From 8c46b10a1af7151f9453651f9e6def0237a6f7d8 Mon Sep 17 00:00:00 2001
From: Jason Sams <rjsams@android.com>
Date: Wed, 18 Aug 2010 12:38:03 -0700
Subject: Fix bug looping non-blocking fifos.

Change-Id: I33dcf575466bfef672af4e113ad692397b5213e9
---
 rsLocklessFifo.cpp | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

(limited to 'rsLocklessFifo.cpp')

diff --git a/rsLocklessFifo.cpp b/rsLocklessFifo.cpp
index 76ca32e9..019ea72b 100644
--- a/rsLocklessFifo.cpp
+++ b/rsLocklessFifo.cpp
@@ -169,6 +169,30 @@ void LocklessCommandFifo::next()
     //dumpState("next");
 }
 
+bool LocklessCommandFifo::makeSpaceNonBlocking(uint32_t bytes)
+{
+    //dumpState("make space non-blocking");
+    if ((mPut+bytes) > mEnd) {
+        // Need to loop regardless of where get is.
+        if((mGet > mPut) && (mBuffer+4 >= mGet)) {
+            return false;
+        }
+
+        // Toss in a reset then the normal wait for space will do the rest.
+        reinterpret_cast<uint16_t *>(mPut)[0] = 0;
+        reinterpret_cast<uint16_t *>(mPut)[1] = 0;
+        mPut = mBuffer;
+        mSignalToWorker.set();
+    }
+
+    // it will fit here so we just need to wait for space.
+    if(getFreeSpace() < bytes) {
+        return false;
+    }
+
+    return true;
+}
+
 void LocklessCommandFifo::makeSpace(uint32_t bytes)
 {
     //dumpState("make space");
@@ -182,6 +206,7 @@ void LocklessCommandFifo::makeSpace(uint32_t bytes)
         reinterpret_cast<uint16_t *>(mPut)[0] = 0;
         reinterpret_cast<uint16_t *>(mPut)[1] = 0;
         mPut = mBuffer;
+        mSignalToWorker.set();
     }
 
     // it will fit here so we just need to wait for space.
@@ -193,6 +218,6 @@ void LocklessCommandFifo::makeSpace(uint32_t bytes)
 
 void LocklessCommandFifo::dumpState(const char *s) const
 {
-    LOGV("%s  put %p, get %p,  buf %p,  end %p", s, mPut, mGet, mBuffer, mEnd);
+    LOGV("%s %p  put %p, get %p,  buf %p,  end %p", s, this, mPut, mGet, mBuffer, mEnd);
 }
 
-- 
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