Add set-capacity API

x0id · Feb 26, 2024 · c2f4757 · c2f4757
1 parent 1185069
commit c2f4757
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Showing 2 changed files with 37 additions and 3 deletions.
diff --git a/c_src/sema_nif.cpp b/c_src/sema_nif.cpp
@@ -86,6 +86,11 @@ struct sema {
 
     sema(unsigned n) : cnt(0), dead_counter(0), max(n) {}
 
+    ERL_NIF_TERM set_capacity(unsigned n) {
+        max = n;
+        return atom_ok;
+    }
+
     ERL_NIF_TERM info(ErlNifEnv *env) {
         ERL_NIF_TERM keys[] = {atom_dead, atom_cnt, atom_max};
         ERL_NIF_TERM vals[] = {
@@ -356,14 +361,37 @@ release(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
     return res->release(env, pid, n);
 }
 
+static ERL_NIF_TERM
+set_capacity(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    if (argc != 2)
+        return enif_make_badarg(env);
+
+    sema *res = nullptr;
+    if (!enif_get_resource(env, argv[0], SEMA, (void **)&res))
+        return enif_make_badarg(env);
+
+    if (res == nullptr)
+        return enif_make_badarg(env);
+
+    unsigned n = 1;
+    if (enif_is_number(env, argv[1]))
+        enif_get_uint(env, argv[1], &n);
+    else
+        return enif_make_badarg(env);
+
+    return n > 0 ? res->set_capacity(n) : enif_make_badarg(env);
+}
+
 static ErlNifFunc nif_funcs[] = {
     {"create", 1, create},
     {"info", 1, info},
     {"acquire", 1, acquire},
     {"acquire", 2, acquire},
     {"release", 1, release},
     {"release", 2, release},
-    {"release", 3, release}
+    {"release", 3, release},
+    {"release", 3, release},
+    {"set_capacity", 2, set_capacity}
 };
 
 ERL_NIF_INIT(sema_nif, nif_funcs, &load, nullptr, nullptr, nullptr);
diff --git a/src/sema_nif.erl b/src/sema_nif.erl
@@ -7,7 +7,8 @@
     acquire/2,
     release/1,
     release/2,
-    release/3
+    release/3,
+    set_capacity/2
 ]).
 
 -nifs([
@@ -17,7 +18,8 @@
     acquire/2,
     release/1,
     release/2,
-    release/3
+    release/3,
+    set_capacity/2
 ]).
 
 -on_load(init/0).
@@ -76,6 +78,10 @@ release(_, _) -> not_loaded(?LINE).
 -spec release(Semaphore :: sema_ref(), Cnt :: pos_integer(), Pid :: pid()) -> Ret :: release_ret().
 release(_, _, _) -> not_loaded(?LINE).
 
+% set (update) semaphore capacity
+-spec set_capacity(Semaphore :: sema_ref(), Cnt :: pos_integer()) -> ok.
+set_capacity(_, _) -> not_loaded(?LINE).
+
 % internal
 init() ->
     SoName =