[Qemu-devel] [PULL for-2.5 00/20] vnc: buffer code improvements, bugfixes.

[Qemu-devel] [PULL for-2.5 00/20] vnc: buffer code improvements, bugfixes.

[Gerd Hoffmann]

  Hi,

Here comes the vnc buffer pull request.  Sorry, due to gsoc mentor
summit travel f*ckup (lufthansa on strike ...) I didn't manage to
prepare this in time for -rc0.  Nevertheless I'd like to see this in
2.5 if it is fine with you.  If not I'll go prepare a new pull with
the bugfixes only and defer the rest to the 2.6 devel cycle.

thanks,
  Gerd

The following changes since commit 79cf9fad341e6e7bd6b55395b71d5c5727d7f5b0:

  Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20151103' into staging (2015-11-03 14:54:40 +0000)

are available in the git repository at:


  git://git.kraxel.org/qemu tags/pull-vnc-20151116-1

for you to fetch changes up to 382e1737d3467b76e8ade34b96afaae91509002e:

  vnc: fix mismerge (2015-11-05 16:01:37 +0100)

----------------------------------------------------------------
vnc: buffer code improvements, bugfixes.

----------------------------------------------------------------
Gerd Hoffmann (15):
      buffer: add buffer_init
      buffer: add buffer_move_empty
      buffer: add buffer_move
      buffer: add buffer_shrink
      buffer: add tracing
      vnc: attach names to buffers
      vnc: kill jobs queue buffer
      vnc-jobs: move buffer reset, use new buffer move
      vnc: zap dead code
      vnc: add vnc_width+vnc_height helpers
      vnc: factor out vnc_update_server_surface
      vnc: use vnc_{width,height} in vnc_set_area_dirty
      vnc: only alloc server surface with clients connected
      vnc: fix local state init
      vnc: fix mismerge

Peter Lieven (5):
      buffer: make the Buffer capacity increase in powers of two
      vnc: recycle empty vs->output buffer
      buffer: factor out buffer_req_size
      buffer: factor out buffer_adj_size
      buffer: allow a buffer to shrink gracefully

 include/qemu/buffer.h |  43 ++++++++++++++++++++
 trace-events          |   6 +++
 ui/vnc-jobs.c         |  34 +++++++++-------
 ui/vnc.c              |  94 ++++++++++++++++++++++++++++++------------
 util/buffer.c         | 110 +++++++++++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 246 insertions(+), 41 deletions(-)

[Qemu-devel] [PULL 01/20] buffer: make the Buffer capacity increase in powers of two

[Gerd Hoffmann]

From: Peter Lieven <pl@kamp.de>

This makes sure the number of reallocs is in O(log N).

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 1446203414-4013-2-git-send-email-kraxel@redhat.com

[ rebased to util/buffer.c ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 util/buffer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/util/buffer.c b/util/buffer.c
index cedd055..7ddd693 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -20,10 +20,13 @@
 
 #include "qemu/buffer.h"
 
+#define BUFFER_MIN_INIT_SIZE 4096
+
 void buffer_reserve(Buffer *buffer, size_t len)
 {
     if ((buffer->capacity - buffer->offset) < len) {
-        buffer->capacity += (len + 1024);
+        buffer->capacity = pow2ceil(buffer->offset + len);
+        buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE);
         buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
     }
 }
-- 
1.8.3.1

[Qemu-devel] [PULL 02/20] buffer: add buffer_init

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-3-git-send-email-kraxel@redhat.com
---
 include/qemu/buffer.h | 12 ++++++++++++
 util/buffer.c         | 11 +++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/qemu/buffer.h b/include/qemu/buffer.h
index b380cec..0710e16 100644
--- a/include/qemu/buffer.h
+++ b/include/qemu/buffer.h
@@ -34,12 +34,24 @@ typedef struct Buffer Buffer;
  */
 
 struct Buffer {
+    char *name;
     size_t capacity;
     size_t offset;
     uint8_t *buffer;
 };
 
 /**
+ * buffer_init:
+ * @buffer: the buffer object
+ * @name: buffer name
+ *
+ * Optionally attach a name to the buffer, to make it easier
+ * to identify in debug traces.
+ */
+void buffer_init(Buffer *buffer, const char *name, ...)
+        GCC_FMT_ATTR(2, 3);
+
+/**
  * buffer_reserve:
  * @buffer: the buffer object
  * @len: the minimum required free space
diff --git a/util/buffer.c b/util/buffer.c
index 7ddd693..12bf2d7 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -22,6 +22,15 @@
 
 #define BUFFER_MIN_INIT_SIZE 4096
 
+void buffer_init(Buffer *buffer, const char *name, ...)
+{
+    va_list ap;
+
+    va_start(ap, name);
+    buffer->name = g_strdup_vprintf(name, ap);
+    va_end(ap);
+}
+
 void buffer_reserve(Buffer *buffer, size_t len)
 {
     if ((buffer->capacity - buffer->offset) < len) {
@@ -49,9 +58,11 @@ void buffer_reset(Buffer *buffer)
 void buffer_free(Buffer *buffer)
 {
     g_free(buffer->buffer);
+    g_free(buffer->name);
     buffer->offset = 0;
     buffer->capacity = 0;
     buffer->buffer = NULL;
+    buffer->name = NULL;
 }
 
 void buffer_append(Buffer *buffer, const void *data, size_t len)
-- 
1.8.3.1

[Qemu-devel] [PULL 03/20] buffer: add buffer_move_empty

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-4-git-send-email-kraxel@redhat.com
---
 include/qemu/buffer.h | 10 ++++++++++
 util/buffer.c         | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/include/qemu/buffer.h b/include/qemu/buffer.h
index 0710e16..f53ee9e 100644
--- a/include/qemu/buffer.h
+++ b/include/qemu/buffer.h
@@ -127,4 +127,14 @@ uint8_t *buffer_end(Buffer *buffer);
  */
 gboolean buffer_empty(Buffer *buffer);
 
