rpc: close channel if stream was closed

f_jobstop()/f_rpcstop() .. process_stop() .. process_close_in(proc)
closes the write-stream of a RPC channel. But there might be
a pending RPC notification on the queue, which may get processed just
before the channel is closed.

To handle that case, check the Stream.closed in
channel.c:receive_msgpack().

Before this change, the above scenario could trigger
this assert(!stream->closed) in wstream_write():

    0x00007f96e1cd3428 in __GI_raise (sig=sig@entry=6) at ../sysdeps/unix/sysv/linux/raise.c:54
    0x00007f96e1cd502a in __GI_abort () at abort.c:89
    0x00007f96e1ccbbd7 in __assert_fail_base (fmt=<optimized out>, assertion=assertion@entry=0x768f9b "!stream->closed",
    file=file@entry=0x768f70 "../src/nvim/event/wstream.c", line=line@entry=77,
    function=function@entry=0x768fb0 <__PRETTY_FUNCTION__.13735> "wstream_write") at assert.c:92
    0x00007f96e1ccbc82 in __GI___assert_fail (assertion=0x768f9b "!stream->closed", file=0x768f70 "../src/nvim/event/wstream.c", line=77,
    function=0x768fb0 <__PRETTY_FUNCTION__.13735> "wstream_write") at assert.c:101
    0x00000000004d2c1f in wstream_write (stream=0x7f96e0a35078, buffer=0x7f96e09f9b40) at ../src/nvim/event/wstream.c:77
    0x00000000005857b2 in channel_write (channel=0x7f96e0ae5800, buffer=0x7f96e09f9b40) at ../src/nvim/msgpack_rpc/channel.c:551
    0x000000000058567d in on_request_event (argv=0x7ffed792efa0) at ../src/nvim/msgpack_rpc/channel.c:523
    0x00000000005854c8 in handle_request (channel=0x7f96e0ae5800, request=0x7ffed792f1b8) at ../src/nvim/msgpack_rpc/channel.c:503
    0x00000000005850cb in parse_msgpack (channel=0x7f96e0ae5800) at ../src/nvim/msgpack_rpc/channel.c:423
    0x0000000000584f90 in receive_msgpack (stream=0x7f96e0a35218, rbuf=0x7f96e0d1d4c0, c=22, data=0x7f96e0ae5800, eof=false)
    at ../src/nvim/msgpack_rpc/channel.c:389
    0x00000000004d0b20 in read_event (argv=0x7ffed792f4a8) at ../src/nvim/event/rstream.c:190
    0x00000000004ce462 in multiqueue_process_events (this=0x7f96e18172d0) at ../src/nvim/event/multiqueue.c:150
    0x000000000059b630 in nv_event (cap=0x7ffed792f620) at ../src/nvim/normal.c:7908
    0x000000000058be69 in normal_execute (state=0x7ffed792f580, key=-25341) at ../src/nvim/normal.c:1137
    0x0000000000652463 in state_enter (s=0x7ffed792f580) at ../src/nvim/state.c:61
    0x000000000058a1fe in normal_enter (cmdwin=false, noexmode=false) at ../src/nvim/normal.c:467
    0x00000000005500c2 in main (argc=2, argv=0x7ffed792f8d8) at ../src/nvim/main.c:554

Alternative approach suggested by bfredl is to use close_cb of the
process. My unsuccessful attempt is below. (It seems close_cb is queued
too late, which is the similar problem addressed by this commit):

    commit 75fc12c6ab15711bdb7b18c6d42ec9d157f5145e
    Author: Justin M. Keyes <justinkz@gmail.com>
    Date:   Fri Aug 18 01:30:41 2017 +0200

        rpc: use Stream's close_cb instead of explicit check in receive_msgpack()

    diff --git a/src/nvim/event/process.c b/src/nvim/event/process.c
    index 8371d3cd482e..e52da23cdc40 100644
    --- a/src/nvim/event/process.c
    +++ b/src/nvim/event/process.c
    @@ -416,6 +416,10 @@ static void on_process_exit(Process *proc)
     static void on_process_stream_close(Stream *stream, void *data)
     {
       Process *proc = data;
    +  ILOG("on_process_stream_close");
    +  if (proc->stream_close_cb != NULL) {
    +    proc->stream_close_cb(stream, proc->stream_close_data);
    +  }
       decref(proc);
     }

