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/*
* Copyright (c) 1997-1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit 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 GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Allocate a file descriptor
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "fd.h"
/* start out with NDFILE */
#define NDFILE 20
#define NDEXTENT 50
/* then extend by `extendby' - which is doubled every time */
static int extendby = NDFILE;
#ifdef THREAD_SAFE
static pthread_mutexattr_t mutex_attributes;
pthread_mutex_t libc_fd_array_mutex;
#endif
static int didinit = 0;
void fd_init(void);
/*
* The 3 stdio descriptors have to be statically initialized so that
* console printf works from the get go. This makes the first real
* allocation a little messy, since we are going to toss this array
* away once we get the intialization call. Life is messy.
*/
extern oskit_stream_t console_stream;
int fd_arraylen = 3;
fd_t initial_fd_array[3] = {
{ (oskit_iunknown_t*) &console_stream },
{ (oskit_iunknown_t*) &console_stream },
{ (oskit_iunknown_t*) &console_stream },
};
fd_t *fd_array = initial_fd_array;
int
fd_alloc(oskit_iunknown_t *obj, int min_fd)
{
int i;
oskit_size_t bytes;
fd_t *newarray;
if (! didinit) {
#ifdef THREAD_SAFE
panic("fd_alloc: oskit_init_libc was not called!");
#else
fd_init();
#endif
}
fd_array_lock();
try_again:
/* search for a free fd */
for (i = min_fd; i < fd_arraylen; i++) {
if (fd_array[i].obj == 0) {
/* found an unused slot */
#ifdef THREAD_SAFE
pthread_mutex_init(fd_array[i].lock,
&mutex_attributes);
pthread_cond_init(fd_array[i].readcond,
&pthread_condattr_default);
pthread_cond_init(fd_array[i].writecond,
&pthread_condattr_default);
fd_array[i].writer = 0;
fd_array[i].reader = 0;
fd_array[i].writecount = 0;
fd_array[i].readcount = 0;
fd_array[i].readwait = 0;
fd_array[i].writewait = 0;
spin_lock_init(&fd_array[i].spinlock);
#ifdef DEBUG
fd_array[i].creator = pthread_self();
#endif
#endif
oskit_iunknown_addref(obj);
fd_array[i].obj = obj;
fd_array_unlock();
return i;
}
}
/*
* Create the fd_array if we don't have one yet, or realloc
* if we do.
*/
if (fd_array == initial_fd_array) {
extendby = NDFILE;
bytes = (fd_arraylen + extendby) * sizeof(fd_t);
newarray = (fd_t *)malloc(bytes);
memcpy(newarray, initial_fd_array, sizeof(initial_fd_array));
}
else {
bytes = (fd_arraylen + extendby) * sizeof(fd_t);
newarray = (fd_t *)realloc(fd_array, bytes);
}
if (newarray == NULL) {
errno = ENOMEM;
fd_array_unlock();
return -1;
}
/* zero out new part of the array */
memset(newarray + fd_arraylen, 0, extendby * sizeof(fd_t));
#ifdef THREAD_SAFE
/* allocate the mutex and condition variable structures. */
{
pthread_mutex_t *pmutex;
pthread_cond_t *pcond;
fd_t *pfd = newarray + fd_arraylen;
if ((pmutex = (pthread_mutex_t *)
calloc(extendby, sizeof(pthread_mutex_t))) == NULL) {
errno = ENOMEM;
fd_array_unlock();
return -1;
}
if ((pcond = (pthread_cond_t *)
calloc(extendby * 2, sizeof(pthread_cond_t))) == NULL) {
free(pmutex);
errno = ENOMEM;
fd_array_unlock();
return -1;
}
for (i = 0; i < extendby; i++) {
pfd[i].lock = pmutex++;
pfd[i].readcond = pcond++;
pfd[i].writecond = pcond++;
}
}
#endif
fd_array = newarray;
fd_arraylen += extendby;
extendby *= 2;
goto try_again;
}
void
fd_init(void)
{
#ifdef THREAD_SAFE
int i;
#endif
if (didinit)
return;
#ifdef THREAD_SAFE
pthread_mutex_init(&libc_fd_array_mutex, &pthread_mutexattr_default);
/*
* Because interrupt routines can call printf, the mutex needs
* to allow recursive lock attempts.
*/
pthread_mutexattr_init(&mutex_attributes);
pthread_mutexattr_settype(&mutex_attributes, PTHREAD_MUTEX_RECURSIVE);
/*
* Initialize the mutex and condition variables in the stdio
* descriptors.
*/
for (i = 0; i < fd_arraylen; i++) {
pthread_mutex_t *pmutex;
pthread_cond_t *pcond;
if ((pmutex = (pthread_mutex_t *)
calloc(1, sizeof(pthread_mutex_t))) == NULL) {
exit(969);
}
if ((pcond = (pthread_cond_t *)
calloc(2, sizeof(pthread_cond_t))) == NULL) {
free(pmutex);
exit(9696);
}
pthread_mutex_init(pmutex, &mutex_attributes);
pthread_cond_init(pcond, &pthread_condattr_default);
pthread_cond_init(&pcond[1], &pthread_condattr_default);
fd_array[i].lock = pmutex;
fd_array[i].readcond = pcond++;
fd_array[i].writecond = pcond;
}
#endif
didinit = 1;
}
/*
* Cleanup routine.
*/
void
fd_cleanup(void)
{
int i;
for (i = 3; i < fd_arraylen; i++) {
if (fd_array[i].obj != 0) {
fd_free(i);
}
}
}
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