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/*========================================================================

//

//      mqueue.cxx

//

//      Message queues tests

//

//========================================================================

//####ECOSGPLCOPYRIGHTBEGIN####

// -------------------------------------------

// This file is part of eCos, the Embedded Configurable Operating System.

// Copyright (C) 1998, 1999, 2000, 2001, 2002 Red Hat, Inc.

//

// eCos 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 or (at your option) any later version.

//

// eCos 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 eCos; if not, write to the Free Software Foundation, Inc.,

// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

//

// As a special exception, if other files instantiate templates or use macros

// or inline functions from this file, or you compile this file and link it

// with other works to produce a work based on this file, this file does not

// by itself cause the resulting work to be covered by the GNU General Public

// License. However the source code for this file must still be made available

// in accordance with section (3) of the GNU General Public License.

//

// This exception does not invalidate any other reasons why a work based on

// this file might be covered by the GNU General Public License.

//

// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.

// at http://sources.redhat.com/ecos/ecos-license/

// -------------------------------------------

//####ECOSGPLCOPYRIGHTEND####

//========================================================================

//#####DESCRIPTIONBEGIN####

//

// Author(s):     jlarmour

// Contributors:

// Date:          2000-05-14

// Purpose:       This file provides the implementation for POSIX message

//                queues

// Description:   It uses eCos kernel mqueues as the underlying

//                implementation

// Usage:

//

//####DESCRIPTIONEND####

//

//======================================================================

*/

/* CONFIGURATION */

#include <pkgconf/posix.h>

#ifdef CYGPKG_POSIX_MQUEUES

#include <pkgconf/kernel.h>

/* INCLUDES */

#include <cyg/infra/cyg_type.h>      // common types etc.

#include <cyg/infra/cyg_ass.h>       // Assertion support

#include <cyg/infra/cyg_trac.h>      // Tracing support

#include <cyg/kernel/mqueue.hxx>     // eCos Mqueue Header

#include <cyg/kernel/sched.hxx>      // Cyg_Scheduler::lock()

#include <cyg/kernel/sched.inl>      // inlines for above

#include <mqueue.h>                  // Standard POSIX mqueue header

#include <sys/types.h>               // mode_t, ssize_t

#include <limits.h>                  // PATH_MAX

#include <stdlib.h>                  // malloc, etc.

#include <errno.h>                   // errno

#include <fcntl.h>                   // O_*

#include <stdarg.h>                  // varargs

#include <pthread.h>                 // mutexes

#include <string.h>                  // strncpy

#include <new>                       // C++ new

#ifdef CYGFUN_POSIX_MQUEUE_NOTIFY

# include <signal.h>

# include "pprivate.h"               // cyg_sigqueue()

#endif

#ifdef CYGFUN_KERNEL_THREADS_TIMER

# include <time.h>

# include "pprivate.h"               // cyg_timespec_to_ticks()

#endif

/* CONSTANTS */

#define MQ_VALID_MAGIC  0x6db256c1

/* TYPE DEFINITIONS */

struct mqtabent;

// this is a queue user - each one of these corresponds to a mqd_t

struct mquser {

    int flags;               // O_RDONLY, O_WRONLY, O_RDWR, O_NONBLOCK

    struct mqtabent *tabent; // back pointer to table entry

    struct mquser *next;

    bool notifieruser;       // POSIX sucks so bad. It requires a mq_close

                             // to only deregister the notification if it

                             // was done via this descriptor. So we have to

                             // know if it was this one

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

    cyg_uint32 magic;        // magic number: MQ_VALID_MAGIC if valid

#endif    

};

struct mqtabent {

    char name[ PATH_MAX ]; // ascii name - set to "" when unused

    Cyg_Mqueue *mq;        // the underlying queue object

    long maxmsg;           // as set on creation

    long msgsize;          // as set on creation

    bool unlinkme;         // unlink when final user closes?

    struct mquser *users;  // each user

#ifdef CYGFUN_POSIX_MQUEUE_NOTIFY

    const struct sigevent *sigev; // notification event

#endif

};

/* GLOBALS */

static struct mqtabent mqtab[ CYGNUM_POSIX_MQUEUE_OPEN_MAX ];

static pthread_mutex_t mqtab_mut = PTHREAD_MUTEX_INITIALIZER;

/* LOCAL FUNCTIONS */

//------------------------------------------------------------------------

// Deallocation callback from Cyg_Mqueue

static void

my_free( void *ptr, size_t )

{

    free( ptr );

}

//------------------------------------------------------------------------

// Do the actual "unlink" of a queue, i.e. mark it invalid in the table.

