Squashed commit of the following:
net/tmp: Rename the unacked field of the tcp connection structure to tx_unacked. Too confusing with the implementation of delayed RX ACKs.
net/tcp: Initial implementation of TCP delayed ACKs.
net/tcp: Add delayed ACK configuration selection. Rename tcp_ack() to tcp_synack(). It may or may not send a ACK. It will always send SYN or SYN/ACK.
1) The change of commit ed9fe70024 left some dangling logic and incorrect, confusing comments. Prior to that commit the 'pstate' variable was non-NULL only when doing a lingering close. Comments to this effect as well as tests of pstate should also have been updated. These are confusing and inappropriate, but do not lead to incorrect behavior.
2) Eliminate an incomplete test when a disconnection event. When a disconnection event occurs, the close logic MUST always terminate the wait. The conditional test was not incorrect, however, it lacked 'else' logic and would simply ignore that disconnection event in some cases. That is bad because there may not be another disconnection event and that can lead to hangs (or at least very, very long delays).
Squashed commit of the following:
net/: Fix some naming inconsistencies, Fix final compilation issies.
net/inet/inet_close(): Now that we have logic to drain the buffered TX data, we can implement a proper lingering close.
net/inet,tcp,udp: Add functions to wait for write buffers to drain.
net/udp: Add support for notification when the UDP write buffer becomes empty.
net/tcp: Add support for notification when the TCP write buffer becomes empty.
net/inet: Fix tcp active close in inet_close.c
In previous implementation, FIN packet was not sent when a socket
is actively closed (e.g. telnetd or webserver) without SO_LINGER.
This issue happens because the socket closing sequence waits for
the status.cl_sem only if lingering timeout is set. However,
in many server use-cases, SO_LINGER is not usually set and even
in these cases, FIN packet must be sent correctly.
This PR changes the logic in inet_close.c so that it can wait
for status.cl_sem regardless of SO_LINGER. Instead, if SO_LINGER
is set, it waits for the semaphore with timeout option.
Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
Approved-by: Gregory Nutt <gnutt@nuttx.org>
Squashed commit of the following:
sched: Rename all use of system_t to clock_t.
syscall: Rename all use of system_t to clock_t.
net: Rename all use of system_t to clock_t.
libs: Rename all use of system_t to clock_t.
fs: Rename all use of system_t to clock_t.
drivers: Rename all use of system_t to clock_t.
arch: Rename all use of system_t to clock_t.
include: Remove definition of systime_t; rename all use of system_t to clock_t.
sched/semaphore: Add nxsem_post() which is identical to sem_post() except that it never modifies the errno variable. Changed all references to sem_post in the OS to nxsem_post().
sched/semaphore: Add nxsem_destroy() which is identical to sem_destroy() except that it never modifies the errno variable. Changed all references to sem_destroy() in the OS to nxsem_destroy().
libc/semaphore and sched/semaphore: Add nxsem_getprotocol() and nxsem_setprotocola which are identical to sem_getprotocol() and set_setprotocol() except that they never modifies the errno variable. Changed all references to sem_setprotocol in the OS to nxsem_setprotocol(). sem_getprotocol() was not used in the OS
libc/semaphore: Add nxsem_getvalue() which is identical to sem_getvalue() except that it never modifies the errno variable. Changed all references to sem_getvalue in the OS to nxsem_getvalue().
sched/semaphore: Rename all internal private functions from sem_xyz to nxsem_xyz. The sem_ prefix is (will be) reserved only for the application semaphore interfaces.
libc/semaphore: Add nxsem_init() which is identical to sem_init() except that it never modifies the errno variable. Changed all references to sem_init in the OS to nxsem_init().
sched/semaphore: Rename sem_tickwait() to nxsem_tickwait() so that it is clear this is an internal OS function.
sched/semaphoate: Rename sem_reset() to nxsem_reset() so that it is clear this is an internal OS function.
Gregory Nutt