diff options
Diffstat (limited to 'source/blender/blenlib/intern/BLI_memarena.c')
| -rw-r--r-- | source/blender/blenlib/intern/BLI_memarena.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/source/blender/blenlib/intern/BLI_memarena.c b/source/blender/blenlib/intern/BLI_memarena.c index fc381c22315..0ab27a5adad 100644 --- a/source/blender/blenlib/intern/BLI_memarena.c +++ b/source/blender/blenlib/intern/BLI_memarena.c @@ -45,6 +45,7 @@ # define VALGRIND_CREATE_MEMPOOL(pool, rzB, is_zeroed) UNUSED_VARS(pool, rzB, is_zeroed) # define VALGRIND_DESTROY_MEMPOOL(pool) UNUSED_VARS(pool) # define VALGRIND_MEMPOOL_ALLOC(pool, addr, size) UNUSED_VARS(pool, addr, size) +# define VALGRIND_MOVE_MEMPOOL(pool_a, pool_b) UNUSED_VARS(pool_a, pool_b) #endif struct MemBuf { @@ -179,6 +180,58 @@ void *BLI_memarena_calloc(MemArena *ma, size_t size) } /** + * Transfer ownership of allocated blocks from `ma_src` into `ma_dst`, + * cleaning the contents of `ma_src`. + * + * \note Useful for multi-threaded tasks that need a thread-local #MemArena + * that is kept after the multi-threaded operation is completed. + * + * \note Avoid accumulating memory pools where possible + * as any unused memory in `ma_src` is wasted every merge. + */ +void BLI_memarena_merge(MemArena *ma_dst, MemArena *ma_src) +{ + /* Memory arenas must be compatible. */ + BLI_assert(ma_dst != ma_src); + BLI_assert(ma_dst->align == ma_src->align); + BLI_assert(ma_dst->use_calloc == ma_src->use_calloc); + BLI_assert(ma_dst->bufsize == ma_src->bufsize); + + if (ma_src->bufs == NULL) { + return; + } + + if (UNLIKELY(ma_dst->bufs == NULL)) { + BLI_assert(ma_dst->curbuf == NULL); + ma_dst->bufs = ma_src->bufs; + ma_dst->curbuf = ma_src->curbuf; + ma_dst->cursize = ma_src->cursize; + } + else { + /* Keep the 'ma_dst->curbuf' for simplicity. + * Insert buffers after the first. */ + if (ma_dst->bufs->next != NULL) { + /* Loop over `ma_src` instead of `ma_dst` since it's likely the destination is larger + * when used for accumulating from multiple sources. */ + struct MemBuf *mb_src = ma_src->bufs; + mb_src = ma_src->bufs; + while (mb_src && mb_src->next) { + mb_src = mb_src->next; + } + mb_src->next = ma_dst->bufs->next; + } + ma_dst->bufs->next = ma_src->bufs; + } + + ma_src->bufs = NULL; + ma_src->curbuf = NULL; + ma_src->cursize = 0; + + VALGRIND_MOVE_MEMPOOL(ma_src, ma_dst); + VALGRIND_CREATE_MEMPOOL(ma_src, 0, false); +} + +/** * Clear for reuse, avoids re-allocation when an arena may * otherwise be free'd and recreated. */ |