From: Andre Noll <maan@tuebingen.mpg.de>
Date: Wed, 8 May 2024 17:48:44 +0000 (+0200)
Subject: Merge topic branch t/btr into next
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=refs%2Fheads%2Fnext;hp=9b6c71b05beb750da78bea312b8b9347d8fda21f

Merge topic branch t/btr into next

Some helpers such as btr_get_input_queue_size() are very expensive
if the buffer tree contains many buffers, which is the case for mp3
and aac streams. This is noticeable in particular with para_play,
which spends more time in the btr subsystem than in the mp3 decoder
if the file is large enough. This branch contains a few patches to
improve that.

* refs/heads/t/btr:
  btr: Streamline the documentation of buffer_tree.h.
  Constify buffer tree API.
  btr: Merge buffers on insertion.
  btr: Speed up btr_node_status().
  Speed up mp3dec filter.
---

diff --git a/Makefile.in b/Makefile.in
index c618561d..396c8de6 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -12,21 +12,26 @@ FLEX := @FLEX@
 BISON := @BISON@
 M4 := @M4@
 LOPSUBGEN := @LOPSUBGEN@
+CRYPTOLIB := @CRYPTOLIB@
 
-executables := @executables@
+NEED_OGG_OBJECTS := @NEED_OGG_OBJECTS@
+NEED_VORBIS_OBJECTS := @NEED_VORBIS_OBJECTS@
+NEED_SPEEX_OBJECTS := @NEED_SPEEX_OBJECTS@
+NEED_OPUS_OBJECTS := @NEED_OPUS_OBJECTS@
+NEED_FLAC_OBJECTS := @NEED_FLAC_OBJECTS@
+NEED_AO_OBJECTS := @NEED_AO_OBJECTS@
 
-recv_objs := @recv_objs@
-filter_objs := @filter_objs@
-client_objs := @client_objs@
-gui_objs := @gui_objs@
-audiod_objs := @audiod_objs@
-audioc_objs := @audioc_objs@
-mixer_objs := @mixer_objs@
-server_objs := @server_objs@
-upgrade_db_objs := @upgrade_db_objs@
-write_objs := @write_objs@
-afh_objs := @afh_objs@
-play_objs := @play_objs@
+HAVE_OSL := @HAVE_OSL@
+HAVE_FAAD := @HAVE_FAAD@
+HAVE_READLINE := @HAVE_READLINE@
+HAVE_FLAC := @HAVE_FLAC@
+HAVE_MAD := @HAVE_MAD@
+HAVE_SAMPLERATE := @HAVE_SAMPLERATE@
+HAVE_AO := @HAVE_AO@
+HAVE_PTHREAD := @HAVE_PTHREAD@
+HAVE_OSS := @HAVE_OSS@
+HAVE_ALSA := @HAVE_ALSA@
+HAVE_CURSES := @HAVE_CURSES@
 
 speex_cppflags := @speex_cppflags@
 opus_cppflags := @opus_cppflags@
diff --git a/Makefile.real b/Makefile.real
index bd2bd9d9..92a5724b 100644
--- a/Makefile.real
+++ b/Makefile.real
@@ -14,7 +14,6 @@ SEVERITIES := \"debug\",\"info\",\"notice\",\"warning\",\"error\",\"crit\",\"eme
 vardir := /var/paraslash
 mandir := $(datarootdir)/man/man1
 MKDIR_P := mkdir -p
-prefixed_executables := $(addprefix para_, $(executables))
 
 build_date := $(shell date)
 uname_s := $(shell uname -s 2>/dev/null || echo "UNKNOWN_OS")
@@ -35,15 +34,263 @@ m4depdir := $(build_dir)/m4deps
 lls_suite_dir := $(build_dir)/lls
 lls_m4_dir := m4/lls
 test_dir := t
-yy_src_dir = yy
-yy_build_dir = $(build_dir)/yy
+yy_src_dir := yy
+yy_build_dir := $(build_dir)/yy
+
+executables := recv filter audioc write afh play
+ifneq ($(CRYPTOLIB),)
+	ifeq ($(HAVE_OSL),yes)
+	executables += server upgrade_db
+		server_objs := $(addsuffix .o, \
+			server afh_common mp3_afh vss command net string \
+			signal time daemon http_send close_on_fork \
+			crypt_common base64 ipc dccp_send fd user_list \
+			chunk_queue afs aft mood mp score attribute blob \
+			playlist sched acl send_common udp_send color fec \
+			wma_afh wma_common sideband version lsu \
+		)
+		ifeq ($(CRYPTOLIB),openssl)
+			server_objs += openssl.o
+		else
+			server_objs += gcrypt.o
+		endif
+		ifeq ($(NEED_OGG_OBJECTS),yes)
+			server_objs += ogg_afh_common.o
+		endif
+		ifeq ($(NEED_VORBIS_OBJECTS),yes)
+			server_objs += ogg_afh.o
+		endif
+		ifeq ($(NEED_SPEEX_OBJECTS),yes)
+			server_objs += spx_afh.o spx_common.o
+		endif
+		ifeq ($(NEED_OPUS_OBJECTS),yes)
+			server_objs += opus_afh.o opus_common.o
+		endif
+		ifeq ($(NEED_FLAC_OBJECTS),yes)
+			server_objs += flac_afh.o
+		endif
+		ifeq ($(HAVE_FAAD),yes)
+			server_objs += aac_afh.o mp4.o
+		endif
+		upgrade_db_objs := $(addsuffix .o, crypt_common exec fd string \
+			upgrade_db version base64)
+	endif
+endif
+ifneq ($(CRYPTOLIB),)
+	executables += client audiod
+	client_objs := $(addsuffix .o, \
+		client net string fd lsu sched stdin stdout time sideband client_common \
+		buffer_tree crypt_common base64 version $(CRYPTOLIB) \
+	)
+	ifeq ($(HAVE_READLINE),yes)
+		client_objs += interactive.o
+	endif
+	audiod_objs := $(addsuffix .o, \
+		audiod signal string daemon stat net crypt_common base64 sideband \
+		time grab_client filter_common wav_filter compress_filter amp_filter \
+		http_recv dccp_recv recv_common fd sched write_common file_write \
+		audiod_command fecdec_filter client_common udp_recv color fec \
+		prebuffer_filter version bitstream imdct wma_common wmadec_filter \
+		buffer_tree sync_filter lsu $(CRYPTOLIB) \
+	)
+	audiod_audio_formats := "wma"
+	ifeq ($(NEED_VORBIS_OBJECTS),yes)
+		audiod_objs += oggdec_filter.o
+		audiod_audio_formats += ,"ogg"
+	endif
+	ifeq ($(NEED_SPEEX_OBJECTS),yes)
+		audiod_objs += spxdec_filter.o spx_common.o
+		audiod_audio_formats += ,"spx"
+	endif
+	ifeq ($(NEED_OPUS_OBJECTS),yes)
+		audiod_objs += opusdec_filter.o opus_common.o
+		audiod_audio_formats += ,"opus"
+	endif
+	ifeq ($(NEED_FLAC_OBJECTS),yes)
+		audiod_objs += flacdec_filter.o
+		audiod_audio_formats += ,"flac"
+	endif
+	ifeq ($(HAVE_FAAD),yes)
+		audiod_objs += aacdec_filter.o
+		audiod_audio_formats += ,"aac"
+	endif
+	ifeq ($(HAVE_MAD),yes)
+		audiod_objs += mp3dec_filter.o
+		audiod_audio_formats += ,"mp3"
+	endif
+	ifeq ($(HAVE_OSS),yes)
+		audiod_objs += oss_write.o
+	endif
+	ifeq ($(HAVE_ALSA),yes)
+		audiod_objs += alsa_write.o
+	endif
+	ifeq ($(NEED_AO_OBJECTS),yes)
+		audiod_objs += ao_write.o
+	endif
+	ifeq ($(HAVE_SAMPLERATE),yes)
+		audiod_objs += resample_filter.o check_wav.o
+	endif
+endif
+ifneq ($(HAVE_OSS)-$(HAVE_ALSA),no-no)
+	executables += mixer
+	mixer_objs := $(addsuffix .o, mixer exec string fd time lsu version)
+	ifeq ($(HAVE_OSS),yes)
+		mixer_objs += oss_mix.o
+	endif
+	ifeq ($(HAVE_ALSA),yes)
+		mixer_objs += alsa_mix.o
+	endif
+endif
+ifeq ($(HAVE_CURSES),yes)
+	executables += gui
+	gui_objs := $(addsuffix .o, exec signal string stat ringbuffer fd \
+		gui gui_theme lsu time sched version)
+endif
+filter_objs := $(addsuffix .o, \
+	filter_common wav_filter compress_filter filter string stdin stdout \
+	sched fd amp_filter fecdec_filter fec lsu version prebuffer_filter \
+	time bitstream imdct wma_common wmadec_filter buffer_tree net \
+	sync_filter \
+)
+ifeq ($(NEED_VORBIS_OBJECTS),yes)
+	filter_objs += oggdec_filter.o
+endif
+ifeq ($(NEED_SPEEX_OBJECTS),yes)
+	filter_objs += spxdec_filter.o spx_common.o
+endif
+ifeq ($(NEED_OPUS_OBJECTS),yes)
+	filter_objs += opusdec_filter.o opus_common.o
+endif
+ifeq ($(NEED_FLAC_OBJECTS),yes)
+	filter_objs += flacdec_filter.o
+endif
+ifeq ($(HAVE_FAAD),yes)
+	filter_objs += aacdec_filter.o
+endif
+ifeq ($(HAVE_MAD),yes)
+	filter_objs += mp3dec_filter.o
+endif
+ifeq ($(HAVE_SAMPLERATE),yes)
+	filter_objs += resample_filter.o check_wav.o
+endif
+
+recv_objs := $(addsuffix .o, \
+	http_recv recv_common recv time string net dccp_recv fd sched stdout \
+	udp_recv buffer_tree afh_recv afh_common wma_afh wma_common mp3_afh \
+	version \
+)
+ifeq ($(NEED_OGG_OBJECTS),yes)
+	recv_objs += ogg_afh_common.o
+endif
+ifeq ($(NEED_VORBIS_OBJECTS),yes)
+	recv_objs += ogg_afh.o
+endif
+ifeq ($(NEED_SPEEX_OBJECTS),yes)
+	recv_objs += spx_afh.o spx_common.o
+endif
+ifeq ($(NEED_OPUS_OBJECTS),yes)
+	recv_objs += opus_afh.o opus_common.o
+endif
+ifeq ($(NEED_FLAC_OBJECTS),yes)
+	recv_objs += flac_afh.o
+endif
+ifeq ($(HAVE_FAAD),yes)
+	recv_objs += aac_afh.o mp4.o
+endif
+
+audio_format_handlers := mp3 wma
+afh_objs := $(addsuffix .o, afh string fd mp3_afh afh_common time wma_afh \
+	wma_common version)
+ifeq ($(NEED_OGG_OBJECTS),yes)
+	afh_objs += ogg_afh_common.o
+endif
+ifeq ($(NEED_VORBIS_OBJECTS),yes)
+	afh_objs += ogg_afh.o
+	audio_format_handlers += ogg
+endif
+ifeq ($(NEED_SPEEX_OBJECTS),yes)
+	afh_objs += spx_common.o
+	audio_format_handlers += spx
+endif
+ifeq ($(NEED_OPUS_OBJECTS),yes)
+	afh_objs += opus_afh.o opus_common.o
+	audio_format_handlers += opus
+endif
+ifeq ($(NEED_FLAC_OBJECTS),yes)
+	afh_objs += flac_afh.o
+	audio_format_handlers += flac
+endif
+ifeq ($(HAVE_FAAD),yes)
+	afh_objs += aac_afh.o mp4.o
+	audio_format_handlers += aac
+endif
+
+play_objs := $(addsuffix .o, \
+	play fd sched buffer_tree time string net afh_recv afh_common \
+	wma_afh wma_common mp3_afh recv_common udp_recv http_recv dccp_recv \
+	filter_common fec bitstream imdct wav_filter compress_filter \
+	amp_filter prebuffer_filter fecdec_filter wmadec_filter write_common \
+	file_write version sync_filter lsu \
+)
+ifeq ($(NEED_OGG_OBJECTS),yes)
+	play_objs += ogg_afh_common.o
+endif
+ifeq ($(NEED_VORBIS_OBJECTS),yes)
+	play_objs += oggdec_filter.o ogg_afh.o
+endif
+ifeq ($(NEED_SPEEX_OBJECTS),yes)
+	play_objs += spxdec_filter.o spx_afh.o spx_common.o
+endif
+ifeq ($(NEED_OPUS_OBJECTS),yes)
+	play_objs += opusdec_filter.o opus_afh.o opus_common.o
+endif
+ifeq ($(NEED_FLAC_OBJECTS),yes)
+	play_objs += flacdec_filter.o flac_afh.o
+endif
+ifeq ($(HAVE_FAAD),yes)
+	play_objs += aac_afh.o aacdec_filter.o mp4.o
+endif
+ifeq ($(HAVE_MAD),yes)
+	play_objs += mp3dec_filter.o
+endif
+ifeq ($(HAVE_OSS),yes)
+	play_objs += oss_write.o
+endif
+ifeq ($(HAVE_ALSA),yes)
+	play_objs += alsa_write.o
+endif
+ifeq ($(NEED_AO_OBJECTS),yes)
+	play_objs += ao_write.o
+endif
+ifeq ($(HAVE_READLINE),yes)
+	play_objs += interactive.o
+endif
+ifeq ($(HAVE_SAMPLERATE),yes)
+	play_objs += resample_filter.o check_wav.o
+endif
+
+write_objs := $(addsuffix .o, write write_common file_write time fd \
+	string sched stdin buffer_tree check_wav version)
+ifeq ($(NEED_AO_OBJECTS),yes)
+	write_objs += ao_write.o
+endif
+ifeq ($(HAVE_OSS),yes)
+	write_objs += oss_write.o
+endif
+ifeq ($(HAVE_ALSA),yes)
+	write_objs += alsa_write.o
+endif
+
+audioc_objs := $(addsuffix .o, audioc string lsu net fd time version)
+ifeq ($(HAVE_READLINE),yes)
+	audioc_objs += buffer_tree.o interactive.o sched.o
+endif
 
