summaryrefslogtreecommitdiff
path: root/src/VBox/Runtime/common/misc/circbuf.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'src/VBox/Runtime/common/misc/circbuf.cpp')
-rw-r--r--src/VBox/Runtime/common/misc/circbuf.cpp121
1 files changed, 62 insertions, 59 deletions
diff --git a/src/VBox/Runtime/common/misc/circbuf.cpp b/src/VBox/Runtime/common/misc/circbuf.cpp
index da6c51f93..0a6f78b07 100644
--- a/src/VBox/Runtime/common/misc/circbuf.cpp
+++ b/src/VBox/Runtime/common/misc/circbuf.cpp
@@ -1,4 +1,4 @@
-/* $Id: circbuf.cpp $ */
+/* $Id: circbuf.cpp 37210 2011-05-25 09:55:16Z vboxsync $ */
/** @file
* IPRT - Lock Free Circular Buffer
*/
@@ -25,18 +25,36 @@
*/
-/******************************************************************************
- * Header Files *
- ******************************************************************************/
+/*******************************************************************************
+* Header Files *
+*******************************************************************************/
#include <iprt/circbuf.h>
#include <iprt/mem.h>
#include <iprt/assert.h>
#include <iprt/asm.h>
#include <iprt/err.h>
-/******************************************************************************
- * Public Functions *
- ******************************************************************************/
+
+/*******************************************************************************
+* Structures and Typedefs *
+*******************************************************************************/
+/** @todo r=bird: this is missing docs and magic. uXPos should be offX.
+ * cbBufSize should be cbBuf. */
+typedef struct RTCIRCBUF
+{
+ /** The current read position in the buffer. */
+ size_t uReadPos;
+ /** The current write position in the buffer. */
+ size_t uWritePos;
+ /** How much space of the buffer is currently in use. */
+ volatile size_t cbBufUsed;
+ /** How big is the buffer. */
+ size_t cbBufSize;
+ /** The buffer itself. */
+ void *pvBuf;
+} RTCIRCBUF;
+
+
RTDECL(int) RTCircBufCreate(PRTCIRCBUF *ppBuf, size_t cbSize)
{
@@ -49,69 +67,59 @@ RTDECL(int) RTCircBufCreate(PRTCIRCBUF *ppBuf, size_t cbSize)
if (!pTmpBuf)
return VERR_NO_MEMORY;
- int rc = VINF_SUCCESS;
- do
+ pTmpBuf->pvBuf = RTMemAlloc(cbSize);
+ if (pTmpBuf->pvBuf)
{
- pTmpBuf->pvBuf = RTMemAlloc(cbSize);
- if (!pTmpBuf)
- {
- rc = VERR_NO_MEMORY;
- break;
- }
-
pTmpBuf->cbBufSize = cbSize;
*ppBuf = pTmpBuf;
- }while (0);
-
- if (RT_FAILURE(rc))
- RTMemFree(pTmpBuf);
+ return VINF_SUCCESS;
+ }
- return rc;
+ RTMemFree(pTmpBuf);
+ return VERR_NO_MEMORY;
}
+
RTDECL(void) RTCircBufDestroy(PRTCIRCBUF pBuf)
{
/* Validate input. */
- AssertPtrNull(pBuf);
-
- if (pBuf)
- {
- if (pBuf->pvBuf)
- RTMemFree(pBuf->pvBuf);
- RTMemFree(pBuf);
- }
+ if (!pBuf)
+ return;
+ AssertPtr(pBuf);
+ RTMemFree(pBuf->pvBuf);
+ RTMemFree(pBuf);
}
+
RTDECL(void) RTCircBufReset(PRTCIRCBUF pBuf)
{
/* Validate input. */
AssertPtr(pBuf);
- pBuf->uReadPos = 0;
+ pBuf->uReadPos = 0;
pBuf->uWritePos = 0;
pBuf->cbBufUsed = 0;
}
+
RTDECL(size_t) RTCircBufFree(PRTCIRCBUF pBuf)
{
/* Validate input. */
AssertPtrReturn(pBuf, 0);
- size_t cbSize = 0;
- ASMAtomicReadSize(&pBuf->cbBufUsed, &cbSize);
- return pBuf->cbBufSize - cbSize;
+ return pBuf->cbBufSize - ASMAtomicReadZ(&pBuf->cbBufUsed);
}
+
RTDECL(size_t) RTCircBufUsed(PRTCIRCBUF pBuf)
{
/* Validate input. */
AssertPtrReturn(pBuf, 0);