+/**
+ * buffer_move_empty:
+ * @to: destination buffer object
+ * @from: source buffer object
+ *
+ * Moves buffer, without copying data.  'to' buffer must be empty.
+ * 'from' buffer is empty and zero-sized on return.
+ */
+void buffer_move_empty(Buffer *to, Buffer *from);
+
 #endif /* QEMU_BUFFER_H__ */
diff --git a/util/buffer.c b/util/buffer.c
index 12bf2d7..c7a39ec 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -77,3 +77,17 @@ void buffer_advance(Buffer *buffer, size_t len)
             (buffer->offset - len));
     buffer->offset -= len;
 }
+
+void buffer_move_empty(Buffer *to, Buffer *from)
+{
+    assert(to->offset == 0);
+
+    g_free(to->buffer);
+    to->offset = from->offset;
+    to->capacity = from->capacity;
+    to->buffer = from->buffer;
+
+    from->offset = 0;
+    from->capacity = 0;
+    from->buffer = NULL;
+}
-- 
1.8.3.1

[Qemu-devel] [PULL 04/20] buffer: add buffer_move

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-5-git-send-email-kraxel@redhat.com
---
 include/qemu/buffer.h | 10 ++++++++++
 util/buffer.c         | 16 ++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/qemu/buffer.h b/include/qemu/buffer.h
index f53ee9e..1358df1 100644
--- a/include/qemu/buffer.h
+++ b/include/qemu/buffer.h
@@ -137,4 +137,14 @@ gboolean buffer_empty(Buffer *buffer);
  */
 void buffer_move_empty(Buffer *to, Buffer *from);
 
+/**
+ * buffer_move:
+ * @to: destination buffer object
+ * @from: source buffer object
+ *
+ * Moves buffer, copying data (unless 'to' buffer happens to be empty).
+ * 'from' buffer is empty and zero-sized on return.
+ */
+void buffer_move(Buffer *to, Buffer *from);
+
 #endif /* QEMU_BUFFER_H__ */
diff --git a/util/buffer.c b/util/buffer.c
index c7a39ec..e8f798e 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -91,3 +91,19 @@ void buffer_move_empty(Buffer *to, Buffer *from)
     from->capacity = 0;
     from->buffer = NULL;
 }
+
+void buffer_move(Buffer *to, Buffer *from)
+{
+    if (to->offset == 0) {
+        buffer_move_empty(to, from);
+        return;
+    }
+
+    buffer_reserve(to, from->offset);
+    buffer_append(to, from->buffer, from->offset);
+
+    g_free(from->buffer);
+    from->offset = 0;
+    from->capacity = 0;
+    from->buffer = NULL;
+}
-- 
1.8.3.1

[Qemu-devel] [PULL 05/20] buffer: add buffer_shrink

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-6-git-send-email-kraxel@redhat.com
---
 include/qemu/buffer.h | 10 ++++++++++
 util/buffer.c         | 20 +++++++++++++++++++-
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/include/qemu/buffer.h b/include/qemu/buffer.h
index 1358df1..0a69b3a 100644
--- a/include/qemu/buffer.h
+++ b/include/qemu/buffer.h
@@ -52,6 +52,16 @@ void buffer_init(Buffer *buffer, const char *name, ...)
         GCC_FMT_ATTR(2, 3);
 
 /**
+ * buffer_shrink:
+ * @buffer: the buffer object
+ *
+ * Try to shrink the buffer.  Checks current buffer capacity and size
+ * and reduces capacity in case only a fraction of the buffer is
+ * actually used.
+ */
+void buffer_shrink(Buffer *buffer);
+
+/**
  * buffer_reserve:
  * @buffer: the buffer object
  * @len: the minimum required free space
diff --git a/util/buffer.c b/util/buffer.c
index e8f798e..234e33d 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -20,7 +20,8 @@
 
 #include "qemu/buffer.h"
 
-#define BUFFER_MIN_INIT_SIZE 4096
+#define BUFFER_MIN_INIT_SIZE     4096
+#define BUFFER_MIN_SHRINK_SIZE  65536
 
 void buffer_init(Buffer *buffer, const char *name, ...)
 {
@@ -31,6 +32,23 @@ void buffer_init(Buffer *buffer, const char *name, ...)
     va_end(ap);
 }
 
+void buffer_shrink(Buffer *buffer)
+{
+    /*
+     * Only shrink in case the used size is *much* smaller than the
+     * capacity, to avoid bumping up & down the buffers all the time.
+     * realloc() isn't exactly cheap ...
+     */
+    if (buffer->offset < (buffer->capacity >> 3) &&
+        buffer->capacity > BUFFER_MIN_SHRINK_SIZE) {
+        return;
+    }
+
+    buffer->capacity = pow2ceil(buffer->offset);
+    buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_SHRINK_SIZE);
+    buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
+}
+
 void buffer_reserve(Buffer *buffer, size_t len)
 {
     if ((buffer->capacity - buffer->offset) < len) {
-- 
1.8.3.1

