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Diffstat (limited to 'src/vppinfra/callback.h')
| -rw-r--r-- | src/vppinfra/callback.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/src/vppinfra/callback.h b/src/vppinfra/callback.h new file mode 100644 index 00000000000..595d69d72ab --- /dev/null +++ b/src/vppinfra/callback.h @@ -0,0 +1,111 @@ +/* + * 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: + */ |