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Diffstat (limited to 'pjlib/include/pj/except.h')
-rw-r--r-- | pjlib/include/pj/except.h | 568 |
1 files changed, 284 insertions, 284 deletions
diff --git a/pjlib/include/pj/except.h b/pjlib/include/pj/except.h index a0143b9c..301242a4 100644 --- a/pjlib/include/pj/except.h +++ b/pjlib/include/pj/except.h @@ -1,284 +1,284 @@ -/* $Id$ */
-/*
- * Copyright (C)2003-2006 Benny Prijono <benny@prijono.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-#ifndef __PJ_EXCEPTION_H__
-#define __PJ_EXCEPTION_H__
-
-/**
- * @file except.h
- * @brief Exception Handling in C.
- */
-
-#include <pj/types.h>
-#include <pj/compat/setjmp.h>
-
-
-PJ_BEGIN_DECL
-
-
-/**
- * @defgroup PJ_EXCEPT Exception Handling
- * @ingroup PJ_MISC
- * @{
- *
- * \section pj_except_sample_sec Quick Example
- *
- * For the impatient, take a look at some examples:
- * - @ref page_pjlib_samples_except_c
- * - @ref page_pjlib_exception_test
- *
- * \section pj_except_except Exception Handling
- *
- * This module provides exception handling syntactically similar to C++ in
- * C language. The underlying mechanism use setjmp() and longjmp(), and since
- * these constructs are ANSI standard, the mechanism here should be available
- * on most platforms/compilers which are ANSI compliant.
- *
- * If ANSI libc is not available, then setjmp()/longjmp() implementation will
- * be provided. See <pj/compat/setjmp.h> for compatibility.
- *
- * The exception handling mechanism is completely thread safe, so the exception
- * thrown by one thread will not interfere with other thread.
- *
- * CAVEATS:
- * - unlike C++ exception, the scheme here won't call destructors of local
- * objects if exception is thrown. Care must be taken when a function
- * hold some resorce such as pool or mutex etc.
- * - You CAN NOT make nested exception in one single function without using
- * a nested PJ_USE_EXCEPTION.
- * - Exceptions will always be caught by the first handle (unlike C++ where
- * exception is only caught if the type matches.
- *
- * The exception handling constructs are similar to C++. The blocks will be
- * constructed similar to the following sample:
- *
- * \verbatim
- #define NO_MEMORY 1
- #define SYNTAX_ERROR 2
-
- int main()
- {
- PJ_USE_EXCEPTION; // declare local exception stack.
-
- PJ_TRY {
- ...// do something..
- }
- PJ_CATCH(NO_MEMORY) {
- ... // handle exception 1
- }
- PJ_CATCH(SYNTAX_ERROR) {
- ... // handle exception 2
- }
- PJ_DEFAULT {
- ... // handle other exceptions.
- }
- PJ_END;
- }
- \endverbatim
- *
- * The above sample uses hard coded exception ID. It is @b strongly
- * recommended that applications request a unique exception ID instead
- * of hard coded value like above.
- *
- * \section pj_except_reg Exception ID Allocation
- *
- * To ensure that exception ID (number) are used consistently and to
- * prevent ID collisions in an application, it is strongly suggested that
- * applications allocate an exception ID for each possible exception
- * type. As a bonus of this process, the application can identify
- * the name of the exception when the particular exception is thrown.
- *
- * Exception ID management are performed with the following APIs:
- * - #pj_exception_id_alloc().
- * - #pj_exception_id_free().
- * - #pj_exception_id_name().
- *
- *
- * PJLIB itself automatically allocates one exception id, i.e.
- * #PJ_NO_MEMORY_EXCEPTION which is declared in <pj/pool.h>. This exception
- * ID is raised by default pool policy when it fails to allocate memory.
- *
- * \section PJ_EX_KEYWORDS Keywords
- *
- * \subsection PJ_THROW PJ_THROW(expression)
- * Throw an exception. The expression thrown is an integer as the result of
- * the \a expression. This keyword can be specified anywhere within the
- * program.
- *
- * \subsection PJ_USE_EXCEPTION PJ_USE_EXCEPTION
- * Specify this in the variable definition section of the function block
- * (or any blocks) to specify that the block has \a PJ_TRY/PJ_CATCH exception
- * block.
- * Actually, this is just a macro to declare local variable which is used to
- * push the exception state to the exception stack.
