X-Git-Url: https://code.delx.au/pulseaudio/blobdiff_plain/fc544a63de7496ab6ea23cce65599c086d730256..eca082a93f2619cfa10733947a81fa779cb49573:/src/pulsecore/pstream.c

diff --git a/src/pulsecore/pstream.c b/src/pulsecore/pstream.c
index e9b6f4c8..2c1444ff 100644
--- a/src/pulsecore/pstream.c
+++ b/src/pulsecore/pstream.c
@@ -1,18 +1,19 @@
-/* $Id$ */
-
 /***
   This file is part of PulseAudio.
- 
+
+  Copyright 2004-2006 Lennart Poettering
+  Copyright 2006 Pierre Ossman <ossman@cendio.se> for Cendio AB
+
   PulseAudio is free software; you can redistribute it and/or modify
   it under the terms of the GNU Lesser General Public License as
   published by the Free Software Foundation; either version 2.1 of the
   License, or (at your option) any later version.
- 
+
   PulseAudio is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
   Lesser General Public License for more details.
- 
+
   You should have received a copy of the GNU Lesser General Public
   License along with PulseAudio; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
@@ -25,39 +26,77 @@
 
 #include <stdio.h>
 #include <stdlib.h>
-#include <assert.h>
 #include <unistd.h>
 
 #ifdef HAVE_NETINET_IN_H
 #include <netinet/in.h>
 #endif
 
-#include "winsock.h"
-
 #include <pulse/xmalloc.h>
 
+#include <pulsecore/socket.h>
 #include <pulsecore/queue.h>
 #include <pulsecore/log.h>
-#include <pulsecore/core-scache.h>
+#include <pulsecore/creds.h>
+#include <pulsecore/refcnt.h>
+#include <pulsecore/flist.h>
+#include <pulsecore/macro.h>
 
 #include "pstream.h"
 
+/* We piggyback information if audio data blocks are stored in SHM on the seek mode */
+#define PA_FLAG_SHMDATA    0x80000000LU
+#define PA_FLAG_SHMRELEASE 0x40000000LU
+#define PA_FLAG_SHMREVOKE  0xC0000000LU
+#define PA_FLAG_SHMMASK    0xFF000000LU
+#define PA_FLAG_SEEKMASK   0x000000FFLU
+
+/* The sequence descriptor header consists of 5 32bit integers: */
 enum {
     PA_PSTREAM_DESCRIPTOR_LENGTH,
     PA_PSTREAM_DESCRIPTOR_CHANNEL,
     PA_PSTREAM_DESCRIPTOR_OFFSET_HI,
     PA_PSTREAM_DESCRIPTOR_OFFSET_LO,
-    PA_PSTREAM_DESCRIPTOR_SEEK,
+    PA_PSTREAM_DESCRIPTOR_FLAGS,
     PA_PSTREAM_DESCRIPTOR_MAX
 };
 
+/* If we have an SHM block, this info follows the descriptor */
+enum {
+    PA_PSTREAM_SHM_BLOCKID,
+    PA_PSTREAM_SHM_SHMID,
+    PA_PSTREAM_SHM_INDEX,
+    PA_PSTREAM_SHM_LENGTH,
+    PA_PSTREAM_SHM_MAX
+};
+
 typedef uint32_t pa_pstream_descriptor[PA_PSTREAM_DESCRIPTOR_MAX];
 
 #define PA_PSTREAM_DESCRIPTOR_SIZE (PA_PSTREAM_DESCRIPTOR_MAX*sizeof(uint32_t))
-#define FRAME_SIZE_MAX PA_SCACHE_ENTRY_SIZE_MAX /* allow uploading a single sample in one frame at max */
+
+#define MINIBUF_SIZE (256)
+
+/* To allow uploading a single sample in one frame, this value should be the
+ * same size (16 MB) as PA_SCACHE_ENTRY_SIZE_MAX from pulsecore/core-scache.h.
+ */
+#define FRAME_SIZE_MAX_ALLOW (1024*1024*16)
+
+PA_STATIC_FLIST_DECLARE(items, 0, pa_xfree);
 
 struct item_info {
-    enum { PA_PSTREAM_ITEM_PACKET, PA_PSTREAM_ITEM_MEMBLOCK } type;
+    enum {
+        PA_PSTREAM_ITEM_PACKET,
+        PA_PSTREAM_ITEM_MEMBLOCK,
+        PA_PSTREAM_ITEM_SHMRELEASE,
+        PA_PSTREAM_ITEM_SHMREVOKE
+    } type;
+
+    /* packet info */
+    pa_packet *packet;
+#ifdef HAVE_CREDS
+    bool with_creds;
+    pa_creds creds;
+#endif
 
     /* memblock info */
     pa_memchunk chunk;
@@ -65,43 +104,51 @@ struct item_info {
     int64_t offset;
     pa_seek_mode_t seek_mode;
 
-    /* packet info */
-    pa_packet *packet;
-#ifdef SCM_CREDENTIALS
-    int with_creds;
-#endif
+    /* release/revoke info */
+    uint32_t block_id;
 };
 
 struct pa_pstream {
-    int ref;
-    
+    PA_REFCNT_DECLARE;
+
     pa_mainloop_api *mainloop;
     pa_defer_event *defer_event;
     pa_iochannel *io;
+
     pa_queue *send_queue;
 