    diff --git a/src/nvim/event/process.h b/src/nvim/event/process.h
    index 5c00e8e7ecd5..34a8d54f6f8c 100644
    --- a/src/nvim/event/process.h
    +++ b/src/nvim/event/process.h
    @@ -26,6 +26,11 @@ struct process {
       Stream *in, *out, *err;
       process_exit_cb cb;
       internal_process_cb internal_exit_cb, internal_close_cb;
    +
    +  // Called when any of the process streams (in/out/err) closes.
    +  stream_close_cb stream_close_cb;
    +  void *stream_close_data;
    +
       bool closed, detach;
       MultiQueue *events;
     };
    @@ -50,6 +55,8 @@ static inline Process process_init(Loop *loop, ProcessType type, void *data)
         .closed = false,
         .internal_close_cb = NULL,
         .internal_exit_cb = NULL,
    +    .stream_close_cb = NULL,
    +    .stream_close_data = NULL,
         .detach = false
       };
     }
    diff --git a/src/nvim/event/stream.c b/src/nvim/event/stream.c
    index 7c865bfe1e8c..c8720d1e45d9 100644
    --- a/src/nvim/event/stream.c
    +++ b/src/nvim/event/stream.c
    @@ -95,7 +95,11 @@ void stream_close(Stream *stream, stream_close_cb on_stream_close, void *data)
     void stream_close_handle(Stream *stream)
       FUNC_ATTR_NONNULL_ALL
     {
    +  ILOG("stream=%d", stream);
    +  // LOG_CALLSTACK();
       if (stream->uvstream) {
    +    // problem:  this schedules on the queue, but channel.c:receive_msgpack may
    +    // be processed before close_cb is called by libuv.
         uv_close((uv_handle_t *)stream->uvstream, close_cb);
       } else {
         uv_close((uv_handle_t *)&stream->uv.idle, close_cb);
    @@ -105,6 +109,7 @@ void stream_close_handle(Stream *stream)
     static void close_cb(uv_handle_t *handle)
     {
       Stream *stream = handle->data;
    +  ILOG(">>>>>>>>>>>>>>>>>>>>>>> stream=%p stream->internal_close_cb=%p", stream, stream->internal_close_cb);
       if (stream->buffer) {
         rbuffer_free(stream->buffer);
       }
    diff --git a/src/nvim/msgpack_rpc/channel.c b/src/nvim/msgpack_rpc/channel.c
    index 782eabe04e4a..dc2b794e366a 100644
    --- a/src/nvim/msgpack_rpc/channel.c
    +++ b/src/nvim/msgpack_rpc/channel.c
    @@ -128,6 +128,8 @@ uint64_t channel_from_process(Process *proc, uint64_t id, char *source)
                                           source);
       incref(channel);  // process channels are only closed by the exit_cb
       channel->data.proc = proc;
    +  channel->data.proc->stream_close_cb = close_cb2;
    +  channel->data.proc->stream_close_data = channel;

       wstream_init(proc->in, 0);
       rstream_init(proc->out, 0);
    @@ -387,17 +389,6 @@ static void receive_msgpack(Stream *stream, RBuffer *rbuf, size_t c,
         goto end;
       }

    -  if ((chan_wstream(channel) != NULL && chan_wstream(channel)->closed)
    -      || (chan_rstream(channel) != NULL && chan_rstream(channel)->closed)) {
    -    char buf[256];
    -    snprintf(buf, sizeof(buf),
    -             "ch %" PRIu64 ": stream closed unexpectedly. "
    -             "closing channel",
    -             channel->id);
    -    call_set_error(channel, buf, WARN_LOG_LEVEL);
    -    goto end;
    -  }
    -
       size_t count = rbuffer_size(rbuf);
       DLOG("ch %" PRIu64 ": parsing %u bytes from msgpack Stream: %p",
            channel->id, count, stream);
    @@ -571,23 +562,6 @@ static Stream *chan_wstream(Channel *chan)
       abort();
     }

    -/// Returns the Stream that a Channel reads from.
    -static Stream *chan_rstream(Channel *chan)
    -{
    -  switch (chan->type) {
    -    case kChannelTypeSocket:
    -      return &chan->data.stream;
    -    case kChannelTypeProc:
    -      return chan->data.proc->out;
    -    case kChannelTypeStdio:
    -      return &chan->data.std.in;
    -    case kChannelTypeInternal:
    -      return NULL;
    -  }
    -  abort();
    -}
    -
    -
     static bool channel_write(Channel *channel, WBuffer *buffer)
     {
       bool success = false;
    @@ -799,6 +773,12 @@ static void close_cb(Stream *stream, void *data)
       decref(data);
     }