 # sort removes duplicate words, which is all we need here
-all_objs := $(sort $(recv_objs) $(filter_objs) $(client_objs) $(gui_objs) \
+dep_objs := $(sort $(recv_objs) $(filter_objs) $(client_objs) $(gui_objs) \
 	$(audiod_objs) $(audioc_objs) $(mixer_objs) $(server_objs) \
-	$(write_objs) $(afh_objs) $(play_objs))
-deps := $(addprefix $(dep_dir)/, $(all_objs:.o=.d))
-deps += $(addprefix $(dep_dir)/, mp.bison.d mp.flex.d)
+	$(write_objs) $(afh_objs) $(play_objs) mp.bison mp.flex)
+deps := $(addprefix $(dep_dir)/, $(dep_objs:.o=.d))
 
 afh_objs += afh.lsg.o
 audioc_objs += audioc.lsg.o
@@ -84,6 +331,7 @@ write_objs := $(addprefix $(object_dir)/, $(write_objs))
 afh_objs := $(addprefix $(object_dir)/, $(afh_objs))
 play_objs := $(addprefix $(object_dir)/, $(play_objs))
 
+prefixed_executables := $(addprefix para_, $(executables))
 man_pages := $(patsubst %, $(man_dir)/%.1, $(prefixed_executables))
 
 autocrap := config.h.in configure
@@ -200,6 +448,10 @@ $(object_dir)/%.o: %.c | $(object_dir)
 OD = $(addsuffix .d, $(addprefix $(dep_dir)/, $(1))) \
 	$(addsuffix .o, $(addprefix $(object_dir)/, $(1)))
 
+$(call OD, audiod): \
+	CPPFLAGS += -DAUDIOD_AUDIO_FORMAT_ARRAY='$(audiod_audio_formats)'
+$(call OD, afh command): \
+	CPPFLAGS += -DAUDIO_FORMAT_HANDLERS='"$(audio_format_handlers)"'
 $(call OD, opus%): CPPFLAGS += $(opus_cppflags)
 $(call OD, gui gui%): CPPFLAGS += $(curses_cppflags)
 $(call OD, spx%): CPPFLAGS += $(speex_cppflags)
diff --git a/NEWS.md b/NEWS.md
index 4b718d8a..d5812289 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,9 +1,24 @@
 NEWS
 ====
 
-----------------------------------------------
-0.7.3 (to be announced) "weighted correctness"
-----------------------------------------------
+---------------------------------------------
+0.7.4 (to be announced) "genetic contraction"
+---------------------------------------------
+
+Downloads:
+[tarball](./releases/paraslash-git.tar.xz)
+
+-----------------------------------------
+0.7.3 (2024-03-12) "weighted correctness"
+-----------------------------------------
+
+The highlight of this release is the new "ls --admissible=m/foo"
+feature described below. Other user-visible changes include minor
+additions to the "ls" and "select" server commands. The release also
+includes a fair number of cleanups for the crypto code and the file
+descriptor utilities, both without visible effects. Old ssh keys
+and outdated openssl library versions are now deprecated and cause
+warnings.
 
 - Old style PEM keys are now deprecated. They still work but their
   use results in a run-time warning. The removal of PEM key support is
@@ -23,7 +38,8 @@ NEWS
 - Cleanup of the openssl-specific code.
 
