X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fmisc%2Fblock.c;h=1d06fec1467f52d47116daecc8c1d86a11b3d6e3;hb=820b4643f98b98aaaa3289c7f8f34bad7dc02e13;hp=1c68a3f249359a6becb37578a9365996ea8e9f96;hpb=530585d11283626347daa78e393f75187fdc5063;p=vlc diff --git a/src/misc/block.c b/src/misc/block.c index 1c68a3f249..1d06fec146 100644 --- a/src/misc/block.c +++ b/src/misc/block.c @@ -2,7 +2,7 @@ * block.c: Data blocks management functions ***************************************************************************** * Copyright (C) 2003-2004 the VideoLAN team - * $Id$ + * Copyright (C) 2007-2009 Rémi Denis-Courmont * * Authors: Laurent Aimar * @@ -30,6 +30,8 @@ #include #include +#include +#include #include "vlc_block.h" /** @@ -57,10 +59,13 @@ static void BlockNoRelease( block_t *b ) void block_Init( block_t *restrict b, void *buf, size_t size ) { /* Fill all fields to their default */ - b->p_next = b->p_prev = NULL; + b->p_next = NULL; b->i_flags = 0; - b->i_pts = b->i_dts = b->i_length = 0; + b->i_pts = + b->i_dts = VLC_TS_INVALID; + b->i_length = 0; b->i_rate = 0; + b->i_nb_samples = 0; b->p_buffer = buf; b->i_buffer = size; #ifndef NDEBUG @@ -73,10 +78,21 @@ static void BlockRelease( block_t *p_block ) free( p_block ); } -/* Memory alignment */ +static void BlockMetaCopy( block_t *restrict out, const block_t *in ) +{ + out->p_next = in->p_next; + 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_nb_samples = in->i_nb_samples; +} + +/* 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 @@ -84,24 +100,41 @@ 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 + * 2 * BLOCK_PADDING -> 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 ); + block_sys_t *p_sys; + uint8_t *buf; + +#define ALIGN(x) (((x) + BLOCK_ALIGN - 1) & ~(BLOCK_ALIGN - 1)) +#if 0 /*def HAVE_POSIX_MEMALIGN */ + /* posix_memalign(,16,) is much slower than malloc() on glibc. + * -- Courmisch, September 2009, glibc 2.5 & 2.9 */ + const size_t i_alloc = ALIGN(sizeof(*p_sys)) + (2 * BLOCK_PADDING) + + ALIGN(i_size); + void *ptr; + + if( posix_memalign( &ptr, BLOCK_ALIGN, i_alloc ) ) + return NULL; + + p_sys = ptr; + buf = p_sys->p_allocated_buffer + (-sizeof(*p_sys) & (BLOCK_ALIGN - 1)); +#else + const size_t i_alloc = sizeof(*p_sys) + BLOCK_ALIGN + (2 * BLOCK_PADDING) + + ALIGN(i_size); + p_sys = malloc( i_alloc ); if( p_sys == NULL ) return NULL; - /* Fill opaque data */ - p_sys->i_allocated_buffer = i_alloc; + buf = (void *)ALIGN((uintptr_t)p_sys->p_allocated_buffer); + +#endif + buf += BLOCK_PADDING; - 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 ); + block_Init( &p_sys->self, buf, i_size ); p_sys->self.pf_release = BlockRelease; + /* Fill opaque data */ + p_sys->i_allocated_buffer = i_alloc - sizeof(*p_sys); return &p_sys->self; } @@ -109,9 +142,10 @@ block_t *block_Alloc( size_t i_size ) 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; - ssize_t i_buffer_size = i_prebody + i_body; + size_t requested = i_prebody + i_body; - if( i_buffer_size <= 0 ) + /* Corner case: empty block requested */ + if( i_prebody <= 0 && i_body <= (size_t)(-i_prebody) ) { block_Release( p_block ); return NULL; @@ -130,68 +164,149 @@ block_t *block_Realloc( block_t *p_block, ssize_t i_prebody, size_t i_body ) p_sys = (block_sys_t *)p_block; } - /* 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 ) + 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 ); + + /* 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 ) + { /* Enough room: recycle buffer */ + size_t extra = available - requested; + + p_block->p_buffer = p_start + (extra / 2); + p_block->i_buffer = requested; + return p_block; + } + /* Not enough room: allocate a new buffer */ + block_t *p_rea = block_Alloc( requested ); + if( p_rea ) + BlockMetaCopy( p_rea, p_block ); + block_Release( p_block ); + return p_rea; + } + + /* First, shrink payload */ + + /* Pull payload start */ + if( i_prebody < 0 ) { + assert( p_block->i_buffer >= (size_t)-i_prebody ); p_block->p_buffer -= i_prebody; p_block->i_buffer += i_prebody; + i_body += i_prebody; i_prebody = 0; } - /* 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_buffer_size; - i_body = 0; - } + /* Trim payload end */ + if( p_block->i_buffer > i_body ) + p_block->i_buffer = i_body; - /* Not enough room, reallocate the buffer */ - if( i_body > 0 || i_prebody > 0 ) + /* 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) < i_body ) { - /* FIXME: this is really dumb, we should use realloc() */ - block_t *p_rea = block_New( NULL, i_buffer_size ); - + block_t *p_rea = block_Alloc( requested ); 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 ) ); + 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 ); - - return p_rea; + if( p_rea == NULL ) + return NULL; + p_block = p_rea; } - + else /* We have a very large reserved footer now? Release some of it. - * XXX it may not keep the algniment of p_buffer */ - if( (p_sys->p_allocated_buffer + p_sys->i_allocated_buffer) - - (p_block->p_buffer + p_block->i_buffer) > BLOCK_WASTE_SIZE ) + * 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_sys->p_allocated_buffer; - const size_t i_new = i_prebody + p_block->i_buffer + 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; } } + + /* NOTE: p_start and p_end are corrupted from this point */ + + /* Third, expand payload */ + + /* Push payload start */ + if( i_prebody > 0 ) + { + p_block->p_buffer -= i_prebody; + p_block->i_buffer += i_prebody; + i_body += i_prebody; + i_prebody = 0; + } + + /* Expand payload to requested size */ + p_block->i_buffer = i_body; + return p_block; } + +typedef struct +{ + block_t self; + void *mem; +} block_heap_t; + +static void block_heap_Release (block_t *self) +{ + block_heap_t *block = (block_heap_t *)self; + + free (block->mem); + free (block); +} + +/** + * Creates a block from a heap allocation. + * This is provided by LibVLC so that manually heap-allocated blocks can safely + * be deallocated even after the origin plugin has been unloaded from memory. + * + * 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 + * @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_heap_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; +} + #ifdef HAVE_MMAP # include @@ -258,7 +373,7 @@ ssize_t pread (int fd, void *buf, size_t count, off_t offset) if (handle == INVALID_HANDLE_VALUE) return -1; - OVERLAPPED olap = { .Offset = offset, .OffsetHigh = (offset >> 32), }; + OVERLAPPED olap; olap.Offset = offset; olap.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 @@ -393,23 +508,27 @@ void block_FifoRelease( block_fifo_t *p_fifo ) 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; + } } /** @@ -431,6 +550,8 @@ void block_FifoEmpty( block_fifo_t *p_fifo ) */ void block_FifoPace (block_fifo_t *fifo, size_t max_depth, size_t max_size) { + vlc_testcancel (); + vlc_mutex_lock (&fifo->lock); while ((fifo->i_depth > max_depth) || (fifo->i_size > max_size)) { @@ -445,25 +566,29 @@ void block_FifoPace (block_fifo_t *fifo, size_t max_depth, size_t max_size) * 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 ); @@ -479,10 +604,18 @@ void block_FifoWake( block_fifo_t *p_fifo ) 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; + vlc_testcancel( ); + vlc_mutex_lock( &p_fifo->lock ); mutex_cleanup_push( &p_fifo->lock ); @@ -519,10 +652,23 @@ block_t *block_FifoGet( block_fifo_t *p_fifo ) 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; + vlc_testcancel( ); + vlc_mutex_lock( &p_fifo->lock ); mutex_cleanup_push( &p_fifo->lock );