    +static void close_cb2(Stream *stream, void *data)
    +{
    +  ILOG("close_cb2");
    +  close_channel(data);
    +}
    +
     /// @param source description of source function, rplugin name, TCP addr, etc
     static Channel *register_channel(ChannelType type, uint64_t id,
                                      MultiQueue *events, char *source)
This commit is contained in:
Justin M. Keyes 2017-07-27 01:08:50 +02:00
parent e006b1d98d
commit af993da435
5 changed files with 80 additions and 23 deletions

View File

@ -250,7 +250,7 @@ static bool v_do_log_to_file(FILE *log_file, int log_level,
static const char *log_levels[] = {
[DEBUG_LOG_LEVEL] = "DEBUG",
[INFO_LOG_LEVEL] = "INFO ",
[WARNING_LOG_LEVEL] = "WARN ",
[WARN_LOG_LEVEL] = "WARN ",
[ERROR_LOG_LEVEL] = "ERROR",
};
assert(log_level >= DEBUG_LOG_LEVEL && log_level <= ERROR_LOG_LEVEL);

View File

@ -6,7 +6,7 @@
#define DEBUG_LOG_LEVEL 0
#define INFO_LOG_LEVEL 1
#define WARNING_LOG_LEVEL 2
#define WARN_LOG_LEVEL 2
#define ERROR_LOG_LEVEL 3
#define DLOG(...)
@ -43,12 +43,12 @@
__VA_ARGS__)
#endif
#if MIN_LOG_LEVEL <= WARNING_LOG_LEVEL
#if MIN_LOG_LEVEL <= WARN_LOG_LEVEL
# undef WLOG
# undef WLOGN
# define WLOG(...) do_log(WARNING_LOG_LEVEL, __func__, __LINE__, true, \
# define WLOG(...) do_log(WARN_LOG_LEVEL, __func__, __LINE__, true, \
__VA_ARGS__)
# define WLOGN(...) do_log(WARNING_LOG_LEVEL, __func__, __LINE__, false, \
# define WLOGN(...) do_log(WARN_LOG_LEVEL, __func__, __LINE__, false, \
__VA_ARGS__)
#endif

View File

@ -62,7 +62,7 @@ typedef struct {
ChannelType type;
msgpack_unpacker *unpacker;
union {
Stream stream;
Stream stream; // bidirectional (socket)
Process *proc;
struct {
Stream in;
@ -154,7 +154,8 @@ void channel_from_connection(SocketWatcher *watcher)
rstream_init(&channel->data.stream, CHANNEL_BUFFER_SIZE);
rstream_start(&channel->data.stream, receive_msgpack, channel);
DLOG("ch %" PRIu64 " in/out-stream=%p", &channel->data.stream);
DLOG("ch %" PRIu64 " in/out-stream=%p", channel->id,
&channel->data.stream);
}
/// @param source description of source function, rplugin name, TCP addr, etc
@ -383,7 +384,18 @@ static void receive_msgpack(Stream *stream, RBuffer *rbuf, size_t c,
char buf[256];
snprintf(buf, sizeof(buf), "ch %" PRIu64 " was closed by the client",
channel->id);
call_set_error(channel, buf, WARNING_LOG_LEVEL);
call_set_error(channel, buf, WARN_LOG_LEVEL);
goto end;
}
if ((chan_wstream(channel) != NULL && chan_wstream(channel)->closed)
|| (chan_rstream(channel) != NULL && chan_rstream(channel)->closed)) {
char buf[256];
snprintf(buf, sizeof(buf),
"ch %" PRIu64 ": stream closed unexpectedly. "
"closing channel",
channel->id);
call_set_error(channel, buf, WARN_LOG_LEVEL);
goto end;
}
@ -445,7 +457,7 @@ static void parse_msgpack(Channel *channel)
// causes for this error(search for 'goto _failed')
//
// A not so uncommon cause for this might be deserializing objects with
// a high nesting level: msgpack will break when it's internal parse stack
// a high nesting level: msgpack will break when its internal parse stack
// size exceeds MSGPACK_EMBED_STACK_SIZE (defined as 32 by default)
send_error(channel, 0, "Invalid msgpack payload. "
"This error can also happen when deserializing "
@ -544,6 +556,39 @@ static void on_request_event(void **argv)
api_clear_error(&error);
}
/// Returns the Stream that a Channel writes to.
static Stream *chan_wstream(Channel *chan)
{
switch (chan->type) {
case kChannelTypeSocket:
return &chan->data.stream;
case kChannelTypeProc:
return chan->data.proc->in;
case kChannelTypeStdio:
return &chan->data.std.out;
case kChannelTypeInternal:
return NULL;
}
abort();
}
/// Returns the Stream that a Channel reads from.
static Stream *chan_rstream(Channel *chan)
{
switch (chan->type) {
case kChannelTypeSocket:
return &chan->data.stream;
case kChannelTypeProc:
return chan->data.proc->out;
case kChannelTypeStdio:
return &chan->data.std.in;
case kChannelTypeInternal:
return NULL;
}
abort();
}
static bool channel_write(Channel *channel, WBuffer *buffer)
{
bool success = false;
@ -555,13 +600,9 @@ static bool channel_write(Channel *channel, WBuffer *buffer)
switch (channel->type) {
case kChannelTypeSocket:
success = wstream_write(&channel->data.stream, buffer);
break;
case kChannelTypeProc:
success = wstream_write(channel->data.proc->in, buffer);
break;
case kChannelTypeStdio:
success = wstream_write(&channel->data.std.out, buffer);
success = wstream_write(chan_wstream(channel), buffer);
break;
case kChannelTypeInternal:
incref(channel);

