feat: responses might be executed before canister_on_low_wasm_memory (#271)

This PR specifies that responses might still be executed after the
condition for `canister_on_low_wasm_memory` is triggered and before the
function `canister_on_low_wasm_memory` is actually executed.

---------

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: mraszyk

docs/references/ic-interface-spec/abstract-behavior.md

@@ -1245,14 +1245,15 @@ Conditions
 S.messages = Older_messages · FuncMessage M · Younger_messages
 (M.queue = Unordered) or (∀ CallMessage M' | FuncMessage M' ∈ Older_messages. M'.queue ≠ M.queue)
 (∀ FuncMessage M' ∈ Older_messages · Younger_messages. M'.receiver ≠ M.receiver or M.entry_point ≠ OnLowWasmMemory)
-S.on_low_wasm_memory_hook_status[M.receiver] ≠ Ready
 S.canisters[M.receiver] ≠ EmptyCanister
 Mod = S.canisters[M.receiver].module
 Ctxt = S.call_contexts[M.call_context]
 Deadline = deadline_of_context(Ctxt)
 
 Is_response = M.entry_point == Callback _ _ _
 
+S.on_low_wasm_memory_hook_status[M.receiver] ≠ Ready or Is_response
+
 Env = {
   time = S.time[M.receiver];
   controllers = S.controllers[M.receiver];

docs/references/ic-interface-spec/canister-interface.md

@@ -179,7 +179,9 @@ The threshold `t` can be defined in the field `wasm_memory_threshold` in the [ca
 :::note
 
 While the above function is scheduled immediately once the condition above is triggered, it may not necessarily be executed immediately if the canister does not have enough cycles.
-If the canister gets frozen immediately after the function is scheduled for execution, the function will run once the canister's unfrozen _if_ the canister's remaining wasm memory size in bytes remains strictly less than the threshold `t`.
+If the canister gets frozen immediately after the function is scheduled for execution, the function will run once the canister is unfrozen _if_ the canister's remaining wasm memory size in bytes remains strictly less than the threshold `t`.
+In particular, inter-canister response callback messages might still be executed after the condition is triggered and before the function `canister_on_low_wasm_memory` is executed.
+
 :::
 
 #### Callbacks

docs/references/ic-interface-spec/changelog.md

@@ -8,6 +8,10 @@ sidebar:
 
 ## Changelog {#changelog}
 
+### 0.62.0 (2025-05-26) {$0_62_0}
+* Inter-canister response callback messages might still be executed after the condition for `canister_on_low_wasm_memory` is triggered
+  and before the function `canister_on_low_wasm_memory` is executed.
+
 ### 0.61.0 (2025-05-18) {$0_61_0}
 * New management canister endpoint `canister_metrics`.