 Downloads:
-[tarball](./releases/paraslash-git.tar.xz)
+[tarball](./releases/paraslash-0.7.3.tar.xz),
+[signature](./releases/paraslash-0.7.3.tar.xz.asc)
 
 -------------------------------------
 0.7.2 (2023-03-08) "optical friction"
diff --git a/aacdec_filter.c b/aacdec_filter.c
index 87a7900a..ab07be8f 100644
--- a/aacdec_filter.c
+++ b/aacdec_filter.c
@@ -41,7 +41,8 @@ struct private_aacdec_data {
 	unsigned int sample_rate;
 };
 
-static int aacdec_execute(struct btr_node *btrn, const char *cmd, char **result)
+static int aacdec_execute(const struct btr_node *btrn, const char *cmd,
+		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
 	struct private_aacdec_data *padd = fn->private_data;
diff --git a/afh_recv.c b/afh_recv.c
index 8449e787..687b77d9 100644
--- a/afh_recv.c
+++ b/afh_recv.c
@@ -30,7 +30,7 @@ struct private_afh_recv_data {
 	void *afh_context;
 };
 
-static int afh_execute(struct btr_node *btrn, const char *cmd, char **result)
+static int afh_execute(const struct btr_node *btrn, const char *cmd, char **result)
 {
 	struct receiver_node *rn = btr_context(btrn);
 	struct private_afh_recv_data *pard = rn->private_data;
diff --git a/audiod.c b/audiod.c
index 7c223995..0fae454c 100644
--- a/audiod.c
+++ b/audiod.c
@@ -46,8 +46,9 @@ static struct lls_parse_result *lpr;
 #define OPT_UINT32_VAL(_name) (lls_uint32_val(0, OPT_RESULT(_name)))
 
 __printf_2_3 void (*para_log)(int, const char*, ...) = daemon_log;
-/** define the array containing all supported audio formats */
-const char *audio_formats[] = {AUDIOD_AUDIO_FORMAT_ARRAY NULL};
+/* Audio formats supported by audiod */
+static const char *audio_formats[] = {AUDIOD_AUDIO_FORMAT_ARRAY};
+#define NUM_AUDIO_FORMATS ARRAY_SIZE(audio_formats)
 
 /** Defines how audiod handles one supported audio format. */
 struct audio_format_info {
diff --git a/audiod.h b/audiod.h
index 39beda1b..d5a9da65 100644
--- a/audiod.h
+++ b/audiod.h
@@ -2,13 +2,6 @@
 
 /** \file audiod.h Symbols exported from audiod.c. */
 
-
-/** enum of audio formats supported by para_audiod */
-enum {AUDIOD_AUDIO_FORMATS_ENUM};
-
-/** array of audio format names supported by para_audiod */
-extern const char *audio_formats[];
-
 extern int audiod_status;
 
 /* defined in audiod.c */
diff --git a/buffer_tree.c b/buffer_tree.c
index 35353f56..255dc475 100644
--- a/buffer_tree.c
+++ b/buffer_tree.c
@@ -103,12 +103,12 @@ void btr_pool_free(struct btr_pool *btrp)
  * \return The same value which was passed during creation time to
  * btr_pool_new().
  */
-size_t btr_pool_size(struct btr_pool *btrp)
+size_t btr_pool_size(const struct btr_pool *btrp)
 {
 	return btrp->area_end - btrp->area_start;
 }
 
-static size_t btr_pool_filled(struct btr_pool *btrp)
+static size_t btr_pool_filled(const struct btr_pool *btrp)
 {
 	if (!btrp->whead)
 		return btr_pool_size(btrp);
@@ -129,7 +129,7 @@ static size_t btr_pool_filled(struct btr_pool *btrp)
  * the largest contiguous buffer that can currently be allocated from the
  * buffer pool.
  */
-size_t btr_pool_unused(struct btr_pool *btrp)
+size_t btr_pool_unused(const struct btr_pool *btrp)
 {
 	return btr_pool_size(btrp) - btr_pool_filled(btrp);
 }
@@ -138,7 +138,7 @@ size_t btr_pool_unused(struct btr_pool *btrp)
  * Return maximal size available for one read. This is
  * smaller than the value returned by btr_pool_unused().
  */
-static size_t btr_pool_available(struct btr_pool *btrp)
+static size_t btr_pool_available(const struct btr_pool *btrp)
 {
 	if (!btrp->whead)
 		return 0;
@@ -156,7 +156,7 @@ static size_t btr_pool_available(struct btr_pool *btrp)
  * \return The maximal amount of bytes that may be written to the returned
  * buffer.
  */
-size_t btr_pool_get_buffer(struct btr_pool *btrp, char **result)
+size_t btr_pool_get_buffer(const struct btr_pool *btrp, char **result)
 {
 	if (result)
 		*result = btrp->whead;
@@ -174,7 +174,7 @@ size_t btr_pool_get_buffer(struct btr_pool *btrp, char **result)
  * consists of two buffers. If this function returns the value n, then n
  * elements of \a iov are initialized.
  */
-int btr_pool_get_buffers(struct btr_pool *btrp, struct iovec iov[2])
+int btr_pool_get_buffers(const struct btr_pool *btrp, struct iovec iov[2])
 {
 	size_t sz, unused;
 	char *buf;
@@ -322,7 +322,7 @@ static void dealloc_buffer(struct btr_buffer *btrb)
 		free(btrb->buf);
 }
 
-static struct btr_buffer_reference *get_first_input_br(struct btr_node *btrn)
+static struct btr_buffer_reference *get_first_input_br(const struct btr_node *btrn)
 {
 	if (list_empty(&btrn->input_queue))
 		return NULL;
@@ -330,6 +330,14 @@ static struct btr_buffer_reference *get_first_input_br(struct btr_node *btrn)
 		struct btr_buffer_reference, node);
 }
 
+static struct btr_buffer_reference *get_last_input_br(const struct btr_node *btrn)
+{
+	if (list_empty(&btrn->input_queue))
+		return NULL;
+	return list_last_entry(&btrn->input_queue,
+		struct btr_buffer_reference, node);
+}
+
 /*
  * Deallocate the reference, release the resources if refcount drops to zero.
  */
@@ -346,6 +354,20 @@ static void btr_drop_buffer_reference(struct btr_buffer_reference *br)
 	}
 }
 
+static bool may_merge_btrb(const struct btr_buffer *btrb,
+		const struct btr_buffer_reference *br)
+{
+	if (!br)
+		return false;
+	if (br->consumed > 0)
+		return false;
+	if (br->btrb->buf + br->btrb->size != btrb->buf)
+		return false;
+	if (!br->btrb->pool)
+		return true;
+	return br->btrb->size + btrb->size < btr_pool_size(br->btrb->pool) / 3;
+}
+
 static void add_btrb_to_children(struct btr_buffer *btrb,
 		struct btr_node *btrn, size_t consumed)
 {
@@ -354,11 +376,17 @@ static void add_btrb_to_children(struct btr_buffer *btrb,
 	if (btrn->start.tv_sec == 0)
 		btrn->start = *now;
 	FOR_EACH_CHILD(ch, btrn) {
-		struct btr_buffer_reference *br = zalloc(sizeof(*br));
-		br->btrb = btrb;
-		br->consumed = consumed;
-		list_add_tail(&br->node, &ch->input_queue);
-		btrb->refcount++;
+		struct btr_buffer_reference *br = get_last_input_br(ch);
+		if (may_merge_btrb(btrb, br)) {
+			br->btrb->size += btrb->size;
+			free(btrb);
+		} else {
+			br = zalloc(sizeof(*br));
+			br->btrb = btrb;
+			br->consumed = consumed;
+			list_add_tail(&br->node, &ch->input_queue);
+			btrb->refcount++;
+		}
 		if (ch->start.tv_sec == 0)
 			ch->start = *now;
 	}
@@ -534,7 +562,7 @@ void btr_pushdown_one(struct btr_node *btrn)
  *
  * \return True if this node has no children. False otherwise.
  */
-static bool btr_no_children(struct btr_node *btrn)
+static bool btr_no_children(const struct btr_node *btrn)
 {
 	return list_empty(&btrn->children);
 }
@@ -551,7 +579,7 @@ static bool btr_no_children(struct btr_node *btrn)
  * After a (non-leaf) node was removed removed from the tree, the function
  * returns true for all child nodes.
  */
-bool btr_no_parent(struct btr_node *btrn)
+bool btr_no_parent(const struct btr_node *btrn)
 {
 	return !btrn->parent;
 }
@@ -574,7 +602,7 @@ bool btr_no_parent(struct btr_node *btrn)
  *
  * \return True if \a btrn has no siblings.
  */
-bool btr_inplace_ok(struct btr_node *btrn)
+bool btr_inplace_ok(const struct btr_node *btrn)
 {
 	struct btr_buffer_reference *br;
 	FOR_EACH_BUFFER_REF(br, btrn) {
@@ -587,12 +615,13 @@ bool btr_inplace_ok(struct btr_node *btrn)
 	return true;
 }
 
-static inline size_t br_available_bytes(struct btr_buffer_reference *br)
+static inline size_t br_available_bytes(const struct btr_buffer_reference *br)
 {
 	return br->btrb->size - br->consumed;
 }
 
