isc_result_t
isc_task_create(isc_taskmgr_t *manager, unsigned int quantum,
isc_task_t **taskp)
{
isc_task_t *task;
isc_boolean_t exiting;
REQUIRE(VALID_MANAGER(manager));
REQUIRE(taskp != NULL && *taskp == NULL);
task = isc_mem_get(manager->mctx, sizeof(*task));
if (task == NULL)
return (ISC_R_NOMEMORY);
XTRACE("isc_task_create");
task->manager = manager;
if (isc_mutex_init(&task->lock) != ISC_R_SUCCESS) {
isc_mem_put(manager->mctx, task, sizeof(*task));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_mutex_init() %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
return (ISC_R_UNEXPECTED);
}
task->state = task_state_idle;
task->references = 1;
INIT_LIST(task->events);
INIT_LIST(task->on_shutdown);
task->quantum = quantum;
task->flags = 0;
task->now = 0;
#ifdef ISC_TASK_NAMES
memset(task->name, 0, sizeof(task->name));
task->tag = NULL;
#endif
INIT_LINK(task, link);
INIT_LINK(task, ready_link);
exiting = ISC_FALSE;
LOCK(&manager->lock);
if (!manager->exiting) {
if (task->quantum == 0)
task->quantum = manager->default_quantum;
APPEND(manager->tasks, task, link);
} else
exiting = ISC_TRUE;
UNLOCK(&manager->lock);
if (exiting) {
DESTROYLOCK(&task->lock);
isc_mem_put(manager->mctx, task, sizeof(*task));
return (ISC_R_SHUTTINGDOWN);
}
task->magic = TASK_MAGIC;
*taskp = task;
return (ISC_R_SUCCESS);
}
static isc_threadresult_t
#ifdef _WIN32 /* XXXDCL */
WINAPI
#endif
run(void *uap) {
isc__timermgr_t *manager = uap;
isc_time_t now;
isc_result_t result;
LOCK(&manager->lock);
while (!manager->done) {
TIME_NOW(&now);
XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_RUNNING,
"running"), now);
dispatch(manager, &now);
if (manager->nscheduled > 0) {
XTRACETIME2(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_GENERAL,
ISC_MSG_WAITUNTIL,
"waituntil"),
manager->due, now);
result = WAITUNTIL(&manager->wakeup, &manager->lock, &manager->due);
INSIST(result == ISC_R_SUCCESS ||
result == ISC_R_TIMEDOUT);
} else {
XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_WAIT, "wait"), now);
WAIT(&manager->wakeup, &manager->lock);
}
XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
ISC_MSG_WAKEUP, "wakeup"));
}
UNLOCK(&manager->lock);
#ifdef OPENSSL_LEAKS
ERR_remove_state(0);
#endif
return ((isc_threadresult_t)0);
}
static void
default_fatal_callback(const char *file, int line, const char *format,
va_list args)
{
fprintf(stderr, "%s:%d: %s: ", file, line,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FATALERROR, "fatal error"));
vfprintf(stderr, format, args);
fprintf(stderr, "\n");
fflush(stderr);
}
static void
print_lock(const char *operation, isc_rwlock_t *rwl, isc_rwlocktype_t type) {
fprintf(stderr,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_PRINTLOCK,
"rwlock %p thread %lu %s(%s): %s, %u active, "
"%u granted, %u rwaiting, %u wwaiting\n"),
rwl, isc_thread_self(), operation,
(type == isc_rwlocktype_read ?
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_READ, "read") :
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_WRITE, "write")),
(rwl->type == isc_rwlocktype_read ?
