update(docs): add a couple of statements about m_ctx_deregister api.

Signed-off-by: Federico Di Pierro <[email protected]>

Author: FedeDP

TODO.md

@@ -23,7 +23,7 @@
 #### DOC
 
 - [x] Fully rewrite documentation per-namespace
-- [ ] Document that m_ctx_deregister() cannot be called on a looping context (`M_PARAM_ASSERT(c && *c && (*c)->state == M_CTX_IDLE);`)
+- [x] Document that m_ctx_deregister() cannot be called on a looping context (`M_PARAM_ASSERT(c && *c && (*c)->state == M_CTX_IDLE);`)
 - [ ] document m_evt_t memref'd behaviour!!!
 - [ ] Document stats and thresh activity_freq (num_action_per_ms)
 

docs/core/ctx.md

@@ -52,6 +52,10 @@ int m_ctx_register(const char *ctx_name, m_ctx_t **c, m_ctx_flags flags, const v
 int m_ctx_deregister(m_ctx_t **c);
 ```
 > Deregister a ctx.  
+> NOTE: this API cannot be called if the ctx is still looping.  
+> Make sure to `m_ctx_quit` the loop before deregistering a context.  
+> NOTE: unless a ctx is registered with `M_CTX_PERSIST` flag, it will get  
+> automatically destroyed when there are no more modules registered in it.  
 
 **Params:**