site: Document some reentrancy hazards in comments

No functional change.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---
New patch in v2 of the series.

diff --git a/site.c b/site.c
index fe0e1a7f6ca14f8ab666442ad808c8c247b9cad1..11690523b066ea66a707769720e92d7f70cb6d88 100644 (file)
--- a/site.c
+++ b/site.c
@@ -1174,6 +1174,7 @@ static void site_resolve_callback(void *sst, struct in_addr *address)
 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
                                 const struct comm_addr *prod_hint)
 {
 static bool_t initiate_key_setup(struct site *st, cstring_t reason,
                                 const struct comm_addr *prod_hint)
 {

+    /* Reentrancy hazard: can call enter_new_state/enter_state_* */

     if (st->state!=SITE_RUN) return False;
     slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
     if (st->address) {
     if (st->state!=SITE_RUN) return False;
     slog(st,LOG_SETUP_INIT,"initiating key exchange (%s)",reason);
     if (st->address) {


@@ -1286,6 +1287,7 @@ static void enter_state_run(struct site *st)
 
 static bool_t enter_state_resolve(struct site *st)
 {
 
 static bool_t enter_state_resolve(struct site *st)
 {

+    /* Reentrancy hazard!  See ensure_resolving. */

     state_assert(st,st->state==SITE_RUN);
     slog(st,LOG_STATE,"entering state RESOLVE");
     st->state=SITE_RESOLVE;
     state_assert(st,st->state==SITE_RUN);
     slog(st,LOG_STATE,"entering state RESOLVE");
     st->state=SITE_RESOLVE;