-static size_t btr_get_buffer_by_reference(struct btr_buffer_reference *br, char **buf)
+static size_t btr_get_buffer_by_reference(const struct btr_buffer_reference *br,
+		char **buf)
 {
 	if (buf)
 		*buf = br->btrb->buf + br->consumed;
@@ -619,7 +648,8 @@ static size_t btr_get_buffer_by_reference(struct btr_buffer_reference *br, char
  * to by \a btrn, the function returns zero and the value of \a bufp is
  * undefined.
  */
-size_t btr_next_buffer_omit(struct btr_node *btrn, size_t omit, char **bufp)
+size_t btr_next_buffer_omit(const struct btr_node *btrn, size_t omit,
+		char **bufp)
 {
 	struct btr_buffer_reference *br;
 	size_t wrap_count, sz, rv = 0;
@@ -684,7 +714,7 @@ out:
  * The call of this function is is equivalent to calling \ref
  * btr_next_buffer_omit() with an \a omit value of zero.
  */
-size_t btr_next_buffer(struct btr_node *btrn, char **bufp)
+size_t btr_next_buffer(const struct btr_node *btrn, char **bufp)
 {
 	return btr_next_buffer_omit(btrn, 0, bufp);
 }
@@ -816,7 +846,7 @@ out:
  * This simply iterates over all buffer references in the input queue and
  * returns the sum of the sizes of all references.
  */
-size_t btr_get_input_queue_size(struct btr_node *btrn)
+size_t btr_get_input_queue_size(const struct btr_node *btrn)
 {
 	struct btr_buffer_reference *br;
 	size_t size = 0, wrap_consumed = 0;
@@ -833,6 +863,22 @@ size_t btr_get_input_queue_size(struct btr_node *btrn)
 	return size;
 }
 
+static bool min_iqs_available(size_t min_iqs, const struct btr_node *btrn)
+{
+	struct btr_buffer_reference *br;
+	size_t have = 0, wrap_consumed = 0;
+
+	FOR_EACH_BUFFER_REF(br, btrn) {
+		if (br->wrap_count != 0) {
+			wrap_consumed = br->consumed;
+			continue;
+		}
+		have += br_available_bytes(br);
+		if (have > wrap_consumed + min_iqs)
+			return true;
+	}
+	return false;
+}
 /**
  * Remove a node from the buffer tree, reconnecting parent and children.
  *
@@ -875,7 +921,7 @@ void btr_splice_out_node(struct btr_node **btrnp)
  * \return This function iterates over all children of the given node and
  * returns the size of the largest input queue.
  */
-size_t btr_get_output_queue_size(struct btr_node *btrn)
+size_t btr_get_output_queue_size(const struct btr_node *btrn)
 {
 	size_t max_size = 0;
 	struct btr_node *ch;
@@ -903,7 +949,7 @@ size_t btr_get_output_queue_size(struct btr_node *btrn)
  *
  * \sa \ref receiver::execute, \ref filter::execute, \ref writer::execute.
  */
-int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
+int btr_exec_up(const struct btr_node *btrn, const char *command, char **value_result)
 {
 	int ret;
 
@@ -933,12 +979,12 @@ int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
  *
  * \sa \ref btr_new_node(), struct \ref btr_node_description.
  */
-void *btr_context(struct btr_node *btrn)
+void *btr_context(const struct btr_node *btrn)
 {
 	return btrn->context;
 }
 
-static bool need_buffer_pool_merge(struct btr_node *btrn)
+static bool need_buffer_pool_merge(const struct btr_node *btrn)
 {
 	struct btr_buffer_reference *br = get_first_input_br(btrn);
 
@@ -1113,7 +1159,7 @@ void btr_merge(struct btr_node *btrn, size_t dest_size)
 	}
 }
 
-static bool btr_eof(struct btr_node *btrn)
+static bool btr_eof(const struct btr_node *btrn)
 {
 	char *buf;
 	size_t len = btr_next_buffer(btrn, &buf);
@@ -1121,7 +1167,7 @@ static bool btr_eof(struct btr_node *btrn)
 	return (len == 0 && btr_no_parent(btrn));
 }
 
-static void log_tree_recursively(struct btr_node *btrn, int loglevel, int depth)
+static void log_tree_recursively(const struct btr_node *btrn, int loglevel, int depth)
 {
 	struct btr_node *ch;
 	const char spaces[] = "                 ", *space = spaces + 16 - depth;
@@ -1139,7 +1185,7 @@ static void log_tree_recursively(struct btr_node *btrn, int loglevel, int depth)
  * \param btrn Start logging at this node.
  * \param loglevel Set severity with which the tree should be logged.
  */
-void btr_log_tree(struct btr_node *btrn, int loglevel)
+void btr_log_tree(const struct btr_node *btrn, int loglevel)
 {
 	return log_tree_recursively(btrn, loglevel, 0);
 }
@@ -1199,12 +1245,9 @@ struct btr_node *btr_search_node(const char *name, struct btr_node *root)
  * btrn, the function also returns zero in order to bound the memory usage of
  * the buffer tree.
  */
-int btr_node_status(struct btr_node *btrn, size_t min_iqs,
+int btr_node_status(const struct btr_node *btrn, size_t min_iqs,
 	enum btr_node_type type)
 {
-	size_t iqs;
-
-	assert(btrn);
 	if (type != BTR_NT_LEAF && btr_no_children(btrn))
 		return -E_BTR_NO_CHILD;
 	if (type != BTR_NT_ROOT && btr_eof(btrn))
@@ -1214,12 +1257,9 @@ int btr_node_status(struct btr_node *btrn, size_t min_iqs,
 		return 0;
 	if (type == BTR_NT_ROOT)
 		return 1;
-	iqs = btr_get_input_queue_size(btrn);
-	if (iqs == 0) /* we have a parent, because not eof */
-		return 0;
-	if (iqs < min_iqs && !btr_no_parent(btrn))
-		return 0;
-	return 1;
+	if (min_iqs_available(min_iqs, btrn))
+		return 1;
+	return btr_no_parent(btrn);
 }
 
 /**
@@ -1230,7 +1270,7 @@ int btr_node_status(struct btr_node *btrn, size_t min_iqs,
  *
  * Mainly useful for the time display of para_audiod.
  */
-void btr_get_node_start(struct btr_node *btrn, struct timeval *tv)
+void btr_get_node_start(const struct btr_node *btrn, struct timeval *tv)
 {
 	*tv = btrn->start;
 }
@@ -1245,7 +1285,7 @@ void btr_get_node_start(struct btr_node *btrn, struct timeval *tv)
  * \return The parent of \a btrn, or \p NULL if \a btrn is the
  * root node of the buffer tree.
  */
-struct btr_node *btr_parent(struct btr_node *btrn)
+struct btr_node *btr_parent(const struct btr_node *btrn)
 {
 	return btrn->parent;
 }
diff --git a/buffer_tree.h b/buffer_tree.h
index 34535219..70fb3055 100644
--- a/buffer_tree.h
+++ b/buffer_tree.h
@@ -3,45 +3,43 @@
 /**
  * \file buffer_tree.h Buffer tree management.
  *
- * \par Buffer trees and buffer tree nodes.
- * The buffer tree API offers a more powerful method than standard unix pipes
- * for managing the data flow from the producer of the data (e.g. the network
- * receiver) to its consumer(s) (e.g. a sound card).
+ * Buffer trees and buffer tree nodes.
  *
- * A buffer tree consists of buffer tree nodes linked via certain parent/child
- * relationships.
+ * The buffer tree API offers an efficient method for managing the data flow
+ * from a producer (e.g. the network receiver) to the consumer(s) (e.g. a sound
+ * card).
+ *
+ * A buffer tree consists of buffer tree nodes which are linked together via
+ * parent/child relationships. Data buffers are propagated down without copying.
  *
  * Each data buffer starts its way from the root of the buffer tree. At each
  * node the data is investigated and possibly changed. New data is then fed to
- * each child.  Everything happens within one single-treaded process. There are
- * no file descriptors and no calls to read() or write().
+ * each child. There are no file descriptors, no processes/threads and no calls
+ * to read() or write().
  *
  * Whenever a node in the buffer tree creates output, either by creating a new
  * buffer or by pushing down buffers received from its parent, references to
- * that buffer are created for all children of the node. The buffer tree code
- * tries hard to avoid to copy buffer contents, but is forced to do so in case
- * there are alignment constraints.
+ * that buffer are created for all children of the node. The code avoids to
+ * copy buffer contents when possible.
  *
- * Communication between nodes is possible via the btr_exec_up() function.
- * For example, in para_audiod the alsa writer asks all parent nodes
- * for for the number of channels and the sample rate of the current
- * audio file.
+ * Communication between nodes is possible via the btr_exec_up() function. For
+ * example, in para_audiod the alsa writer asks all parent nodes for the number
+ * of channels and the sample rate of the current audio file.
  *
  * Buffer pools - An alternative to malloc/free buffer management.
  *
- * Non-leaf nodes usually create output to be processed by their children.  The
- * data must be fed through the output channel(s) of the node in order to make
- * that data available to each child.
+ * Non-leaf nodes usually create output to be processed by their child nodes.
+ * The data must be fed through the output channel(s) of the node in order to
+ * make that data available to each child.
  *
  * The easiest way to do so is to malloc() a buffer, fill it, and then call
  * btr_add_output(). This adds references to that buffer to all children. The
  * buffer is automatically freed if no buffer tree node is using it any more.
  *
- * This approach, while being simple, has some drawbacks, especially affecting
- * the root nodes of the buffer tree. Often the data source which is
- * represented by a root node does not know in advance how much data will be
- * available.  Therefore the allocated buffer is either larger than what can
- * currently be read, or is too small so that multiple buffers have to be used.
+ * This approach is simple but has some drawbacks. For example the data source
+ * represented by the root node does not know in advance how much data will be
+ * available. Therefore the allocated buffer will either be larger than
+ * necessary or too small so that multiple buffers have to be used.
  *
  * While this could be worked around by using a large buffer and calling
  * realloc() afterwards to shrink the buffer according to how much has been
@@ -131,7 +129,7 @@ enum btr_node_type {
  * know the sample rate of its input known to e.g. the mp3dec node further up
  * in the buffer tree.
  */
-typedef int (*btr_command_handler)(struct btr_node *btrn,
+typedef int (*btr_command_handler)(const struct btr_node *btrn,
 		const char *command, char **result);
 
