include/common/initcall.h - haproxy - Gitiles

 /*
  * 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.
  */
 /*
  * Please keep those names short enough, they are used to generate section
  * names, Mac OS X accepts section names up to 16 characters, and we prefix
  * them with i_, so stage name can't be more than 14 characters.
  */
 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;
 };

 #ifdef __APPLE__
 #define HA_SECTION(s) __section__("__DATA, i_" # s)
 #else
 #define HA_SECTION(s) __section__("init_" # s)
 #endif

 /* Declare a static variable in the init section dedicated to stage <stg>,
  * with an element referencing function <function> and arguments <a1..a3>.
  * <linenum> is needed to deduplicate entries created from a same file. The
  * trick with (stg<STG_SIZE) consists in verifying that stg if a valid enum
  * value from the initcall set, and to emit a warning or error if it is not.
  * The function's type is cast so that it is technically possible to call a
  * function taking other argument types, provided they are all the same size
  * as a pointer (args are cast to (void*)). Do not use this macro directly,
  * use INITCALL{0..3}() instead.
  */
 #define __DECLARE_INITCALL(stg, linenum, function, a1, a2, a3)     \
         static const struct initcall *__initcb_##linenum           \
 	    __attribute__((__used__,HA_SECTION(stg))) =            \
 	        (stg < STG_SIZE) ? &(const struct initcall) {      \
 		.fct = (void (*)(void *,void *,void *))function,   \
 		.arg1 = (void *)(a1),                              \
 		.arg2 = (void *)(a2),                              \
 		.arg3 = (void *)(a3),                              \
 	} : NULL

 /* This is used to resolve <linenum> 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 <function> is called with pointer argument
  * <argument> during init stage <stage> which must be one of init_stage.
  */
 #define INITCALL0(stage, function)                                     \
 	_DECLARE_INITCALL(stage, __LINE__, function, 0, 0, 0)

 /* This requires that function <function> is called with pointer argument
  * <argument> during init stage <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 <function> is called with pointer arguments
  * <arg1..2> during init stage <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 <function> is called with pointer arguments
  * <arg1..3> during init stage <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 <stg>.
  */
 #define FOREACH_INITCALL(p,stg)                                               \
 	for ((p) = &(__start_init_##stg); (p) < &(__stop_init_##stg); (p)++)

 /* Declare a section for stage <stg>. 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.
  */
 #ifdef __APPLE__
 #define DECLARE_INIT_SECTION(stg)                                                   \
 	extern __attribute__((__weak__)) const struct initcall *__start_init_##stg __asm("section$start$__DATA$i_" # stg); \
 	extern __attribute__((__weak__)) const struct initcall *__stop_init_##stg __asm("section$end$__DATA$i_" # stg)

 #else
 #define DECLARE_INIT_SECTION(stg)                                                   \
 	extern __attribute__((__weak__)) const struct initcall *__start_init_##stg; \
 	extern __attribute__((__weak__)) const struct initcall *__stop_init_##stg
 #endif

 /* 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 <stg>. The test on <stg> 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:
  */
	/*
	* 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.
	*/
	/*
	* Please keep those names short enough, they are used to generate section
	* names, Mac OS X accepts section names up to 16 characters, and we prefix
	* them with i_, so stage name can't be more than 14 characters.
	*/
	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;
	};

	#ifdef __APPLE__
	#define HA_SECTION(s) __section__("__DATA, i_" # s)
	#else
	#define HA_SECTION(s) __section__("init_" # s)
	#endif

	/* Declare a static variable in the init section dedicated to stage <stg>,
	* with an element referencing function <function> and arguments <a1..a3>.
	* <linenum> is needed to deduplicate entries created from a same file. The
	* trick with (stg<STG_SIZE) consists in verifying that stg if a valid enum
	* value from the initcall set, and to emit a warning or error if it is not.
	* The function's type is cast so that it is technically possible to call a
	* function taking other argument types, provided they are all the same size
	* as a pointer (args are cast to (void*)). Do not use this macro directly,
	* use INITCALL{0..3}() instead.
	*/
	#define __DECLARE_INITCALL(stg, linenum, function, a1, a2, a3) \
	static const struct initcall *__initcb_##linenum \
	__attribute__((__used__,HA_SECTION(stg))) = \
	(stg < STG_SIZE) ? &(const struct initcall) { \
	.fct = (void ()(void ,void ,void ))function, \
	.arg1 = (void *)(a1), \
	.arg2 = (void *)(a2), \
	.arg3 = (void *)(a3), \
	} : NULL

	/* This is used to resolve <linenum> 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 <function> is called with pointer argument
	* <argument> during init stage <stage> which must be one of init_stage.
	*/
	#define INITCALL0(stage, function) \
	_DECLARE_INITCALL(stage, __LINE__, function, 0, 0, 0)

	/* This requires that function <function> is called with pointer argument
	* <argument> during init stage <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 <function> is called with pointer arguments
	* <arg1..2> during init stage <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 <function> is called with pointer arguments
	* <arg1..3> during init stage <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 <stg>.
	*/
	#define FOREACH_INITCALL(p,stg) \
	for ((p) = &(__start_init_##stg); (p) < &(__stop_init_##stg); (p)++)

	/* Declare a section for stage <stg>. 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.
	*/
	#ifdef __APPLE__
	#define DECLARE_INIT_SECTION(stg) \
	extern __attribute__((__weak__)) const struct initcall *__start_init_##stg __asm("section$start$__DATA$i_" # stg); \
	extern __attribute__((__weak__)) const struct initcall *__stop_init_##stg __asm("section$end$__DATA$i_" # stg)

	#else
	#define DECLARE_INIT_SECTION(stg) \
	extern __attribute__((__weak__)) const struct initcall *__start_init_##stg; \
	extern __attribute__((__weak__)) const struct initcall *__stop_init_##stg
	#endif

	/* 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 <stg>. The test on <stg> 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:
	*/