erlang hibernate函數不會清除進程字典

一直想知道，erlang進程hibernate會不會把狀態值給刪除，經過代碼知道，不會。

-module(hibernate_procs).
-behaviour(gen_server).
-export([start_link/0]).
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
		 terminate/2, code_change/3]).
-define(SERVER, ?MODULE).
-record(state, {}).
start_link() ->
	gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).
init([]) ->
	process_flag(trap_exit, true),
	{ok, #state{}}.
handle_call(_Request, _From, State) ->
	Reply = ok,
	{reply, Reply, State}.
handle_cast(_Msg, State) ->
	{noreply, State}.
handle_info({put, Key, Value}, State) ->
	io:format("I am :~p~n", [self()]),
	put(Key, Value),
	{noreply, State};
handle_info(hibernate_proc, State) ->
	io:format("hibernate, I am:~p~n", [self()]),
	{noreply, State, hibernate};
handle_info(get_info, State) ->
	io:format("all the get() info:~p~n", [get()]),
	{noreply, State};
handle_info(_Info, State) ->
	{noreply, State}.
terminate(_Reason, _State) ->
	ok.
code_change(_OldVsn, State, _Extra) ->
	{ok, State}.

測試過程：

$erlc hibernate_procs.erl 
$erl
1> {ok, Pid} =  hibernate_procs:start_link().
2>[Pid ! {put , I, I} || I <- lists:seq(1, 20)].

3> rp(process_info(Pid)).
[{registered_name,hibernate_procs},
 {current_function,{gen_server,loop,6}},
 {initial_call,{proc_lib,init_p,5}},
 {status,waiting},
 {message_queue_len,0},
 {messages,[]},
 {links,[<0.36.0>]},
 {dictionary,[{'$initial_call',{hibernate_procs,init,1}},
              {20,20},
              {19,19},
              {18,18},
              {17,17},
              {16,16},
              {'$ancestors',[<0.36.0>]},
              {15,15},
              {14,14},
              {13,13},
              {12,12},
              {11,11},
              {10,10},
              {9,9},
              {8,8},
              {7,7},
              {6,6},
              {5,5},
              {4,4},
              {3,3},
              {2,2},
              {1,1}]},
 {trap_exit,true},
 {error_handler,error_handler},
 {priority,normal},
 {group_leader,<0.27.0>},
 {total_heap_size,1220},
 {heap_size,610},
 {stack_size,9},
 {reductions,477},
 {garbage_collection,[{min_bin_vheap_size,46422},
                      {min_heap_size,233},
                      {fullsweep_after,65535},
                      {minor_gcs,2}]},
 {suspending,[]}]


4>Pid ! hibernate_proc.

5>rp(process_info(Pid)).
[{registered_name,hibernate_procs},
 {current_function,{erlang,hibernate,3}},
 {initial_call,{proc_lib,init_p,5}},
 {status,waiting},
 {message_queue_len,0},
 {messages,[]},
 {links,[<0.36.0>]},
 {dictionary,[{'$initial_call',{hibernate_procs,init,1}},
              {20,20},
              {19,19},
              {18,18},
              {17,17},
              {16,16},
              {'$ancestors',[<0.36.0>]},
              {15,15},
              {14,14},
              {13,13},
              {12,12},
              {11,11},
              {10,10},
              {9,9},
              {8,8},
              {7,7},
              {6,6},
              {5,5},
              {4,4},
              {3,3},
              {2,2},
              {1,1}]},
 {trap_exit,true},
 {error_handler,error_handler},
 {priority,normal},
 {group_leader,<0.27.0>},
 {total_heap_size,96},
 {heap_size,96},
 {stack_size,0},
 {reductions,498},
 {garbage_collection,[{min_bin_vheap_size,46422},
                      {min_heap_size,233},
                      {fullsweep_after,65535},
                      {minor_gcs,2}]},
 {suspending,[]}]

能夠看到，更新了20個數據到進程字典裏面，經過hibernate操做，能夠把total_heap_size、heap_size給減小不少，並且能夠看到，當前進程的確是在運算erlang, hibernate函數。這裏用的是gen_server模塊，它裏面調用了proc_lib:hibernate函數，proc_lib:hibernate函數經過try...catch調用erlang:hibernate函數。有利於咱們調試和調用。