 /**
@@ -166,38 +164,38 @@ struct btr_node_description {
 	void *context;
 };
 
-size_t btr_pool_size(struct btr_pool *btrp);
+size_t btr_pool_size(const struct btr_pool *btrp);
 struct btr_pool *btr_pool_new(const char *name, size_t area_size);
 void btr_pool_free(struct btr_pool *btrp);
-size_t btr_pool_get_buffer(struct btr_pool *btrp, char **result);
-int btr_pool_get_buffers(struct btr_pool *btrp, struct iovec iov[2]);
+size_t btr_pool_get_buffer(const struct btr_pool *btrp, char **result);
+int btr_pool_get_buffers(const struct btr_pool *btrp, struct iovec iov[2]);
 void btr_add_output_pool(struct btr_pool *btrp, size_t size,
 	struct btr_node *btrn);
-size_t btr_pool_unused(struct btr_pool *btrp);
+size_t btr_pool_unused(const struct btr_pool *btrp);
 void btr_copy(const void *src, size_t n, struct btr_pool *btrp,
 	struct btr_node *btrn);
-
 struct btr_node *btr_new_node(struct btr_node_description *bnd);
 void btr_remove_node(struct btr_node **btrnp);
 void btr_add_output(char *buf, size_t size, struct btr_node *btrn);
 void btr_add_output_dont_free(const char *buf, size_t size, struct btr_node *btrn);
-size_t btr_get_input_queue_size(struct btr_node *btrn);
-size_t btr_get_output_queue_size(struct btr_node *btrn);
-bool btr_no_parent(struct btr_node *btrn);
-size_t btr_next_buffer(struct btr_node *btrn, char **bufp);
-size_t btr_next_buffer_omit(struct btr_node *btrn, size_t omit, char **bufp);
+size_t btr_get_input_queue_size(const struct btr_node *btrn);
+size_t btr_get_output_queue_size(const struct btr_node *btrn);
+bool btr_no_parent(const struct btr_node *btrn);
+size_t btr_next_buffer(const struct btr_node *btrn, char **bufp);
+size_t btr_next_buffer_omit(const struct btr_node *btrn, size_t omit,
+		char **bufp);
 void btr_consume(struct btr_node *btrn, size_t numbytes);
-int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result);
+int btr_exec_up(const struct btr_node *btrn, const char *command, char **value_result);
 void btr_splice_out_node(struct btr_node **btrnp);
 void btr_pushdown(struct btr_node *btrn);
-void *btr_context(struct btr_node *btrn);
+void *btr_context(const struct btr_node *btrn);
 void btr_merge(struct btr_node *btrn, size_t dest_size);
-void btr_log_tree(struct btr_node *btrn, int ll);
+void btr_log_tree(const struct btr_node *btrn, int ll);
 void btr_pushdown_one(struct btr_node *btrn);
-bool btr_inplace_ok(struct btr_node *btrn);
-int btr_node_status(struct btr_node *btrn, size_t min_iqs,
+bool btr_inplace_ok(const struct btr_node *btrn);
+int btr_node_status(const struct btr_node *btrn, size_t min_iqs,
 		enum btr_node_type type);
-void btr_get_node_start(struct btr_node *btrn, struct timeval *tv);
+void btr_get_node_start(const struct btr_node *btrn, struct timeval *tv);
 struct btr_node *btr_search_node(const char *name, struct btr_node *root);
 void btr_drain(struct btr_node *btrn);
-struct btr_node *btr_parent(struct btr_node *btrn);
+struct btr_node *btr_parent(const struct btr_node *btrn);
diff --git a/check_wav.c b/check_wav.c
index 3789f30a..cb39eb54 100644
--- a/check_wav.c
+++ b/check_wav.c
@@ -54,7 +54,7 @@ void check_wav_pre_monitor(struct sched *s, struct check_wav_context *cwc)
 		sched_min_delay(s);
 }
 
-static int check_wav_exec(struct btr_node *btrn, const char *cmd, char **result)
+static int check_wav_exec(const struct btr_node *btrn, const char *cmd, char **result)
 {
 	struct check_wav_context *cwc = btr_context(btrn);
 	int val, header_val, given, arg;
diff --git a/client.c b/client.c
index 84b7580c..d2d11fd3 100644
--- a/client.c
+++ b/client.c
@@ -549,6 +549,7 @@ __noreturn static void interactive_session(void)
 	i9e_close();
 	para_log = stderr_log;
 out:
+	free(ici.history_file);
 	if (ret < 0)
 		PARA_ERROR_LOG("%s\n", para_strerror(-ret));
 	exit(ret < 0? EXIT_FAILURE : EXIT_SUCCESS);
diff --git a/configure.ac b/configure.ac
index 92560e00..34dcd060 100644
--- a/configure.ac
+++ b/configure.ac
@@ -5,7 +5,6 @@ AC_INIT([paraslash], [m4_esyscmd_s(./GIT-VERSION-GEN)],
 AC_CONFIG_HEADERS([config.h])
 
 AC_CONFIG_FILES([Makefile])
-AC_DEFUN([add_dot_o],[$(for i in $@; do printf "$i.o "; done)])
 AC_DEFUN([LIB_ARG_WITH], [
 	AC_ARG_WITH($1-headers, [AS_HELP_STRING(--with-$1-headers=dir,
 		[look for $1 headers in dir])])
@@ -38,6 +37,7 @@ AC_DEFUN([LIB_SUBST_FLAGS], [
 	if test "$HAVE_[]m4_toupper([$1])" = 'yes'; then
 		AC_DEFINE(HAVE_[]m4_toupper([$1]), 1,
 			define to 1 to turn on $1 support)
+		AC_SUBST(HAVE_[]m4_toupper([$1]))
 	else
 		$1_cppflags=
 		$1_ldflags=
@@ -61,7 +61,6 @@ REQUIRE_EXECUTABLE([bison])
 REQUIRE_EXECUTABLE([flex])
 REQUIRE_EXECUTABLE([m4])
 
-executables="recv filter audioc write afh play"
 ########################################################################### osl
 STASH_FLAGS
 LIB_ARG_WITH([osl], [-losl])
@@ -110,15 +109,6 @@ if test $HAVE_OPENSSL = yes; then
 	will be removed in the next major paraslash release. Please upgrade
 	your openssl installation.])
 	fi
-	HAVE_CRYPTO_CLEANUP_ALL_EX_DATA=yes
-	AC_CHECK_DECL([CRYPTO_cleanup_all_ex_data], [],
-		[HAVE_CRYPTO_CLEANUP_ALL_EX_DATA=no],
-		[#include <openssl/rsa.h>])
-	AC_CHECK_LIB([crypto], [CRYPTO_cleanup_all_ex_data], [],
-		[HAVE_CRYPTO_CLEANUP_ALL_EX_DATA=no])
-	test $HAVE_CRYPTO_CLEANUP_ALL_EX_DATA = yes &&
-		AC_DEFINE([HAVE_CRYPTO_CLEANUP_ALL_EX_DATA], [1],
-			[not available on FreeBSD 12])
 	HAVE_OPENSSL_THREAD_STOP=yes
 	AC_CHECK_DECL([OPENSSL_thread_stop], [],
 		[HAVE_OPENSSL_THREAD_STOP=no],
@@ -172,6 +162,7 @@ case "$enable_cryptolib" in
 	;;
 esac
 AC_SUBST(crypto_ldflags)
+AC_SUBST(CRYPTOLIB)
 ########################################################################## iconv
 STASH_FLAGS
 LIBS=
@@ -273,27 +264,26 @@ AC_CHECK_LIB([FLAC], [FLAC__stream_decoder_init_file], [], HAVE_FLAC=no)
 LIB_SUBST_FLAGS(flac)
 UNSTASH_FLAGS
 
