Gecko [ sachasauda.akalacademy.ac.in ]

Name	Size	Permission
aes.h	1.05 KB	-rw-r--r--
app.h	10.23 KB	-rw-r--r--
assertions.h	2.78 KB	-rw-r--r--
atomic.h	4.15 KB	-rw-r--r--
backtrace.h	3.8 KB	-rw-r--r--
base32.h	3.94 KB	-rw-r--r--
base64.h	2.39 KB	-rw-r--r--
bind9.h	849 B	-rw-r--r--
boolean.h	746 B	-rw-r--r--
buffer.h	25.69 KB	-rw-r--r--
bufferlist.h	1.42 KB	-rw-r--r--
commandline.h	1.69 KB	-rw-r--r--
condition.h	1.44 KB	-rw-r--r--
counter.h	1.88 KB	-rw-r--r--
crc64.h	986 B	-rw-r--r--
deprecated.h	622 B	-rw-r--r--
dir.h	1.96 KB	-rw-r--r--
entropy.h	8.76 KB	-rw-r--r--
errno.h	658 B	-rw-r--r--
errno2result.h	893 B	-rw-r--r--
error.h	1.4 KB	-rw-r--r--
event.h	2.98 KB	-rw-r--r--
eventclass.h	1.35 KB	-rw-r--r--
file.h	11.43 KB	-rw-r--r--
formatcheck.h	892 B	-rw-r--r--
fsaccess.h	7.25 KB	-rw-r--r--
hash.h	7.52 KB	-rw-r--r--
heap.h	5.14 KB	-rw-r--r--
hex.h	2.33 KB	-rw-r--r--
hmacmd5.h	1.75 KB	-rw-r--r--
hmacsha.h	4.44 KB	-rw-r--r--
ht.h	4.29 KB	-rw-r--r--
httpd.h	2.26 KB	-rw-r--r--
int.h	1.37 KB	-rw-r--r--
interfaceiter.h	3.03 KB	-rw-r--r--
iterated_hash.h	1.02 KB	-rw-r--r--
json.h	1.42 KB	-rw-r--r--
keyboard.h	976 B	-rw-r--r--
lang.h	636 B	-rw-r--r--
lex.h	9.42 KB	-rw-r--r--
lfsr.h	2.88 KB	-rw-r--r--
lib.h	1.04 KB	-rw-r--r--
likely.h	718 B	-rw-r--r--
list.h	5.65 KB	-rw-r--r--
log.h	28.06 KB	-rw-r--r--
magic.h	993 B	-rw-r--r--
md5.h	2.34 KB	-rw-r--r--
mem.h	20.63 KB	-rw-r--r--
meminfo.h	690 B	-rw-r--r--
msgcat.h	2.66 KB	-rw-r--r--
msgs.h	8.22 KB	-rw-r--r--
mutex.h	3.44 KB	-rw-r--r--
mutexblock.h	1.34 KB	-rw-r--r--
net.h	10.32 KB	-rw-r--r--
netaddr.h	4.56 KB	-rw-r--r--
netdb.h	862 B	-rw-r--r--
netscope.h	947 B	-rw-r--r--
offset.h	699 B	-rw-r--r--
once.h	981 B	-rw-r--r--
ondestroy.h	2.79 KB	-rw-r--r--
os.h	670 B	-rw-r--r--
parseint.h	1.49 KB	-rw-r--r--
platform.h	9.31 KB	-rw-r--r--
pool.h	3.42 KB	-rw-r--r--
portset.h	3.21 KB	-rw-r--r--
print.h	2.49 KB	-rw-r--r--
queue.h	4.66 KB	-rw-r--r--
quota.h	2.29 KB	-rw-r--r--
radix.h	6.37 KB	-rw-r--r--
random.h	2.99 KB	-rw-r--r--
ratelimiter.h	3.38 KB	-rw-r--r--
refcount.h	7.89 KB	-rw-r--r--
regex.h	766 B	-rw-r--r--
region.h	1.99 KB	-rw-r--r--
resource.h	2.8 KB	-rw-r--r--
result.h	4.62 KB	-rw-r--r--
resultclass.h	1.56 KB	-rw-r--r--
rwlock.h	3.6 KB	-rw-r--r--
safe.h	1.21 KB	-rw-r--r--
serial.h	1.4 KB	-rw-r--r--
sha1.h	1.52 KB	-rw-r--r--
sha2.h	5.65 KB	-rw-r--r--
sockaddr.h	6 KB	-rw-r--r--
socket.h	35.81 KB	-rw-r--r--
stat.h	805 B	-rw-r--r--
stats.h	3.02 KB	-rw-r--r--
stdio.h	1.74 KB	-rw-r--r--
stdlib.h	703 B	-rw-r--r--
stdtime.h	1.3 KB	-rw-r--r--
strerror.h	776 B	-rw-r--r--
string.h	5.94 KB	-rw-r--r--
symtab.h	4.21 KB	-rw-r--r--
syslog.h	843 B	-rw-r--r--
task.h	21.08 KB	-rw-r--r--
taskpool.h	3.61 KB	-rw-r--r--
thread.h	1.47 KB	-rw-r--r--
time.h	8.66 KB	-rw-r--r--
timer.h	10.54 KB	-rw-r--r--
tm.h	894 B	-rw-r--r--
types.h	5.54 KB	-rw-r--r--
util.h	7.49 KB	-rw-r--r--
version.h	688 B	-rw-r--r--
xml.h	1.07 KB	-rw-r--r--