-    int dead;
+    bool dead;
 
     struct {
+        union {
+            uint8_t minibuf[MINIBUF_SIZE];
+            pa_pstream_descriptor descriptor;
+        };
         struct item_info* current;
-        pa_pstream_descriptor descriptor;
         void *data;
         size_t index;
+        int minibuf_validsize;
+        pa_memchunk memchunk;
     } write;
 
     struct {
+        pa_pstream_descriptor descriptor;
         pa_memblock *memblock;
         pa_packet *packet;
-        pa_pstream_descriptor descriptor;
+        uint32_t shm_info[PA_PSTREAM_SHM_MAX];
         void *data;
         size_t index;
     } read;
 
-    pa_pstream_packet_cb_t recieve_packet_callback;
-    void *recieve_packet_callback_userdata;
+    bool use_shm;
+    pa_memimport *import;
+    pa_memexport *export;
 
-    pa_pstream_memblock_cb_t recieve_memblock_callback;
-    void *recieve_memblock_callback_userdata;
+    pa_pstream_packet_cb_t receive_packet_callback;
+    void *receive_packet_callback_userdata;
+
+    pa_pstream_memblock_cb_t receive_memblock_callback;
+    void *receive_memblock_callback_userdata;
 
     pa_pstream_notify_cb_t drain_callback;
     void *drain_callback_userdata;
@@ -109,34 +156,43 @@ struct pa_pstream {
     pa_pstream_notify_cb_t die_callback;
     void *die_callback_userdata;
 
-    pa_memblock_stat *memblock_stat;
+    pa_pstream_block_id_cb_t revoke_callback;
+    void *revoke_callback_userdata;
+
+    pa_pstream_block_id_cb_t release_callback;
+    void *release_callback_userdata;
 
-#ifdef SCM_CREDENTIALS
-    int send_creds_now;
-    struct ucred ucred;
-    int creds_valid;
+    pa_mempool *mempool;
+
+#ifdef HAVE_CREDS
+    pa_creds read_creds, write_creds;
+    bool read_creds_valid, send_creds_now;
 #endif
 };
 
 static int do_write(pa_pstream *p);
 static int do_read(pa_pstream *p);
 
-static void do_something(pa_pstream *p) {
-    assert(p);
-
-    p->mainloop->defer_enable(p->defer_event, 0);
+static void do_pstream_read_write(pa_pstream *p) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
     pa_pstream_ref(p);
 
+    p->mainloop->defer_enable(p->defer_event, 0);
+
     if (!p->dead && pa_iochannel_is_readable(p->io)) {
         if (do_read(p) < 0)
             goto fail;
     } else if (!p->dead && pa_iochannel_is_hungup(p->io))
         goto fail;
 
-    if (!p->dead && pa_iochannel_is_writable(p->io)) {
-        if (do_write(p) < 0)
+    while (!p->dead && pa_iochannel_is_writable(p->io)) {
+        int r = do_write(p);
+        if (r < 0)
             goto fail;
+        if (r == 0)
+            break;
     }
 
     pa_pstream_unref(p);
@@ -144,202 +200,354 @@ static void do_something(pa_pstream *p) {
 
 fail:
 
-    p->dead = 1;
-    
     if (p->die_callback)
         p->die_callback(p, p->die_callback_userdata);
-    
+
+    pa_pstream_unlink(p);
     pa_pstream_unref(p);
 }
 
 static void io_callback(pa_iochannel*io, void *userdata) {
     pa_pstream *p = userdata;
-    
-    assert(p);
-    assert(p->io == io);
-    
-    do_something(p);
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+    pa_assert(p->io == io);
+
+    do_pstream_read_write(p);
 }
 
 static void defer_callback(pa_mainloop_api *m, pa_defer_event *e, void*userdata) {
     pa_pstream *p = userdata;
 
-    assert(p);
-    assert(p->defer_event == e);
-    assert(p->mainloop == m);
-    
-    do_something(p);
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+    pa_assert(p->defer_event == e);
+    pa_assert(p->mainloop == m);
+
+    do_pstream_read_write(p);
 }
 
-pa_pstream *pa_pstream_new(pa_mainloop_api *m, pa_iochannel *io, pa_memblock_stat *s) {
+static void memimport_release_cb(pa_memimport *i, uint32_t block_id, void *userdata);
+
+pa_pstream *pa_pstream_new(pa_mainloop_api *m, pa_iochannel *io, pa_mempool *pool) {
     pa_pstream *p;
-    assert(io);
 
-    p = pa_xnew(pa_pstream, 1);
-    
-    p->ref = 1;
+    pa_assert(m);
+    pa_assert(io);
+    pa_assert(pool);
+
+    p = pa_xnew0(pa_pstream, 1);
+    PA_REFCNT_INIT(p);
     p->io = io;
     pa_iochannel_set_callback(io, io_callback, p);
 
-    p->dead = 0;
-
     p->mainloop = m;
     p->defer_event = m->defer_new(m, defer_callback, p);
     m->defer_enable(p->defer_event, 0);
-    
-    p->send_queue = pa_queue_new();
-    assert(p->send_queue);
-
-    p->write.current = NULL;
-    p->write.index = 0;
 