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_READING, "reading") :
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_WRITING, "writing")),
rwl->active, rwl->granted, rwl->readers_waiting,
rwl->writers_waiting);
}
static isc_threadresult_t
#ifdef _WIN32
WINAPI
#endif
run(void *uap) {
isc__taskmgr_t *manager = uap;
XTHREADTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_STARTING, "starting"));
dispatch(manager);
XTHREADTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_EXITING, "exiting"));
#ifdef OPENSSL_LEAKS
ERR_remove_state(0);
#endif
return ((isc_threadresult_t)0);
}
static void
default_callback(const char *file, int line, isc_assertiontype_t type,
const char *cond)
{
fprintf(stderr, "%s:%d: %s(%s) %s.\n",
file, line, isc_assertion_typetotext(type), cond,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
fflush(stderr);
abort();
/* NOTREACHED */
}
unsigned int
isc_sockaddr_hash(const isc_sockaddr_t *sockaddr, isc_boolean_t address_only) {
unsigned int length = 0;
const unsigned char *s = NULL;
unsigned int h = 0;
unsigned int g;
unsigned int p = 0;
const struct in6_addr *in6;
REQUIRE(sockaddr != NULL);
switch (sockaddr->type.sa.sa_family) {
case AF_INET:
s = (const unsigned char *)&sockaddr->type.sin.sin_addr;
p = ntohs(sockaddr->type.sin.sin_port);
length = sizeof(sockaddr->type.sin.sin_addr.s_addr);
break;
case AF_INET6:
in6 = &sockaddr->type.sin6.sin6_addr;
if (IN6_IS_ADDR_V4MAPPED(in6)) {
s = (const unsigned char *)&in6[12];
length = sizeof(sockaddr->type.sin.sin_addr.s_addr);
} else {
s = (const unsigned char *)in6;
length = sizeof(sockaddr->type.sin6.sin6_addr);
}
p = ntohs(sockaddr->type.sin6.sin6_port);
break;
default:
UNEXPECTED_ERROR(__FILE__, __LINE__,
"%s: %d",
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_SOCKADDR,
ISC_MSG_UNKNOWNFAMILY,
"unknown address family"),
(int)sockaddr->type.sa.sa_family);
s = (const unsigned char *)&sockaddr->type;
length = sockaddr->length;
p = 0;
}
h = isc_hash_calc(s, length, ISC_TRUE);
if (!address_only) {
g = isc_hash_calc((const unsigned char *)&p, sizeof(p),
ISC_TRUE);
h = h ^ g; /* XXX: we should concatenate h and p first */
}
return (h);
}
isc_result_t
isc_condition_waituntil(isc_condition_t *c, isc_mutex_t *m, isc_time_t *t) {
int presult;
isc_result_t result;
struct timespec ts;
char strbuf[ISC_STRERRORSIZE];
REQUIRE(c != NULL && m != NULL && t != NULL);
/*
* POSIX defines a timespec's tv_sec as time_t.
*/
result = isc_time_secondsastimet(t, &ts.tv_sec);
/*
* If we have a range error ts.tv_sec is most probably a signed
* 32 bit value. Set ts.tv_sec to INT_MAX. This is a kludge.
*/
if (result == ISC_R_RANGE)
ts.tv_sec = INT_MAX;
else if (result != ISC_R_SUCCESS)
return (result);
/*!
* POSIX defines a timespec's tv_nsec as long. isc_time_nanoseconds
* ensures its return value is < 1 billion, which will fit in a long.
*/
ts.tv_nsec = (long)isc_time_nanoseconds(t);
do {
#if ISC_MUTEX_PROFILE
presult = pthread_cond_timedwait(c, &m->mutex, &ts);
#else
presult = pthread_cond_timedwait(c, m, &ts);
#endif
if (presult == 0)
return (ISC_R_SUCCESS);
if (presult == ETIMEDOUT)
return (ISC_R_TIMEDOUT);
} while (presult == EINTR);
isc__strerror(presult, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"pthread_cond_timedwait() %s %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_RETURNED, "returned"),
strbuf);
return (ISC_R_UNEXPECTED);
}
isc_result_t
isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
isc_interfaceiter_t *iter;
isc_result_t result;
char strbuf[ISC_STRERRORSIZE];
REQUIRE(mctx != NULL);
REQUIRE(iterp != NULL);
REQUIRE(*iterp == NULL);
iter = isc_mem_get(mctx, sizeof(*iter));
if (iter == NULL)
return (ISC_R_NOMEMORY);
iter->mctx = mctx;
iter->buf = NULL;
iter->bufsize = 0;
iter->ifaddrs = NULL;
if (getifaddrs(&iter->ifaddrs) < 0) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_IFITERGETIFADDRS,
ISC_MSG_GETIFADDRS,
"getting interface "
"addresses: getifaddrs: %s"),
strbuf);
result = ISC_R_UNEXPECTED;
goto failure;
}
/*
* A newly created iterator has an undefined position
* until isc_interfaceiter_first() is called.