- *
- * \subsection PJ_TRY PJ_TRY
- * The \a PJ_TRY keyword is typically followed by a block. If an exception is
- * thrown in this block, then the execution will resume to the \a PJ_CATCH
- * handler.
- *
- * \subsection PJ_CATCH PJ_CATCH(expression)
- * The \a PJ_CATCH is normally followed by a block. This block will be executed
- * if the exception being thrown is equal to the expression specified in the
- * \a PJ_CATCH.
- *
- * \subsection PJ_DEFAULT PJ_DEFAULT
- * The \a PJ_DEFAULT keyword is normally followed by a block. This block will
- * be executed if the exception being thrown doesn't match any of the \a
- * PJ_CATCH specification. The \a PJ_DEFAULT block \b MUST be placed as the
- * last block of the handlers.
- *
- * \subsection PJ_END PJ_END
- * Specify this keyword to mark the end of \a PJ_TRY / \a PJ_CATCH blocks.
- *
- * \subsection PJ_GET_EXCEPTION PJ_GET_EXCEPTION(void)
- * Get the last exception thrown. This macro is normally called inside the
- * \a PJ_CATCH or \a PJ_DEFAULT block, altough it can be used anywhere where
- * the \a PJ_USE_EXCEPTION definition is in scope.
- *
- *
- * \section pj_except_examples_sec Examples
- *
- * For some examples on how to use the exception construct, please see:
- * - @ref page_pjlib_samples_except_c
- * - @ref page_pjlib_exception_test
- */
-
-/**
- * Allocate a unique exception id.
- * Applications don't have to allocate a unique exception ID before using
- * the exception construct. However, by doing so it ensures that there is
- * no collisions of exception ID.
- *
- * As a bonus, when exception number is acquired through this function,
- * the library can assign name to the exception (only if
- * PJ_HAS_EXCEPTION_NAMES is enabled (default is yes)) and find out the
- * exception name when it catches an exception.
- *
- * @param name Name to be associated with the exception ID.
- * @param id Pointer to receive the ID.
- *
- * @return PJ_SUCCESS on success or PJ_ETOOMANY if the library
- * is running out out ids.
- */
-PJ_DECL(pj_status_t) pj_exception_id_alloc(const char *name,
- pj_exception_id_t *id);
-
-/**
- * Free an exception id.
- *
- * @param id The exception ID.
- *
- * @return PJ_SUCCESS or the appropriate error code.
- */
-PJ_DECL(pj_status_t) pj_exception_id_free(pj_exception_id_t id);
-
-/**
- * Retrieve name associated with the exception id.
- *
- * @param id The exception ID.
- *
- * @return The name associated with the specified ID.
- */
-PJ_DECL(const char*) pj_exception_id_name(pj_exception_id_t id);
-
-
-/** @} */
-
-/**
- * This structure (which should be invisible to user) manages the TRY handler
- * stack.
- */
-struct pj_exception_state_t
-{
- struct pj_exception_state_t *prev; /**< Previous state in the list. */
- pj_jmp_buf state; /**< jmp_buf. */
-};
-
-/**
- * Throw exception.
- * @param id Exception Id.
- */
-PJ_DECL_NO_RETURN(void)
-pj_throw_exception_(pj_exception_id_t id) PJ_ATTR_NORETURN;
-
-/**
- * Push exception handler.
- */
-PJ_DECL(void) pj_push_exception_handler_(struct pj_exception_state_t *rec);
-
-/**
- * Pop exception handler.
- */
-PJ_DECL(void) pj_pop_exception_handler_(void);
-
-/**
- * Declare that the function will use exception.
- * @hideinitializer
- */
-#define PJ_USE_EXCEPTION struct pj_exception_state_t pj_x_except__; int pj_x_code__
-
-/**
- * Start exception specification block.
- * @hideinitializer
- */
-#define PJ_TRY if (1) { \
- pj_push_exception_handler_(&pj_x_except__); \
- pj_x_code__ = pj_setjmp(pj_x_except__.state); \
- if (pj_x_code__ == 0)
-/**
- * Catch the specified exception Id.
- * @param id The exception number to catch.
- * @hideinitializer
- */
-#define PJ_CATCH(id) else if (pj_x_code__ == (id))
-
-/**
- * Catch any exception number.
- * @hideinitializer
- */
-#define PJ_DEFAULT else
-
-/**
- * End of exception specification block.