-# some helper functions for codecs which use the ogg container format
-AC_DEFUN([NEED_OGG_OBJECTS], [{
-	test "$HAVE_OGG" = 'yes' -a \( \
+# some helpers for the ogg container format
+AS_IF([test "$HAVE_OGG" = 'yes' -a \( \
 		 "$HAVE_VORBIS" = 'yes' \
 		-o "$HAVE_SPEEX" = 'yes' \
 		-o "$HAVE_OPUS" = 'yes' \
 		-o "$HAVE_FLAC" = 'yes' \
-	\)
-}])
-AC_DEFUN([NEED_VORBIS_OBJECTS], [{
-	test "$HAVE_OGG" = 'yes' -a "$HAVE_VORBIS" = 'yes'
-}])
-AC_DEFUN([NEED_SPEEX_OBJECTS], [{
-	test "$HAVE_OGG" = 'yes' -a "$HAVE_SPEEX" = 'yes'
-}])
-AC_DEFUN([NEED_OPUS_OBJECTS], [{
-	test "$HAVE_OGG" = 'yes' -a "$HAVE_OPUS" = 'yes'
-}])
-AC_DEFUN([NEED_FLAC_OBJECTS], [{
-	test "$HAVE_OGG" = 'yes' -a "$HAVE_FLAC" = 'yes'
-}])
+\)], [NEED_OGG_OBJECTS=yes], [NEED_OGG_OBJECTS=no])
+AC_SUBST([NEED_OGG_OBJECTS])
+AS_IF([test "$HAVE_OGG" = 'yes' -a "$HAVE_VORBIS" = 'yes'],
+	[NEED_VORBIS_OBJECTS=yes], [NEED_VORBIS_OBJECTS=no])
+AC_SUBST([NEED_VORBIS_OBJECTS])
+AS_IF([test "$HAVE_OGG" = 'yes' -a "$HAVE_SPEEX" = 'yes'],
+	[NEED_SPEEX_OBJECTS=yes], [NEED_SPEEX_OBJECTS=no])
+AC_SUBST([NEED_SPEEX_OBJECTS])
+AS_IF([test "$HAVE_OGG" = 'yes' -a "$HAVE_OPUS" = 'yes'],
+	[NEED_OPUS_OBJECTS=yes], [NEED_OPUS_OBJECTS=no])
+AC_SUBST([NEED_OPUS_OBJECTS])
+AS_IF([test "$HAVE_OGG" = 'yes' -a "$HAVE_FLAC" = 'yes'],
+	[NEED_FLAC_OBJECTS=yes], [NEED_FLAC_OBJECTS=no])
+AC_SUBST([NEED_FLAC_OBJECTS])
 ########################################################################### faad
 STASH_FLAGS
 LIB_ARG_WITH([faad], [-lfaad])
@@ -349,7 +339,9 @@ AC_CHECK_HEADER(ao/ao.h, [], HAVE_AO=no)
 AC_CHECK_LIB([ao], [ao_initialize], [], HAVE_AO=no)
 LIB_SUBST_FLAGS(ao)
 UNSTASH_FLAGS
-AC_DEFUN([NEED_AO_OBJECTS], [{ test $HAVE_AO = yes -a $HAVE_PTHREAD = yes; }])
+AS_IF([test $HAVE_AO = yes -a $HAVE_PTHREAD = yes],
+	[NEED_AO_OBJECTS]=yes, [NEED_AO_OBJECTS=no])
+AC_SUBST([NEED_AO_OBJECTS])
 ######################################################################## readline
 STASH_FLAGS
 AC_SEARCH_LIBS([tgetent], [tinfo curses terminfo termcap])
@@ -381,502 +373,5 @@ AC_ARG_ENABLE([ubsan], [AS_HELP_STRING(--enable-ubsan,
 	[Detect and report undefined behaviour.])],
 	[ENABLE_UBSAN=yes], [ENABLE_UBSAN=no])
 AC_SUBST(ENABLE_UBSAN)
-######################################################################### server
-if test -n "$CRYPTOLIB" && test $HAVE_OSL = yes && test -n "$BISON" && \
-		test -n "$FLEX"; then
-	build_server="yes"
-	executables="$executables server upgrade_db"
-	server_errlist_objs="
-		server
-		afh_common
-		mp3_afh
-		vss
-		command
-		net
-		string
-		signal
-		time
-		daemon
-		http_send
-		close_on_fork
-		crypt_common
-		base64
-		ipc
-		dccp_send
-		fd
-		user_list
-		chunk_queue
-		afs
-		aft
-		mood
-		mp
-		score
-		attribute
-		blob
-		playlist
-		sched
-		acl
-		send_common
-		udp_send
-		color
-		fec
-		wma_afh
-		wma_common
-		sideband
-		version
-		lsu
-	"
-	if test "$CRYPTOLIB" = openssl; then
-		server_errlist_objs="$server_errlist_objs openssl"
-	else
-		server_errlist_objs="$server_errlist_objs gcrypt"
-	fi
-	NEED_OGG_OBJECTS() && server_errlist_objs="$server_errlist_objs ogg_afh_common"
-	NEED_VORBIS_OBJECTS() && server_errlist_objs="$server_errlist_objs ogg_afh"
-	NEED_SPEEX_OBJECTS() && server_errlist_objs="$server_errlist_objs spx_afh spx_common"
-	NEED_OPUS_OBJECTS() && server_errlist_objs="$server_errlist_objs opus_afh opus_common"
-	NEED_FLAC_OBJECTS && server_errlist_objs="$server_errlist_objs flac_afh"
-	if test $HAVE_FAAD = yes; then
-		server_errlist_objs="$server_errlist_objs aac_afh mp4"
-	fi
-	server_objs="$server_errlist_objs"
-	AC_SUBST(server_objs, add_dot_o($server_objs))
-else
-	build_server="no"
-fi
-############################################################# upgrade_db
-upgrade_db_objs='
-	crypt_common
-	exec
-	fd
-	string
-	upgrade_db
-	version
-	base64
-'
-AC_SUBST(upgrade_db_objs, add_dot_o($upgrade_db_objs))
-############################################################# client
-if test -n "$CRYPTOLIB"; then
-	build_client="yes"
-	executables="$executables client"
-	client_errlist_objs="
-		client
-		net
-		string
-		fd
-		lsu
-		sched
-		stdin
-		stdout
-		time
-		sideband
-		client_common
-		buffer_tree
-		crypt_common
-		base64
-		version
-	"
-	if test "$CRYPTOLIB" = openssl; then
-		client_errlist_objs="$client_errlist_objs openssl"
-	else
-		client_errlist_objs="$client_errlist_objs gcrypt"
-	fi
-	if test $HAVE_READLINE = yes; then
-		client_errlist_objs="$client_errlist_objs interactive"
-	fi
-	client_objs="$client_errlist_objs"
-	AC_SUBST(client_objs, add_dot_o($client_errlist_objs))
-else
-	build_client="no"
-fi
-############################################################# audiod
-if test -n "$CRYPTOLIB"; then
-	build_audiod="yes"
-	executables="$executables audiod"
-	audiod_audio_formats="wma"
-	audiod_errlist_objs="$audiod_errlist_objs
-		audiod
-		signal
-		string
-		daemon
-		stat
-		net
-		crypt_common
-		base64
-		sideband
-		time
-		grab_client
-		filter_common
-		wav_filter
-		compress_filter
-		amp_filter
-		http_recv
-		dccp_recv
-		recv_common
-		fd
-		sched
-		write_common
-		file_write
-		audiod_command
-		fecdec_filter
-		client_common
-		udp_recv
-		color
-		fec
-		prebuffer_filter
-		version
-		bitstream
-		imdct
-		wma_common
-		wmadec_filter
-		buffer_tree
-		sync_filter
-		lsu
-	"
-	if test "$CRYPTOLIB" = openssl; then
-		audiod_errlist_objs="$audiod_errlist_objs openssl"
-	else
-		audiod_errlist_objs="$audiod_errlist_objs gcrypt"
-	fi
-	NEED_VORBIS_OBJECTS && {
-		audiod_errlist_objs="$audiod_errlist_objs oggdec_filter"
-		audiod_audio_formats="$audiod_audio_formats ogg"
-	}
-	NEED_SPEEX_OBJECTS && {
-		audiod_errlist_objs="$audiod_errlist_objs spxdec_filter spx_common"
-		audiod_audio_formats="$audiod_audio_formats spx"
-	}
-	NEED_OPUS_OBJECTS && {
-		audiod_errlist_objs="$audiod_errlist_objs opusdec_filter opus_common"
-		audiod_audio_formats="$audiod_audio_formats opus"
-	}
-	NEED_FLAC_OBJECTS && {
-		audiod_errlist_objs="$audiod_errlist_objs flacdec_filter"
-		audiod_audio_formats="$audiod_audio_formats flac"
-	}
-	if test $HAVE_FAAD = yes; then
-		audiod_errlist_objs="$audiod_errlist_objs aacdec_filter"
-		audiod_audio_formats="$audiod_audio_formats aac"
-	fi
-	if test $HAVE_MAD = yes; then
-		audiod_audio_formats="$audiod_audio_formats mp3"
-		audiod_errlist_objs="$audiod_errlist_objs mp3dec_filter"
-	fi
-	if test $HAVE_OSS = yes; then
-		audiod_errlist_objs="$audiod_errlist_objs oss_write"
-	fi
-	if test $HAVE_ALSA = yes; then
-		audiod_errlist_objs="$audiod_errlist_objs alsa_write"
-	fi
-	NEED_AO_OBJECTS && {
-		audiod_errlist_objs="$audiod_errlist_objs ao_write"
-	}
-	if test $HAVE_SAMPLERATE = yes; then
-		audiod_errlist_objs="$audiod_errlist_objs resample_filter check_wav"
-	fi
-	audiod_objs="$audiod_errlist_objs"
-	AC_SUBST(audiod_objs, add_dot_o($audiod_objs))
-
-	enum="$(for i in $audiod_audio_formats; do printf "AUDIO_FORMAT_${i}, " | tr '[a-z]' '[A-Z]'; done)"
-	AC_DEFINE_UNQUOTED(AUDIOD_AUDIO_FORMATS_ENUM, $enum NUM_AUDIO_FORMATS,