// The table mutex is assumed to be locked

static void

do_mq_unlink( struct mqtabent *tabent )

{

    CYG_REPORT_FUNCTION();

    CYG_CHECK_DATA_PTRC( tabent );

    tabent->name[0] = '\0'; // won't match anything the user sends now

    tabent->mq->~Cyg_Mqueue();

    free( tabent->mq );

    tabent->mq=NULL;

    CYG_REPORT_RETURN();

}

//------------------------------------------------------------------------

#ifdef CYGFUN_POSIX_MQUEUE_NOTIFY

static void

notifyme( Cyg_Mqueue &q, CYG_ADDRWORD data )

{

    CYG_REPORT_FUNCTION();

    struct mquser *user = (struct mquser *)data;

    CYG_CHECK_DATA_PTRC( user );

    struct mqtabent *tabent = user->tabent;

    CYG_CHECK_DATA_PTRC( tabent );

    Cyg_Scheduler::lock();

    // we may have been pre-empted before this, so check there's still a

    // notification to do

    if ( NULL == tabent->sigev ) {

        Cyg_Scheduler::unlock();

        CYG_REPORT_RETURN();

        return;

    } // if

    const struct sigevent *ev = tabent->sigev;

    // first deregister

    q.setnotify( NULL, 0 );

    tabent->sigev = NULL;

    user->notifieruser = false; // not any more

    // now the rest of the world can go

    Cyg_Scheduler::unlock();

    // queue event. If it fails... nothing we can do :-( so ignore return code

    cyg_sigqueue( ev, SI_MESGQ );

    cyg_deliver_signals();

    CYG_REPORT_RETURN();

}

#endif // ifdef CYGFUN_POSIX_MQUEUE_NOTIFY

//------------------------------------------------------------------------

/* EXPORTED FUNCTIONS */

externC mqd_t

mq_open( const char *name, int oflag, ... )

{

    CYG_REPORT_FUNCTYPE( "returning %08x" );

    CYG_REPORT_FUNCARG2( "name=%08x, oflag=%d", name, oflag );

    CYG_CHECK_DATA_PTRC( name );

    if ( ((oflag & O_RDONLY) != O_RDONLY) &&

         ((oflag & O_WRONLY) != O_WRONLY) &&

         ((oflag & O_RDWR) != O_RDWR)) {

        // user didn't specify mode

        errno = EINVAL;

        CYG_REPORT_RETVAL( -1 );

        return (mqd_t)-1;

    } // if

    mqd_t retval;

    cyg_ucount32 i;

    struct mqtabent *qtabent=NULL;

    int interr;

    interr = pthread_mutex_lock( &mqtab_mut );

    // should never fail

    CYG_ASSERT( interr == 0, "internal lock failed!" );

    // find if a matching entry exists first

    // FIXME: Should check for length and return ENAMETOOLONG

    for ( i=0; i < CYGNUM_POSIX_MQUEUE_OPEN_MAX; i++ ) {

        if ( 0 == strncmp(name, mqtab[i].name, PATH_MAX) ) {

            qtabent = &mqtab[i];

            break;

        } // if

    } // for

    if ( (NULL != qtabent) && (O_EXCL == (oflag & O_EXCL)) ) {

        errno = EEXIST;

        retval = (mqd_t)-1;

        goto exit_unlock;

    }

    if ( (NULL == qtabent) && (O_CREAT != (oflag & O_CREAT)) ) {

        errno = ENOENT;

        retval = (mqd_t)-1;

        goto exit_unlock;

    }

    // so if we didn't find something, we must be being asked to create it

    if (NULL == qtabent) {

        mode_t mode; // FIXME: mode ignored for now

        const struct mq_attr *attr;

        const struct mq_attr default_attr = { 0, MQ_OPEN_MAX, 128 };

        va_list args;

        va_start( args, oflag );

        mode = va_arg( args, mode_t );

        attr = va_arg( args, struct mq_attr * );

        va_end( args );

        // find an empty table entry

        for ( i=0; i < CYGNUM_POSIX_MQUEUE_OPEN_MAX; i++ ) {

            if ( NULL == mqtab[i].mq )

                break;

