if( p_list->p_next == NULL )
+    for (size_t i = 0; i < length;)
     {
-        /* only one, so no need */
-        return p_list;
-    }
-
-    for( b = p_list; b != NULL; b = b->p_next )
-    {
-        i_total += b->i_buffer;
+        ssize_t len = pread (fd, block->p_buffer + i, length - i, i);
+        if (len == -1)
+        {
+            block_Release (block);
+            return NULL;
+        }
+        i += len;
     }
-
-    g = block_New( p_list->p_manager, i_total );
-    block_ChainExtract( p_list, g->p_buffer, g->i_buffer );
-
-    g->b_frame_display = p_list->b_frame_display;
-    g->b_frame_start   = p_list->b_frame_start;
-    g->i_pts           = p_list->i_pts;
-    g->i_dts           = p_list->i_dts;
-
-    /* free p_list */
-    block_ChainRelease( p_list );
-    return g;
+    return block;
 }
 
 /*****************************************************************************
  * block_fifo_t management
  *****************************************************************************/
-block_fifo_t *__block_FifoNew( vlc_object_t *p_obj )
+struct block_fifo_t
+{
+    vlc_mutex_t         lock;                         /* fifo data lock */
+    vlc_cond_t          wait;         /* fifo data conditional variable */
+
+    block_t             *p_first;
+    block_t             **pp_last;
+    size_t              i_depth;
+    size_t              i_size;
+    bool          b_force_wake;
+};
+
+block_fifo_t *block_FifoNew( void )
 {
-    block_fifo_t *p_fifo;
+    block_fifo_t *p_fifo = malloc( sizeof( block_fifo_t ) );
+    if( !p_fifo )
+        return NULL;
 
-    p_fifo = malloc( sizeof( vlc_object_t ) );
-    vlc_mutex_init( p_obj, &p_fifo->lock );
-    vlc_cond_init( p_obj, &p_fifo->wait );
-    p_fifo->i_depth = 0;
+    vlc_mutex_init( &p_fifo->lock );
+    vlc_cond_init( NULL, &p_fifo->wait );
     p_fifo->p_first = NULL;
     p_fifo->pp_last = &p_fifo->p_first;
+    p_fifo->i_depth = p_fifo->i_size = 0;
+    p_fifo->b_force_wake = false;
 
     return p_fifo;
 }
@@ -369,15 +388,15 @@ void block_FifoEmpty( block_fifo_t *p_fifo )
         b = p_next;
     }
 
-    p_fifo->i_depth = 0;
+    p_fifo->i_depth = p_fifo->i_size = 0;
     p_fifo->p_first = NULL;
     p_fifo->pp_last = &p_fifo->p_first;
     vlc_mutex_unlock( &p_fifo->lock );
 }
 
-int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
+size_t block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
 {
-    int i_size = 0;
+    size_t i_size = 0;
     vlc_mutex_lock( &p_fifo->lock );
 
     do
@@ -387,6 +406,7 @@ int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
         *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;
 
@@ -399,21 +419,41 @@ int block_FifoPut( block_fifo_t *p_fifo, block_t *p_block )
     return i_size;
 }
 
+void block_FifoWake( block_fifo_t *p_fifo )
+{
+    vlc_mutex_lock( &p_fifo->lock );
+    if( p_fifo->p_first == NULL )
+        p_fifo->b_force_wake = true;
+    vlc_cond_signal( &p_fifo->wait );
+    vlc_mutex_unlock( &p_fifo->lock );
+}
+
 block_t *block_FifoGet( block_fifo_t *p_fifo )
 {
     block_t *b;
 
     vlc_mutex_lock( &p_fifo->lock );
 
-    if( p_fifo->p_first == NULL )
+    /* Remember vlc_cond_wait() may cause spurious wakeups
+     * (on both Win32 and POSIX) */
+    while( ( p_fifo->p_first == NULL ) && !p_fifo->b_force_wake )
     {
         vlc_cond_wait( &p_fifo->wait, &p_fifo->lock );
     }
 
     b = p_fifo->p_first;
 
+    p_fifo->b_force_wake = false;
+    if( b == NULL )
+    {
+        /* Forced wakeup */
+        vlc_mutex_unlock( &p_fifo->lock );
+        return NULL;
+    }
+
     p_fifo->p_first = b->p_next;
     p_fifo->i_depth--;
+    p_fifo->i_size -= b->i_buffer;
 
     if( p_fifo->p_first == NULL )
     {
@@ -423,7 +463,7 @@ block_t *block_FifoGet( block_fifo_t *p_fifo )
     vlc_mutex_unlock( &p_fifo->lock );
 
     b->p_next = NULL;
-    return( b );
+    return b;
 }
 
 block_t *block_FifoShow( block_fifo_t *p_fifo )
@@ -442,23 +482,14 @@ block_t *block_FifoShow( block_fifo_t *p_fifo )
     vlc_mutex_unlock( &p_fifo->lock );
 
     return( b );
-
 }
 
-block_t *block_FifoGetFrame( block_fifo_t *p_fifo )
+size_t block_FifoSize( const block_fifo_t *p_fifo )
 {
-    block_t *b = NULL;
-
-    for( ;; )
-    {
-        block_t *p_next;
-        block_ChainAppend( &b, block_FifoGet( p_fifo ) );
-        p_next = block_FifoShow( p_fifo );
-        if( p_next == NULL || p_next->b_frame_start )
-        {
-            break;
-        }
-    }
+    return p_fifo->i_size;
+}
 
-    return b;
+size_t block_FifoCount( const block_fifo_t *p_fifo )
+{
+    return p_fifo->i_depth;
 }