*/
iter->pos = NULL;
iter->result = ISC_R_FAILURE;
iter->magic = IFITER_MAGIC;
*iterp = iter;
return (ISC_R_SUCCESS);
failure:
if (iter->ifaddrs != NULL) /* just in case */
freeifaddrs(iter->ifaddrs);
isc_mem_put(mctx, iter, sizeof(*iter));
return (result);
}
static void
initialize_action(void) {
isc_result_t result;
RUNTIME_CHECK(isc_mutex_init(&lock) == ISC_R_SUCCESS);
ISC_LIST_INIT(tables);
result = register_table(ISC_RESULTCLASS_ISC, ISC_R_NRESULTS, text,
isc_msgcat, ISC_RESULT_RESULTSET);
if (result != ISC_R_SUCCESS)
UNEXPECTED_ERROR(__FILE__, __LINE__,
"register_table() %s: %u",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"),
result);
}
static void
try_ipv6pktinfo(void) {
SOCKET s;
int on;
char strbuf[ISC_STRERRORSIZE];
isc_result_t result;
int optname;
result = isc_net_probeipv6();
if (result != ISC_R_SUCCESS) {
ipv6pktinfo_result = result;
return;
}
/* we only use this for UDP sockets */
s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
if (s == INVALID_SOCKET) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"socket() %s: %s",
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_GENERAL,
ISC_MSG_FAILED,
"failed"),
strbuf);
ipv6pktinfo_result = ISC_R_UNEXPECTED;
return;
}
#ifdef IPV6_RECVPKTINFO
optname = IPV6_RECVPKTINFO;
#else
optname = IPV6_PKTINFO;
#endif
on = 1;
if (setsockopt(s, IPPROTO_IPV6, optname, (const char *) &on,
sizeof(on)) < 0) {
ipv6pktinfo_result = ISC_R_NOTFOUND;
goto close;
}
ipv6pktinfo_result = ISC_R_SUCCESS;
close:
closesocket(s);
return;
}
void
isc_sockaddr_setport(isc_sockaddr_t *sockaddr, in_port_t port) {
switch (sockaddr->type.sa.sa_family) {
case AF_INET:
sockaddr->type.sin.sin_port = htons(port);
break;
case AF_INET6:
sockaddr->type.sin6.sin6_port = htons(port);
break;
default:
FATAL_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKADDR,
ISC_MSG_UNKNOWNFAMILY,
"unknown address family: %d"),
(int)sockaddr->type.sa.sa_family);
}
}
unsigned int
isc_sockaddr_hash(const isc_sockaddr_t *sockaddr, isc_boolean_t address_only) {
unsigned int length = 0;
const unsigned char *s = NULL;
unsigned int h = 0;
unsigned int p = 0;
const struct in6_addr *in6;
REQUIRE(sockaddr != NULL);
switch (sockaddr->type.sa.sa_family) {
case AF_INET:
s = (const unsigned char *)&sockaddr->type.sin.sin_addr;
p = ntohs(sockaddr->type.sin.sin_port);
length = sizeof(sockaddr->type.sin.sin_addr.s_addr);
break;
case AF_INET6:
in6 = &sockaddr->type.sin6.sin6_addr;
s = (const unsigned char *)in6;
if (IN6_IS_ADDR_V4MAPPED(in6)) {
s += 12;
length = sizeof(sockaddr->type.sin.sin_addr.s_addr);
} else
length = sizeof(sockaddr->type.sin6.sin6_addr);
p = ntohs(sockaddr->type.sin6.sin6_port);
break;
default:
UNEXPECTED_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_SOCKADDR,
ISC_MSG_UNKNOWNFAMILY,
"unknown address family: %d"),
(int)sockaddr->type.sa.sa_family);
s = (const unsigned char *)&sockaddr->type;
length = sockaddr->length;
p = 0;
}
h = isc_hash_function(s, length, ISC_TRUE, NULL);
if (!address_only)
h = isc_hash_function(&p, sizeof(p), ISC_TRUE, &h);
return (h);
}
void
isc_sockaddr_format(const isc_sockaddr_t *sa, char *array, unsigned int size) {
isc_result_t result;
isc_buffer_t buf;
isc_buffer_init(&buf, array, size);
result = isc_sockaddr_totext(sa, &buf);
if (result != ISC_R_SUCCESS) {
/*
* The message is the same as in netaddr.c.