        }

        // if not found, table is full

        if ( i == CYGNUM_POSIX_MQUEUE_OPEN_MAX ) {

            errno = ENFILE;

            retval = (mqd_t)-1;

            goto exit_unlock;

        }

        Cyg_Mqueue::qerr_t qerr;

        // user can specify NULL attr, which means arbitrary message queue

        // size! Duh.

        if ( NULL == attr )

            attr = &default_attr;

        else {

            // if they do supply one, POSIX says we're meant to check it

            if (attr->mq_maxmsg <= 0 || attr->mq_msgsize <= 0) {

                errno = EINVAL;

                retval = (mqd_t)-1;

                goto exit_unlock;

            }

        } // else

        // allocate the underlying queue

        Cyg_Mqueue *mqholder = (Cyg_Mqueue *)malloc( sizeof(Cyg_Mqueue) );

        if ( NULL == mqholder ) {

            errno = ENOSPC;

            retval = (mqd_t)-1;

            goto exit_unlock;

        }

        // construct it with placement new

        mqtab[i].mq = new (mqholder) Cyg_Mqueue( attr->mq_maxmsg,

                                                 attr->mq_msgsize,

                                                 &malloc, &my_free, &qerr );

        switch (qerr) {

        case Cyg_Mqueue::OK:

            break;

        case Cyg_Mqueue::NOMEM:

            free( mqholder );

            errno = ENOSPC;

            retval = (mqd_t)-1;

            goto exit_unlock;

        default:

            CYG_FAIL("Unhandled Cyg_Mqueue constructor return error");

            break;

        } // switch

        mqtab[i].users = (struct mquser *) malloc( sizeof(struct mquser) );

        if ( NULL == mqtab[i].users ) {

            mqtab[i].mq->~Cyg_Mqueue();

            free( mqholder );

            errno = ENOSPC;

            retval = (mqd_t)-1;

            goto exit_unlock;

        }

        // initialize mqtab[i]

        mqtab[i].maxmsg  = attr->mq_maxmsg;

        mqtab[i].msgsize = attr->mq_msgsize;

        mqtab[i].unlinkme = false;

#ifdef CYGFUN_POSIX_MQUEUE_NOTIFY

        mqtab[i].sigev = NULL;

#endif

        strncpy( mqtab[i].name, name, PATH_MAX );

        // initialize first mqtab[i].users

        mqtab[i].users->next = NULL;

        // set the mode for later, but also note that O_NONBLOCK can

        // be set in oflags *or* the attr the user passed

        mqtab[i].users->flags = oflag | (attr->mq_flags & O_NONBLOCK);

        // set back pointer so that message queue handle can find actual queue

        mqtab[i].users->tabent = &mqtab[i];

        mqtab[i].users->notifieruser = false;

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

        mqtab[i].users->magic = MQ_VALID_MAGIC; // now valid

#endif

        retval=(mqd_t)mqtab[i].users;

        goto exit_unlock;

    } // if (NULL == qtabent)

    // so we're not creating, and we have a valid qtabent

    // But this qtabent may be being unlinked. If so, we are permitted

    // to return an error, so we will. (see under mq_unlink() in POSIX)

    // Which error though? EINVAL seems best, but POSIX doesn't say :-/

    if (true == qtabent->unlinkme) {

        errno = EINVAL;

        retval = (mqd_t)-1;

        goto exit_unlock;

    }

    // now we have a usable qtabent

    struct mquser *user;

    user = (struct mquser *) malloc( sizeof(struct mquser) );

    if ( NULL == user ) {

            errno = ENOSPC;

            retval = (mqd_t)-1;

            goto exit_unlock;

    }

    // prepend to qtab user list

    user->next = qtabent->users;

    qtabent->users = user;

    // set back pointer so that message queue handle can find actual queue

    user->tabent = qtabent;

    user->flags = oflag;

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

    user->magic = MQ_VALID_MAGIC; // now valid

#endif

    retval=(mqd_t)user;

 exit_unlock:

    interr = pthread_mutex_unlock( &mqtab_mut );

    // should never fail

    CYG_ASSERT( interr == 0, "internal lock failed!" );

    CYG_REPORT_RETVAL( retval );

    return retval;

} // mq_open()

//------------------------------------------------------------------------

// NOTE: It is the *user*'s responsibility to ensure that nothing is

// blocked in mq_send() or mq_receive() when closing the queue with

// that descriptor. The standard does not specify the behaviour, so that's

// what I am assuming

externC int

mq_close( mqd_t mqdes )

{

    CYG_REPORT_FUNCTYPE( "returning %d" );

    CYG_REPORT_FUNCARG1XV( mqdes );

    struct mquser *user = (struct mquser *)mqdes;

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

    if ( user->magic != MQ_VALID_MAGIC ) {

        errno  = EBADF;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    }

#endif

    int interr;

    interr = pthread_mutex_lock( &mqtab_mut );

    // should never fail

    CYG_ASSERT( interr == 0, "internal lock failed!" );

    struct mqtabent *tabent = user->tabent;

    struct mquser *usertmp;

    // perhaps should return EBADF instead of assert?

