request.end() would sometimes try to write a zero-length buffer to the socket.
Don't do that, it triggers an unnecessary EPIPE when the other end has closed
the connection.
Fixes#3257.
Before this commit, process._getActiveHandles() returned a list of internal
handles. Now, it returns the user objects that handles are attached to.
For example, a tcp_wrap handle will now return its parent net.Socket object.
It works for all handle types except timers because timer handles are shared
across multiple user objects.
* process._getActiveHandles() returns a list containing all active handles
(timers, sockets, etc.) that have not been unref'd.
* process._getActiveRequests() returns a list of active requests (in-flight
actions like connecting to a remote host, writing data to a socket, etc.).
Share persistent strings process_symbol and domain_symbol across compilation
units. Avoids redefinition errors when src/node.cc includes src/req_wrap.h.
child_process.fork() support sending native hander object, this patch add support for sending
net.Server and net.Socket object by converting the object to a native handle object and back
to a useful object again.
Note when sending a Socket there was emitted by a net Server object, the server.connections
property becomes null, because it is no longer possible to known when it is destroyed.
Prevents accidental inheritance by child processes. If the child process is a
node process, it would try to set up a channel with the parent and consequently
never quit because the channel kept the event loop alive.
Fixes#3240.
This frees us from manually having to copy over functions to SlowBuffer's
prototype (which has bitten us multiple times in the past).
As an added bonus, the `inspect()` function is now shared between Buffer
and SlowBuffer, removing some duplicate code.
Closes#3228.