Some dependent packages on some platforms may also define HAVE_DLOPEN
and that definition may have different syntax or semantics. This change
avoids the potential symbol conflict.
As reported in #1098
Also provide a way to build so that the IPv6 fallback stubs can be tested on
systems with native IPv6 support when compiled with TEST_INFO_STUBS
defined.
Outbound connections are rare and most may have wanted explicit blocking
behavior, so no one noticed the missing non-blocking case.
Any place which did do outbound connects have explicitly added
SIM_SOCK_OPT_BLOCKING so that the prior behavior is preserved.
The SIM_SOCK_OPT_BLOCKING flag is no honored as it was originally
intended to be.
These changes facilitate more robust parameter type checking and helps
to identify unexpected coding errors.
Most simulators can now also be compiled with a C++ compiler without
warnings.
Additionally, these changes have also been configured to facilitate easier
backporting of simulator and device simulation modules to run under the
simh v3.9+ SCP framework.
Cleanup/Simplification by:
1) removing irrelevant master flag variable from sim_close_sock and thus sim_err_sock
2) change previous boolean feature arguments (datagram, nodelay, reuseaddr) to flag bits in a single option argument. This allows for features to be added by new flag bits which don't change the calling signatures.
3) changed all status returns to be int (vs t_stat) with success being 0 and error being -1
4) removed unneeded simh specific type references to allow sim_sock to be used by n
Extended API by providing flags to influence socket setup/behavior:
SIM_SOCK_OPT_REUSEADDR Retains prior behavior when sim_switches had -U set
SIM_SOCK_OPT_DATAGRAM UDP socket setup provided for when prior datagram argument was specified
SIM_SOCK_OPT_NODELAY TCP Nagle disable provided for when prior nodelay argument was specified
SIM_SOCK_OPT_BLOCKING Blocking socket mode (detault is non blocking)
Avoid permanent network network hangs when a network transport starts to return errors for various reasons.
These hangs also result in at least one thread in a CPU bound loop attempting to read on a pcap connection which will never be useful again.
When transmit or receive errors occur, the invoking thread sleeps for 1 second and subsequent operations proceed. When the total of read + write errors reaches a multiple of ETH_ERROR_REOPEN_THRESHOLD the current transport connection (usually pcap) is closed and re-opened after a ETH_ERROR_REOPEN_PAUSE second delay. If the open succeeds, we're happy. If it fails, then the link behaves as if it were never attached until some subsequent operator intervention is performed.
Activities which are known to induce this problems include (but are not limited to) when a simulator is running in a Windows Virtual Machine on a Hyper-V host system and the Hyper-V host system performs a SAVE and a subsequent Restart of the Guest Windows Virtual Machine. This operation can occur due to specific operator requests or merely when the Hyper-V host system reboots.
The goals here being to simplify calling code while getting consistent output delivered everywhere it may be useful.
Modified most places which explicitly used sim_log or merely called printf to now avoid doing that and merely call sim_printf().
- Avoid assignments of void * values. Cast all memory allocation return values to appropriate types.
- Add output to sim_log where missing in various places.
- Fixed issue with lost file positions after a restore for devices which leverage the UNIT_SEQ flag.
1. getaddrinfo returns IPv6 address even if IPv6 is not configured.
The socket syscalls fails to create IPv6 socket. This is fixed by retrying for all possible addresses returned by getaddrinfo.
2. On HP-UX EAGAIN is used, not EWOULDBLOCK.