    CYG_ASSERT( tabent->users != NULL, "Null message queue user list" );

#ifdef CYGFUN_POSIX_MQUEUE_NOTIFY

    // deregister notification iff this was the message queue descriptor

    // that was used to register it (POSIX says)

    if ( true == user->notifieruser ) {

        tabent->mq->setnotify( NULL, 0 );

        tabent->sigev = NULL;

        // not worth clearing notifieruser

    }

#endif

    // find in the list for this queue and remove - sucks a bit, but seems

    // best over all - the list shouldn't be too long

    if ( tabent->users == user ) {

        tabent->users = user->next;  // remove

    } else {

        for ( usertmp=tabent->users;

              NULL != usertmp->next;

              usertmp = usertmp->next ) {

            if ( usertmp->next == user )

                break;

        } // for

        // perhaps should return EBADF instead of assert?

        CYG_ASSERT( usertmp->next != NULL, "Couldn't find message queue user" );

        usertmp->next = user->next; // remove

    } // else

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

    user->magic = 0; // invalidate

#endif

    // free it up

    free( user );

    if ( (true == tabent->unlinkme) && (NULL == tabent->users) ) {

        do_mq_unlink( tabent );

    } // if

    interr = pthread_mutex_unlock( &mqtab_mut );

    // should never fail

    CYG_ASSERT( interr == 0, "internal lock failed!" );

    CYG_REPORT_RETVAL( 0 );

    return 0;

} // mq_close()

//------------------------------------------------------------------------

externC int

mq_unlink( const char *name )

{

    CYG_REPORT_FUNCTYPE( "returning %d" );

    CYG_REPORT_FUNCARG1( "name=%s", name );

    int retval, interr;

    cyg_ucount32 i;

    struct mqtabent *qtabent=NULL;

    interr = pthread_mutex_lock( &mqtab_mut );

    // should never fail

    CYG_ASSERT( interr == 0, "internal lock failed!" );

    // find the entry first

    // FIXME: Should check for length and return ENAMETOOLONG

    for ( i=0; i < CYGNUM_POSIX_MQUEUE_OPEN_MAX; i++ ) {

        if ( 0 == strncmp(name, mqtab[i].name, PATH_MAX) ) {

            qtabent = &mqtab[i];

            break;

        } // if

    } // for

    if ( NULL == qtabent ) { // not found

        errno = ENOENT;

        retval = -1;

        goto exit_unlock;

    }

    if ( NULL != qtabent->users ) {   // still in use

        qtabent->unlinkme = true;     // so mark it as pending deletion

    } else {

        do_mq_unlink( qtabent );

    } // else

    retval = 0;

 exit_unlock:

    interr = pthread_mutex_unlock( &mqtab_mut );

    // should never fail

    CYG_ASSERT( interr == 0, "internal lock failed!" );

    CYG_REPORT_RETVAL( retval );

    return retval;

} // mq_unlink()

//------------------------------------------------------------------------

externC int

mq_send( mqd_t mqdes, const char *msg_ptr, size_t msg_len,

         unsigned int msg_prio )

{

    CYG_REPORT_FUNCTYPE( "returning %d" );

    CYG_REPORT_FUNCARG4( "mqdes=%08x, msg_ptr=%08x, msg_len=%u, msg_prio=%u",

                         mqdes, msg_ptr, msg_len, msg_prio );

    CYG_CHECK_DATA_PTRC( msg_ptr );

    struct mquser *user = (struct mquser *)mqdes;

    struct mqtabent *tabent = user->tabent;

