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Diffstat (limited to 'inc/platform_libs.h')
| -rw-r--r-- | inc/platform_libs.h | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/inc/platform_libs.h b/inc/platform_libs.h new file mode 100644 index 0000000..fc6c751 --- /dev/null +++ b/inc/platform_libs.h @@ -0,0 +1,182 @@ +#ifndef PLATFORM_LIBS_H +#define PLATFORM_LIBS_H + +/** + * Copyright (c) 2019, The Linux Foundation. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials provided + * with the distribution. + * * Neither the name of The Linux Foundation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS + * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR + * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE + * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN + * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* +Platfrom Library Loader +----------------------- + +proj/platform_libs is a library to help manage interdependencies between +other libraries. + + +to use you will need to add + +incs = { 'proj/platform_libs' } + +in source of the library implementation define the entry point + +#include "platform_libs.h" +PL_DEFINE(svfs, svfs_init, svfs_deinit); + +Platfrom Library List +--------------------- + +This list contains top level libraries to be initialized at boot. To make +sure that this library is loaded you would need to call PLRegister or +PLRegisterDefault in your scons build command. + + +Handling Interdependencies and Order +------------------------------------ + +To make sure that library A is loaded before library B, library B's +constructor and destructor should initialize and cleanup libraryB. + +#include "platform_libs.h" + +PL_DEP(libraryB) +void libraryA_deinit(void) { + PL_DEINIT(libraryB); +} + +int libraryA_init(void) { + int nErr = 0; + // my init code + VERIFY(0 == PL_INIT(libraryB)); +bail: + if(nErr) { libraryA_deinit() } + return nErr; +} + + +libraryB does not need to appear in the platform library list. +*/ + +#include <stdint.h> + +struct platform_lib { + const char* name; + uint32_t uRefs; + int nErr; + int (*init)(void); + void (*deinit)(void); +}; + +/** + * use this macro to pull in external dependencies + */ +#ifdef __cplusplus +#define PL_DEP(name)\ + extern "C" {\ + extern struct platform_lib* _pl_##name(void); \ + } +#else +#define PL_DEP(name)\ + extern struct platform_lib* _pl_##name(void); +#endif /* __cplusplus */ + +/** + * should be declared in source in the library + * if constructor fails, destructor is not called + */ +#ifdef __cplusplus +#define PL_DEFINE(name, init, deinit) \ + extern "C" {\ + struct platform_lib* _pl_##name(void) {\ + static struct platform_lib _gpl_##name = { #name, 0, -1, init, deinit };\ + return &_gpl_##name;\ + }\ + } +#else +#define PL_DEFINE(name, init, deinit) \ + struct platform_lib* _pl_##name(void) {\ + static struct platform_lib _gpl_##name = { #name, 0, -1, init, deinit };\ + return &_gpl_##name;\ + } +#endif /* __cplusplus */ + +/** + * should be added to platform_libs_list.c pl_list table + * for all top level modules + */ +#define PL_ENTRY(name) _pl_##name + +/** + * should be called within a constructor to ensure that a + * dependency has been initialized. so if foo depends on bar + * + * #include "bar.h" + * int foo_init() { + * return PL_INIT(bar); + * } + */ +#define PL_INIT(name) pl_lib_init(PL_ENTRY(name)) + +/** + * should be called within a destructor to ensure that a + * dependency has been cleaned up + */ +#define PL_DEINIT(name) pl_lib_deinit(PL_ENTRY(name)) + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/** + * initalize the static list of library constructors and destructors + * should be called from main() + * + * see platform_libs_list.h to add high level libraries + * + */ +int pl_init(void); + +/** + * calls all the destructors. + */ +void pl_deinit(void); + +/** + * initialize a single library. called via PL_INIT + */ +int pl_lib_init(struct platform_lib* (*pl)(void)); + +/** + * deinitialize a single library called via PL_DEINIT + */ +void pl_lib_deinit(struct platform_lib* (*pl)(void)); + +#ifdef __cplusplus +} +#endif + +#endif //PLATFORM_LIBS |