X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/837788ebd988892ad55ee58b2ff15c1c9c93a319..234b2f4e892e942c28fa9c8bc4f57af1214b1424:/include/xbt/ex.h diff --git a/include/xbt/ex.h b/include/xbt/ex.h index 5405c36354..f8751366f7 100644 --- a/include/xbt/ex.h +++ b/include/xbt/ex.h @@ -1,479 +1,103 @@ -/* -** OSSP ex - Exception Handling (modified to fit into SimGrid) -** Copyright (c) 2005 Martin Quinson. -** Copyright (c) 2002-2004 Ralf S. Engelschall -** Copyright (c) 2002-2004 The OSSP Project -** Copyright (c) 2002-2004 Cable & Wireless -** -** This file is part of OSSP ex, an exception handling library -** which can be found at http://www.ossp.org/pkg/lib/ex/. -** -** Permission to use, copy, modify, and distribute this software for -** any purpose with or without fee is hereby granted, provided that -** the above copyright notice and this permission notice appear in all -** copies. -** -** THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED -** WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF -** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. -** IN NO EVENT SHALL THE AUTHORS AND COPYRIGHT HOLDERS AND THEIR -** 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. -** -** ex.h: exception handling (pre-processor part) -*/ +/* Copyright (c) 2005-2018. The SimGrid Team. + * All rights reserved. */ -#ifndef __XBT_EX_H__ -#define __XBT_EX_H__ +/* This program is free software; you can redistribute it and/or modify it + * under the terms of the license (GNU LGPL) which comes with this package. */ -#include -#include +#ifndef XBT_EX_H +#define XBT_EX_H -/* required ISO-C standard facilities */ -#include +#include -/* the machine context */ -#if defined(__EX_MCTX_MCSC__) -#include /* POSIX.1 ucontext(3) */ -#define __ex_mctx_struct ucontext_t uc; -#define __ex_mctx_save(mctx) (getcontext(&(mctx)->uc) == 0) -#define __ex_mctx_restored(mctx) /* noop */ -#define __ex_mctx_restore(mctx) (void)setcontext(&(mctx)->uc) +#include "xbt/base.h" +#include "xbt/sysdep.h" +#include "xbt/misc.h" +#include "xbt/virtu.h" -#elif defined(__EX_MCTX_SSJLJ__) -#include /* POSIX.1 sigjmp_buf(3) */ -#define __ex_mctx_struct sigjmp_buf jb; -#define __ex_mctx_save(mctx) (sigsetjmp((mctx)->jb, 1) == 0) -#define __ex_mctx_restored(mctx) /* noop */ -#define __ex_mctx_restore(mctx) (void)siglongjmp((mctx)->jb, 1) - -#elif defined(__EX_MCTX_SJLJ__) || !defined(__EX_MCTX_CUSTOM__) -#include /* ISO-C jmp_buf(3) */ -#define __ex_mctx_struct jmp_buf jb; -#define __ex_mctx_save(mctx) (setjmp((mctx)->jb) == 0) -#define __ex_mctx_restored(mctx) /* noop */ -#define __ex_mctx_restore(mctx) (void)longjmp((mctx)->jb, 1) -#endif - -/* declare the machine context type */ -typedef struct { __ex_mctx_struct } __ex_mctx_t; -/** @addtogroup XBT_ex - * - * This module is a small ISO-C++ style exception handling library - * for use in the ISO-C language. It allows you to use the paradigm - * of throwing and catching exceptions in order to reduce the amount - * of error handling code without hindering program robustness. - * - * This is achieved by directly transferring exceptional return codes - * (and the program control flow) from the location where the exception - * is raised (throw point) to the location where it is handled (catch - * point) -- usually from a deeply nested sub-routine to a parent - * routine. All intermediate routines no longer have to make sure that - * the exceptional return codes from sub-routines are correctly passed - * back to the parent. - * - * These features are brought to you by a modified version of the libex - * library, one of the numerous masterpiece of Ralf S. Engelschall. - * - * @section Introduction - * - * In SimGrid, exceptions is a triple <\a msg , \a category , \a value> - * where \a msg is a human-readable text describing the exceptional - * condition, \a code an integer describing what went wrong and \a value - * providing a sort of sub-category. (this is different in the original libex). - * - * @section Basic usage - * - * \em xbt_try \b TRIED_BLOCK [\em xbt_cleanup \b CLEANUP_BLOCK] \em xbt_catch (variable) \b CATCH_BLOCK - * - * This is the primary syntactical construct provided. It is modeled after the - * ISO-C++ try-catch clause and should sound familiar to most of you. - * - * Any exception thrown directly from the TRIED_BLOCK block or from called - * subroutines is caught. Cleanups which must be done after this block - * (whenever an exception arised or not) should be placed into the optionnal - * CLEANUP_BLOCK. The code dealing with the exceptions when they arise should - * be placed into the (mandatory) CATCH_BLOCK. - * - * - * In absence of exception, the control flow goes into the blocks TRIED_BLOCK - * and CLEANUP_BLOCK (if present); The CATCH_BLOCK block is then ignored. - * - * When an exception is thrown, the control flow goes through the following - * blocks: TRIED_BLOCK (up to the statement throwing the exception), - * CLEANUP_BLOCK (if any) and CATCH_BLOCK. The exception is stored in a - * variable for inspection inside the CATCH_BLOCK. This variable must be - * declared in the outter scope, but its value is only valid within the - * CATCH_BLOCK block. - * - * Some notes: - * - xbt_try, xbt_cleanup and xbt_catch cannot be used separately, they work - * only in combination and form a language clause as a whole. - * - In contrast to the syntax of other languages (such as C++ or Jave) there - * is only one xbt_catch block and not multiple ones (all exceptions are - * of the same C type xbt_t). - * - the variable of xbt_catch can naturally be reused in subsequent - * xbt_catch clauses. - * - it is possible to nest xbt_try clauses. - * - * The xbt_try block is a regular ISO-C language statement block, but it is not - * allowed to jump into it via "goto" or longjmp(3) or out of it via "break", - * "return", "goto" or longjmp(3) because there is some hidden setup and - * cleanup that needs to be done regardless of whether an exception is - * caught. Bypassing these steps will break the exception handling facility. - * - * The xbt_cleanup and xbt_catch blocks are regular ISO-C language statement - * blocks without any restrictions. You are even allowed to throw (and in the - * xbt_catch block to re-throw) exceptions. - * - * There is one subtle detail you should remember about xbt_try blocks: - * Variables used in the xbt_cleanup or xbt_catch clauses must be declared with - * the storage class "volatile", otherwise they might contain outdated - * information if an exception it thrown. - * - * - * This is because you usually do not know which commands in the xbt_try - * were already successful before the exception was thrown (logically speaking) - * and because the underlying ISO-C setjmp(3) facility applies those - * restrictions (technically speaking). As a matter of fact, value changes - * between the xbt_try and the xbt_throw may be discarded if you forget the - * "volatile" keyword. - * - * @section