*/
snprintf(array, size,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_NETADDR,
ISC_MSG_UNKNOWNADDR,
"<unknown address, family %u>"),
sa->type.sa.sa_family);
array[size - 1] = '\0';
}
}
static void
print_lock(const char *operation, isc_rwlock_t *rwl, isc_rwlocktype_t type) {
#if defined(ISC_PLATFORM_HAVEXADD) && defined(ISC_PLATFORM_HAVECMPXCHG)
fprintf(stderr,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_PRINTLOCK2,
"rwlock %p thread %lu %s(%s): "
"write_requests=%u, write_completions=%u, "
"cnt_and_flag=0x%x, readers_waiting=%u, "
"write_granted=%u, write_quota=%u\n"),
rwl, isc_thread_self(), operation,
(type == isc_rwlocktype_read ?
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_READ, "read") :
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_WRITE, "write")),
rwl->write_requests, rwl->write_completions,
rwl->cnt_and_flag, rwl->readers_waiting,
rwl->write_granted, rwl->write_quota);
#else
fprintf(stderr,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_PRINTLOCK,
"rwlock %p thread %lu %s(%s): %s, %u active, "
"%u granted, %u rwaiting, %u wwaiting\n"),
rwl, isc_thread_self(), operation,
(type == isc_rwlocktype_read ?
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_READ, "read") :
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_WRITE, "write")),
(rwl->type == isc_rwlocktype_read ?
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_READING, "reading") :
isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_WRITING, "writing")),
rwl->active, rwl->granted,
rwl->readers_waiting, rwl->writers_waiting);
#endif
}
in_port_t
isc_sockaddr_getport(const isc_sockaddr_t *sockaddr) {
in_port_t port = 0;
switch (sockaddr->type.sa.sa_family) {
case AF_INET:
port = ntohs(sockaddr->type.sin.sin_port);
break;
case AF_INET6:
port = ntohs(sockaddr->type.sin6.sin6_port);
break;
default:
FATAL_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_SOCKADDR,
ISC_MSG_UNKNOWNFAMILY,
"unknown address family: %d"),
(int)sockaddr->type.sa.sa_family);
}
return (port);
}
static isc_result_t
handle_signal(int sig, void (*handler)(int)) {
struct sigaction sa;
char strbuf[ISC_STRERRORSIZE];
memset(&sa, 0, sizeof(sa));
sa.sa_handler = handler;
if (sigfillset(&sa.sa_mask) != 0 ||
sigaction(sig, &sa, NULL) < 0) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_APP,
ISC_MSG_SIGNALSETUP,
"handle_signal() %d setup: %s"),
sig, strbuf);
return (ISC_R_UNEXPECTED);
}
return (ISC_R_SUCCESS);
}
static inline isc_boolean_t
task_shutdown(isc__task_t *task) {
isc_boolean_t was_idle = ISC_FALSE;
isc_event_t *event, *prev;
/*
* Caller must be holding the task's lock.
*/
XTRACE("task_shutdown");
if (! TASK_SHUTTINGDOWN(task)) {
XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_SHUTTINGDOWN, "shutting down"));
task->flags |= TASK_F_SHUTTINGDOWN;
if (task->state == task_state_idle) {
INSIST(EMPTY(task->events));
task->state = task_state_ready;
was_idle = ISC_TRUE;
}
INSIST(task->state == task_state_ready ||
task->state == task_state_running);
/*
* Note that we post shutdown events LIFO.
*/
for (event = TAIL(task->on_shutdown);
event != NULL;
event = prev) {
prev = PREV(event, ev_link);
DEQUEUE(task->on_shutdown, event, ev_link);
ENQUEUE(task->events, event, ev_link);
}
}
return (was_idle);
}
/* coverity[+kill] */
static void
default_callback(const char *file, int line, isc_assertiontype_t type,
const char *cond)
{
void *tracebuf[BACKTRACE_MAXFRAME];
int i, nframes;
const char *logsuffix = ".";
const char *fname;
isc_result_t result;
result = isc_backtrace_gettrace(tracebuf, BACKTRACE_MAXFRAME, &nframes);
if (result == ISC_R_SUCCESS && nframes > 0)
logsuffix = ", back trace";
fprintf(stderr, "%s:%d: %s(%s) %s%s\n",
file, line, isc_assertion_typetotext(type), cond,
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"), logsuffix);
if (result == ISC_R_SUCCESS) {
for (i = 0; i < nframes; i++) {
unsigned long offset;
fname = NULL;
result = isc_backtrace_getsymbol(tracebuf[i], &fname,
&offset);
if (result == ISC_R_SUCCESS) {
fprintf(stderr, "#%d %p in %s()+0x%lx\n", i,
tracebuf[i], fname, offset);
} else {
fprintf(stderr, "#%d %p in ??\n", i,
tracebuf[i]);
}
}
}
fflush(stderr);
}
isc_result_t
isc_rwlock_trylock(isc_rwlock_t *rwl, isc_rwlocktype_t type) {
isc_int32_t cntflag;
REQUIRE(VALID_RWLOCK(rwl));
#ifdef ISC_RWLOCK_TRACE
print_lock(isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_PRELOCK, "prelock"), rwl, type);
#endif
if (type == isc_rwlocktype_read) {
/* If a writer is waiting or working, we fail. */
if (rwl->write_requests != rwl->write_completions)
return (ISC_R_LOCKBUSY);
/* Otherwise, be ready for reading. */
cntflag = isc_atomic_xadd(&rwl->cnt_and_flag, READER_INCR);
if ((cntflag & WRITER_ACTIVE) != 0) {
/*
* A writer is working. We lose, and cancel the read
* request.
