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VILLASnode/include/villas/nodes/shmem.h
2017-04-05 12:52:21 +02:00

59 lines
2.1 KiB
C

#ifndef _SHMEM_H_
#define _SHMEM_H_
#include "node.h"
#include "memory.h"
#include "pool.h"
#include "queue.h"
#define DEFAULT_SHMEM_QUEUESIZE 512
/** Per-direction shared datastructure for a shmem node. */
struct shmem_queue {
struct queue queue; /**< Actual queue where the samples are passed */
pthread_cond_t ready; /**< Condition variable to signal writes to the queue */
pthread_condattr_t readyattr;
pthread_mutex_t mt; /**< Mutex for ready */
pthread_mutexattr_t mtattr;
};
/** The structure that actually resides in the shared memory. TODO better name?*/
struct shmem_shared {
struct shmem_queue in; /**< Queue for samples passed from external program to node.*/
struct shmem_queue out; /**< Queue for samples passed from node to external program.*/
struct pool pool; /**< Pool for the samples in the queues. */
};
struct shmem {
const char* name; /**< Name of the shm object. */
int sample_size; /**< Number of data entries for each sample. */
int insize, outsize; /**< Size of ingoing and outgoing queue, respectively. */
int cond_out; /**< Whether to use a pthread_cond_t to signal if new samples are written to outqueue. */
int cond_in; /**< Whether to use a pthread_cond_t to signal if new samples are written to inqueue. */
size_t len; /**< Overall size of shared memory object. */
struct memtype *manager; /**< Manager for the shared memory region. */
int fd; /**< Handle as returned by shm_open().*/
void *base; /**< Pointer to the shared memory region. */
struct shmem_shared *shared; /**< Shared datastructure. */
};
char *shmem_print(struct node *n);
int shmem_parse(struct node *n, config_setting_t *cfg);
int shmem_open(struct node *n);
int shmem_close(struct node *n);
int shmem_read(struct node *n, struct sample *smps[], unsigned cnt);
int shmem_write(struct node *n, struct sample *smps[], unsigned cnt);
/* The interface functions that the external program should use. TODO put this
* in another file? */
struct shmem_shared * shmem_int_open(const char* name, size_t len);
size_t shmem_total_size(int insize, int outsize, int sample_size);
#endif /* _SHMEM_H_ */