Advanced usage - * - * @subsection xbt_defer DEFERING_BLOCK - * - * This directive executes DEFERING_BLOCK while deferring the throwing of - * exceptions, i.e., exceptions thrown within this block are remembered, but - * the control flow still continues until the end of the block. At its end, the - * first exception which occured within the block (if any) is rethrown (any - * subsequent exceptions are ignored). - * - * DEFERING_BLOCK is a regular ISO-C language statement block, but it is not - * allowed to jump into it via "goto" or longjmp(3) or out of it via "break", - * "return", "goto" or longjmp(3). It is however allowed to nest xbt_defer - * clauses. - * - * @subsection xbt_shield SHIELDED_BLOCK - * - * This directive executes SHIELDED_BLOCK while shielding it against the - * throwing of exceptions, i.e., any exception thrown from this block or its - * subroutines are silently ignored. - * - * SHIELDED_BLOCK is a regular ISO-C language statement block, but it is not - * allowed to jump into it via "goto" or longjmp(3) or out of it via "break", - * "return", "goto" or longjmp(3). It is however allowed to nest xbt_shield - * clauses. - * - * @subsection Retrieving the current execution condition - * - * \a xbt_catching, \a xbt_deferred and \a xbt_shielding return a boolean - * indicating whether the current scope is within a TRYIED_BLOCK, - * DEFERING_BLOCK and SHIELDED_BLOCK (respectively) - * - * \section PROGRAMMING PITFALLS - * - * Exception handling is a very elegant and efficient way of dealing with - * exceptional situation. Nevertheless it requires additional discipline in - * programming and there are a few pitfalls one must be aware of. Look the - * following code which shows some pitfalls and contains many errors (assuming - * a mallocex() function which throws an exception if malloc(3) fails): +/** @addtogroup XBT_ex_c + * @brief Exceptions support (C) * - \verbatim -// BAD EXAMPLE -xbt_try { - char *cp1, *cp2, cp3; - - cp1 = mallocex(SMALLAMOUNT); - globalcontext->first = cp1; - cp2 = mallocex(TOOBIG); - cp3 = mallocex(SMALLAMOUNT); - strcpy(cp1, "foo"); - strcpy(cp2, "bar"); -} xbt_cleanup { - if (cp3 != NULL) free(cp3); - if (cp2 != NULL) free(cp2); - if (cp1 != NULL) free(cp1); -} xbt_catch(ex) { - printf("cp3=%s", cp3); - ex_rethrow; -}\endverbatim - - * This example raises a few issues: - * -# \b variable scope\n - * Variables which are used in the xbt_cleanup or xbt_catch clauses must be - * declared before the xbt_try clause, otherwise they only exist inside the - * xbt_try block. In the example above, cp1, cp2 and cp3 only exist in the - * xbt_try block and are invisible from the xbt_cleanup and xbt_catch - * blocks. - * -# \b variable initialization \n - * Variables which are used in the xbt_cleanup or xbt_catch clauses must - * be initialized before the point of the first possible xbt_throw is - * reached. In the example above, xbt_cleanup would have trouble using cp3 - * if mallocex() throws a exception when allocating a TOOBIG buffer. - * -# \b volatile variable \n - * Variables which are used in the xbt_cleanup or xbt_catch clauses MUST BE - * DECLARED AS "volatile", otherwise they might contain outdated - * information when an exception is thrown. - * -# \b clean before catch \n - * The xbt_cleanup clause is not only place before the xbt_catch clause in - * the source code, it also occures before in the control flow. So, - * resources being cleaned up cannot be used in the