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

    if ( user->magic != MQ_VALID_MAGIC ) {

        errno  = EBADF;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    }

#endif

    if ( msg_len > (size_t)tabent->msgsize ) {

        errno = EMSGSIZE;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    }

    if ( msg_prio > MQ_PRIO_MAX ) {

        errno = EINVAL;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    }

    if ( (O_WRONLY != (user->flags & O_WRONLY)) &&

         (O_RDWR != (user->flags & O_RDWR)) ) {

        errno = EBADF;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    }

    // go for it

    Cyg_Mqueue::qerr_t err;

    err = tabent->mq->put( msg_ptr, msg_len, msg_prio,

                           ((user->flags & O_NONBLOCK) != O_NONBLOCK) );

    switch (err) {

    case Cyg_Mqueue::INTR:

        errno = EINTR;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    case Cyg_Mqueue::WOULDBLOCK:

        CYG_ASSERT( (user->flags & O_NONBLOCK) == O_NONBLOCK,

                    "Message queue assumed non-blocking when blocking requested"

            );

        errno = EAGAIN;

        CYG_REPORT_RETVAL( -1 );

        return -1;

    case Cyg_Mqueue::OK:

        CYG_REPORT_RETVAL( 0 );

        return 0;

    default:

        CYG_FAIL( "unhandled message queue return code" );

        return -1; // keep compiler happy

    } // switch

} // mq_send()

//------------------------------------------------------------------------

externC ssize_t

mq_receive( mqd_t mqdes, char *msg_ptr, size_t msg_len,

            unsigned int *msg_prio )

{

    CYG_REPORT_FUNCTYPE( "returning %ld" );

    CYG_REPORT_FUNCARG4( "mqdes=%08x, msg_ptr=%08x, msg_len=%u, msg_prio=%08x",

                         mqdes, msg_ptr, msg_len, msg_prio );

    CYG_CHECK_DATA_PTRC( msg_ptr );

    CYG_CHECK_DATA_PTRC( msg_ptr+msg_len-1 );

    if ( NULL != msg_prio )

        CYG_CHECK_DATA_PTRC( msg_prio );

    struct mquser *user = (struct mquser *)mqdes;

    struct mqtabent *tabent = user->tabent;

#ifdef CYGIMP_POSIX_MQUEUE_VALIDATE_DESCRIPTOR

    if ( user->magic != MQ_VALID_MAGIC ) {

        errno  = EBADF;

        CYG_REPORT_RETVAL( -1 );

        return (ssize_t)-1;

    }

#endif

    if ( (O_RDONLY != (user->flags & O_RDONLY)) &&

         (O_RDWR != (user->flags & O_RDWR)) ) {

        errno = EBADF;

        CYG_REPORT_RETVAL( -1 );

        return (ssize_t)-1;

    }

    if ( msg_len < (size_t)tabent->msgsize ) {

        errno = EMSGSIZE;

        CYG_REPORT_RETVAL( -1 );

        return (ssize_t)-1;

    }

    // go for it

    Cyg_Mqueue::qerr_t err;

    err = tabent->mq->get( msg_ptr, &msg_len, msg_prio,

                           ((user->flags & O_NONBLOCK) != O_NONBLOCK) );

    switch (err) {

    case Cyg_Mqueue::INTR:

        errno = EINTR;

        CYG_REPORT_RETVAL( -1 );

        return (ssize_t)-1;

    case Cyg_Mqueue::WOULDBLOCK:

        CYG_ASSERT( (user->flags & O_NONBLOCK) == O_NONBLOCK,

                    "Message queue assumed non-blocking when blocking requested"

            );

        errno = EAGAIN;

        CYG_REPORT_RETVAL( -1 );

        return (ssize_t)-1;

    case Cyg_Mqueue::OK:

        CYG_ASSERT( msg_len <= (size_t)tabent->msgsize,

                    "returned message too long" );

        if ( NULL != msg_prio )

            CYG_ASSERT( *msg_prio <= MQ_PRIO_MAX,

                        "returned message has invalid priority" );

        CYG_REPORT_RETVAL( msg_len );

        return (ssize_t)msg_len;

    default:

        CYG_FAIL( "unhandled message queue return code" );

        return (ssize_t)-1; // keep compiler happy

    } // switch

} // mq_receive()

//------------------------------------------------------------------------

#ifdef CYGFUN_KERNEL_THREADS_TIMER

externC int

mq_timedsend( mqd_t mqdes, const char *msg_ptr, size_t msg_len,

              unsigned int msg_prio, const struct timespec *abs_timeout)

{

    CYG_REPORT_FUNCTYPE( "returning %d" );