View File

@ -361,7 +361,7 @@ typedef struct {
size_t idx;
} APIToMPObjectStackItem;
/// Convert type used by Neovim API to msgpack
/// Convert type used by Nvim API to msgpack type.
///
/// @param[in] result Object to convert.
/// @param[out] res Structure that defines where conversion results are saved.

View File

@ -20,6 +20,22 @@ describe('server -> client', function()
cid = nvim('get_api_info')[1]
end)
it('handles unexpected closed stream while preparing RPC response', function()
source([[
let g:_nvim_args = [v:progpath, '--embed', '-n', '-u', 'NONE', '-i', 'NONE', ]
let ch1 = jobstart(g:_nvim_args, {'rpc': v:true})
let child1_ch = rpcrequest(ch1, "nvim_get_api_info")[0]
call rpcnotify(ch1, 'nvim_eval', 'rpcrequest('.child1_ch.', "nvim_get_api_info")')
let ch2 = jobstart(g:_nvim_args, {'rpc': v:true})
let child2_ch = rpcrequest(ch2, "nvim_get_api_info")[0]
call rpcnotify(ch2, 'nvim_eval', 'rpcrequest('.child2_ch.', "nvim_get_api_info")')
call jobstop(ch1)
]])
eq(2, eval("1+1")) -- Still alive?
end)
describe('simple call', function()
it('works', function()
local function on_setup()
@ -141,7 +157,7 @@ describe('server -> client', function()
end)
end)
describe('when the client is a recursive vim instance', function()
describe('recursive (child) nvim client', function()
if os.getenv("TRAVIS") and helpers.os_name() == "osx" then
-- XXX: Hangs Travis macOS since e9061117a5b8f195c3f26a5cb94e18ddd7752d86.
pending("[Hangs on Travis macOS. #5002]", function() end)
@ -155,7 +171,7 @@ describe('server -> client', function()
after_each(function() command('call rpcstop(vim)') end)
it('can send/recieve notifications and make requests', function()
it('can send/receive notifications and make requests', function()
nvim('command', "call rpcnotify(vim, 'vim_set_current_line', 'SOME TEXT')")
-- Wait for the notification to complete.
@ -188,7 +204,7 @@ describe('server -> client', function()
end)
end)
describe('when using jobstart', function()
describe('jobstart()', function()
local jobid
before_each(function()
local channel = nvim('get_api_info')[1]
@ -227,7 +243,7 @@ describe('server -> client', function()
end)
end)
describe('when connecting to another nvim instance', function()
describe('connecting to another (peer) nvim', function()
local function connect_test(server, mode, address)
local serverpid = funcs.getpid()
local client = spawn(nvim_argv)
@ -256,7 +272,7 @@ describe('server -> client', function()
client:close()
end
it('over a named pipe', function()
it('via named pipe', function()
local server = spawn(nvim_argv)
set_session(server)
local address = funcs.serverlist()[1]
@ -265,7 +281,7 @@ describe('server -> client', function()
connect_test(server, 'pipe', address)
end)
it('to an ip adress', function()
it('via ip address', function()
local server = spawn(nvim_argv)
set_session(server)
local address = funcs.serverstart("127.0.0.1:")
@ -273,7 +289,7 @@ describe('server -> client', function()
connect_test(server, 'tcp', address)
end)
it('to a hostname', function()
it('via hostname', function()
local server = spawn(nvim_argv)
set_session(server)
local address = funcs.serverstart("localhost:")