Asserts are fine even if the input is supposed to already be validated. But as I said, asserting that a pointer is not NULL is not so useful since you crash anyway when dereferencing it. Possibly it can be useful as a way do document the code, to say that you know this pointer is not NULL. Both humans and e.g. static analysis tools can make use of such information.
regards, Anders Widell 2014-04-04 16:33, Hans Nordebäck skrev: > "external" API normally needs to validate its input and further calling > "internal" function these validations are not needed. Asserts can be used to > detect bugs and are normally compiled away in release builds. > I can add osafassert in these functions, but shouldn't the input already have > been validated in calling functions? /BR HansN > > -----Original Message----- > From: Anders Widell > Sent: den 4 april 2014 16:27 > To: Nagendra Kumar; Hans Nordebäck; Hans Feldt; Praveen Malviya > Cc: opensaf-devel@lists.sourceforge.net > Subject: Re: [devel] [PATCH 1 of 1] amfd: use template class db to replace > patricia tree db V2 [#713] > > Just some thoughts regarding NULL pointers: > > When I write a function, I by default assume that pointers passed to it as > arguments are not NULL. Only if the API documentation explicitly states that > a NULL pointer is a valid input for that argument, then the function needs to > handle it. Otherwise it is fine to crash (or assert) when receiving a NULL > pointer. An assert is typically not needed, since the program will crash when > dereferencing a NULL pointer anyway. > > Sometimes it is useful to allow function arguments to be NULL pointers. > One typical example is the C library functions free() and realloc(), where it > can be very handy to be able to pass a NULL pointer in case no memory has > been allocated (yet). The API documentation here clearly says what happens > when you pass a NULL pointer. > > regards, > Anders Widell > > 2014-04-04 15:04, Nagendra Kumar skrev: >> Ack with comment the functions added are not NULL safe. It crashed if passed >> NULL. Do we want to have some checks ? >> >> Thanks >> -Nagu >> >>> -----Original Message----- >>> From: Hans Nordeback [mailto:hans.nordeb...@ericsson.com] >>> Sent: 26 March 2014 16:58 >>> To: hans.fe...@ericsson.com; Nagendra Kumar; Praveen Malviya >>> Cc: opensaf-devel@lists.sourceforge.net >>> Subject: [PATCH 1 of 1] amfd: use template class db to replace >>> patricia tree db >>> V2 [#713] >>> >>> osaf/services/saf/amf/amfd/include/db_template.h | 63 >>> ++++++++++++++++++++++++ >>> 1 files changed, 63 insertions(+), 0 deletions(-) >>> >>> >>> diff --git a/osaf/services/saf/amf/amfd/include/db_template.h >>> b/osaf/services/saf/amf/amfd/include/db_template.h >>> new file mode 100644 >>> --- /dev/null >>> +++ b/osaf/services/saf/amf/amfd/include/db_template.h >>> @@ -0,0 +1,63 @@ >>> +/* -*- OpenSAF -*- >>> + * >>> + * (C) Copyright 2014 The OpenSAF Foundation >>> + * >>> + * 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. This file and program are >>> +licensed >>> + * under the GNU Lesser General Public License Version 2.1, February 1999. >>> + * The complete license can be accessed from the following location: >>> + * http://opensource.org/licenses/lgpl-license.php >>> + * See the Copying file included with the OpenSAF distribution for >>> +full >>> + * licensing terms. >>> + * >>> + * Author(s): Ericsson AB >>> + * >>> + */ >>> +#ifndef DB_TEMPLATE_H >>> +#define DB_TEMPLATE_H >>> + >>> +#include <map> >>> +#include <string> >>> + >>> +template <typename T> >>> +class AmfDb { >>> + public: >>> + void insert(T *obj); >>> + void erase(T *obj); >>> + T *find(const SaNameT *name); >>> + >>> + typedef std::map<std::string, T*> AmfDbMap; >>> + typedef typename AmfDbMap::const_iterator const_iterator; >>> + >>> + const_iterator begin() const {return db.begin();} >>> + const_iterator end() const {return db.end();} >>> + >>> + private: >>> + AmfDbMap db; >>> +}; >>> + >>> +template <typename T> >>> +void AmfDb<T>::insert(T *obj) { >>> + std::string name((const char*)obj->name.value, obj->name.length); >>> + db[name] = obj; >>> +} >>> + >>> +template <typename T> >>> +void AmfDb<T>::erase(T *obj) { >>> + std::string name((const char*)obj->name.value, obj->name.length); >>> + typename AmfDbMap::iterator it = db.find(name); >>> + db.erase(it); >>> +} >>> + >>> +template <typename T> >>> +T *AmfDb<T>::find(const SaNameT *dn) { >>> + std::string name((const char*)dn->value, dn->length); >>> + typename AmfDbMap::iterator it = db.find(name); >>> + if (it == db.end()) >>> + return NULL; >>> + else >>> + return it->second; >>> +} >>> + >>> +#endif /* DB_TEMPLATE_H */ >> ---------------------------------------------------------------------- >> -------- _______________________________________________ >> Opensaf-devel mailing list >> Opensaf-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/opensaf-devel >> >> ------------------------------------------------------------------------------ _______________________________________________ Opensaf-devel mailing list Opensaf-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/opensaf-devel