-    p->read.memblock = NULL;
-    p->read.packet = NULL;
-    p->read.index = 0;
-
-    p->recieve_packet_callback = NULL;
-    p->recieve_packet_callback_userdata = NULL;
-    
-    p->recieve_memblock_callback = NULL;
-    p->recieve_memblock_callback_userdata = NULL;
-
-    p->drain_callback = NULL;
-    p->drain_callback_userdata = NULL;
+    p->send_queue = pa_queue_new();
 
-    p->die_callback = NULL;
-    p->die_callback_userdata = NULL;
+    p->mempool = pool;
 
-    p->memblock_stat = s;
+    /* We do importing unconditionally */
+    p->import = pa_memimport_new(p->mempool, memimport_release_cb, p);
 
-    pa_iochannel_socket_set_rcvbuf(io, 1024*8); 
-    pa_iochannel_socket_set_sndbuf(io, 1024*8);
+    pa_iochannel_socket_set_rcvbuf(io, pa_mempool_block_size_max(p->mempool));
+    pa_iochannel_socket_set_sndbuf(io, pa_mempool_block_size_max(p->mempool));
 
-#ifdef SCM_CREDENTIALS
-    p->send_creds_now = 0;
-    p->creds_valid = 0;
-#endif
     return p;
 }
 
-static void item_free(void *item, PA_GCC_UNUSED void *p) {
+static void item_free(void *item) {
     struct item_info *i = item;
-    assert(i);
+    pa_assert(i);
 
     if (i->type == PA_PSTREAM_ITEM_MEMBLOCK) {
-        assert(i->chunk.memblock);
+        pa_assert(i->chunk.memblock);
         pa_memblock_unref(i->chunk.memblock);
-    } else {
-        assert(i->type == PA_PSTREAM_ITEM_PACKET);
-        assert(i->packet);
+    } else if (i->type == PA_PSTREAM_ITEM_PACKET) {
+        pa_assert(i->packet);
         pa_packet_unref(i->packet);
     }
 
-    pa_xfree(i);
+    if (pa_flist_push(PA_STATIC_FLIST_GET(items), i) < 0)
+        pa_xfree(i);
 }
 
 static void pstream_free(pa_pstream *p) {
-    assert(p);
+    pa_assert(p);
 
-    pa_pstream_close(p);
-    
-    pa_queue_free(p->send_queue, item_free, NULL);
+    pa_pstream_unlink(p);
+
+    pa_queue_free(p->send_queue, item_free);
 
     if (p->write.current)
-        item_free(p->write.current, NULL);
+        item_free(p->write.current);
+
+    if (p->write.memchunk.memblock)
+        pa_memblock_unref(p->write.memchunk.memblock);
 
     if (p->read.memblock)
         pa_memblock_unref(p->read.memblock);
-    
+
     if (p->read.packet)
         pa_packet_unref(p->read.packet);
 
     pa_xfree(p);
 }
 
-void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet, int with_creds) {
+void pa_pstream_send_packet(pa_pstream*p, pa_packet *packet, const pa_creds *creds) {
     struct item_info *i;
-    assert(p && packet && p->ref >= 1);
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+    pa_assert(packet);
 
     if (p->dead)
         return;
-    
-/*     pa_log(__FILE__": push-packet %p", packet); */
-    
-    i = pa_xnew(struct item_info, 1);
+
+    if (!(i = pa_flist_pop(PA_STATIC_FLIST_GET(items))))
+        i = pa_xnew(struct item_info, 1);
+
     i->type = PA_PSTREAM_ITEM_PACKET;
     i->packet = pa_packet_ref(packet);
-#ifdef SCM_CREDENTIALS
-    i->with_creds = with_creds;
+
+#ifdef HAVE_CREDS
+    if ((i->with_creds = !!creds))
+        i->creds = *creds;
 #endif
 
     pa_queue_push(p->send_queue, i);
+
     p->mainloop->defer_enable(p->defer_event, 1);
 }
 
 void pa_pstream_send_memblock(pa_pstream*p, uint32_t channel, int64_t offset, pa_seek_mode_t seek_mode, const pa_memchunk *chunk) {
-    struct item_info *i;
-    assert(p && channel != (uint32_t) -1 && chunk && p->ref >= 1);
+    size_t length, idx;
+    size_t bsm;
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+    pa_assert(channel != (uint32_t) -1);
+    pa_assert(chunk);
 
     if (p->dead)
         return;
-    
-/*     pa_log(__FILE__": push-memblock %p", chunk); */
-    
-    i = pa_xnew(struct item_info, 1);
-    i->type = PA_PSTREAM_ITEM_MEMBLOCK;
-    i->chunk = *chunk;
-    i->channel = channel;
-    i->offset = offset;
-    i->seek_mode = seek_mode;
-    i->with_creds = 0;
-
-    pa_memblock_ref(i->chunk.memblock);
 