Code Editor : queue.h

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*
 * This is a generic implementation of a two-lock concurrent queue.
 * There are built-in mutex locks for the head and tail of the queue,
 * allowing elements to be safely added and removed at the same time.
 *
 * NULL is "end of list"
 * -1 is "not linked"
 */

#ifndef ISC_QUEUE_H
#define ISC_QUEUE_H 1
#include <isc/assertions.h>
#include <isc/boolean.h>
#include <isc/mutex.h>

#ifdef ISC_QUEUE_CHECKINIT
#define ISC_QLINK_INSIST(x) ISC_INSIST(x)
#else
#define ISC_QLINK_INSIST(x) (void)0
#endif

#define ISC_QLINK(type) struct { type *prev, *next; }

#define ISC_QLINK_INIT(elt, link) \
	do { \
		(elt)->link.next = (elt)->link.prev = (void *)(-1); \
	} while(0)

#define ISC_QLINK_LINKED(elt, link) ((void*)(elt)->link.next != (void*)(-1))

#define ISC_QUEUE(type) struct { \
	type *head, *tail; \
	isc_mutex_t headlock, taillock; \
}

#define ISC_QUEUE_INIT(queue, link) \
	do { \
		(void) isc_mutex_init(&(queue).taillock); \
		(void) isc_mutex_init(&(queue).headlock); \
		(queue).tail = (queue).head = NULL; \
	} while (0)

#define ISC_QUEUE_EMPTY(queue) ISC_TF((queue).head == NULL)

#define ISC_QUEUE_DESTROY(queue) \
	do { \
		ISC_QLINK_INSIST(ISC_QUEUE_EMPTY(queue)); \
		(void) isc_mutex_destroy(&(queue).taillock); \
		(void) isc_mutex_destroy(&(queue).headlock); \
	} while (0)

/*
 * queues are meant to separate the locks at either end.  For best effect, that
 * means keeping the ends separate - i.e. non-empty queues work best.
 *
 * a push to an empty queue has to take the pop lock to update
 * the pop side of the queue.
 * Popping the last entry has to take the push lock to update
 * the push side of the queue.
 *
 * The order is (pop, push), because a pop is presumably in the
 * latency path and a push is when we're done.
 *
 * We do an MT hot test in push to see if we need both locks, so we can
 * acquire them in order.  Hopefully that makes the case where we get
 * the push lock and find we need the pop lock (and have to release it) rare.
 *
 * > 1 entry - no collision, push works on one end, pop on the other
 *   0 entry - headlock race
 *     pop wins - return(NULL), push adds new as both head/tail
 *     push wins - updates head/tail, becomes 1 entry case.
 *   1 entry - taillock race
 *     pop wins - return(pop) sets head/tail NULL, becomes 0 entry case
 *     push wins - updates {head,tail}->link.next, pop updates head
 *                 with new ->link.next and doesn't update tail
 *
 */
#define ISC_QUEUE_PUSH(queue, elt, link) \
	do { \
		isc_boolean_t headlocked = ISC_FALSE; \
		ISC_QLINK_INSIST(!ISC_QLINK_LINKED(elt, link)); \
		if ((queue).head == NULL) { \
			LOCK(&(queue).headlock); \
			headlocked = ISC_TRUE; \
		} \
		LOCK(&(queue).taillock); \
		if ((queue).tail == NULL && !headlocked) { \
			UNLOCK(&(queue).taillock); \
			LOCK(&(queue).headlock); \
			LOCK(&(queue).taillock); \
			headlocked = ISC_TRUE; \
		} \
		(elt)->link.prev = (queue).tail; \
		(elt)->link.next = NULL; \
		if ((queue).tail != NULL) \
			(queue).tail->link.next = (elt); \
		(queue).tail = (elt); \
		UNLOCK(&(queue).taillock); \
		if (headlocked) { \
			if ((queue).head == NULL) \
				(queue).head = (elt); \
			UNLOCK(&(queue).headlock); \
		} \
	} while (0)

#define ISC_QUEUE_POP(queue, link, ret) \
	do { \
		LOCK(&(queue).headlock); \
		ret = (queue).head; \
		while (ret != NULL) { \
			if (ret->link.next == NULL) { \
				LOCK(&(queue).taillock); \
				if (ret->link.next == NULL) { \
					(queue).head = (queue).tail = NULL; \
					UNLOCK(&(queue).taillock); \
					break; \
				}\
				UNLOCK(&(queue).taillock); \
			} \
			(queue).head = ret->link.next; \
			(queue).head->link.prev = NULL; \
			break; \
		} \
		UNLOCK(&(queue).headlock); \
		if (ret != NULL) \
			(ret)->link.next = (ret)->link.prev = (void *)(-1); \
	} while(0)

#define ISC_QUEUE_UNLINK(queue, elt, link) \
	do { \
		ISC_QLINK_INSIST(ISC_QLINK_LINKED(elt, link)); \
		LOCK(&(queue).headlock); \
		LOCK(&(queue).taillock); \
		if ((elt)->link.prev == NULL) \
			(queue).head = (elt)->link.next; \
		else \
			(elt)->link.prev->link.next = (elt)->link.next; \
		if ((elt)->link.next == NULL) \
			(queue).tail = (elt)->link.prev; \
		else \
			(elt)->link.next->link.prev = (elt)->link.prev; \
		UNLOCK(&(queue).taillock); \
		UNLOCK(&(queue).headlock); \
		(elt)->link.next = (elt)->link.prev = (void *)(-1); \
	} while(0)

#endif /* ISC_QUEUE_H */

${this.title}

Code Editor : queue.h