-		enum of audio formats supported by audiod)
-	names="$(for i in $audiod_audio_formats; do printf \"$i\",' ' ; done)"
-	AC_DEFINE_UNQUOTED(AUDIOD_AUDIO_FORMAT_ARRAY, $names, array of audio formats supported by audiod)
-else
-	build_audiod="no"
-fi
-########################################################################### mixer
-if test $HAVE_OSS = yes -o $HAVE_ALSA = yes; then
-	build_mixer="yes"
-	executables="$executables mixer"
-	mixer_errlist_objs="mixer exec string fd time lsu version"
-	if test $HAVE_OSS = yes; then
-		mixer_errlist_objs="$mixer_errlist_objs oss_mix"
-	fi
-	if test $HAVE_ALSA = yes; then
-		mixer_errlist_objs="$mixer_errlist_objs alsa_mix"
-	fi
-	mixer_objs="$mixer_errlist_objs"
-	AC_SUBST(mixer_objs, add_dot_o($mixer_objs))
-else
-	build_mixer="no"
-	AC_MSG_WARN([no mixer support])
-fi
-########################################################################### gui
-if test $HAVE_CURSES = yes; then
-	build_gui="yes"
-	executables="$executables gui"
-	gui_errlist_objs="
-		exec
-		signal
-		string
-		stat
-		ringbuffer
-		fd
-		gui
-		gui_theme
-		lsu
-		time
-		sched
-		version
-	"
-	gui_objs="$gui_errlist_objs"
-	AC_SUBST(gui_objs, add_dot_o($gui_objs))
-else
-	build_gui="no"
-	AC_MSG_WARN([no curses lib, cannot build para_gui])
-fi
-######################################################################## filter
-filter_errlist_objs="
-	filter_common
-	wav_filter
-	compress_filter
-	filter
-	string
-	stdin
-	stdout
-	sched
-	fd
-	amp_filter
-	fecdec_filter
-	fec
-	lsu
-	version
-	prebuffer_filter
-	time
-	bitstream
-	imdct
-	wma_common
-	wmadec_filter
-	buffer_tree
-	net
-	sync_filter
-"
-NEED_VORBIS_OBJECTS && filter_errlist_objs="$filter_errlist_objs oggdec_filter"
-NEED_SPEEX_OBJECTS && filter_errlist_objs="$filter_errlist_objs spxdec_filter spx_common"
-NEED_OPUS_OBJECTS && filter_errlist_objs="$filter_errlist_objs opusdec_filter opus_common"
-NEED_FLAC_OBJECTS && filter_errlist_objs="$filter_errlist_objs flacdec_filter"
-if test $HAVE_FAAD = yes; then
-	filter_errlist_objs="$filter_errlist_objs aacdec_filter"
-fi
-if test $HAVE_MAD = yes; then
-	filter_errlist_objs="$filter_errlist_objs mp3dec_filter"
-fi
-if test $HAVE_SAMPLERATE = yes; then
-	filter_errlist_objs="$filter_errlist_objs resample_filter check_wav"
-fi
-filter_objs="$filter_errlist_objs"
-
-AC_SUBST(filter_objs, add_dot_o($filter_objs))
-########################################################################## recv
-recv_errlist_objs="
-	http_recv
-	recv_common
-	recv
-	time
-	string
-	net
-	dccp_recv
-	fd
-	sched
-	stdout
-	udp_recv
-	buffer_tree
-	afh_recv
-	afh_common
-	wma_afh
-	wma_common
-	mp3_afh
-	version
-"
-NEED_OGG_OBJECTS && recv_errlist_objs="$recv_errlist_objs ogg_afh_common"
-NEED_VORBIS_OBJECTS && recv_errlist_objs="$recv_errlist_objs ogg_afh"
-NEED_SPEEX_OBJECTS && recv_errlist_objs="$recv_errlist_objs spx_afh spx_common"
-NEED_OPUS_OBJECTS && recv_errlist_objs="$recv_errlist_objs opus_afh opus_common"
-NEED_FLAC_OBJECTS && recv_errlist_objs="$recv_errlist_objs flac_afh"
-
-if test $HAVE_FAAD = yes; then
-	recv_errlist_objs="$recv_errlist_objs aac_afh mp4"
-fi
-recv_objs="$recv_errlist_objs"
-AC_SUBST(recv_objs, add_dot_o($recv_objs))
-########################################################################### afh
-audio_format_handlers="mp3 wma"
-afh_errlist_objs="
-	afh
-	string
-	fd
-	mp3_afh
-	afh_common
-	time
-	wma_afh
-	wma_common
-	version
-"
-NEED_OGG_OBJECTS && afh_errlist_objs="$afh_errlist_objs ogg_afh_common"
-NEED_VORBIS_OBJECTS && {
-	afh_errlist_objs="$afh_errlist_objs ogg_afh"
-	audio_format_handlers="$audio_format_handlers ogg"
-}
-NEED_SPEEX_OBJECTS && {
-	afh_errlist_objs="$afh_errlist_objs spx_afh spx_common"
-	audio_format_handlers="$audio_format_handlers spx"
-}
-NEED_OPUS_OBJECTS && {
-	afh_errlist_objs="$afh_errlist_objs opus_afh opus_common"
-	audio_format_handlers="$audio_format_handlers opus"
-}
-NEED_FLAC_OBJECTS && {
-	afh_errlist_objs="$afh_errlist_objs flac_afh"
-	audio_format_handlers="$audio_format_handlers flac"
-}
-if test $HAVE_FAAD = yes; then
-	afh_errlist_objs="$afh_errlist_objs aac_afh mp4"
-	audio_format_handlers="$audio_format_handlers aac"
-fi
-
-afh_objs="$afh_errlist_objs"
-
-AC_SUBST(afh_objs, add_dot_o($afh_objs))
-########################################################################## play
-play_errlist_objs="
-	play
-	fd
-	sched
-	buffer_tree
-	time
-	string
-	net
-	afh_recv
-	afh_common
-	wma_afh
-	wma_common
-	mp3_afh
-	recv_common
-	udp_recv
-	http_recv
-	dccp_recv
-	filter_common
-	fec
-	bitstream
-	imdct
-	wav_filter
-	compress_filter
-	amp_filter
-	prebuffer_filter
-	fecdec_filter
-	wmadec_filter
-	write_common
-	file_write
-	version
-	sync_filter
-	lsu
-"
-NEED_OGG_OBJECTS && play_errlist_objs="$play_errlist_objs ogg_afh_common"
-NEED_VORBIS_OBJECTS && {
-	play_errlist_objs="$play_errlist_objs oggdec_filter ogg_afh"
-}
-NEED_SPEEX_OBJECTS && {
-	play_errlist_objs="$play_errlist_objs spxdec_filter spx_afh spx_common"
-}
-NEED_OPUS_OBJECTS &&
-	play_errlist_objs="$play_errlist_objs
-		opusdec_filter
-		opus_afh
-		opus_common
-	"
-NEED_FLAC_OBJECTS && {
-	play_errlist_objs="$play_errlist_objs flacdec_filter flac_afh"
-}
-if test $HAVE_FAAD = yes; then
-	play_errlist_objs="$play_errlist_objs aac_afh aacdec_filter mp4"
-fi
-if test $HAVE_MAD = yes; then
-	play_errlist_objs="$play_errlist_objs mp3dec_filter"
-fi
-if test $HAVE_OSS = yes; then
-	play_errlist_objs="$play_errlist_objs oss_write"
-fi
-if test $HAVE_ALSA = yes; then
-	play_errlist_objs="$play_errlist_objs alsa_write"
-fi
-NEED_AO_OBJECTS && {
-	play_errlist_objs="$play_errlist_objs ao_write"
-}
-if test $HAVE_READLINE = yes; then
-	play_errlist_objs="$play_errlist_objs interactive"
-fi
-if test $HAVE_SAMPLERATE = yes; then
-	play_errlist_objs="$play_errlist_objs resample_filter check_wav"
-fi
-
-play_objs="$play_errlist_objs"
-AC_SUBST(play_objs, add_dot_o($play_objs))
-######################################################################### write
-write_errlist_objs="
-	write
-	write_common
-	file_write
-	time
-	fd
-	string
-	sched
-	stdin
-	buffer_tree
-	check_wav
-	version
-"
-
-NEED_AO_OBJECTS && {
-	write_errlist_objs="$write_errlist_objs ao_write"
-}
-if test $HAVE_OSS = yes; then
-	write_errlist_objs="$write_errlist_objs oss_write"
-fi
-if test $HAVE_ALSA = yes; then
-	write_errlist_objs="$write_errlist_objs alsa_write"
-fi
-write_objs="$write_errlist_objs"
-AC_SUBST(write_objs, add_dot_o($write_objs))
-######################################################################## audioc
-audioc_errlist_objs="
-	audioc
-	string
-	lsu
-	net
-	fd
-	time
-	version
-"
-if test $HAVE_READLINE = yes; then
-	audioc_errlist_objs="$audioc_errlist_objs
-		buffer_tree
-		interactive
-		sched
-	"
-fi
-audioc_objs="$audioc_errlist_objs"
-AC_SUBST(audioc_objs, add_dot_o($audioc_objs))
-
-AC_DEFINE_UNQUOTED(AUDIO_FORMAT_HANDLERS, "$audio_format_handlers",
-	[formats supported by para_server and para_afh])
-AC_SUBST(executables)
 