-    pa_queue_push(p->send_queue, i);
+    idx = 0;
+    length = chunk->length;
+
+    bsm = pa_mempool_block_size_max(p->mempool);
+
+    while (length > 0) {
+        struct item_info *i;
+        size_t n;
+
+        if (!(i = pa_flist_pop(PA_STATIC_FLIST_GET(items))))
+            i = pa_xnew(struct item_info, 1);
+        i->type = PA_PSTREAM_ITEM_MEMBLOCK;
+
+        n = PA_MIN(length, bsm);
+        i->chunk.index = chunk->index + idx;
+        i->chunk.length = n;
+        i->chunk.memblock = pa_memblock_ref(chunk->memblock);
+
+        i->channel = channel;
+        i->offset = offset;
+        i->seek_mode = seek_mode;
+#ifdef HAVE_CREDS
+        i->with_creds = false;
+#endif
+
+        pa_queue_push(p->send_queue, i);
+
+        idx += n;
+        length -= n;
+    }
+
+    p->mainloop->defer_enable(p->defer_event, 1);
+}
+
+void pa_pstream_send_release(pa_pstream *p, uint32_t block_id) {
+    struct item_info *item;
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    if (p->dead)
+        return;
+
+/*     pa_log("Releasing block %u", block_id); */
+
+    if (!(item = pa_flist_pop(PA_STATIC_FLIST_GET(items))))
+        item = pa_xnew(struct item_info, 1);
+    item->type = PA_PSTREAM_ITEM_SHMRELEASE;
+    item->block_id = block_id;
+#ifdef HAVE_CREDS
+    item->with_creds = false;
+#endif
+
+    pa_queue_push(p->send_queue, item);
+    p->mainloop->defer_enable(p->defer_event, 1);
+}
+
+/* might be called from thread context */
+static void memimport_release_cb(pa_memimport *i, uint32_t block_id, void *userdata) {
+    pa_pstream *p = userdata;
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    if (p->dead)
+        return;
+
+    if (p->release_callback)
+        p->release_callback(p, block_id, p->release_callback_userdata);
+    else
+        pa_pstream_send_release(p, block_id);
+}
+
+void pa_pstream_send_revoke(pa_pstream *p, uint32_t block_id) {
+    struct item_info *item;
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    if (p->dead)
+        return;
+/*     pa_log("Revoking block %u", block_id); */
+
+    if (!(item = pa_flist_pop(PA_STATIC_FLIST_GET(items))))
+        item = pa_xnew(struct item_info, 1);
+    item->type = PA_PSTREAM_ITEM_SHMREVOKE;
+    item->block_id = block_id;
+#ifdef HAVE_CREDS
+    item->with_creds = false;
+#endif
+
+    pa_queue_push(p->send_queue, item);
     p->mainloop->defer_enable(p->defer_event, 1);
 }
 
+/* might be called from thread context */
+static void memexport_revoke_cb(pa_memexport *e, uint32_t block_id, void *userdata) {
+    pa_pstream *p = userdata;
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    if (p->revoke_callback)
+        p->revoke_callback(p, block_id, p->revoke_callback_userdata);
+    else
+        pa_pstream_send_revoke(p, block_id);
+}
+
 static void prepare_next_write_item(pa_pstream *p) {
-    assert(p);
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    p->write.current = pa_queue_pop(p->send_queue);
 
-    if (!(p->write.current = pa_queue_pop(p->send_queue)))
+    if (!p->write.current)
         return;
-    
     p->write.index = 0;
-    
+    p->write.data = NULL;
+    p->write.minibuf_validsize = 0;
+    pa_memchunk_reset(&p->write.memchunk);
+
+    p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = 0;
+    p->write.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL] = htonl((uint32_t) -1);
+    p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = 0;
+    p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = 0;
+    p->write.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS] = 0;
+
     if (p->write.current->type == PA_PSTREAM_ITEM_PACKET) {
-        /*pa_log(__FILE__": pop-packet %p", p->write.current->packet);*/
-        
-        assert(p->write.current->packet);
+
+        pa_assert(p->write.current->packet);
         p->write.data = p->write.current->packet->data;
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl(p->write.current->packet->length);
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL] = htonl((uint32_t) -1);
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = 0;
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = 0;
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK] = 0;
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl((uint32_t) p->write.current->packet->length);
+
+        if (p->write.current->packet->length <= MINIBUF_SIZE - PA_PSTREAM_DESCRIPTOR_SIZE) {
+            memcpy(&p->write.minibuf[PA_PSTREAM_DESCRIPTOR_SIZE], p->write.data, p->write.current->packet->length);
+            p->write.minibuf_validsize = PA_PSTREAM_DESCRIPTOR_SIZE + p->write.current->packet->length;
+        }
+
+    } else if (p->write.current->type == PA_PSTREAM_ITEM_SHMRELEASE) {
+
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS] = htonl(PA_FLAG_SHMRELEASE);
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = htonl(p->write.current->block_id);
+
+    } else if (p->write.current->type == PA_PSTREAM_ITEM_SHMREVOKE) {
+
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS] = htonl(PA_FLAG_SHMREVOKE);
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = htonl(p->write.current->block_id);
 
