summaryrefslogtreecommitdiff
path: root/ringbuffer.c
diff options
context:
space:
mode:
authorKlaus Schmidinger <vdr@tvdr.de>2002-04-19 12:40:04 +0200
committerKlaus Schmidinger <vdr@tvdr.de>2002-04-19 12:40:04 +0200
commit8ec5c0d9268a5f1194d7aea704f289a0e1004af1 (patch)
tree9fe76ed4b3bc60583b61c5602063efc2130e5495 /ringbuffer.c
parent849ec98c3da5a63a2003a515c35aaaf83caf238f (diff)
downloadvdr-8ec5c0d9268a5f1194d7aea704f289a0e1004af1.tar.gz
vdr-8ec5c0d9268a5f1194d7aea704f289a0e1004af1.tar.bz2
Improved thread locking in the ring buffer to avoid possible race conditions under heavy load
Diffstat (limited to 'ringbuffer.c')
-rw-r--r--ringbuffer.c66
1 files changed, 35 insertions, 31 deletions
diff --git a/ringbuffer.c b/ringbuffer.c
index 8b8420c1..88b515b4 100644
--- a/ringbuffer.c
+++ b/ringbuffer.c
@@ -7,7 +7,7 @@
* Parts of this file were inspired by the 'ringbuffy.c' from the
* LinuxDVB driver (see linuxtv.org).
*
- * $Id: ringbuffer.c 1.5 2001/11/03 09:50:46 kls Exp $
+ * $Id: ringbuffer.c 1.6 2002/04/19 12:38:44 kls Exp $
*/
#include "ringbuffer.h"
@@ -154,7 +154,6 @@ int cRingBufferLinear::Put(const uchar *Data, int Count)
Lock();
int rest = Size() - head;
int diff = tail - head;
- Unlock();
int free = (diff > 0) ? diff - 1 : Size() + diff - 1;
if (statistics) {
int fill = Size() - free - 1 + Count;
@@ -167,22 +166,25 @@ int cRingBufferLinear::Put(const uchar *Data, int Count)
dsyslog(LOG_INFO, "buffer usage: %d%%", percent);
}
}
- if (free <= 0)
- return 0;
- if (free < Count)
- Count = free;
- if (Count > maxFill)
- maxFill = Count;
- if (Count >= rest) {
- memcpy(buffer + head, Data, rest);
- if (Count - rest)
- memcpy(buffer, Data + rest, Count - rest);
- head = Count - rest;
- }
- else {
- memcpy(buffer + head, Data, Count);
- head += Count;
+ if (free > 0) {
+ if (free < Count)
+ Count = free;
+ if (Count > maxFill)
+ maxFill = Count;
+ if (Count >= rest) {
+ memcpy(buffer + head, Data, rest);
+ if (Count - rest)
+ memcpy(buffer, Data + rest, Count - rest);
+ head = Count - rest;
+ }
+ else {
+ memcpy(buffer + head, Data, Count);
+ head += Count;
+ }
}
+ else
+ Count = 0;
+ Unlock();
}
return Count;
}
@@ -193,22 +195,24 @@ int cRingBufferLinear::Get(uchar *Data, int Count)
Lock();
int rest = Size() - tail;
int diff = head - tail;
- Unlock();
int cont = (diff >= 0) ? diff : Size() + diff;
- if (rest <= 0)
- return 0;
- if (cont < Count)
- Count = cont;
- if (Count >= rest) {
- memcpy(Data, buffer + tail, rest);
- if (Count - rest)
- memcpy(Data + rest, buffer, Count - rest);
- tail = Count - rest;
- }
- else {
- memcpy(Data, buffer + tail, Count);
- tail += Count;
+ if (rest > 0) {
+ if (cont < Count)
+ Count = cont;
+ if (Count >= rest) {
+ memcpy(Data, buffer + tail, rest);
+ if (Count - rest)
+ memcpy(Data + rest, buffer, Count - rest);
+ tail = Count - rest;
+ }
+ else {
+ memcpy(Data, buffer + tail, Count);
+ tail += Count;
+ }
}
+ else
+ Count = 0;
+ Unlock();
}
return Count;
}