#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.
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 )
#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->i_length = in->i_length;
}
-/* Memory alignment (must be a multiple of sizeof(void*) and a power of two) */
-#define BLOCK_ALIGN 16
-/* Initial reserved header and footer size (must be multiple of alignment) */
+/** Initial memory alignment of data block.
+ * @note This must be a multiple of sizeof(void*) and a power of two.
+ * libavcodec AVX optimizations require at least 32-bytes. */
+#define BLOCK_ALIGN 32
+
+/** Initial reserved header and footer size. */
#define BLOCK_PADDING 32
-/* Maximum size of reserved footer before we release with realloc() */
+
+/* Maximum size of reserved footer before shrinking with realloc(). */
#define BLOCK_WASTE_SIZE 2048
block_t *block_Alloc (size_t size)
if (unlikely(b == NULL))
return NULL;
- block_Init (b, b + 1, alloc);
+ 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 = BlockRelease;
+ b->pf_release = block_generic_Release;
return b;
}
{
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) )
{
static void block_heap_Release (block_t *block)
{
+ block_Invalidate (block);
free (block->p_start);
free (block);
}
static void block_mmap_Release (block_t *block)
{
+ block_Invalidate (block);
munmap (block->p_start, block->i_size);
free (block);
}
}
#endif
+#ifdef HAVE_SYS_SHM_H
+# include <sys/shm.h>
+
+typedef struct block_shm_t
+{
+ block_t self;
+ void *base_addr;
+} block_shm_t;
+
+static void block_shm_Release (block_t *block)
+{
+ block_shm_t *p_sys = (block_shm_t *)block;
+
+ shmdt (p_sys->base_addr);
+ free (p_sys);
+}
+
+/**
+ * Creates a block from a System V shared memory segment (shmget()).
+ * This is provided by LibVLC so that segments can safely be deallocated
+ * even after the allocating plugin has been unloaded from memory.
+ *
+ * @param addr base address of the segment (as returned by shmat())
+ * @param length length (bytes) of the segment (as passed to shmget())
+ * @return NULL if an error occurred (in that case, shmdt(addr) is invoked
+ * before returning NULL).
+ */
+block_t *block_shm_Alloc (void *addr, size_t length)
+{
+ block_shm_t *block = malloc (sizeof (*block));
+ if (unlikely(block == NULL))
+ {
+ shmdt (addr);
+ return NULL;
+ }
+
+ block_Init (&block->self, (uint8_t *)addr, length);
+ block->self.pf_release = block_shm_Release;
+ block->base_addr = addr;
+ return &block->self;
+}
+#else
+block_t *block_shm_Alloc (void *addr, size_t length)
+{
+ (void) addr; (void) length;
+ abort ();
+}
+#endif
+
-#ifdef WIN32
+#ifdef _WIN32
# include <io.h>
-# ifdef UNDER_CE
-# define _get_osfhandle(a) ((long) (a))
-# endif
static
ssize_t pread (int fd, void *buf, size_t count, off_t offset)
return written;
return -1;
}
-#elif !defined( HAVE_PREAD )
-static
-ssize_t pread(int fd, const void * buf, size_t size, off_t offset) {
- off_t offs0;
- ssize_t rd;
- if ((offs0 = lseek(fd, 0, SEEK_CUR)) == (off_t)-1) return -1;
- if (lseek(fd, offset, SEEK_SET) == (off_t)-1) return -1;
- rd = read(fd, (void *)buf, size);
- if (lseek(fd, offs0, SEEK_SET) == (off_t)-1) return -1;
- return rd;
-}
-
-static
-ssize_t pwrite(int fd, const void * buf, size_t size, off_t offset) {
- off_t offs0;
- ssize_t wr;
- if ((offs0 = lseek(fd, 0, SEEK_CUR)) == (off_t)-1) return -1;
- if (lseek(fd, offset, SEEK_SET) == (off_t)-1) return -1;
- wr = write(fd, (void *)buf, size);
- if (lseek(fd, offs0, SEEK_SET) == (off_t)-1) return -1;
- return wr;
-}
#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
}
/* Prevent an integer overflow in mmap() and malloc() */
- if (st.st_size >= SIZE_MAX)
+ if ((uintmax_t)st.st_size >= SIZE_MAX)
{
errno = ENOMEM;
return NULL;
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
*/
projects / vlc / blobdiff