 AC_OUTPUT
-AC_MSG_NOTICE([
-paraslash configuration:
-~~~~~~~~~~~~~~~~~~~~~~~~
-crypto lib: ${CRYPTOLIB:-[none]}
-unix socket credentials: $have_ucred
-readline (interactive CLIs): $HAVE_READLINE
-id3 version 2 support: $HAVE_ID3TAG
-faad: $HAVE_FAAD
-audio format handlers: $audio_format_handlers
-
-exe: $executables
-para_server: $build_server
-para_gui: $build_gui
-para_mixer: $build_mixer
-para_client: $build_client
-para_audiod: $build_audiod
-])
diff --git a/flacdec_filter.c b/flacdec_filter.c
index fb8ebf15..bc3a678b 100644
--- a/flacdec_filter.c
+++ b/flacdec_filter.c
@@ -187,7 +187,7 @@ static int flacdec_init(struct filter_node *fn)
 	return -E_FLACDEC_DECODER_INIT;
 }
 
-static int flacdec_execute(struct btr_node *btrn, const char *cmd,
+static int flacdec_execute(const struct btr_node *btrn, const char *cmd,
 		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
diff --git a/ipc.c b/ipc.c
index 8e9dd51a..c245f690 100644
--- a/ipc.c
+++ b/ipc.c
@@ -218,7 +218,7 @@ size_t shm_get_shmmax(void)
 	{
 		int fd = open("/proc/sys/kernel/shmmax", O_RDONLY);
 		if (fd >= 0) {
-			char buf[100] = "";
+			char buf[100];
 			int ret = read(fd, buf, sizeof(buf) - 1);
 			if (ret > 0) {
 				buf[ret] = '\0';
diff --git a/list.h b/list.h
index 78c302fa..82f5b36d 100644
--- a/list.h
+++ b/list.h
@@ -161,3 +161,5 @@ static inline int list_is_singular(const struct list_head *head)
  */
 #define list_first_entry(ptr, type, member) \
 	list_entry((ptr)->next, type, member)
+#define list_last_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, member)
diff --git a/mp3dec_filter.c b/mp3dec_filter.c
index d40df85e..d4d4712f 100644
--- a/mp3dec_filter.c
+++ b/mp3dec_filter.c
@@ -79,12 +79,11 @@ static int mp3dec_post_monitor(__a_unused struct sched *s, void *context)
 	int i, ret;
 	struct private_mp3dec_data *pmd = fn->private_data;
 	struct btr_node *btrn = fn->btrn;
-	size_t loaded = 0, len, iqs;
+	size_t loaded = 0, len;
 	char *inbuffer, *outbuffer;
 
 next_buffer:
 	pmd->stream.error = 0;
-	iqs = btr_get_input_queue_size(btrn);
 	ret = btr_node_status(btrn, fn->min_iqs, BTR_NT_INTERNAL);
 	if (ret < 0)
 		goto err;
@@ -104,7 +103,7 @@ next_frame:
 	if (ret < 0) {
 		mp3dec_consume(btrn, &pmd->stream, len);
 		if (pmd->stream.error == MAD_ERROR_BUFLEN) {
-			if (len == iqs && btr_no_parent(btrn)) {
+			if (fn->min_iqs > 0 && btr_no_parent(btrn)) {
 				ret = -E_EOF;
 				goto err;
 			}
@@ -128,7 +127,7 @@ decode:
 		mad_stream_sync(&pmd->stream);
 		if (pmd->stream.error == MAD_ERROR_BUFLEN) {
 			ret = -E_EOF;
-			if (len == iqs && btr_no_parent(btrn))
+			if (btr_no_parent(btrn))
 				goto err;
 			fn->min_iqs += 100;
 			ret = -E_MP3DEC_CORRUPT;
@@ -176,7 +175,8 @@ static void mp3dec_open(struct filter_node *fn)
 		mad_stream_options(&pmd->stream, MAD_OPTION_IGNORECRC);
 }
 
-static int mp3dec_execute(struct btr_node *btrn, const char *cmd, char **result)
+static int mp3dec_execute(const struct btr_node *btrn, const char *cmd,
+		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
 	struct private_mp3dec_data *pmd = fn->private_data;
diff --git a/oggdec_filter.c b/oggdec_filter.c
index b1aec4bc..91c18c48 100644
--- a/oggdec_filter.c
+++ b/oggdec_filter.c
@@ -107,7 +107,8 @@ static void ogg_close(struct filter_node *fn)
 	fn->private_data = NULL;
 }
 
-static int oggdec_execute(struct btr_node *btrn, const char *cmd, char **result)
+static int oggdec_execute(const struct btr_node *btrn, const char *cmd,
+		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
 	struct private_oggdec_data *pod = fn->private_data;
diff --git a/openssl.c b/openssl.c
index f696cd9e..13550e7a 100644
--- a/openssl.c
+++ b/openssl.c
@@ -54,9 +54,6 @@ void crypt_init(void)
 
 void crypt_shutdown(void)
 {
-#ifdef HAVE_CRYPTO_CLEANUP_ALL_EX_DATA
-	CRYPTO_cleanup_all_ex_data();
-#endif
 #ifdef HAVE_OPENSSL_THREAD_STOP /* openssl-1.1 or later */
 	OPENSSL_thread_stop();
 #else /* openssl-1.0 */
diff --git a/opusdec_filter.c b/opusdec_filter.c
index f36990fa..504ba0e8 100644
--- a/opusdec_filter.c
+++ b/opusdec_filter.c
@@ -75,7 +75,7 @@ struct opusdec_context {
 	ogg_int32_t opus_serialno;
 };
 
-static int opusdec_execute(struct btr_node *btrn, const char *cmd,
+static int opusdec_execute(const struct btr_node *btrn, const char *cmd,
 		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
diff --git a/resample_filter.c b/resample_filter.c
index 72cb3f62..6d4599a8 100644
--- a/resample_filter.c
+++ b/resample_filter.c
@@ -28,7 +28,8 @@ struct resample_context {
 	struct check_wav_context *cwc;
 };
 
-static int resample_execute(struct btr_node *btrn, const char *cmd, char **result)
+static int resample_execute(const struct btr_node *btrn, const char *cmd,
+		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
 	struct resample_context *ctx = fn->private_data;
diff --git a/spxdec_filter.c b/spxdec_filter.c
index 08eac02a..ce72125e 100644
--- a/spxdec_filter.c
+++ b/spxdec_filter.c
@@ -102,7 +102,7 @@ static void speexdec_close(struct filter_node *fn)
 	fn->private_data = NULL;
 }
 
-static int speexdec_execute(struct btr_node *btrn, const char *cmd,
+static int speexdec_execute(const struct btr_node *btrn, const char *cmd,
 		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
diff --git a/t/makefile.test b/t/makefile.test
index 904c7793..1ef3ac69 100644
--- a/t/makefile.test
+++ b/t/makefile.test
@@ -7,7 +7,7 @@ test_options := --executables-dir $(shell pwd)
 test_options += --results-dir $(results_dir)
 test_options += --trash-dir $(trash_dir)
 test_options += --executables "$(prefixed_executables)"
-test_options += --objects "$(basename $(all_objs))"
+test_options += --objects "$(basename $(dep_objs))"
 test_options += --man-dir $(man_dir)
 
 ifdef V
diff --git a/wmadec_filter.c b/wmadec_filter.c
index f2ca273c..5b3d9874 100644
--- a/wmadec_filter.c
+++ b/wmadec_filter.c
@@ -1147,7 +1147,8 @@ static void wmadec_close(struct filter_node *fn)
 	fn->private_data = NULL;
 }
 
-static int wmadec_execute(struct btr_node *btrn, const char *cmd, char **result)
+static int wmadec_execute(const struct btr_node *btrn, const char *cmd,
+		char **result)
 {
 	struct filter_node *fn = btr_context(btrn);
 	struct private_wmadec_data *pwd = fn->private_data;