SocketStats Class is added to collect and provide the statistics information.
In this phase only socket information is collected and max sockets that can
be recorded at any time are configurable through 'MBED_CONF_NSAPI_SOCKET_STATS_MAX_COUNT'
Network statistics can be enabled through a macro MBED_NW_STATS_ENABLED
More information on design is captured in #8743
* Move IP Socket stuff to InternetSocket class which is inherited by TCP/UDP
* Implement sendto() and recvfrom() on TCP socket
* Implement connect() call on UDP
* Implement send() and recv() calls on UDP socket
Note, the registered callback is still disabled by a call to
socket_attach. This will avoid being called after the socket is closed
unless close is called from the attached callback, which is in irq
context.
As pointed out by kjbracey-arm, the previous behaviour was broken
for sockets that started out listening.
It's currently possible to generate a socket event when a non-blocking socket is closed:
1. _pending is set to 0 in https://github.com/ARMmbed/mbed-os/blob/master/features/netsocket/TCPSocket.cpp#L22
when the socket is created.
2. close() calls event() in https://github.com/ARMmbed/mbed-os/blob/master/features/netsocket/Socket.cpp#L66
3. event() increments _pending, and since _pending is 1 it will call _callback() in https://github.com/ARMmbed/mbed-os/blob/master/features/netsocket/TCPSocket.cpp#L167
However, if send() (for example) is called, this can happen:
- send() is called and sets _pending to 0.
- when the data is sent, event() is called, which sets _pending to 1 and calls _callback().
- if close() is called at this point, there won't be an event generated for close() anymore,
since _pending will be set to 2.
Same thing for recv. Also, same thing for TCPServer and UDPSocket.
This PR changes the initial value of _pending to 1 instead of 0, so that
events are never generated for close().
Initially these assertions were added to protected simultaneous
send/recv from the same socket when similarly purposed mutexes were
removed.
However, simultaneous send/recv can still be useful for UDP if the
payload is guaranteed to be less than the MTU across the entire
connection.
nsapi_error_t - enum of errors or 0 for NSAPI_ERROR_OK
nsapi_size_t - unsigned size of data that could be sent
nsapi_size_or_error_t - either a non-negative size or negative error
Deepika
Michal Paszta
Amanda Butler
paul-szczepanek-arm
Martin Kojtal
Seppo Takalo
Christopher Haster
Bogdan Marinescu
Martin Kojtal
Jimmy Brisson