- * @hideinitializer
- */
-#define PJ_END pj_pop_exception_handler_(); \
- } else {}
-
-/**
- * Throw exception.
- * @param exception_id The exception number.
- * @hideinitializer
- */
-#define PJ_THROW(exception_id) pj_throw_exception_(exception_id)
-
-/**
- * Get current exception.
- * @return Current exception code.
- * @hideinitializer
- */
-#define PJ_GET_EXCEPTION() (pj_x_code__)
-
-PJ_END_DECL
-
-
-
-#endif /* __PJ_EXCEPTION_H__ */
-
-
+/* $Id$ */ +/* + * Copyright (C)2003-2006 Benny Prijono <benny@prijono.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#ifndef __PJ_EXCEPTION_H__ +#define __PJ_EXCEPTION_H__ + +/** + * @file except.h + * @brief Exception Handling in C. + */ + +#include <pj/types.h> +#include <pj/compat/setjmp.h> + + +PJ_BEGIN_DECL + + +/** + * @defgroup PJ_EXCEPT Exception Handling + * @ingroup PJ_MISC + * @{ + * + * \section pj_except_sample_sec Quick Example + * + * For the impatient, take a look at some examples: + * - @ref page_pjlib_samples_except_c + * - @ref page_pjlib_exception_test + * + * \section pj_except_except Exception Handling + * + * This module provides exception handling syntactically similar to C++ in + * C language. The underlying mechanism use setjmp() and longjmp(), and since + * these constructs are ANSI standard, the mechanism here should be available + * on most platforms/compilers which are ANSI compliant. + * + * If ANSI libc is not available, then setjmp()/longjmp() implementation will + * be provided. See <pj/compat/setjmp.h> for compatibility. + * + * The exception handling mechanism is completely thread safe, so the exception + * thrown by one thread will not interfere with other thread. + * + * CAVEATS: + * - unlike C++ exception, the scheme here won't call destructors of local + * objects if exception is thrown. Care must be taken when a function + * hold some resorce such as pool or mutex etc. + * - You CAN NOT make nested exception in one single function without using + * a nested PJ_USE_EXCEPTION. + * - Exceptions will always be caught by the first handle (unlike C++ where + * exception is only caught if the type matches. + * + * The exception handling constructs are similar to C++. The blocks will be + * constructed similar to the following sample: + * + * \verbatim + #define NO_MEMORY 1 + #define SYNTAX_ERROR 2 + + int main() + { + PJ_USE_EXCEPTION; // declare local exception stack. + + PJ_TRY { + ...// do something.. + } + PJ_CATCH(NO_MEMORY) { + ... // handle exception 1 + } + PJ_CATCH(SYNTAX_ERROR) { + ... // handle exception 2 + } + PJ_DEFAULT { + ... // handle other exceptions. + } + PJ_END; + } + \endverbatim + * + * The above sample uses hard coded exception ID. It is @b strongly + * recommended that applications request a unique exception ID instead + * of hard coded value like above. + * + * \section pj_except_reg Exception ID Allocation + * + * To ensure that exception ID (number) are used consistently and to + * prevent ID collisions in an application, it is strongly suggested that + * applications allocate an exception ID for each possible exception + * type. As a bonus of this process, the application can identify + * the name of the exception when the particular exception is thrown. + * + * Exception ID management are performed with the following APIs: + * - #pj_exception_id_alloc(). + * - #pj_exception_id_free(). + * - #pj_exception_id_name(). + * + * + * PJLIB itself automatically allocates one exception id, i.e. + * #PJ_NO_MEMORY_EXCEPTION which is declared in <pj/pool.h>. This exception + * ID is raised by default pool policy when it fails to allocate memory. + * + * \section PJ_EX_KEYWORDS Keywords + * + * \subsection PJ_THROW PJ_THROW(expression) + * Throw an exception. The expression thrown is an integer as the result of + * the \a expression. This keyword can be specified anywhere within the + * program. + * + * \subsection PJ_USE_EXCEPTION PJ_USE_EXCEPTION + * Specify this in the variable definition section of the function block + * (or any blocks) to specify that the block has \a PJ_TRY/PJ_CATCH exception + * block. + * Actually, this is just a macro to declare local variable which is used to + * push the exception state to the exception stack. + * + * \subsection PJ_TRY PJ_TRY + * The \a PJ_TRY keyword is typically followed by a block. If an exception is + * thrown in this block, then the execution will resume to the \a PJ_CATCH + * handler. + * + * \subsection PJ_CATCH PJ_CATCH(expression) + * The \a PJ_CATCH is normally followed by a block. This block will be executed + * if the exception being thrown is equal to the expression specified in the + * \a PJ_CATCH. + * + * \subsection PJ_DEFAULT PJ_DEFAULT + * The \a PJ_DEFAULT keyword is normally followed by a block. This block will + * be executed if the exception being thrown doesn't match any of the \a + * PJ_CATCH specification. The \a PJ_DEFAULT block \b MUST be placed as the + * last block of the handlers. + * + * \subsection PJ_END PJ_END + * Specify this keyword to mark the end of \a PJ_TRY / \a PJ_CATCH blocks. + * + * \subsection PJ_GET_EXCEPTION PJ_GET_EXCEPTION(void) + * Get the last exception thrown. This macro is normally called inside the + * \a PJ_CATCH or \a PJ_DEFAULT block, altough it can be used anywhere where + * the \a PJ_USE_EXCEPTION definition is in scope. + * + * + * \section pj_except_examples_sec Examples + * + * For some examples on how to use the exception construct, please see: + * - @ref page_pjlib_samples_except_c + * - @ref page_pjlib_exception_test + */ + +/** + * Allocate a unique exception id. + * Applications don't have to allocate a unique exception ID before using + * the exception construct. However, by doing so it ensures that there is + * no collisions of exception ID. + * + * As a bonus, when exception number is acquired through this function, + * the library can assign name to the exception (only if + * PJ_HAS_EXCEPTION_NAMES is enabled (default is yes)) and find out the + * exception name when it catches an exception. + * + * @param name Name to be associated with the exception ID. + * @param id Pointer to receive the ID. + * + * @return PJ_SUCCESS on success or PJ_ETOOMANY if the library + * is running out out ids. + */ +PJ_DECL(pj_status_t) pj_exception_id_alloc(const char *name, + pj_exception_id_t *id); + +/** + * Free an exception id. + * + * @param id The exception ID. + * + * @return PJ_SUCCESS or the appropriate error code. + */ +PJ_DECL(pj_status_t) pj_exception_id_free(pj_exception_id_t id); + +/** + * Retrieve name associated with the exception id. + * + * @param id The exception ID. + * + * @return The name associated with the specified ID. + */ +PJ_DECL(const char*) pj_exception_id_name(pj_exception_id_t id); + + +/** @} */ + +/** + * This structure (which should be invisible to user) manages the TRY handler + * stack. + */ +struct pj_exception_state_t +{ + struct pj_exception_state_t *prev; /**< Previous state in the list. */ + pj_jmp_buf state; /**< jmp_buf. */ +}; + +/** + * Throw exception. + * @param id Exception Id. + */ +PJ_DECL_NO_RETURN(void) +pj_throw_exception_(pj_exception_id_t id) PJ_ATTR_NORETURN; + +/** + * Push exception handler. + */ +PJ_DECL(void) pj_push_exception_handler_(struct pj_exception_state_t *rec); + +/** + * Pop exception handler. + */ +PJ_DECL(void) pj_pop_exception_handler_(void); + +/** + * Declare that the function will use exception. + * @hideinitializer + */ +#define PJ_USE_EXCEPTION struct pj_exception_state_t pj_x_except__; int pj_x_code__ + +/** + * Start exception specification block. + * @hideinitializer + */ +#define PJ_TRY if (1) { \ + pj_push_exception_handler_(&pj_x_except__); \ + pj_x_code__ = pj_setjmp(pj_x_except__.state); \ + if (pj_x_code__ == 0) +/** + * Catch the specified exception Id. + * @param id The exception number to catch. + * @hideinitializer + */ +#define PJ_CATCH(id) else if (pj_x_code__ == (id)) + +/** + * Catch any exception number. + * @hideinitializer + */ +#define PJ_DEFAULT else + +/** + * End of exception specification block. + * @hideinitializer + */ +#define PJ_END pj_pop_exception_handler_(); \ + } else {} + +/** + * Throw exception. + * @param exception_id The exception number. + * @hideinitializer + */ +#define PJ_THROW(exception_id) pj_throw_exception_(exception_id) + +/** + * Get current exception. + * @return Current exception code. + * @hideinitializer + */ +#define PJ_GET_EXCEPTION() (pj_x_code__) + +PJ_END_DECL + + + +#endif /* __PJ_EXCEPTION_H__ */ + + |