-        
     } else {
-        assert(p->write.current->type == PA_PSTREAM_ITEM_MEMBLOCK && p->write.current->chunk.memblock);
-        p->write.data = (uint8_t*) p->write.current->chunk.memblock->data + p->write.current->chunk.index;
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl(p->write.current->chunk.length);
+        uint32_t flags;
+        bool send_payload = true;
+
+        pa_assert(p->write.current->type == PA_PSTREAM_ITEM_MEMBLOCK);
+        pa_assert(p->write.current->chunk.memblock);
+
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL] = htonl(p->write.current->channel);
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] = htonl((uint32_t) (((uint64_t) p->write.current->offset) >> 32));
         p->write.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = htonl((uint32_t) ((uint64_t) p->write.current->offset));
-        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK] = htonl(p->write.current->seek_mode);
+
+        flags = (uint32_t) (p->write.current->seek_mode & PA_FLAG_SEEKMASK);
+
+        if (p->use_shm) {
+            uint32_t block_id, shm_id;
+            size_t offset, length;
+            uint32_t *shm_info = (uint32_t *) &p->write.minibuf[PA_PSTREAM_DESCRIPTOR_SIZE];
+            size_t shm_size = sizeof(uint32_t) * PA_PSTREAM_SHM_MAX;
+
+            pa_assert(p->export);
+
+            if (pa_memexport_put(p->export,
+                                 p->write.current->chunk.memblock,
+                                 &block_id,
+                                 &shm_id,
+                                 &offset,
+                                 &length) >= 0) {
+
+                flags |= PA_FLAG_SHMDATA;
+                send_payload = false;
+
+                shm_info[PA_PSTREAM_SHM_BLOCKID] = htonl(block_id);
+                shm_info[PA_PSTREAM_SHM_SHMID] = htonl(shm_id);
+                shm_info[PA_PSTREAM_SHM_INDEX] = htonl((uint32_t) (offset + p->write.current->chunk.index));
+                shm_info[PA_PSTREAM_SHM_LENGTH] = htonl((uint32_t) p->write.current->chunk.length);
+
+                p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl(shm_size);
+                p->write.minibuf_validsize = PA_PSTREAM_DESCRIPTOR_SIZE + shm_size;
+            }
+/*             else */
+/*                 pa_log_warn("Failed to export memory block."); */
+        }
+
+        if (send_payload) {
+            p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH] = htonl((uint32_t) p->write.current->chunk.length);
+            p->write.memchunk = p->write.current->chunk;
+            pa_memblock_ref(p->write.memchunk.memblock);
+            p->write.data = NULL;
+        }
+
+        p->write.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS] = htonl(flags);
     }
 
-#ifdef SCM_CREDENTIALS
-    p->send_creds_now = p->write.current->with_creds;
+#ifdef HAVE_CREDS
+    if ((p->send_creds_now = p->write.current->with_creds))
+        p->write_creds = p->write.current->creds;
 #endif
-
 }
 
 static int do_write(pa_pstream *p) {
     void *d;
     size_t l;
     ssize_t r;
-    assert(p);
+    pa_memblock *release_memblock = NULL;
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
     if (!p->write.current)
         prepare_next_write_item(p);
@@ -347,131 +555,233 @@ static int do_write(pa_pstream *p) {
     if (!p->write.current)
         return 0;
 
-    assert(p->write.data);
-
-    if (p->write.index < PA_PSTREAM_DESCRIPTOR_SIZE) {
+    if (p->write.minibuf_validsize > 0) {
+        d = p->write.minibuf + p->write.index;
+        l = p->write.minibuf_validsize - p->write.index;
+    } else if (p->write.index < PA_PSTREAM_DESCRIPTOR_SIZE) {
         d = (uint8_t*) p->write.descriptor + p->write.index;
         l = PA_PSTREAM_DESCRIPTOR_SIZE - p->write.index;
     } else {
-        d = (uint8_t*) p->write.data + p->write.index - PA_PSTREAM_DESCRIPTOR_SIZE;
+        pa_assert(p->write.data || p->write.memchunk.memblock);
+
+        if (p->write.data)
+            d = p->write.data;
+        else {
+            d = pa_memblock_acquire_chunk(&p->write.memchunk);
+            release_memblock = p->write.memchunk.memblock;
+        }
+
+        d = (uint8_t*) d + p->write.index - PA_PSTREAM_DESCRIPTOR_SIZE;
         l = ntohl(p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) - (p->write.index - PA_PSTREAM_DESCRIPTOR_SIZE);
     }
 
-#ifdef SCM_CREDENTIALS
+    pa_assert(l > 0);
+
+#ifdef HAVE_CREDS
     if (p->send_creds_now) {
 
-        if ((r = pa_iochannel_write_with_creds(p->io, d, l)) < 0)
-            return -1;
+        if ((r = pa_iochannel_write_with_creds(p->io, d, l, &p->write_creds)) < 0)
+            goto fail;
 
-        p->send_creds_now = 0;
+        p->send_creds_now = false;
     } else
 #endif
 
     if ((r = pa_iochannel_write(p->io, d, l)) < 0)
-        return -1;
+        goto fail;
+
+    if (release_memblock)
+        pa_memblock_release(release_memblock);
 
-    p->write.index += r;
+    p->write.index += (size_t) r;
 
-    if (p->write.index >= PA_PSTREAM_DESCRIPTOR_SIZE+ntohl(p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH])) {
-        assert(p->write.current);
-        item_free(p->write.current, (void *) 1);
+    if (p->write.index >= PA_PSTREAM_DESCRIPTOR_SIZE + ntohl(p->write.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH])) {
+        pa_assert(p->write.current);
+        item_free(p->write.current);
         p->write.current = NULL;
 