[Qemu-devel] [PULL 06/20] buffer: add tracing

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-7-git-send-email-kraxel@redhat.com
---
 trace-events  |  6 ++++++
 util/buffer.c | 18 ++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/trace-events b/trace-events
index 72136b9..e67ad81 100644
--- a/trace-events
+++ b/trace-events
@@ -1387,6 +1387,12 @@ ppc_tb_adjust(uint64_t offs1, uint64_t offs2, int64_t diff, int64_t seconds) "ad
 prep_io_800_writeb(uint32_t addr, uint32_t val) "0x%08" PRIx32 " => 0x%02" PRIx32
 prep_io_800_readb(uint32_t addr, uint32_t retval) "0x%08" PRIx32 " <= 0x%02" PRIx32
 
+# io/buffer.c
+buffer_resize(const char *buf, size_t olen, size_t len) "%s: old %zd, new %zd"
+buffer_move_empty(const char *buf, size_t len, const char *from) "%s: %zd bytes from %s"
+buffer_move(const char *buf, size_t len, const char *from) "%s: %zd bytes from %s"
+buffer_free(const char *buf, size_t len) "%s: capacity %zd"
+
 # util/hbitmap.c
 hbitmap_iter_skip_words(const void *hb, void *hbi, uint64_t pos, unsigned long cur) "hb %p hbi %p pos %"PRId64" cur 0x%lx"
 hbitmap_reset(void *hb, uint64_t start, uint64_t count, uint64_t sbit, uint64_t ebit) "hb %p items %"PRIu64",%"PRIu64" bits %"PRIu64"..%"PRIu64
diff --git a/util/buffer.c b/util/buffer.c
index 234e33d..ae2907e 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -19,6 +19,7 @@
  */
 
 #include "qemu/buffer.h"
+#include "trace.h"
 
 #define BUFFER_MIN_INIT_SIZE     4096
 #define BUFFER_MIN_SHRINK_SIZE  65536
@@ -34,6 +35,8 @@ void buffer_init(Buffer *buffer, const char *name, ...)
 
 void buffer_shrink(Buffer *buffer)
 {
+    size_t old;
+
     /*
      * Only shrink in case the used size is *much* smaller than the
      * capacity, to avoid bumping up & down the buffers all the time.
@@ -44,17 +47,25 @@ void buffer_shrink(Buffer *buffer)
         return;
     }
 
+    old = buffer->capacity;
     buffer->capacity = pow2ceil(buffer->offset);
     buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_SHRINK_SIZE);
     buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
+    trace_buffer_resize(buffer->name ?: "unnamed",
+                        old, buffer->capacity);
 }
 
 void buffer_reserve(Buffer *buffer, size_t len)
 {
+    size_t old;
+
     if ((buffer->capacity - buffer->offset) < len) {
+        old = buffer->capacity;
         buffer->capacity = pow2ceil(buffer->offset + len);
         buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE);
         buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
+        trace_buffer_resize(buffer->name ?: "unnamed",
+                            old, buffer->capacity);
     }
 }
 
@@ -75,6 +86,7 @@ void buffer_reset(Buffer *buffer)
 
 void buffer_free(Buffer *buffer)
 {
+    trace_buffer_free(buffer->name ?: "unnamed", buffer->capacity);
     g_free(buffer->buffer);
     g_free(buffer->name);
     buffer->offset = 0;
@@ -98,6 +110,9 @@ void buffer_advance(Buffer *buffer, size_t len)
 
 void buffer_move_empty(Buffer *to, Buffer *from)
 {
+    trace_buffer_move_empty(to->name ?: "unnamed",
+                            from->offset,
+                            from->name ?: "unnamed");
     assert(to->offset == 0);
 
     g_free(to->buffer);
@@ -117,6 +132,9 @@ void buffer_move(Buffer *to, Buffer *from)
         return;
     }
 
+    trace_buffer_move(to->name ?: "unnamed",
+                      from->offset,
+                      from->name ?: "unnamed");
     buffer_reserve(to, from->offset);
     buffer_append(to, from->buffer, from->offset);
 
-- 
1.8.3.1

[Qemu-devel] [PULL 07/20] vnc: attach names to buffers

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-8-git-send-email-kraxel@redhat.com
---
 ui/vnc-jobs.c |  3 +++
 ui/vnc.c      | 20 ++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 22c9abc..2e6c15f 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -218,6 +218,8 @@ static int vnc_worker_thread_loop(VncJobQueue *queue)
     int n_rectangles;
     int saved_offset;
 
+    buffer_init(&vs.output, "vnc-worker-output");
+
     vnc_lock_queue(queue);
     while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
         qemu_cond_wait(&queue->cond, &queue->mutex);
@@ -302,6 +304,7 @@ static VncJobQueue *vnc_queue_init(void)
 
     qemu_cond_init(&queue->cond);
     qemu_mutex_init(&queue->mutex);
+    buffer_init(&queue->buffer, "vnc-job-queue");
     QTAILQ_INIT(&queue->jobs);
     return queue;
 }
diff --git a/ui/vnc.c b/ui/vnc.c
index a47f2b3..cdafd09d 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -2988,6 +2988,26 @@ static void vnc_connect(VncDisplay *vd, int csock,
     vs->csock = csock;
     vs->vd = vd;
 