xbt_catch block. In the - * example, c3 gets freed before the printf placed in xbt_catch. - * -# \b variable uninitialization \n - * If resources are passed out of the scope of the - * xbt_try/xbt_cleanup/xbt_catch construct, they naturally shouldn't get - * cleaned up. The example above does free(3) cp1 in xbt_cleanup although - * its value was affected to globalcontext->first, invalidating this - * pointer. - - * The following is fixed version of the code (annotated with the pitfall items - * for reference): - \verbatim -// GOOD EXAMPLE -{ / *01* / - char * volatile / *03* / cp1 = NULL / *02* /; - char * volatile / *03* / cp2 = NULL / *02* /; - char * volatile / *03* / cp3 = NULL / *02* /; - try { - cp1 = mallocex(SMALLAMOUNT); - globalcontext->first = cp1; - cp1 = NULL / *05 give away* /; - cp2 = mallocex(TOOBIG); - cp3 = mallocex(SMALLAMOUNT); - strcpy(cp1, "foo"); - strcpy(cp2, "bar"); - } - clean { / *04* / - printf("cp3=%s", cp3 == NULL / *02* / ? "" : cp3); - if (cp3 != NULL) - free(cp3); - if (cp2 != NULL) - free(cp2); - / *05 cp1 was given away * / - } - catch(ex) { - / *05 global context untouched * / - rethrow; - } -}\endverbatim + * Those fonctions are used to throw C++ exceptions from C code. This feature + * should probably be removed in the future because C and exception do not + * exactly play nicely together. + */ +/** Categories of errors * - * @{ + * This very similar to std::error_catgory and should probably be replaced + * by this in the future. + * + * @ingroup XBT_ex_c */ +typedef enum { + unknown_error = 0, /**< unknown error */ + arg_error, /**< Invalid argument */ + bound_error, /**< Out of bounds argument */ + mismatch_error, /**< The provided ID does not match */ + not_found_error, /**< The searched element was not found */ + system_error, /**< a syscall did fail */ + network_error, /**< error while sending/receiving data */ + timeout_error, /**< not quick enough, dude */ + cancel_error, /**< an action was canceled */ + thread_error, /**< error while [un]locking */ + host_error, /**< host failed */ + tracing_error, /**< error during the simulation tracing */ + io_error, /**< disk or file error */ + vm_error /**< vm error */ +} xbt_errcat_t; + +SG_BEGIN_DECL() + +/** Get the name of a category + * @ingroup XBT_ex_c + */ +XBT_PUBLIC(const char *) xbt_ex_catname(xbt_errcat_t cat); -/** @brief Structure describing an exception */ -typedef struct { - char *msg; /**< human readable message; to be freed */ - int category; /**< category like HTTP (what went wrong) */ - int value; /**< like errno (why did it went wrong) */ - /* throw point */ - char *host; /* NULL for localhost; hostname:port if remote */ - char *procname; - char *file; /**< to be freed only for remote exceptions */ - int line; - char *func; /**< to be freed only for remote exceptions */ -} ex_t; - -/* declare the context type (private) */ -typedef struct { - __ex_mctx_t *ctx_mctx; /* permanent machine context of enclosing try/catch */ - int ctx_deferred; /* permanent flag whether exception is deferred */ - int ctx_deferring;/* permanent counter of exception deferring level */ - int ctx_defer; /* temporary flag for exception deferring macro */ - int ctx_shielding;/* permanent counter of exception shielding level */ - int ctx_shield; /* temporary flag for exception shielding macro */ - int ctx_caught; /* temporary flag whether exception was caught */ - volatile ex_t ctx_ex; /* temporary exception storage */ -} ex_ctx_t; - -/* the