+        if (p->write.memchunk.memblock)
+            pa_memblock_unref(p->write.memchunk.memblock);
+
+        pa_memchunk_reset(&p->write.memchunk);
+
         if (p->drain_callback && !pa_pstream_is_pending(p))
             p->drain_callback(p, p->drain_callback_userdata);
     }
 
-    return 0;
+    return (size_t) r == l ? 1 : 0;
+
+fail:
+
+    if (release_memblock)
+        pa_memblock_release(release_memblock);
+
+    return -1;
 }
 
 static int do_read(pa_pstream *p) {
     void *d;
-    size_t l; 
+    size_t l;
     ssize_t r;
-    assert(p);
+    pa_memblock *release_memblock = NULL;
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
     if (p->read.index < PA_PSTREAM_DESCRIPTOR_SIZE) {
         d = (uint8_t*) p->read.descriptor + p->read.index;
         l = PA_PSTREAM_DESCRIPTOR_SIZE - p->read.index;
     } else {
-        assert(p->read.data);
-        d = (uint8_t*) p->read.data + p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE;
+        pa_assert(p->read.data || p->read.memblock);
+
+        if (p->read.data)
+            d = p->read.data;
+        else {
+            d = pa_memblock_acquire(p->read.memblock);
+            release_memblock = p->read.memblock;
+        }
+
+        d = (uint8_t*) d + p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE;
         l = ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) - (p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE);
     }
 
-#ifdef SCM_CREDENTIALS
+#ifdef HAVE_CREDS
     {
-        int b;
-        
-        if ((r = pa_iochannel_read_with_creds(p->io, d, l, &p->ucred, &b)) <= 0)
-            return -1;
+        bool b = 0;
 
-        p->creds_valid = p->creds_valid || b;
+        if ((r = pa_iochannel_read_with_creds(p->io, d, l, &p->read_creds, &b)) <= 0)
+            goto fail;
+
+        p->read_creds_valid = p->read_creds_valid || b;
     }
 #else
     if ((r = pa_iochannel_read(p->io, d, l)) <= 0)
-        return -1;
+        goto fail;
 #endif
-    
-    p->read.index += r;
+
+    if (release_memblock)
+        pa_memblock_release(release_memblock);
+
+    p->read.index += (size_t) r;
 
     if (p->read.index == PA_PSTREAM_DESCRIPTOR_SIZE) {
+        uint32_t flags, length, channel;
         /* Reading of frame descriptor complete */
 
-        /* Frame size too large */
-        if (ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) > FRAME_SIZE_MAX) {
-            pa_log_warn(__FILE__": Frame size too large: %lu > %lu", (unsigned long) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]), (unsigned long) FRAME_SIZE_MAX);
+        flags = ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS]);
+
+        if (!p->use_shm && (flags & PA_FLAG_SHMMASK) != 0) {
+            pa_log_warn("Received SHM frame on a socket where SHM is disabled.");
             return -1;
         }
-        
-        assert(!p->read.packet && !p->read.memblock);
 
-        if (ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL]) == (uint32_t) -1) {
+        if (flags == PA_FLAG_SHMRELEASE) {
+
+            /* This is a SHM memblock release frame with no payload */
+
+/*             pa_log("Got release frame for %u", ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI])); */
+
+            pa_assert(p->export);
+            pa_memexport_process_release(p->export, ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI]));
+
+            goto frame_done;
+
+        } else if (flags == PA_FLAG_SHMREVOKE) {
+
+            /* This is a SHM memblock revoke frame with no payload */
+
+/*             pa_log("Got revoke frame for %u", ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI])); */
+
+            pa_assert(p->import);
+            pa_memimport_process_revoke(p->import, ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI]));
+
+            goto frame_done;
+        }
+
+        length = ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]);
+
+        if (length > FRAME_SIZE_MAX_ALLOW || length <= 0) {
+            pa_log_warn("Received invalid frame size: %lu", (unsigned long) length);
+            return -1;
+        }
+
+        pa_assert(!p->read.packet && !p->read.memblock);
+
+        channel = ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL]);
+
+        if (channel == (uint32_t) -1) {
+
+            if (flags != 0) {
+                pa_log_warn("Received packet frame with invalid flags value.");
+                return -1;
+            }
+
             /* Frame is a packet frame */
-            p->read.packet = pa_packet_new(ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]));
+            p->read.packet = pa_packet_new(length);
             p->read.data = p->read.packet->data;
+
         } else {
-            /* Frame is a memblock frame */
-            p->read.memblock = pa_memblock_new(ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]), p->memblock_stat);
-            p->read.data = p->read.memblock->data;
 