+    buffer_init(&vs->input,          "vnc-input/%d", csock);
+    buffer_init(&vs->output,         "vnc-output/%d", csock);
+    buffer_init(&vs->ws_input,       "vnc-ws_input/%d", csock);
+    buffer_init(&vs->ws_output,      "vnc-ws_output/%d", csock);
+    buffer_init(&vs->jobs_buffer,    "vnc-jobs_buffer/%d", csock);
+
+    buffer_init(&vs->tight.tight,    "vnc-tight/%d", csock);
+    buffer_init(&vs->tight.zlib,     "vnc-tight-zlib/%d", csock);
+    buffer_init(&vs->tight.gradient, "vnc-tight-gradient/%d", csock);
+#ifdef CONFIG_VNC_JPEG
+    buffer_init(&vs->tight.jpeg,     "vnc-tight-jpeg/%d", csock);
+#endif
+#ifdef CONFIG_VNC_PNG
+    buffer_init(&vs->tight.png,      "vnc-tight-png/%d", csock);
+#endif
+    buffer_init(&vs->zlib.zlib,      "vnc-zlib/%d", csock);
+    buffer_init(&vs->zrle.zrle,      "vnc-zrle/%d", csock);
+    buffer_init(&vs->zrle.fb,        "vnc-zrle-fb/%d", csock);
+    buffer_init(&vs->zrle.zlib,      "vnc-zrle-zlib/%d", csock);
+
     if (skipauth) {
 	vs->auth = VNC_AUTH_NONE;
 	vs->subauth = VNC_AUTH_INVALID;
-- 
1.8.3.1

[Qemu-devel] [PULL 08/20] vnc: kill jobs queue buffer

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-9-git-send-email-kraxel@redhat.com
---
 ui/vnc-jobs.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 2e6c15f..329d13e 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -54,7 +54,6 @@ struct VncJobQueue {
     QemuCond cond;
     QemuMutex mutex;
     QemuThread thread;
-    Buffer buffer;
     bool exit;
     QTAILQ_HEAD(, VncJob) jobs;
 };
@@ -193,7 +192,6 @@ static void vnc_async_encoding_start(VncState *orig, VncState *local)
     local->zlib = orig->zlib;
     local->hextile = orig->hextile;
     local->zrle = orig->zrle;
-    local->output =  queue->buffer;
     local->csock = -1; /* Don't do any network work on this thread */
 
     buffer_reset(&local->output);
@@ -206,8 +204,6 @@ static void vnc_async_encoding_end(VncState *orig, VncState *local)
     orig->hextile = local->hextile;
     orig->zrle = local->zrle;
     orig->lossy_rect = local->lossy_rect;
-
-    queue->buffer = local->output;
 }
 
 static int vnc_worker_thread_loop(VncJobQueue *queue)
@@ -304,7 +300,6 @@ static VncJobQueue *vnc_queue_init(void)
 
     qemu_cond_init(&queue->cond);
     qemu_mutex_init(&queue->mutex);
-    buffer_init(&queue->buffer, "vnc-job-queue");
     QTAILQ_INIT(&queue->jobs);
     return queue;
 }
@@ -313,7 +308,6 @@ static void vnc_queue_clear(VncJobQueue *q)
 {
     qemu_cond_destroy(&queue->cond);
     qemu_mutex_destroy(&queue->mutex);
-    buffer_free(&queue->buffer);
     g_free(q);
     queue = NULL; /* Unset global queue */
 }
-- 
1.8.3.1

[Qemu-devel] [PULL 09/20] vnc-jobs: move buffer reset, use new buffer move

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-10-git-send-email-kraxel@redhat.com
---
 ui/vnc-jobs.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 329d13e..fd9ed39 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -29,6 +29,7 @@
 #include "vnc.h"
 #include "vnc-jobs.h"
 #include "qemu/sockets.h"
+#include "qemu/main-loop.h"
 #include "block/aio.h"
 
 /*
@@ -165,8 +166,11 @@ void vnc_jobs_consume_buffer(VncState *vs)
 
     vnc_lock_output(vs);
     if (vs->jobs_buffer.offset) {
-        vnc_write(vs, vs->jobs_buffer.buffer, vs->jobs_buffer.offset);
-        buffer_reset(&vs->jobs_buffer);
+        if (vs->csock != -1 && buffer_empty(&vs->output)) {
+            qemu_set_fd_handler(vs->csock, vnc_client_read,
+                                vnc_client_write, vs);
+        }
+        buffer_move(&vs->output, &vs->jobs_buffer);
     }
     flush = vs->csock != -1 && vs->abort != true;
     vnc_unlock_output(vs);
@@ -193,8 +197,6 @@ static void vnc_async_encoding_start(VncState *orig, VncState *local)
     local->hextile = orig->hextile;
     local->zrle = orig->zrle;
     local->csock = -1; /* Don't do any network work on this thread */
-
-    buffer_reset(&local->output);
 }
 
 static void vnc_async_encoding_end(VncState *orig, VncState *local)
@@ -272,14 +274,13 @@ static int vnc_worker_thread_loop(VncJobQueue *queue)
 
     vnc_lock_output(job->vs);
     if (job->vs->csock != -1) {
-        buffer_reserve(&job->vs->jobs_buffer, vs.output.offset);
-        buffer_append(&job->vs->jobs_buffer, vs.output.buffer,
-                      vs.output.offset);
+        buffer_move(&job->vs->jobs_buffer, &vs.output);
         /* Copy persistent encoding data */
         vnc_async_encoding_end(job->vs, &vs);
 
 	qemu_bh_schedule(job->vs->bh);
     }  else {
+        buffer_reset(&vs.output);
         /* Copy persistent encoding data */
         vnc_async_encoding_end(job->vs, &vs);
     }
-- 
1.8.3.1

