diff --git a/include/common/initcall.h b/include/common/initcall.h new file mode 100644 index 000000000..35d237fdd --- /dev/null +++ b/include/common/initcall.h @@ -0,0 +1,150 @@ +/* + * include/common/initcall.h + * + * Initcall management. + * + * Copyright (C) 2018 Willy Tarreau - w@1wt.eu + * + * Permission is hereby granted, free of charge, to any person obtaining + * a copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to + * permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#ifndef _COMMON_INIT_H +#define _COMMON_INIT_H + +/* List of known init stages. If others are added, please declare their + * section at the end of the file below. + */ +enum init_stage { + STG_PREPARE = 0, // preset variables, tables, list heads + STG_LOCK, // pre-initialize locks + STG_ALLOC, // allocate required structures + STG_POOL, // create pools + STG_REGISTER, // register static lists (keywords etc) + STG_INIT, // subsystems normal initialization + STG_SIZE // size of the stages array, must be last +}; + +/* This is the descriptor for an initcall */ +struct initcall { + void (*const fct)(void *arg1, void *arg2, void *arg3); + void *arg1; + void *arg2; + void *arg3; +}; + +/* Declare a static variable in the init section dedicated to stage , + * with an element referencing function and arguments . + * is needed to deduplicate entries created from a same file. The + * trick with (stg to an integer before calling + * __DECLARE_INITCALL(). Do not use this macro directly, use INITCALL{0..3}() + * instead. + */ +#define _DECLARE_INITCALL(...) \ + __DECLARE_INITCALL(__VA_ARGS__) + +/* This requires that function is called with pointer argument + * during init stage which must be one of init_stage. + */ +#define INITCALL0(stage, function) \ + _DECLARE_INITCALL(stage, __LINE__, function, 0, 0, 0) + +/* This requires that function is called with pointer argument + * during init stage which must be one of init_stage. + */ +#define INITCALL1(stage, function, arg1) \ + _DECLARE_INITCALL(stage, __LINE__, function, arg1, 0, 0) + +/* This requires that function is called with pointer arguments + * during init stage which must be one of init_stage. + */ +#define INITCALL2(stage, function, arg1, arg2) \ + _DECLARE_INITCALL(stage, __LINE__, function, arg1, arg2, 0) + +/* This requires that function is called with pointer arguments + * during init stage which must be one of init_stage. + */ +#define INITCALL3(stage, function, arg1, arg2, arg3) \ + _DECLARE_INITCALL(stage, __LINE__, function, arg1, arg2, arg3) + +/* Iterate pointer p (of type initcall**) over all registered calls at + * stage . + */ +#define FOREACH_INITCALL(p,stg) \ + for ((p) = &(__start_init_##stg); (p) < &(__stop_init_##stg); (p)++) + +/* Declare a section for stage . The start and stop pointers are set by + * the linker itself, which is why they're declared extern here. The weak + * attribute is used so that we declare them ourselves if the section is + * empty. The corresponding sections must contain exclusively pointers to + * make sure each location may safely be visited by incrementing a pointer. + */ +#define DECLARE_INIT_SECTION(stg) \ + extern __attribute__((__weak__)) const struct initcall *__start_init_##stg; \ + extern __attribute__((__weak__)) const struct initcall *__stop_init_##stg + +/* Declare all initcall sections here */ +DECLARE_INIT_SECTION(STG_PREPARE); +DECLARE_INIT_SECTION(STG_LOCK); +DECLARE_INIT_SECTION(STG_ALLOC); +DECLARE_INIT_SECTION(STG_POOL); +DECLARE_INIT_SECTION(STG_REGISTER); +DECLARE_INIT_SECTION(STG_INIT); + +/* not needed anymore */ +#undef DECLARE_INIT_SECTION + +/* Run the initcalls for stage . The test on is only there to + * ensure it is a valid initcall stage. + */ +#define RUN_INITCALLS(stg) \ + do { \ + const struct initcall **ptr; \ + if (stg >= STG_SIZE) \ + break; \ + FOREACH_INITCALL(ptr, stg) \ + (*ptr)->fct((*ptr)->arg1, (*ptr)->arg2, (*ptr)->arg3); \ + } while (0) + +#endif /* _COMMON_INIT_H */ + +/* + * Local variables: + * c-indent-level: 8 + * c-basic-offset: 8 + * End: + */