-            if (ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK]) > PA_SEEK_RELATIVE_END) {
-                pa_log_warn(__FILE__": Invalid seek mode");
+            if ((flags & PA_FLAG_SEEKMASK) > PA_SEEK_RELATIVE_END) {
+                pa_log_warn("Received memblock frame with invalid seek mode.");
+                return -1;
+            }
+
+            if ((flags & PA_FLAG_SHMMASK) == PA_FLAG_SHMDATA) {
+
+                if (length != sizeof(p->read.shm_info)) {
+                    pa_log_warn("Received SHM memblock frame with invalid frame length.");
+                    return -1;
+                }
+
+                /* Frame is a memblock frame referencing an SHM memblock */
+                p->read.data = p->read.shm_info;
+
+            } else if ((flags & PA_FLAG_SHMMASK) == 0) {
+
+                /* Frame is a memblock frame */
+
+                p->read.memblock = pa_memblock_new(p->mempool, length);
+                p->read.data = NULL;
+            } else {
+
+                pa_log_warn("Received memblock frame with invalid flags value.");
                 return -1;
             }
         }
-            
+
     } else if (p->read.index > PA_PSTREAM_DESCRIPTOR_SIZE) {
         /* Frame payload available */
-        
-        if (p->read.memblock && p->recieve_memblock_callback) { /* Is this memblock data? Than pass it to the user */
-            l = (p->read.index - r) < PA_PSTREAM_DESCRIPTOR_SIZE ? p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE : (size_t) r;
-                
+
+        if (p->read.memblock && p->receive_memblock_callback) {
+
+            /* Is this memblock data? Than pass it to the user */
+            l = (p->read.index - (size_t) r) < PA_PSTREAM_DESCRIPTOR_SIZE ? (size_t) (p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE) : (size_t) r;
+
             if (l > 0) {
                 pa_memchunk chunk;
-                
+
                 chunk.memblock = p->read.memblock;
                 chunk.index = p->read.index - PA_PSTREAM_DESCRIPTOR_SIZE - l;
                 chunk.length = l;
 
-                if (p->recieve_memblock_callback) {
+                if (p->receive_memblock_callback) {
                     int64_t offset;
 
                     offset = (int64_t) (
                             (((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI])) << 32) |
                             (((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO]))));
-                    
-                    p->recieve_memblock_callback(
+
+                    p->receive_memblock_callback(
                         p,
                         ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL]),
                         offset,
-                        ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK]),
+                        ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS]) & PA_FLAG_SEEKMASK,
                         &chunk,
-                        p->recieve_memblock_callback_userdata);
+                        p->receive_memblock_callback_userdata);
                 }
 
                 /* Drop seek info for following callbacks */
-                p->read.descriptor[PA_PSTREAM_DESCRIPTOR_SEEK] =
+                p->read.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS] =
                     p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI] =
                     p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO] = 0;
             }
@@ -479,97 +789,184 @@ static int do_read(pa_pstream *p) {
 
         /* Frame complete */
         if (p->read.index >= ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_LENGTH]) + PA_PSTREAM_DESCRIPTOR_SIZE) {
+
             if (p->read.memblock) {
-                assert(!p->read.packet);
-                
+
+                /* This was a memblock frame. We can unref the memblock now */
                 pa_memblock_unref(p->read.memblock);
-                p->read.memblock = NULL;
-            } else {
-                assert(p->read.packet);
-                
-                if (p->recieve_packet_callback)
-#ifdef SCM_CREDENTIALS                    
-                    p->recieve_packet_callback(p, p->read.packet, p->creds_valid ? &p->ucred : NULL, p->recieve_packet_callback_userdata);
+
+            } else if (p->read.packet) {
+
+                if (p->receive_packet_callback)
+#ifdef HAVE_CREDS
+                    p->receive_packet_callback(p, p->read.packet, p->read_creds_valid ? &p->read_creds : NULL, p->receive_packet_callback_userdata);
 #else
-                    p->recieve_packet_callback(p, p->read.packet, NULL, p->recieve_packet_callback_userdata);
+                    p->receive_packet_callback(p, p->read.packet, NULL, p->receive_packet_callback_userdata);
 #endif
 
                 pa_packet_unref(p->read.packet);
-                p->read.packet = NULL;
+            } else {
+                pa_memblock *b;
+
+                pa_assert((ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS]) & PA_FLAG_SHMMASK) == PA_FLAG_SHMDATA);
+
+                pa_assert(p->import);
+
+                if (!(b = pa_memimport_get(p->import,
+                                          ntohl(p->read.shm_info[PA_PSTREAM_SHM_BLOCKID]),
+                                          ntohl(p->read.shm_info[PA_PSTREAM_SHM_SHMID]),
+                                          ntohl(p->read.shm_info[PA_PSTREAM_SHM_INDEX]),
+                                          ntohl(p->read.shm_info[PA_PSTREAM_SHM_LENGTH])))) {
+
+                    if (pa_log_ratelimit(PA_LOG_DEBUG))
+                        pa_log_debug("Failed to import memory block.");
+                }
+
+                if (p->receive_memblock_callback) {
+                    int64_t offset;
+                    pa_memchunk chunk;
+
+                    chunk.memblock = b;
+                    chunk.index = 0;
+                    chunk.length = b ? pa_memblock_get_length(b) : ntohl(p->read.shm_info[PA_PSTREAM_SHM_LENGTH]);
+
+                    offset = (int64_t) (
+                            (((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_HI])) << 32) |
+                            (((uint64_t) ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_OFFSET_LO]))));
+
+                    p->receive_memblock_callback(
+                            p,
+                            ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_CHANNEL]),
+                            offset,
+                            ntohl(p->read.descriptor[PA_PSTREAM_DESCRIPTOR_FLAGS]) & PA_FLAG_SEEKMASK,
+                            &chunk,
+                            p->receive_memblock_callback_userdata);
+                }
+
+                if (b)
+                    pa_memblock_unref(b);
             }
 