static and dynamic initializers for a context structure */ -#define XBT_CTX_INITIALIZER \ - { NULL, 0, 0, 0, 0, 0, 0, { /* content */ NULL, 0, 0, \ - /*throw point*/ NULL, NULL, NULL, 0, NULL } } -#define XBT_CTX_INITIALIZE(ctx) \ - do { \ - (ctx)->ctx_mctx = NULL; \ - (ctx)->ctx_deferred = 0; \ - (ctx)->ctx_deferring = 0; \ - (ctx)->ctx_defer = 0; \ - (ctx)->ctx_shielding = 0; \ - (ctx)->ctx_shield = 0; \ - (ctx)->ctx_caught = 0; \ - (ctx)->ctx_ex.msg = NULL; \ - (ctx)->ctx_ex.category = 0; \ - (ctx)->ctx_ex.value = 0; \ - (ctx)->ctx_ex.host = NULL; \ - (ctx)->ctx_ex.procname = NULL; \ - (ctx)->ctx_ex.file = NULL; \ - (ctx)->ctx_ex.line = 0; \ - (ctx)->ctx_ex.func = NULL; \ - } while (0) - -/* the exception context */ -typedef ex_ctx_t *(*ex_ctx_cb_t)(void); -extern ex_ctx_cb_t __xbt_ex_ctx; -extern ex_ctx_t *__xbt_ex_ctx_default(void); +typedef struct xbt_ex xbt_ex_t; -/* the termination handler */ -typedef void (*ex_term_cb_t)(ex_t *); -extern ex_term_cb_t __xbt_ex_terminate; -extern void __xbt_ex_terminate_default(ex_t *e); +/** Helper function used to throw exceptions in C */ +XBT_ATTRIB_NORETURN XBT_PUBLIC(void) + _xbt_throw(char* message, xbt_errcat_t errcat, int value, const char* file, int line, const char* func); -/** @brief Introduce a block where exception may be dealed with +/** Builds and throws an exception + * @ingroup XBT_ex_c * @hideinitializer */ -#define xbt_try \ - { \ - ex_ctx_t *__xbt_ex_ctx_ptr = __xbt_ex_ctx(); \ - int __ex_cleanup = 0; \ - __ex_mctx_t *__ex_mctx_en; \ - __ex_mctx_t __ex_mctx_me; \ - __ex_mctx_en = __xbt_ex_ctx_ptr->ctx_mctx; \ - __xbt_ex_ctx_ptr->ctx_mctx = &__ex_mctx_me; \ - if (__ex_mctx_save(&__ex_mctx_me)) { \ - if (1) +#define THROW(c, v) { _xbt_throw(NULL, (xbt_errcat_t) c, v, __FILE__, __LINE__, __func__); } -/** @brief optional(!) block for cleanup +/** Builds and throws an exception with a printf-like formatted message + * @ingroup XBT_ex_c * @hideinitializer */ -#define xbt_cleanup \ - else { \ - } \ - __xbt_ex_ctx_ptr->ctx_caught = 0; \ - } \ - else { \ - __ex_mctx_restored(&__ex_mctx_me); \ - __xbt_ex_ctx_ptr->ctx_caught = 1; \ - } \ - __xbt_ex_ctx_ptr->ctx_mctx = __ex_mctx_en; \ - __ex_cleanup = 1; \ - if (1) { \ - if (1) +#define THROWF(c, v, ...) _xbt_throw(bprintf(__VA_ARGS__), (xbt_errcat_t) c, v, __FILE__, __LINE__, __func__) -/** @brief the block for catching (ie, deal with) an exception - * @hideinitializer +/** Throw an exception because someting impossible happened + * @ingroup XBT_ex_c */ -#define xbt_catch(e) \ - else { \ - } \ - if (!(__ex_cleanup)) \ - __xbt_ex_ctx_ptr->ctx_caught = 0; \ - } \ - else { \ - if (!(__ex_cleanup)) { \ - __ex_mctx_restored(&__ex_mctx_me); \ - __xbt_ex_ctx_ptr->ctx_caught = 1; \ - } \ - } \ - __xbt_ex_ctx_ptr->ctx_mctx = __ex_mctx_en; \ - } \ - if ( !(__xbt_ex_ctx()->ctx_caught) \ - || ((e) = __xbt_ex_ctx()->ctx_ex, 0)) { \ - } \ - else +#define THROW_IMPOSSIBLE \ + THROWF(unknown_error, 0, "The Impossible Did Happen (yet again)") -/** @brief Build an exception from the supplied arguments and throws it - * @hideinitializer - * - * If called from within a sg_try/sg_catch construct, this exception - * is copied into the sg_catch relevant variable program control flow - * is derouted to the sg_catch (after the optional sg_cleanup). - * - * If no sg_try/sg_catch conctruct embeeds this call, the program calls - * abort(3). - * - * The sg_throw can be performed everywhere, including inside sg_try, - * sg_cleanup and sg_catch blocks. - */ -#define xbt_throw(c,v,m) \ - (( __xbt_ex_ctx()->ctx_shielding > 0 \ - || (__xbt_ex_ctx()->ctx_deferring > 0 && __xbt_ex_ctx()->ctx_deferred == 1)) ? 