- size_t cbSize = 0;
- ASMAtomicReadSize(&pBuf->cbBufUsed, &cbSize);
- return cbSize;
+ return ASMAtomicReadZ(&pBuf->cbBufUsed);
}
+
RTDECL(size_t) RTCircBufSize(PRTCIRCBUF pBuf)
{
/* Validate input. */
@@ -120,6 +128,7 @@ RTDECL(size_t) RTCircBufSize(PRTCIRCBUF pBuf)
return pBuf->cbBufSize;
}
+
RTDECL(void) RTCircBufAcquireReadBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void **ppvStart, size_t *pcbSize)
{
/* Validate input. */
@@ -128,29 +137,27 @@ RTDECL(void) RTCircBufAcquireReadBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void *
AssertPtr(ppvStart);
AssertPtr(pcbSize);
- size_t uUsed = 0;
- size_t uSize = 0;
-
*ppvStart = 0;
*pcbSize = 0;
/* How much is in use? */
- ASMAtomicReadSize(&pBuf->cbBufUsed, &uUsed);
- if (uUsed > 0)
+ size_t cbUsed = ASMAtomicReadZ(&pBuf->cbBufUsed);
+ if (cbUsed > 0)
{
/* Get the size out of the requested size, the read block till the end
* of the buffer & the currently used size. */
- uSize = RT_MIN(cbReqSize, RT_MIN(pBuf->cbBufSize - pBuf->uReadPos, uUsed));
- if (uSize > 0)
+ size_t cbSize = RT_MIN(cbReqSize, RT_MIN(pBuf->cbBufSize - pBuf->uReadPos, cbUsed));
+ if (cbSize > 0)
{
/* Return the pointer address which point to the current read
* position. */
- *ppvStart = (char*)pBuf->pvBuf + pBuf->uReadPos;
- *pcbSize = uSize;
+ *ppvStart = (char *)pBuf->pvBuf + pBuf->uReadPos;
+ *pcbSize = cbSize;
}
}
}
+
RTDECL(void) RTCircBufReleaseReadBlock(PRTCIRCBUF pBuf, size_t cbSize)
{
/* Validate input. */
@@ -159,10 +166,10 @@ RTDECL(void) RTCircBufReleaseReadBlock(PRTCIRCBUF pBuf, size_t cbSize)
/* Split at the end of the buffer. */
pBuf->uReadPos = (pBuf->uReadPos + cbSize) % pBuf->cbBufSize;
- size_t cbOld = 0;
- ASMAtomicSubSize(&pBuf->cbBufUsed, cbSize, &cbOld);
+ ASMAtomicSubZ(&pBuf->cbBufUsed, cbSize);
}
+
RTDECL(void) RTCircBufAcquireWriteBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void **ppvStart, size_t *pcbSize)
{
/* Validate input. */
@@ -171,31 +178,27 @@ RTDECL(void) RTCircBufAcquireWriteBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void
AssertPtr(ppvStart);
AssertPtr(pcbSize);
- size_t uFree;
- size_t uSize;
-
*ppvStart = 0;
*pcbSize = 0;
/* How much is free? */
- size_t cbSize = 0;
- ASMAtomicReadSize(&pBuf->cbBufUsed, &cbSize);
- uFree = pBuf->cbBufSize - cbSize;
- if (uFree > 0)
+ size_t cbFree = pBuf->cbBufSize - ASMAtomicReadZ(&pBuf->cbBufUsed);
+ if (cbFree > 0)
{
/* Get the size out of the requested size, the write block till the end
* of the buffer & the currently free size. */
- uSize = RT_MIN(cbReqSize, RT_MIN(pBuf->cbBufSize - pBuf->uWritePos, uFree));
- if (uSize > 0)
+ size_t cbSize = RT_MIN(cbReqSize, RT_MIN(pBuf->cbBufSize - pBuf->uWritePos, cbFree));
+ if (cbSize > 0)
{
/* Return the pointer address which point to the current write
* position. */
*ppvStart = (char*)pBuf->pvBuf + pBuf->uWritePos;
- *pcbSize = uSize;
+ *pcbSize = cbSize;
}
}
}
+
RTDECL(void) RTCircBufReleaseWriteBlock(PRTCIRCBUF pBuf, size_t cbSize)
{
/* Validate input. */
@@ -204,7 +207,7 @@ RTDECL(void) RTCircBufReleaseWriteBlock(PRTCIRCBUF pBuf, size_t cbSize)
/* Split at the end of the buffer. */
pBuf->uWritePos = (pBuf->uWritePos + cbSize) % pBuf->cbBufSize;
- size_t cbOld = 0;
- ASMAtomicAddSize(&pBuf->cbBufUsed, cbSize, &cbOld);
+ size_t cbOldIgnored = 0;
+ ASMAtomicAddZ(&pBuf->cbBufUsed, cbSize);
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-09 13:59:10 +0000