static SEM_ID alloc_xsem(int options, int initval, int maxval)
{
int sobj_flags = 0, ret;
struct wind_sem *sem;
if (options & ~SEM_Q_PRIORITY) {
errno = S_semLib_INVALID_OPTION;
return (SEM_ID)0;
}
sem = alloc_sem(options, &xsem_ops);
if (sem == NULL) {
errno = S_memLib_NOT_ENOUGH_MEMORY;
return (SEM_ID)0;
}
if (options & SEM_Q_PRIORITY)
sobj_flags = SYNCOBJ_PRIO;
sem->u.xsem.value = initval;
sem->u.xsem.maxvalue = maxval;
ret = syncobj_init(&sem->u.xsem.sobj, CLOCK_COPPERPLATE, sobj_flags,
fnref_put(libvxworks, sem_finalize));
if (ret) {
xnfree(sem);
errno = S_memLib_NOT_ENOUGH_MEMORY;
return (SEM_ID)0;
}
return mainheap_ref(sem, SEM_ID);
}
/**
* @fn int rt_buffer_create(RT_BUFFER *bf, const char *name, size_t bufsz, int mode)
* @brief Create an IPC buffer.
*
* This routine creates an IPC object that allows tasks to send and
* receive data asynchronously via a memory buffer. Data may be of an
* arbitrary length, albeit this IPC is best suited for small to
* medium-sized messages, since data always have to be copied to the
* buffer during transit. Large messages may be more efficiently
* handled by message queues (RT_QUEUE).
*
* @param bf The address of a buffer descriptor which can be later
* used to identify uniquely the created object, upon success of this
* call.
*
* @param name An ASCII string standing for the symbolic name of the
* buffer. When non-NULL and non-empty, a copy of this string is used
* for indexing the created buffer into the object registry.
*
* @param bufsz The size of the buffer space available to hold
* data. The required memory is obtained from the main heap.
*
* @param mode The buffer creation mode. The following flags can be
* OR'ed into this bitmask, each of them affecting the new buffer:
*
* - B_FIFO makes tasks pend in FIFO order for reading data from the
* buffer.
*
* - B_PRIO makes tasks pend in priority order for reading data from
* the buffer.
*
* This parameter also applies to tasks blocked on the buffer's write
* side (see rt_buffer_write()).
*
* @return Zero is returned upon success. Otherwise:
*
* - -ENOMEM is returned if the system fails to get memory from the
* main heap in order to create the buffer.
*
* - -EEXIST is returned if the @a name is conflicting with an already
* registered buffer.
*
* - -EPERM is returned if this service was called from an
* asynchronous context.
*
* Valid calling context:
*
* - Regular POSIX threads
* - Xenomai threads
*
* @note Buffers can be shared by multiple processes which belong to
* the same Xenomai session.
*/
int rt_buffer_create(RT_BUFFER *bf, const char *name,
size_t bufsz, int mode)
{
struct alchemy_buffer *bcb;
struct service svc;
int sobj_flags = 0;
int ret;
if (threadobj_irq_p())
return -EPERM;
if (bufsz == 0)
return -EINVAL;
CANCEL_DEFER(svc);
bcb = xnmalloc(sizeof(*bcb));
if (bcb == NULL) {
ret = __bt(-ENOMEM);
goto fail;
}
bcb->buf = xnmalloc(bufsz);
if (bcb == NULL) {
ret = __bt(-ENOMEM);
goto fail_bufalloc;
}
generate_name(bcb->name, name, &buffer_namegen);
bcb->magic = buffer_magic;
bcb->mode = mode;
bcb->bufsz = bufsz;
bcb->rdoff = 0;
bcb->wroff = 0;
bcb->fillsz = 0;
if (mode & B_PRIO)
sobj_flags = SYNCOBJ_PRIO;
syncobj_init(&bcb->sobj, CLOCK_COPPERPLATE, sobj_flags,
fnref_put(libalchemy, buffer_finalize));
if (syncluster_addobj(&alchemy_buffer_table, bcb->name, &bcb->cobj)) {
ret = -EEXIST;
goto fail_register;
}
bf->handle = mainheap_ref(bcb, uintptr_t);
CANCEL_RESTORE(svc);
return 0;
fail_register:
syncobj_uninit(&bcb->sobj);
xnfree(bcb->buf);
fail_bufalloc:
xnfree(bcb);
fail:
CANCEL_RESTORE(svc);
return ret;
}