[Qemu-devel] [PULL 10/20] vnc: zap dead code

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-11-git-send-email-kraxel@redhat.com
---
 ui/vnc.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index cdafd09d..49de39d 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -732,10 +732,6 @@ static void vnc_dpy_switch(DisplayChangeListener *dcl,
                                           width, height, NULL, 0);
 
     /* guest surface */
-#if 0 /* FIXME */
-    if (ds_get_bytes_per_pixel(ds) != vd->guest.ds->pf.bytes_per_pixel)
-        console_color_init(ds);
-#endif
     qemu_pixman_image_unref(vd->guest.fb);
     vd->guest.fb = pixman_image_ref(surface->image);
     vd->guest.format = surface->format;
-- 
1.8.3.1

[Qemu-devel] [PULL 11/20] vnc: add vnc_width+vnc_height helpers

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-12-git-send-email-kraxel@redhat.com
---
 ui/vnc.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 49de39d..9ffad16 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -615,6 +615,17 @@ static void framebuffer_update_request(VncState *vs, int incremental,
 static void vnc_refresh(DisplayChangeListener *dcl);
 static int vnc_refresh_server_surface(VncDisplay *vd);
 
+static int vnc_width(VncDisplay *vd)
+{
+    return MIN(VNC_MAX_WIDTH, ROUND_UP(surface_width(vd->ds),
+                                       VNC_DIRTY_PIXELS_PER_BIT));
+}
+
+static int vnc_height(VncDisplay *vd)
+{
+    return MIN(VNC_MAX_HEIGHT, surface_height(vd->ds));
+}
+
 static void vnc_set_area_dirty(DECLARE_BITMAP(dirty[VNC_MAX_HEIGHT],
                                VNC_MAX_WIDTH / VNC_DIRTY_PIXELS_PER_BIT),
                                int width, int height,
@@ -725,9 +736,8 @@ static void vnc_dpy_switch(DisplayChangeListener *dcl,
     /* server surface */
     qemu_pixman_image_unref(vd->server);
     vd->ds = surface;
-    width = MIN(VNC_MAX_WIDTH, ROUND_UP(surface_width(vd->ds),
-                                        VNC_DIRTY_PIXELS_PER_BIT));
-    height = MIN(VNC_MAX_HEIGHT, surface_height(vd->ds));
+    width = vnc_width(vd);
+    height = vnc_height(vd);
     vd->server = pixman_image_create_bits(VNC_SERVER_FB_FORMAT,
                                           width, height, NULL, 0);
 
-- 
1.8.3.1

[Qemu-devel] [PULL 12/20] vnc: factor out vnc_update_server_surface

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-13-git-send-email-kraxel@redhat.com
---
 ui/vnc.c | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 9ffad16..58a66b5 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -724,6 +724,17 @@ void *vnc_server_fb_ptr(VncDisplay *vd, int x, int y)
     return ptr;
 }
 
+static void vnc_update_server_surface(VncDisplay *vd)
+{
+    qemu_pixman_image_unref(vd->server);
+    vd->server = NULL;
+
+    vd->server = pixman_image_create_bits(VNC_SERVER_FB_FORMAT,
+                                          vnc_width(vd),
+                                          vnc_height(vd),
+                                          NULL, 0);
+}
+
 static void vnc_dpy_switch(DisplayChangeListener *dcl,
                            DisplaySurface *surface)
 {
@@ -732,19 +743,17 @@ static void vnc_dpy_switch(DisplayChangeListener *dcl,
     int width, height;
 
     vnc_abort_display_jobs(vd);
-
-    /* server surface */
-    qemu_pixman_image_unref(vd->server);
     vd->ds = surface;
-    width = vnc_width(vd);
-    height = vnc_height(vd);
-    vd->server = pixman_image_create_bits(VNC_SERVER_FB_FORMAT,
-                                          width, height, NULL, 0);
+
+    /* server surface */
+    vnc_update_server_surface(vd);
 
     /* guest surface */
     qemu_pixman_image_unref(vd->guest.fb);
     vd->guest.fb = pixman_image_ref(surface->image);
     vd->guest.format = surface->format;
+    width = vnc_width(vd);
+    height = vnc_height(vd);
     memset(vd->guest.dirty, 0x00, sizeof(vd->guest.dirty));
     vnc_set_area_dirty(vd->guest.dirty, width, height, 0, 0,
                        width, height);
-- 
1.8.3.1

[Qemu-devel] [PULL 13/20] vnc: use vnc_{width, height} in vnc_set_area_dirty

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-14-git-send-email-kraxel@redhat.com
---
 ui/vnc.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index 58a66b5..eb1fcb3 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -628,8 +628,12 @@ static int vnc_height(VncDisplay *vd)
 
 static void vnc_set_area_dirty(DECLARE_BITMAP(dirty[VNC_MAX_HEIGHT],
                                VNC_MAX_WIDTH / VNC_DIRTY_PIXELS_PER_BIT),
-                               int width, int height,
-                               int x, int y, int w, int h) {
+                               VncDisplay *vd,
+                               int x, int y, int w, int h)
+{
+    int width = vnc_width(vd);
+    int height = vnc_height(vd);
+
     /* this is needed this to ensure we updated all affected
      * blocks if x % VNC_DIRTY_PIXELS_PER_BIT != 0 */
     w += (x % VNC_DIRTY_PIXELS_PER_BIT);
@@ -651,10 +655,8 @@ static void vnc_dpy_update(DisplayChangeListener *dcl,
 {
     VncDisplay *vd = container_of(dcl, VncDisplay, dcl);
     struct VncSurface *s = &vd->guest;
-    int width = pixman_image_get_width(vd->server);
-    int height = pixman_image_get_height(vd->server);
 
