This is still in a just-for-testing phase. Found a way to better stress test
this code, hence these changes:
- decreased the growth threshold from 1/2 to 1/3. IOW the goal is always for
66% of the buffer to be free; this increases the working set, but the
alternative (handling overflows by spilling over to the unused portion)
makes thing more complex.
- made buffers grow by 1.5x, not 2x. Related to above.
- increased the initial bufsize from 128k to 192k.
- removed some now redundant Read() code.
- dropped the controversial cRecorder::Receive hunk (I'm keeping this locally
as it prevents (very rare) data corruption while testing. Overflows will
be logged even w/o this change, so it makes no difference otherwise).
- added verbose cRecorder::Action sleep logging. Shorter delays are a side
effect, but do not help all that much (from the few times this triggered
here so far less than half of the delays were <<100ms).
Patch attached (apparently this makes extracting it easier for gmail users).
artur
diff --git a/dvbdevice.c b/dvbdevice.c
index 955483e..20dcf29 100644
--- a/dvbdevice.c
+++ b/dvbdevice.c
@@ -1184,7 +1184,7 @@ bool cDvbDevice::OpenDvr(void)
CloseDvr();
fd_dvr = DvbOpen(DEV_DVB_DVR, CardIndex(), O_RDONLY | O_NONBLOCK, true);
if (fd_dvr >= 0)
- tsBuffer = new cTSBuffer(fd_dvr, MEGABYTE(2), CardIndex() + 1);
+ tsBuffer = new cTSBuffer(fd_dvr, MEGABYTE(8), CardIndex() + 1);
return fd_dvr >= 0;
}
diff --git a/recorder.c b/recorder.c
index 8bb1621..0b625d6 100644
--- a/recorder.c
+++ b/recorder.c
@@ -171,8 +171,22 @@ void cRecorder::Action(void)
int Count = remux->Put(b, r);
if (Count)
ringBuffer->Del(Count);
- else
- cCondWait::SleepMs(100); // avoid busy loop when resultBuffer is full in cRemux::Put()
- }
+ else { // avoid busy loop when resultBuffer is full in cRemux::Put()
+ int ms;
+ for (ms=5; Running() && ms<100; ms+=ms) {
+ cCondWait::SleepMs(ms);
+ if (!Running())
+ return;
+ Count = remux->Put(b, r);
+ if (Count) {
+ ringBuffer->Del(Count);
+ dsyslog("cRecorder::Action() ring buffer consumer slept %d ms", ms);
+ break;
+ }
+ }
+ if (ms>=100)
+ dsyslog("cRecorder::Action() ring buffer consumer slept >100 ms");
+ }
+ }
}
}
diff --git a/remux.c b/remux.c
index da805b7..bd29b2f 100644
--- a/remux.c
+++ b/remux.c
@@ -1851,7 +1851,7 @@ void cTS2PES::ts_to_pes(const uint8_t *Buf) // don't need count (=188)
// --- cRemux ----------------------------------------------------------------
-#define RESULTBUFFERSIZE KILOBYTE(256)
+#define RESULTBUFFERSIZE MEGABYTE(2)
cRemux::cRemux(int VPid, const int *APids, const int *DPids, const int *SPids, bool ExitOnFailure)
{
diff --git a/ringbuffer.c b/ringbuffer.c
index 0633bd3..68ce081 100644
--- a/ringbuffer.c
+++ b/ringbuffer.c
@@ -151,13 +151,31 @@ void cRingBufferLinear::PrintDebugRBL(void)
}
#endif
+// cRingBufferLinear are dynamically sized, or at least we can pretend they are ;)
+// We treat 'Size' as the maximum size, but start with a small buffer, which can
+// grow later as it fills up. Memory is always allocated for the full buffer, but
+// the unused RAM portion remains untouched until (if at all) it is actually needed.
+// Note that we can not start with a larger than requested buffer because there are
+// ring buffer users that cause crashes then (eg softdevice mpegdecoder absolutely
+// needs 32/64k).
