Changeset 39350 in vbox

Timestamp:

Nov 17, 2011 3:07:24 PM (13 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

74932

Message:

Runtime: add methods for checking if something is in use in a circular buffer

Location:

trunk

Files:

• include/iprt/circbuf.h (modified) (1 diff)
• include/iprt/mangling.h (modified) (1 diff)
• src/VBox/Runtime/common/misc/circbuf.cpp (modified) (8 diffs)

trunk/include/iprt/circbuf.h ¶

@@ -92 +92 @@
 RTDECL(size_t) RTCircBufSize(PRTCIRCBUF pBuf);
 
+RTDECL(bool) RTCircBufIsReading(PRTCIRCBUF pBuf);
+RTDECL(bool) RTCircBufIsWriting(PRTCIRCBUF pBuf);
+
 /**
  * Acquire a block of the circular buffer for reading.

trunk/include/iprt/mangling.h ¶

@@ -279 +279 @@
 # define RTCircBufDestroy                               RT_MANGLER(RTCircBufDestroy)
 # define RTCircBufFree                                  RT_MANGLER(RTCircBufFree)
+# define RTCircBufIsReading                             RT_MANGLER(RTCircBufIsReading)
+# define RTCircBufIsWriting                             RT_MANGLER(RTCircBufIsWriting)
 # define RTCircBufReleaseReadBlock                      RT_MANGLER(RTCircBufReleaseReadBlock)
 # define RTCircBufReleaseWriteBlock                     RT_MANGLER(RTCircBufReleaseWriteBlock)

trunk/src/VBox/Runtime/common/misc/circbuf.cpp ¶

@@ -44 +44 @@
     /** The current read position in the buffer. */
     size_t          offRead;
+    /** Is a read block acquired currently? */
+    bool            fReading;
+    /** Is a write block acquired currently? */
+    bool            fWriting;
     /** The current write position in the buffer. */
     size_t          offWrite;
@@ -97 +101 @@
     pBuf->offRead  = 0;
     pBuf->offWrite = 0;
-    pBuf->cbUsed = 0;
+    pBuf->cbUsed   = 0;
+    pBuf->fReading = false;
+    pBuf->fWriting = false;
 }
 
@@ -118 +124 @@
 }
 
-
 RTDECL(size_t) RTCircBufSize(PRTCIRCBUF pBuf)
 {
@@ -127 +132 @@
 }
 
+RTDECL(bool) RTCircBufIsReading(PRTCIRCBUF pBuf)
+{
+    /* Validate input. */
+    AssertPtrReturn(pBuf, 0);
+
+    return ASMAtomicReadBool(&pBuf->fReading);
+}
+
+RTDECL(bool) RTCircBufIsWriting(PRTCIRCBUF pBuf)
+{
+    /* Validate input. */
+    AssertPtrReturn(pBuf, 0);
+
+    return ASMAtomicReadBool(&pBuf->fWriting);
+}
 
 RTDECL(void) RTCircBufAcquireReadBlock(PRTCIRCBUF pBuf, size_t cbReqSize, void **ppvStart, size_t *pcbSize)
@@ -152 +172 @@
             *ppvStart = (char *)pBuf->pvBuf + pBuf->offRead;
             *pcbSize = cbSize;
+
+            ASMAtomicWriteBool(&pBuf->fReading, true);
         }
     }
@@ -166 +188 @@
 
     ASMAtomicSubZ(&pBuf->cbUsed, cbSize);
+    ASMAtomicWriteBool(&pBuf->fReading, false);
 }
 
@@ -193 +216 @@
             *ppvStart = (char*)pBuf->pvBuf + pBuf->offWrite;
             *pcbSize = cbSize;
+
+            ASMAtomicWriteBool(&pBuf->fWriting, true);
         }
     }
@@ -207 +232 @@
 
     ASMAtomicAddZ(&pBuf->cbUsed, cbSize);
-}
-
+    ASMAtomicWriteBool(&pBuf->fWriting, false);
+}
+