Original issue (data race when updating hostname): mdns_service_add()
makes a copy of the local hostname and calls using the local copy
mdns_service_add_for_host().
When mdns's hostname is updated the local copy gets out of sync.
**API race issue**: Most of the current API correctly lock the mdns service,
but sometimes unlocks it before sending an action to the action queue,
so it's possible that the situation changes before the actual action
takes place.
**Fix**: After locking the mdns service, we proceed directly with updating
internal structures and do not post actions into the action queue.
**Fix wrtt hostname**: Use mdns_service_add_for_host(hostname=NULL)
for all self hosted services.
MAJOR CHANGE: Fixed mdns API issues when add/remove/update records from multiple threads
This and the following commits fix the API race issues for these mdns APIs:
* mdns_service_add_for_host
* mdns_service_port_set_for_host
* mdns_service_txt_set_for_host
* mdns_service_txt_item_set_for_host_with_explicit_value_len
* mdns_service_txt_item_remove_for_host
* mdns_service_subtype_add_for_host
* mdns_service_instance_name_set_for_host
* mdns_service_remove_for_host
* mdns_service_remove_all
the lookup_service API calls _copy_mdns_txt_items(), which tries to
allocate new TXT records, but didn't handle the case with no TXT.
Originally the _copy_mdns_txt_items() called calloc() with zero's which
returned NULL (on espressif toolchain), so it's safe, but we could see
an error message:
E (1170) mdns: Cannot allocate memory (line: 6191, free heap: 281368 bytes)
This commit addresses the empty TXT case and gets rid of the error
message.
0.2.0
Features
- Add support for SDIO transport (085dd790)
Bug Fixes
- Fixed strict prototype API decl issue in SDIO (eb09e426)
- Fix SIDO host to check/clear interrupts atomically (402176c9)
* private field 'netif' is not used [clang-diagnostic-unused-private-field]
* private field 'instance' is not used [clang-diagnostic-unused-private-field]
* Call to virtual method 'FdTerminal::stop' during destruction bypasses virtual dispatch [clang-analyzer-optin.cplusplus.VirtualCall]
* unused variable 'TAG' [clang-diagnostic-unused-const-variable]
* Null pointer passed as 2nd argument to memory copy function [clang-analyzer-unix.cstring.NullArg]
* Array access (from variable 'data') results in a null pointer dereference [clang-analyzer-core.NullDereference]