memory_leak_blogpost_01.ex

# Create a long enough string that it will be stored off of this process' heap
iex(1)> long_binary = "This is a long binary that will need to be at least 64 bytes in length"
"This is a long binary that will need to be at least 64 bytes in length"

# Verify that our string is longer than 64 bytes
iex(2)> byte_size(long_binary)                                                                
70

# Inspect the IEx process' binary info.  We can see our binary is there by correlating the 70 byte
# length.  The tuple that is returned is of the form {binary id, byte length, reference count}. So
# right now we can see that only one thing has a reference to this binary.
iex(3)> :erlang.process_info(self(), :binary)                                                 
{:binary, [{515928504, 70, 1}]}

# Create a new ETS table and insert out binary
iex(4)> :ets.new(:my_ets, [:public, :named_table])                                            
:my_ets

iex(5)> :ets.insert(:my_ets, {long_binary, 99})                                               
true

# Instpect the IEx process' binary info again and observe that now the reference count has been
# incremented to 2, since the IEx process and the ETS table are both referencing the binary
iex(6)> :erlang.process_info(self(), :binary)                                                 
{:binary, [{515928504, 70, 2}]}

# Delete everything our binary from the ETS table
iex(7)> :ets.delete_all_objects(:my_ets)                                                      
true

# Check the IEX process' binary info one last time to confirm that the reference count has gone
# back down to 1
iex(8)> :erlang.process_info(self(), :binary)  
{:binary, [{515928504, 70, 1}]}