0 : \ - (__xbt_ex_ctx()->ctx_ex.msg = bprintf(m), \ - __xbt_ex_ctx()->ctx_ex.category = (c), \ - __xbt_ex_ctx()->ctx_ex.value = (v), \ - __xbt_ex_ctx()->ctx_ex.host = (char*)NULL, \ - __xbt_ex_ctx()->ctx_ex.procname = strdup(xbt_procname()), \ - __xbt_ex_ctx()->ctx_ex.file = (char*)__FILE__, \ - __xbt_ex_ctx()->ctx_ex.line = __LINE__, \ - __xbt_ex_ctx()->ctx_ex.func = (char*)_XBT_FUNCTION, \ - __xbt_ex_ctx()->ctx_deferred = 1, \ - (__xbt_ex_ctx()->ctx_deferring > 0 ? 0 : \ - (__xbt_ex_ctx()->ctx_mctx == NULL \ - ? (__xbt_ex_terminate((ex_t *)&(__xbt_ex_ctx()->ctx_ex)), -1) \ - : (__ex_mctx_restore(__xbt_ex_ctx()->ctx_mctx), 1) )))) - -/** @brief re-throwing of an already caught exception (ie, pass it to the upper catch block) - * @hideinitializer +/** Throw an exception because someting unimplemented stuff has been attempted + * @ingroup XBT_ex_c */ -#define xbt_rethrow \ - (( __xbt_ex_ctx()->ctx_shielding > 0 \ - || __xbt_ex_ctx()->ctx_deferring > 0) ? 0 : \ - ( __xbt_ex_ctx()->ctx_mctx == NULL \ - ? (__xbt_ex_terminate((ex_t *)&(__xbt_ex_ctx()->ctx_ex)), -1) \ - : (__ex_mctx_restore(__xbt_ex_ctx()->ctx_mctx), 1) )) +#define THROW_UNIMPLEMENTED \ + THROWF(unknown_error, 0, "Function %s unimplemented",__func__) -/** @brief shield an operation from exception handling - * @hideinitializer +/** Throw an exception because some dead code was reached + * @ingroup XBT_ex_c */ -#define xbt_shield \ - for (__xbt_ex_ctx()->ctx_shielding++, \ - __xbt_ex_ctx()->ctx_shield = 1; \ - __xbt_ex_ctx()->ctx_shield == 1; \ - __xbt_ex_ctx()->ctx_shield = 0, \ - __xbt_ex_ctx()->ctx_shielding--) +#define THROW_DEADCODE \ + THROWF(unknown_error, 0, "Function %s was supposed to be DEADCODE, but it's not",__func__) -/** @brief defer immediate exception handling - * @hideinitializer +/** Die because something impossible happened + * @ingroup XBT_ex_c */ -#define xbt_defer \ - for (((__xbt_ex_ctx()->ctx_deferring)++ == 0 ? __xbt_ex_ctx()->ctx_deferred = 0 : 0), \ - __xbt_ex_ctx()->ctx_defer = 1; \ - __xbt_ex_ctx()->ctx_defer == 1; \ - __xbt_ex_ctx()->ctx_defer = 0, \ - ((--(__xbt_ex_ctx()->ctx_deferring) == 0 && __xbt_ex_ctx()->ctx_deferred == 1) ? xbt_rethrow : 0)) +#define DIE_IMPOSSIBLE xbt_die("The Impossible Did Happen (yet again)") -/** @brief exception handling tests - * @hideinitializer - */ -#define xbt_catching \ - (__xbt_ex_ctx()->ctx_mctx != NULL) -/** @brief exception handling tests - * @hideinitializer - */ -#define xbt_shielding \ - (__xbt_ex_ctx()->ctx_shielding > 0) -/** @brief exception handling tests - * @hideinitializer - */ -#define xbt_deferring \ - (__xbt_ex_ctx()->ctx_deferring > 0) +/** Display an exception */ +XBT_PUBLIC(void) xbt_ex_display(xbt_ex_t * e); -/* optional namespace mapping */ -#if defined(__EX_NS_UCCXX__) -#define Try xbt_try -#define Cleanup xbt_cleanup -#define Catch xbt_catch -#define Throw xbt_throw -#define Rethrow xbt_rethrow -#define Shield xbt_shield -#define Defer xbt_defer -#elif defined(__EX_NS_CXX__) || (!defined(__cplusplus) && !defined(__EX_NS_CUSTOM__)) -#define try xbt_try -#define cleanup xbt_cleanup -#define catch xbt_catch -#define throw xbt_throw -#define rethrow xbt_rethrow -#define shield xbt_shield -#define defer xbt_defer -#endif +SG_END_DECL() -/** @} */ -#endif /* __XBT_EX_H__ */ - +/** @} */ +#endif /* __XBT_EX_H__ */