paraslash/buffer_tree.c, branch pu

btr: Simplify btr_drop_buffer_reference().

2026-05-08T20:19:58Z

Drop the bool flag which indicates whether the buffer itself should also be deallocated. The function can answer this itself by consulting the dont_free flag of the buffer pointer.

Switch to SPDX identifiers.

2026-03-17T22:45:43Z

Generated with sed -i 's|Copyright.*Andre Noll.*|SPDX-License-Identifier: GPL-2.0 */|g' *.c *.h followed by manually tweaking the result a bit. No license change intended.

btr: Fix memory leak in btr_add_output_dont_free().

2026-03-17T18:20:42Z

Quite a massive leak indeed, albeit only triggered by para_play: ==25044== 423,420 bytes in 21,171 blocks are definitely lost in loss record 90 of 90 ==25044== at 0x404ADDE: realloc (vg_replace_malloc.c:1804) ==25044== by 0x805AC34: arr_realloc (string.c:40) ==25044== by 0x805AC63: arr_alloc (string.c:61) ==25044== by 0x805AC7B: arr_zalloc (string.c:76) ==25044== by 0x805ACA2: zalloc (string.c:98) ==25044== by 0x8055445: new_btrb (buffer_tree.c:306) ==25044== by 0x8057070: btr_add_output_dont_free (buffer_tree.c:457) ==25044== by 0x805DC86: afh_recv_post_monitor (afh_recv.c:204) ==25044== by 0x805491C: call_post_monitor (sched.c:117) ==25044== by 0x805491C: sched_post_monitor (sched.c:143) ==25044== by 0x805491C: schedule (sched.c:183) ==25044== by 0x804F217: main (play.c:1228) We leak one buffer reference (20 bytes on x86-32) per chunk when the buffer can merged, which is true unless we reach the end of the buffer pool.

Improve buffer tree documentation.

2025-10-08T18:58:23Z

Minor improvements to the API description in buffer_tree.h, a lot of \a and \p removal in buffer_tree.c, and the addition of some missing \ref statements.

btr: Fix buffer tree merging.

2025-07-13T14:38:46Z

The merge case of add_btrb_to_children() is rather broken. For one, if the node has more than one child and we end up freeing the btr buffer in the first iteration, we read stale contents when calling may_merge_btrb() in the next iteration of the loop. Secondly, not all callers of add_btrb_to_children() cope with btrb being freed after merging occurred. In particular, the alsa writer triggers an invalid read such as: at 0x804C7AC: btr_drop_buffer_reference (buffer_tree.c:351) by 0x804CD4A: btr_pushdown_br (buffer_tree.c:520) by 0x804CD4A: btr_pushdown (buffer_tree.c:539) by 0x804D948: check_wav_post_monitor (check_wav.c:194) by 0x804C31B: call_post_monitor (sched.c:118) by 0x804C31B: sched_post_monitor (sched.c:144) by 0x804C31B: schedule (sched.c:184) by 0x804A9CE: setup_and_schedule (write.c:97) by 0x804A9CE: main (write.c:149) The problem is that btr_pushdown_br() calls add_btrb_to_children(), followed by btr_drop_buffer_reference(). The first function frees br->btrb in the may-merge case and the second function reads from this pointer. This patch addresses both issues. It renames may_merge_btrb() to try_merge_btrb(), checks more carefully if a merge is possible, and performs the merge. This function needs to return whether the buffer was merged because the callers have to clean up in different ways depending on whether or not buffers were merged. This retains the nice speedup of f64cbcc03484 at the cost of even more complicated buffer tree code. Reproducer (must run on a slow machine or under valgrind to trigger): para sender udp add 224.0.1.38:8000 para_recv -r udp > fec-encoded-data ./para_filter -f fecdec -f mp3dec < fec-encoded-data | ./para_write Fixes: f64cbcc034844628b7e7817e27205cc6b48e9a18

Remove ->execute() of struct writer.

2025-06-25T21:16:15Z

No writer implements this method.

buffer_tree: Assert that we don't pass NULL to memcpy().

2025-05-22T14:44:39Z

The buffer pointer cannot be NULL here because this only happens when the buffer tree area is full, which is not the case thanks to the previous n <= btr_pool_unused(btrp) check.

Include regex.h from para.h.

2025-05-19T17:35:58Z

Every .c file includes it anyway.

Constify buffer tree API.

2024-05-08T17:45:52Z

A lot of functions of the buffer tree API don't modify the memory referenced by the pointers passed. This patch marks these pointer arguments as constant.

btr: Merge buffers on insertion.

2024-05-08T17:45:52Z

Currently add_btrb_to_children() simply adds the given buffer reference to the input queue of all children of the given node even if the newly added buffer reference points memory adjacent to the previously added buffer. Since several helpers iterate over all buffer references, performance suffers, given enough buffer references. So merge buffers when possible. User time: 147s -> 83s, speedup: 44%.