uem.h

Advanced UNIX Programming is the long-awaited (19 years!) update to the 1985 original. Maybe "update

/*
	Copyright 2003 by Marc J. Rochkind. All rights reserved. (Will be released for free public use upon publication of a forthcoming book. For now, released only for review purposes.)
*/
#ifndef _UEM_H_
#define _UEM_H_

#ifdef SOLARIS // must be changed
#define POSIX_IPC
#endif

#include <pthread.h>
#include <sys/select.h>
#ifdef POSIX_IPC
#include <mqueue.h>
#include <semaphore.h>
#endif
/*[UEM_TYPE]*/
enum UEM_TYPE {
	UEM_SVMSG,      /* System V message */
	UEM_PXMSG,      /* POSIX message */
	UEM_SVSEM,      /* System V semaphore */
	UEM_PXSEM,      /* POSIX semaphore */
	UEM_FD_READ,    /* file-descriptor set - read */
	UEM_FD_WRITE,   /* file-descriptor set - write */
	UEM_FD_ERROR,   /* file-descriptor set  - error */
	UEM_SIG,        /* signal */
	UEM_PROCESS,    /* process */
	UEM_HEARTBEAT,  /* heartbeat */
	UEM_NONE        /* none */
};
/*[uem_reg]*/
struct uem_reg {
	enum UEM_TYPE ur_type;          /* type of registration */
	pthread_t ur_tid;               /* thread ID */
	union {
		int ur_mqid;				/* System V message-queue ID */
		struct {
			int s_semid;			/* System V semaphore-set ID */
			struct sembuf *s_sops;	/* semaphore operations */
		} ur_svsem;
#ifdef POSIX_IPC
		mqd_t ur_mqd;				/* POSIX message-queue descriptor */
		sem_t *ur_sem;				/* POSIX semaphore */
#endif
		int ur_signum;				/* signal number */
		pid_t ur_pid;				/* process ID */
		long ur_usecs;				/* microseconds (for heartbeat) */
		fd_set ur_fdset;			/* file-descriptor set */
	} ur_resource;
	void *ur_data;					/* data to be queued with event */
	size_t ur_size;					/* size (used for various purposes) */
};
/*[uem_event]*/
struct uem_event {
	struct uem_reg *ue_reg;
	void *ue_buf;
	ssize_t ue_result;
	int ue_errno;
	struct uem_event *ue_next;
};
/*[]*/

bool uem_bgn(void);
bool uem_end(void);
bool uem_register_svmsg(int mqid, size_t msgsize, void *data);
bool uem_register_svsem(int semid, struct sembuf *sops, size_t nsops,
  void *data);
#ifdef POSIX_IPC
bool uem_register_pxmsg(mqd_t mqd, void *data);
bool uem_register_pxsem(sem_t *sem, void *data);
#endif
bool uem_register_signal(int signum, void *data);
bool uem_register_process(pid_t pid, void *data); /* also array of pids? */
bool uem_register_fdset(int nfds, fd_set *fdset, enum UEM_TYPE type,
  void *data);
bool uem_register_heartbeat(long usecs, void *data);

struct uem_event *uem_wait(void);
void uem_free(struct uem_event *e);
bool uem_unregister(struct uem_event *e);

// call to unregister?
// is it the same as cancelling the thread that blocks?

#endif