-    vnc_set_area_dirty(s->dirty, width, height, x, y, w, h);
+    vnc_set_area_dirty(s->dirty, vd, x, y, w, h);
 }
 
 void vnc_framebuffer_update(VncState *vs, int x, int y, int w, int h,
@@ -755,7 +757,7 @@ static void vnc_dpy_switch(DisplayChangeListener *dcl,
     width = vnc_width(vd);
     height = vnc_height(vd);
     memset(vd->guest.dirty, 0x00, sizeof(vd->guest.dirty));
-    vnc_set_area_dirty(vd->guest.dirty, width, height, 0, 0,
+    vnc_set_area_dirty(vd->guest.dirty, vd, 0, 0,
                        width, height);
 
     QTAILQ_FOREACH(vs, &vd->clients, next) {
@@ -765,7 +767,7 @@ static void vnc_dpy_switch(DisplayChangeListener *dcl,
             vnc_cursor_define(vs);
         }
         memset(vs->dirty, 0x00, sizeof(vs->dirty));
-        vnc_set_area_dirty(vs->dirty, width, height, 0, 0,
+        vnc_set_area_dirty(vs->dirty, vd, 0, 0,
                            width, height);
     }
 }
@@ -2021,9 +2023,6 @@ static void ext_key_event(VncState *vs, int down,
 static void framebuffer_update_request(VncState *vs, int incremental,
                                        int x, int y, int w, int h)
 {
-    int width = pixman_image_get_width(vs->vd->server);
-    int height = pixman_image_get_height(vs->vd->server);
-
     vs->need_update = 1;
 
     if (incremental) {
@@ -2031,7 +2030,7 @@ static void framebuffer_update_request(VncState *vs, int incremental,
     }
 
     vs->force_update = 1;
-    vnc_set_area_dirty(vs->dirty, width, height, x, y, w, h);
+    vnc_set_area_dirty(vs->dirty, vs->vd, x, y, w, h);
 }
 
 static void send_ext_key_event_ack(VncState *vs)
-- 
1.8.3.1

[Qemu-devel] [PULL 14/20] vnc: only alloc server surface with clients connected

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-15-git-send-email-kraxel@redhat.com
---
 ui/vnc.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/ui/vnc.c b/ui/vnc.c
index eb1fcb3..a8cce5a 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -731,6 +731,10 @@ static void vnc_update_server_surface(VncDisplay *vd)
     qemu_pixman_image_unref(vd->server);
     vd->server = NULL;
 
+    if (QTAILQ_EMPTY(&vd->clients)) {
+        return;
+    }
+
     vd->server = pixman_image_create_bits(VNC_SERVER_FB_FORMAT,
                                           vnc_width(vd),
                                           vnc_height(vd),
@@ -1241,6 +1245,10 @@ void vnc_disconnect_finish(VncState *vs)
     if (vs->initialized) {
         QTAILQ_REMOVE(&vs->vd->clients, vs, next);
         qemu_remove_mouse_mode_change_notifier(&vs->mouse_mode_notifier);
+        if (QTAILQ_EMPTY(&vs->vd->clients)) {
+            /* last client gone */
+            vnc_update_server_surface(vs->vd);
+        }
     }
 
     if (vs->vd->lock_key_sync)
@@ -3079,6 +3087,7 @@ void vnc_init_state(VncState *vs)
 {
     vs->initialized = true;
     VncDisplay *vd = vs->vd;
+    bool first_client = QTAILQ_EMPTY(&vd->clients);
 
     vs->last_x = -1;
     vs->last_y = -1;
@@ -3092,6 +3101,9 @@ void vnc_init_state(VncState *vs)
     vs->bh = qemu_bh_new(vnc_jobs_bh, vs);
 
     QTAILQ_INSERT_TAIL(&vd->clients, vs, next);
+    if (first_client) {
+        vnc_update_server_surface(vd);
+    }
 
     graphic_hw_update(vd->dcl.con);
 
-- 
1.8.3.1

[Qemu-devel] [PULL 15/20] vnc: fix local state init

[Gerd Hoffmann]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-16-git-send-email-kraxel@redhat.com
---
 ui/vnc-jobs.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index fd9ed39..12389cc 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -185,6 +185,9 @@ void vnc_jobs_consume_buffer(VncState *vs)
  */
 static void vnc_async_encoding_start(VncState *orig, VncState *local)
 {
+    buffer_init(&local->output, "vnc-worker-output");
+    local->csock = -1; /* Don't do any network work on this thread */
+
     local->vnc_encoding = orig->vnc_encoding;
     local->features = orig->features;
     local->vd = orig->vd;
@@ -196,7 +199,6 @@ static void vnc_async_encoding_start(VncState *orig, VncState *local)
     local->zlib = orig->zlib;
     local->hextile = orig->hextile;
     local->zrle = orig->zrle;
-    local->csock = -1; /* Don't do any network work on this thread */
 }
 
 static void vnc_async_encoding_end(VncState *orig, VncState *local)
@@ -212,12 +214,10 @@ static int vnc_worker_thread_loop(VncJobQueue *queue)
 {
     VncJob *job;
     VncRectEntry *entry, *tmp;
-    VncState vs;
+    VncState vs = {};
     int n_rectangles;
     int saved_offset;
 
-    buffer_init(&vs.output, "vnc-worker-output");
-
     vnc_lock_queue(queue);
     while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
         qemu_cond_wait(&queue->cond, &queue->mutex);
-- 
1.8.3.1

[Qemu-devel] [PULL 16/20] vnc: recycle empty vs->output buffer

[Gerd Hoffmann]

From: Peter Lieven <pl@kamp.de>

If the vs->output buffer is empty it will be dropped
by the next qio_buffer_move_empty in vnc_jobs_consume_buffer
anyway. So reuse the allocated buffer from this buffer
in the worker thread where we otherwise would start with
an empty (unallocated buffer).

Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-17-git-send-email-kraxel@redhat.com

[ added a comment describing the non-obvious optimization ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 ui/vnc-jobs.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ui/vnc-jobs.c b/ui/vnc-jobs.c
index 12389cc..08f0163 100644
--- a/ui/vnc-jobs.c
+++ b/ui/vnc-jobs.c
@@ -235,6 +235,14 @@ static int vnc_worker_thread_loop(VncJobQueue *queue)
         vnc_unlock_output(job->vs);
         goto disconnected;
     }
+    if (buffer_empty(&job->vs->output)) {
+        /*
+         * Looks like a NOP as it obviously moves no data.  But it
+         * moves the empty buffer, so we don't have to malloc a new
+         * one for vs.output
+         */
+        buffer_move_empty(&vs.output, &job->vs->output);
+    }
     vnc_unlock_output(job->vs);
 
     /* Make a local copy of vs and switch output buffers */
-- 
1.8.3.1

[Qemu-devel] [PULL 17/20] buffer: factor out buffer_req_size

[Gerd Hoffmann]

From: Peter Lieven <pl@kamp.de>

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-18-git-send-email-kraxel@redhat.com
---
 util/buffer.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/util/buffer.c b/util/buffer.c
index ae2907e..31f1d9f 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -24,6 +24,13 @@
 #define BUFFER_MIN_INIT_SIZE     4096
 #define BUFFER_MIN_SHRINK_SIZE  65536
 
+static size_t buffer_req_size(Buffer *buffer, size_t len)
+{
+    return MAX(BUFFER_MIN_INIT_SIZE,
+               pow2ceil(buffer->offset + len));
+}
+
+
 void buffer_init(Buffer *buffer, const char *name, ...)
 {
     va_list ap;
@@ -61,8 +68,7 @@ void buffer_reserve(Buffer *buffer, size_t len)
 
     if ((buffer->capacity - buffer->offset) < len) {
         old = buffer->capacity;
-        buffer->capacity = pow2ceil(buffer->offset + len);
-        buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_INIT_SIZE);
+        buffer->capacity = buffer_req_size(buffer, len);
         buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
         trace_buffer_resize(buffer->name ?: "unnamed",
                             old, buffer->capacity);
-- 
1.8.3.1

[Qemu-devel] [PULL 18/20] buffer: factor out buffer_adj_size

[Gerd Hoffmann]

From: Peter Lieven <pl@kamp.de>

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-19-git-send-email-kraxel@redhat.com
---
 util/buffer.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/util/buffer.c b/util/buffer.c
index 31f1d9f..fe5a44e 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -30,6 +30,14 @@ static size_t buffer_req_size(Buffer *buffer, size_t len)
                pow2ceil(buffer->offset + len));
 }
 
+static void buffer_adj_size(Buffer *buffer, size_t len)
+{
+    size_t old = buffer->capacity;
+    buffer->capacity = buffer_req_size(buffer, len);
+    buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
+    trace_buffer_resize(buffer->name ?: "unnamed",
+                        old, buffer->capacity);
+}
 
 void buffer_init(Buffer *buffer, const char *name, ...)
 {
@@ -42,8 +50,6 @@ void buffer_init(Buffer *buffer, const char *name, ...)
 
 void buffer_shrink(Buffer *buffer)
 {
-    size_t old;
-
     /*
      * Only shrink in case the used size is *much* smaller than the
      * capacity, to avoid bumping up & down the buffers all the time.
@@ -54,24 +60,13 @@ void buffer_shrink(Buffer *buffer)
         return;
     }
 
-    old = buffer->capacity;
-    buffer->capacity = pow2ceil(buffer->offset);
-    buffer->capacity = MAX(buffer->capacity, BUFFER_MIN_SHRINK_SIZE);
-    buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
-    trace_buffer_resize(buffer->name ?: "unnamed",
-                        old, buffer->capacity);
+    buffer_adj_size(buffer, 0);
 }
 
 void buffer_reserve(Buffer *buffer, size_t len)
 {
-    size_t old;
-
     if ((buffer->capacity - buffer->offset) < len) {
-        old = buffer->capacity;
-        buffer->capacity = buffer_req_size(buffer, len);
-        buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
-        trace_buffer_resize(buffer->name ?: "unnamed",
-                            old, buffer->capacity);
+        buffer_adj_size(buffer, len);
     }
 }
 
-- 
1.8.3.1

[Qemu-devel] [PULL 19/20] buffer: allow a buffer to shrink gracefully

[Gerd Hoffmann]

From: Peter Lieven <pl@kamp.de>

the idea behind this patch is to allow the buffer to shrink, but
make this a seldom operation. The buffers average size is measured
exponentionally smoothed with am alpha of 1/128.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Message-id: 1446203414-4013-20-git-send-email-kraxel@redhat.com
---
 include/qemu/buffer.h |  1 +
 util/buffer.c         | 41 +++++++++++++++++++++++++++++++++--------
 2 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/include/qemu/buffer.h b/include/qemu/buffer.h
index 0a69b3a..dead9b7 100644
--- a/include/qemu/buffer.h
+++ b/include/qemu/buffer.h
@@ -37,6 +37,7 @@ struct Buffer {
     char *name;
     size_t capacity;
     size_t offset;
+    uint64_t avg_size;
     uint8_t *buffer;
 };
 
diff --git a/util/buffer.c b/util/buffer.c
index fe5a44e..8b27c08 100644
--- a/util/buffer.c
+++ b/util/buffer.c
@@ -24,6 +24,11 @@
 #define BUFFER_MIN_INIT_SIZE     4096
 #define BUFFER_MIN_SHRINK_SIZE  65536
 
