What do the 'size' numbers mean in the windbg !heap output?
- by pj4533
I see output like this in my DMP file:
Heap entries for Segment00 in Heap 00150000
00150640: 00640 . 00040 [01] - busy (40)
00150680: 00040 . 01808 [01] - busy (1800)
00151e88: 01808 . 00210 [01] - busy (208)
00152098: 00210 . 00228 [00]
001522c0: 00228 . 00030 [01] - busy (22)
001522f0: 00030 . 00018 [01] - busy (10)
00152308: 00018 . 00048 [01] - busy (3c)
The WinDbg docs say this:
Heap entries for Segment00 in Heap 250000
0x01 - HEAP_ENTRY_BUSY
0x02 - HEAP_ENTRY_EXTRA_PRESENT
0x04 - HEAP_ENTRY_FILL_PATTERN
0x08 - HEAP_ENTRY_VIRTUAL_ALLOC
0x10 - HEAP_ENTRY_LAST_ENTRY
0x20 - HEAP_ENTRY_SETTABLE_FLAG1
0x40 - HEAP_ENTRY_SETTABLE_FLAG2
Entry Prev Cur 0x80 - HEAP_ENTRY_SETTABLE_FLAG3
Address Size Size flags (Bytes used) (Tag name)
00250000: 00000 . 00b90 [01] - busy (b90)
00250b90: 00b90 . 00038 [01] - busy (38)
00250bc8: 00038 . 00040 [07] - busy (24), tail fill (NTDLL!LDR Database)
The spacing is weird in the docs though. Does that mean 'entry address' and 'prev size' and 'cur size', or are the 'entry' 'prev' and 'cur' not for the line below?
What does 'prev size' and 'cur size' mean? Especially with regard to 'bytes used'. What is the difference between 'bytes used' and 'cur size'?