-            p->read.index = 0;
-#ifdef SCM_CREDENTIALS
-            p->creds_valid = 0;
-#endif
+            goto frame_done;
         }
     }
 
-    return 0;   
+    return 0;
+
+frame_done:
+    p->read.memblock = NULL;
+    p->read.packet = NULL;
+    p->read.index = 0;
+    p->read.data = NULL;
+
+#ifdef HAVE_CREDS
+    p->read_creds_valid = false;
+#endif
+
+    return 0;
+
+fail:
+    if (release_memblock)
+        pa_memblock_release(release_memblock);
+
+    return -1;
 }
 
 void pa_pstream_set_die_callback(pa_pstream *p, pa_pstream_notify_cb_t cb, void *userdata) {
-    assert(p);
-    assert(p->ref >= 1);
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
     p->die_callback = cb;
     p->die_callback_userdata = userdata;
 }
 
-
 void pa_pstream_set_drain_callback(pa_pstream *p, pa_pstream_notify_cb_t cb, void *userdata) {
-    assert(p);
-    assert(p->ref >= 1);
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
     p->drain_callback = cb;
     p->drain_callback_userdata = userdata;
 }
 
-void pa_pstream_set_recieve_packet_callback(pa_pstream *p, pa_pstream_packet_cb_t cb, void *userdata) {
-    assert(p);
-    assert(p->ref >= 1);
+void pa_pstream_set_receive_packet_callback(pa_pstream *p, pa_pstream_packet_cb_t cb, void *userdata) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    p->receive_packet_callback = cb;
+    p->receive_packet_callback_userdata = userdata;
+}
+
+void pa_pstream_set_receive_memblock_callback(pa_pstream *p, pa_pstream_memblock_cb_t cb, void *userdata) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    p->receive_memblock_callback = cb;
+    p->receive_memblock_callback_userdata = userdata;
+}
+
+void pa_pstream_set_release_callback(pa_pstream *p, pa_pstream_block_id_cb_t cb, void *userdata) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
-    p->recieve_packet_callback = cb;
-    p->recieve_packet_callback_userdata = userdata;
+    p->release_callback = cb;
+    p->release_callback_userdata = userdata;
 }
 
-void pa_pstream_set_recieve_memblock_callback(pa_pstream *p, pa_pstream_memblock_cb_t cb, void *userdata) {
-    assert(p);
-    assert(p->ref >= 1);
+void pa_pstream_set_revoke_callback(pa_pstream *p, pa_pstream_block_id_cb_t cb, void *userdata) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
-    p->recieve_memblock_callback = cb;
-    p->recieve_memblock_callback_userdata = userdata;
+    p->release_callback = cb;
+    p->release_callback_userdata = userdata;
 }
 
-int pa_pstream_is_pending(pa_pstream *p) {
-    assert(p);
+bool pa_pstream_is_pending(pa_pstream *p) {
+    bool b;
+
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
     if (p->dead)
-        return 0;
+        b = false;
+    else
+        b = p->write.current || !pa_queue_isempty(p->send_queue);
 
-    return p->write.current || !pa_queue_is_empty(p->send_queue);
+    return b;
 }
 
 void pa_pstream_unref(pa_pstream*p) {
-    assert(p);
-    assert(p->ref >= 1);
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
 
-    if (--p->ref == 0)
+    if (PA_REFCNT_DEC(p) <= 0)
         pstream_free(p);
 }
 
 pa_pstream* pa_pstream_ref(pa_pstream*p) {
-    assert(p);
-    assert(p->ref >= 1);
-    
-    p->ref++;
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    PA_REFCNT_INC(p);
     return p;
 }
 
-void pa_pstream_close(pa_pstream *p) {
-    assert(p);
+void pa_pstream_unlink(pa_pstream *p) {
+    pa_assert(p);
+
+    if (p->dead)
+        return;
+
+    p->dead = true;
 
-    p->dead = 1;
+    if (p->import) {
+        pa_memimport_free(p->import);
+        p->import = NULL;
+    }
+
+    if (p->export) {
+        pa_memexport_free(p->export);
+        p->export = NULL;
+    }
 
     if (p->io) {
         pa_iochannel_free(p->io);
@@ -583,6 +980,33 @@ void pa_pstream_close(pa_pstream *p) {
 
     p->die_callback = NULL;
     p->drain_callback = NULL;
-    p->recieve_packet_callback = NULL;
-    p->recieve_memblock_callback = NULL;
+    p->receive_packet_callback = NULL;
+    p->receive_memblock_callback = NULL;
+}
+
+void pa_pstream_enable_shm(pa_pstream *p, bool enable) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    p->use_shm = enable;
+
+    if (enable) {
+
+        if (!p->export)
+            p->export = pa_memexport_new(p->mempool, memexport_revoke_cb, p);
+
+    } else {
+
+        if (p->export) {
+            pa_memexport_free(p->export);
+            p->export = NULL;
+        }
+    }
+}
+
+bool pa_pstream_get_shm(pa_pstream *p) {
+    pa_assert(p);
+    pa_assert(PA_REFCNT_VALUE(p) > 0);
+
+    return p->use_shm;
 }