Mesa (master): swr: [rasterizer archrast] fix open file handle limit issue

[Tim Rowley]

Module: Mesa
Branch: master
Commit: e6f7d8a0946822d2f90099df2bf2a3d0969ebd74
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=e6f7d8a0946822d2f90099df2bf2a3d0969ebd74

Author: Tim Rowley <timothy.o.rowley at intel.com>
Date:   Sat Oct 29 01:08:09 2016 -0500

swr: [rasterizer archrast] fix open file handle limit issue

Buffer events ourselves and then when that's full or we're destroying
the context then write the contents to file. Previously, we're relying
ofstream to buffer for us.

Reviewed-by: Bruce Cherniak <bruce.cherniak at intel.com>

---

 .../templates/ar_eventhandlerfile_h.template       | 50 +++++++++++++++++++---
 1 file changed, 44 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/swr/rasterizer/scripts/templates/ar_eventhandlerfile_h.template b/src/gallium/drivers/swr/rasterizer/scripts/templates/ar_eventhandlerfile_h.template
index 0a651a4..97eca59 100644
--- a/src/gallium/drivers/swr/rasterizer/scripts/templates/ar_eventhandlerfile_h.template
+++ b/src/gallium/drivers/swr/rasterizer/scripts/templates/ar_eventhandlerfile_h.template
@@ -43,6 +43,7 @@ namespace ArchRast
     {
     public:
         EventHandlerFile(uint32_t id)
+        : mBufOffset(0)
         {
 #if defined(_WIN32)
             DWORD pid = GetCurrentProcessId();
@@ -71,21 +72,55 @@ namespace ArchRast
 
         virtual ~EventHandlerFile()
         {
-            if (mFile.is_open()) mFile.close();
+            FlushBuffer();
         }
 
+        //////////////////////////////////////////////////////////////////////////
+        /// @brief Flush buffer to file.
+        bool FlushBuffer()
+        {
+            if (mBufOffset > 0)
+            {
+                std::ofstream file;
+                file.open(mFilename, std::ios::out | std::ios::app | std::ios::binary);
+
+                if (!file.is_open())
+                {
+                    SWR_ASSERT(0, "ArchRast: Could not open event file!");
+                    return false;
+                }
+
+                file.write((char*)mBuffer, mBufOffset);
+                file.close();
+
+                mBufOffset = 0;
+            }
+            return true;
+        }
+
+        //////////////////////////////////////////////////////////////////////////
+        /// @brief Write event and its payload to the memory buffer.
         void Write(uint32_t eventId, const char* pBlock, uint32_t size)
         {
-            if (!mFile.is_open())
+            if ((mBufOffset + size + sizeof(eventId)) > mBufferSize)
             {
-                mFile.open(mFilename, std::ios::out | std::ios::app | std::ios::binary);
+                if (!FlushBuffer())
+                {
+                    // Don't corrupt what's already in the buffer?
+                    /// @todo Maybe add corrupt marker to buffer here in case we can open file in future?
+                    return;
+                }
             }
 
-            mFile.write((char*)&eventId, sizeof(eventId));
-            mFile.write(pBlock, size);
+            memcpy(&mBuffer[mBufOffset], (char*)&eventId, sizeof(eventId));
+            mBufOffset += sizeof(eventId);
+            memcpy(&mBuffer[mBufOffset], pBlock, size);
+            mBufOffset += size;
         }
 
 % for name in protos['event_names']:
+        //////////////////////////////////////////////////////////////////////////
+        /// @brief Handle ${name} event
         virtual void Handle(${name}& event)
         {
 % if protos['events'][name]['num_fields'] == 0:
@@ -96,7 +131,10 @@ namespace ArchRast
         }
 % endfor
 
-        std::ofstream mFile;
         std::string mFilename;
+
+        static const uint32_t mBufferSize = 1024;
+        uint8_t mBuffer[mBufferSize];
+        uint32_t mBufOffset{0};
     };
 }