+
+// Startup size. 64k still causes overflows before buffer starts to grow, 128k doesn't.
+// The buffers grow to 200..500k anyway, so maybe increasing this a bit more would
+// make sense, but let's first see if it's really needed.
+// In fact 128k is on the low side, but let's try not going for 256k yet.
+#define DEFRBSIZE KILOBYTE(192)
+
cRingBufferLinear::cRingBufferLinear(int Size, int Margin, bool Statistics, const char *Description)
-:cRingBuffer(Size, Statistics)
+:cRingBuffer(min(Size,DEFRBSIZE), Statistics)
{
description = Description ? strdup(Description) : NULL;
tail = head = margin = Margin;
gotten = 0;
buffer = NULL;
+ maxsize = Size;
+ growthresh = size<maxsize ? size/3 : maxsize+1;
+ growbuf = 0;
+ dsyslog("New ring buffer \"%s\" size: %d margin: %d", description, Size, Margin );
if (Size > 1) { // 'Size - 1' must not be 0!
if (Margin <= Size / 2) {
buffer = MALLOC(uchar, Size);
@@ -183,6 +201,8 @@ cRingBufferLinear::~cRingBufferLinear()
#ifdef DEBUGRINGBUFFERS
DelDebugRBL(this);
#endif
+ dsyslog("Deleting ring buffer \"%s\" size: %d / %d (used %g%% of requested size)", description,
+ size, maxsize, size/(double)maxsize*100.0 );
free(buffer);
free(description);
}
@@ -205,8 +225,20 @@ void cRingBufferLinear::Clear(void)
EnablePut();
}
+// Must only be called by the producer (ie Read()/Put()), not the consumer (Get()).
+void cRingBufferLinear::GrowBuffer(void)
+{
+ size = min(size+size/2, maxsize);
+ growthresh = size<maxsize ? size/3 : maxsize+1;
+ dsyslog("Enlarging ring buffer \"%s\": %d bytes (trigger %d, thresh %d)",
+ description, size, growbuf, growthresh);
+ growbuf = 0;
+}
+
int cRingBufferLinear::Read(int FileHandle, int Max)
{
+ if (growbuf && head>=tail && size<maxsize)
+ GrowBuffer();
int Tail = tail;
int diff = Tail - head;
int free = (diff > 0) ? diff - 1 : Size() - head;
@@ -219,6 +251,10 @@ int cRingBufferLinear::Read(int FileHandle, int Max)
Count = safe_read(FileHandle, buffer + head, free);
if (Count > 0) {
int Head = head + Count;
+ if (Available()+Count >= growthresh)
+ growbuf = 2;
+ if (growbuf && head>=tail && size<maxsize)
+ GrowBuffer();
if (Head >= Size())
Head = margin;
head = Head;
@@ -245,6 +281,10 @@ int cRingBufferLinear::Read(int FileHandle, int Max)
int cRingBufferLinear::Put(const uchar *Data, int Count)
{
if (Count > 0) {
+ if (Available()+Count >= growthresh)
+ growbuf = 3;
+ if (growbuf && head>=tail && size<maxsize)
+ GrowBuffer();
int Tail = tail;
int rest = Size() - head;
int diff = Tail - head;
diff --git a/ringbuffer.h b/ringbuffer.h
index dba0e61..3545520 100644
--- a/ringbuffer.h
+++ b/ringbuffer.h
@@ -18,11 +18,11 @@ private:
cCondWait readyForPut, readyForGet;
int putTimeout;
int getTimeout;
- int size;
time_t lastOverflowReport;
int overflowCount;
int overflowBytes;
protected:
+ int size;
tThreadId getThreadTid;
int maxFill;//XXX
int lastPercent;
@@ -59,7 +59,11 @@ private:
int margin, head, tail;
int gotten;
uchar *buffer;
+ int growbuf;
+ int growthresh;
+ int maxsize;
char *description;
+ void GrowBuffer(void);
public:
cRingBufferLinear(int Size, int Margin = 0, bool Statistics = false, const char *Description = NULL);
///< Creates a linear ring buffer.
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