[Lldb-commits] [lldb] r215239 - Fix a thinko in the memory allocator that was causing us to strand an allocation range

[Jim Ingham]

Author: jingham
Date: Fri Aug  8 15:01:41 2014
New Revision: 215239

URL: http://llvm.org/viewvc/llvm-project?rev=215239&view=rev
Log:
Fix a thinko in the memory allocator that was causing us to strand an allocation range
in all but one of the AllocatedBlocks that matched the requested permissions.

Over time this would make the performance of expressions slow down considerably.

Also added a little bit of logging that was helpful in resolving the issue.

<rdar://problem/17954438>

Modified:
    lldb/trunk/source/Target/Memory.cpp

Modified: lldb/trunk/source/Target/Memory.cpp
URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Target/Memory.cpp?rev=215239&r1=215238&r2=215239&view=diff
==============================================================================
--- lldb/trunk/source/Target/Memory.cpp (original)
+++ lldb/trunk/source/Target/Memory.cpp Fri Aug  8 15:01:41 2014
@@ -241,16 +241,16 @@ lldb::addr_t
 AllocatedBlock::ReserveBlock (uint32_t size)
 {
     addr_t addr = LLDB_INVALID_ADDRESS;
+    Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
     if (size <= m_byte_size)
     {
         const uint32_t needed_chunks = CalculateChunksNeededForSize (size);
-        Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
 
         if (m_offset_to_chunk_size.empty())
         {
             m_offset_to_chunk_size[0] = needed_chunks;
             if (log)
-                log->Printf ("[1] AllocatedBlock::ReserveBlock (size = %u (0x%x)) => offset = 0x%x, %u %u bit chunks", size, size, 0, needed_chunks, m_chunk_size);
+                log->Printf ("[1] AllocatedBlock::ReserveBlock(%p) (size = %u (0x%x)) => offset = 0x%x, %u %u bit chunks", this, size, size, 0, needed_chunks, m_chunk_size);
             addr = m_addr;
         }
         else
@@ -268,7 +268,7 @@ AllocatedBlock::ReserveBlock (uint32_t s
                     {
                         m_offset_to_chunk_size[last_offset] = needed_chunks;
                         if (log)
-                            log->Printf ("[2] AllocatedBlock::ReserveBlock (size = %u (0x%x)) => offset = 0x%x, %u %u bit chunks", size, size, last_offset, needed_chunks, m_chunk_size);
+                            log->Printf ("[2] AllocatedBlock::ReserveBlock(%p) (size = %u (0x%x)) => offset = 0x%x, %u %u bit chunks - num_chunks %lu", this, size, size, last_offset, needed_chunks, m_chunk_size, m_offset_to_chunk_size.size());
                         addr = m_addr + last_offset;
                         break;
                     }
@@ -284,7 +284,7 @@ AllocatedBlock::ReserveBlock (uint32_t s
                     {
                         m_offset_to_chunk_size[last_offset] = needed_chunks;
                         if (log)
-                            log->Printf ("[3] AllocatedBlock::ReserveBlock (size = %u (0x%x)) => offset = 0x%x, %u %u bit chunks", size, size, last_offset, needed_chunks, m_chunk_size);
+                            log->Printf ("[3] AllocatedBlock::ReserveBlock(%p) (size = %u (0x%x)) => offset = 0x%x, %u %u bit chunks - num_chunks %lu", this, size, size, last_offset, needed_chunks, m_chunk_size, m_offset_to_chunk_size.size());
                         addr = m_addr + last_offset;
                         break;
                     }
@@ -343,9 +343,9 @@ AllocatedBlock::ReserveBlock (uint32_t s
 //            return m_addr + m_chunk_size * first_chunk_idx;
 //        }
     }
-    Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
+
     if (log)
-        log->Printf ("AllocatedBlock::ReserveBlock (size = %u (0x%x)) => 0x%16.16" PRIx64, size, size, (uint64_t)addr);
+        log->Printf ("AllocatedBlock::ReserveBlock(%p) (size = %u (0x%x)) => 0x%16.16" PRIx64, this, size, size, (uint64_t)addr);
     return addr;
 }
 
@@ -362,7 +362,7 @@ AllocatedBlock::FreeBlock (addr_t addr)
     }
     Log *log (GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS | LIBLLDB_LOG_VERBOSE));
     if (log)
-        log->Printf ("AllocatedBlock::FreeBlock (addr = 0x%16.16" PRIx64 ") => %i", (uint64_t)addr, success);
+        log->Printf ("AllocatedBlock::FreeBlock(%p) (addr = 0x%16.16" PRIx64 ") => %i, num_chunks: %lu", this, (uint64_t)addr, success, m_offset_to_chunk_size.size());
     return success;
 }
 
@@ -436,6 +436,8 @@ AllocatedMemoryCache::AllocateMemory (si
     for (PermissionsToBlockMap::iterator pos = range.first; pos != range.second; ++pos)
     {
         addr = (*pos).second->ReserveBlock (byte_size);
+        if (addr != LLDB_INVALID_ADDRESS)
+            break;
     }
     
     if (addr == LLDB_INVALID_ADDRESS)