/* * Copyright (c) 2019 Cisco and/or its affiliates. * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ /** @file * @brief Callback multiplex scheme * For a fully worked-out example, see .../src/vlib/main.[ch] and * .../src/plugins/perfmon.c */ #ifndef included_callback_h #define included_callback_h #include <vppinfra/clib.h> /** @brief Add or remove a callback to the specified callback set * @param h head of the callback vector * @param tmp vector to build result * @param l clib_spinlock_t lock to protect the vector, may be 0 * @param f function to add or remove * @param enable 1 adds f to the vector, 0 removes f from the vector * * Add or remove a callback from the indicated callback vector. * Caller must provide locking to prevent > 1 concurrent writer * Swaps the head of the callback vector and a tmp vector in one * motion, after a write barrier to ensure that the write is atomic. */ #define clib_callback_enable_disable(h,tmp,l,f,enable) \ do { \ void *tmp2; \ clib_spinlock_lock_if_init(&l); \ vec_reset_length(tmp); \ vec_append(tmp, h); \ if (enable) \ vec_add1 (tmp,(void *)f); \ else \ { \ int i; \ for (i = 0; i < vec_len (tmp); i++) \ if (((void *)tmp[i]) == (void *)f) \ { \ vec_delete (tmp, 1, i); \ break; \ } \ } \ tmp2 = h; \ CLIB_MEMORY_STORE_BARRIER(); \ h = tmp; \ tmp = tmp2; \ clib_spinlock_unlock_if_init(&l); \ } while(0); /** @brief call the specified callback set * @param h the callback set * @param varargs additional callback parameters */ #define clib_call_callbacks(h, ... ) \ do { \ /* \ * Note: fp exists to shut up gcc-6, which \ * produces a warning not seen with gcc-7 or 8 \ */ \ void (*fp)(void *a1, ...); \ int i; \ for (i = 0; i < vec_len (h); i++) \ { \ fp = (void *)(h[i]); \ (*fp) (__VA_ARGS__); \ } \ } while (0); /** @brief predicate function says whether the specified function is enabled * @param h the callback set * @param l clib_spinlock_t lock to protect the vector, may be 0 * @param f the function to search for * @return 1 if the function is enabled, 0 if not */ #define clib_callback_is_set(h,l,f) \ ({ \ int _i; \ int _found = 0; \ clib_spinlock_lock_if_init(&l); \ for (_i = 0; _i < vec_len (h); _i++) \ if (((void *)h[_i]) == (void *) f) \ { \ _found=1; \ break; \ } \ clib_spinlock_unlock_if_init(&l); \ _found; \ }) #endif /* included_callback_h */ /* * fd.io coding-style-patch-verification: ON * * Local Variables: * eval: (c-set-style "gnu") * End: */