+/* define the factor alpha for the expentional smoothing
+ * that is used in the average size calculation. a shift
+ * of 7 results in an alpha of 1/2^7. */
+#define BUFFER_AVG_SIZE_SHIFT       7
+
 static size_t buffer_req_size(Buffer *buffer, size_t len)
 {
     return MAX(BUFFER_MIN_INIT_SIZE,
@@ -37,6 +42,11 @@ static void buffer_adj_size(Buffer *buffer, size_t len)
     buffer->buffer = g_realloc(buffer->buffer, buffer->capacity);
     trace_buffer_resize(buffer->name ?: "unnamed",
                         old, buffer->capacity);
+
+    /* make it even harder for the buffer to shrink, reset average size
+     * to currenty capacity if it is larger than the average. */
+    buffer->avg_size = MAX(buffer->avg_size,
+                           buffer->capacity << BUFFER_AVG_SIZE_SHIFT);
 }
 
 void buffer_init(Buffer *buffer, const char *name, ...)
@@ -48,16 +58,29 @@ void buffer_init(Buffer *buffer, const char *name, ...)
     va_end(ap);
 }
 
+static uint64_t buffer_get_avg_size(Buffer *buffer)
+{
+    return buffer->avg_size >> BUFFER_AVG_SIZE_SHIFT;
+}
+
 void buffer_shrink(Buffer *buffer)
 {
-    /*
-     * Only shrink in case the used size is *much* smaller than the
-     * capacity, to avoid bumping up & down the buffers all the time.
-     * realloc() isn't exactly cheap ...
-     */
-    if (buffer->offset < (buffer->capacity >> 3) &&
-        buffer->capacity > BUFFER_MIN_SHRINK_SIZE) {
-        return;
+    size_t new;
+
+    /* Calculate the average size of the buffer as
+     * avg_size = avg_size * ( 1 - a ) + required_size * a
+     * where a is 1 / 2 ^ BUFFER_AVG_SIZE_SHIFT. */
+    buffer->avg_size *= (1 << BUFFER_AVG_SIZE_SHIFT) - 1;
+    buffer->avg_size >>= BUFFER_AVG_SIZE_SHIFT;
+    buffer->avg_size += buffer_req_size(buffer, 0);
+
+    /* And then only shrink if the average size of the buffer is much
+     * too big, to avoid bumping up & down the buffers all the time.
+     * realloc() isn't exactly cheap ...  */
+    new = buffer_req_size(buffer, buffer_get_avg_size(buffer));
+    if (new < buffer->capacity >> 3 &&
+        new >= BUFFER_MIN_SHRINK_SIZE) {
+        buffer_adj_size(buffer, buffer_get_avg_size(buffer));
     }
 
     buffer_adj_size(buffer, 0);
@@ -83,6 +106,7 @@ uint8_t *buffer_end(Buffer *buffer)
 void buffer_reset(Buffer *buffer)
 {
     buffer->offset = 0;
+    buffer_shrink(buffer);
 }
 
 void buffer_free(Buffer *buffer)
@@ -107,6 +131,7 @@ void buffer_advance(Buffer *buffer, size_t len)
     memmove(buffer->buffer, buffer->buffer + len,
             (buffer->offset - len));
     buffer->offset -= len;
+    buffer_shrink(buffer);
 }
 
 void buffer_move_empty(Buffer *to, Buffer *from)
-- 
1.8.3.1

[Qemu-devel] [PULL 20/20] vnc: fix mismerge

[Gerd Hoffmann]

Commit "4d77b1f vnc: fix bug: vnc server can't start when 'to' is
specified" was rebased incorrectly, fix it.

Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Yang Hongyang <hongyang.yang@easystack.cn>
Message-id: 1446714738-22400-1-git-send-email-kraxel@redhat.com
---
 ui/vnc.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/ui/vnc.c b/ui/vnc.c
index a8cce5a..369ad7b 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3617,8 +3617,6 @@ void vnc_display_open(const char *id, Error **errp)
 
             if (to) {
                 saddr->u.inet->has_to = true;
-                saddr->u.inet->to = to;
-                saddr->u.inet->has_to = true;
                 saddr->u.inet->to = to + 5900;
             }
             saddr->u.inet->ipv4 = saddr->u.inet->has_ipv4 = has_ipv4;
-- 
1.8.3.1

Re: [Qemu-devel] [PULL for-2.5 00/20] vnc: buffer code improvements, bugfixes.

[Peter Maydell]

On 16 November 2015 at 17:25, Gerd Hoffmann <kraxel@redhat.com> wrote:
>   Hi,
>
> Here comes the vnc buffer pull request.  Sorry, due to gsoc mentor
> summit travel f*ckup (lufthansa on strike ...) I didn't manage to
> prepare this in time for -rc0.  Nevertheless I'd like to see this in
> 2.5 if it is fine with you.  If not I'll go prepare a new pull with
> the bugfixes only and defer the rest to the 2.6 devel cycle.

I hovered back and forth about applying this but since the
patches all seem to be reasonably small and focussed and
have been reviewed I've applied it to master.

thanks
-- PMM