*/
cntflag = isc_atomic_xadd(&rwl->cnt_and_flag,
-READER_INCR);
/*
* If no other readers are waiting and we've suspended
* new writers in this short period, wake them up.
*/
if (cntflag == READER_INCR &&
rwl->write_completions != rwl->write_requests) {
LOCK(&rwl->lock);
BROADCAST(&rwl->writeable);
UNLOCK(&rwl->lock);
}
return (ISC_R_LOCKBUSY);
}
} else {
/* Try locking without entering the waiting queue. */
cntflag = isc_atomic_cmpxchg(&rwl->cnt_and_flag, 0,
WRITER_ACTIVE);
if (cntflag != 0)
return (ISC_R_LOCKBUSY);
/*
* XXXJT: jump into the queue, possibly breaking the writer
* order.
*/
(void)isc_atomic_xadd(&rwl->write_completions, -1);
rwl->write_granted++;
}
#ifdef ISC_RWLOCK_TRACE
print_lock(isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_POSTLOCK, "postlock"), rwl, type);
#endif
return (ISC_R_SUCCESS);
}
/***
*** Task Manager.
***/
static void
dispatch(isc_taskmgr_t *manager) {
isc_task_t *task;
#ifndef ISC_PLATFORM_USETHREADS
unsigned int total_dispatch_count = 0;
isc_tasklist_t ready_tasks;
#endif /* ISC_PLATFORM_USETHREADS */
REQUIRE(VALID_MANAGER(manager));
/*
* Again we're trying to hold the lock for as short a time as possible
* and to do as little locking and unlocking as possible.
*
* In both while loops, the appropriate lock must be held before the
* while body starts. Code which acquired the lock at the top of
* the loop would be more readable, but would result in a lot of
* extra locking. Compare:
*
* Straightforward:
*
* LOCK();
* ...
* UNLOCK();
* while (expression) {
* LOCK();
* ...
* UNLOCK();
*
* Unlocked part here...
*
* LOCK();
* ...
* UNLOCK();
* }
*
* Note how if the loop continues we unlock and then immediately lock.
* For N iterations of the loop, this code does 2N+1 locks and 2N+1
* unlocks. Also note that the lock is not held when the while
* condition is tested, which may or may not be important, depending
* on the expression.
*
* As written:
*
* LOCK();
* while (expression) {
* ...
* UNLOCK();
*
* Unlocked part here...
*
* LOCK();
* ...
* }
* UNLOCK();
*
* For N iterations of the loop, this code does N+1 locks and N+1
* unlocks. The while expression is always protected by the lock.
*/
#ifndef ISC_PLATFORM_USETHREADS
ISC_LIST_INIT(ready_tasks);
#endif
LOCK(&manager->lock);
while (!FINISHED(manager)) {
#ifdef ISC_PLATFORM_USETHREADS
/*
* For reasons similar to those given in the comment in
* isc_task_send() above, it is safe for us to dequeue
* the task while only holding the manager lock, and then
* change the task to running state while only holding the
* task lock.
*/
while ((EMPTY(manager->ready_tasks) ||
manager->exclusive_requested) &&
!FINISHED(manager))
{
XTHREADTRACE(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_GENERAL,
ISC_MSG_WAIT, "wait"));
WAIT(&manager->work_available, &manager->lock);
XTHREADTRACE(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TASK,
ISC_MSG_AWAKE, "awake"));
}
#else /* ISC_PLATFORM_USETHREADS */
if (total_dispatch_count >= DEFAULT_TASKMGR_QUANTUM ||
EMPTY(manager->ready_tasks))
break;
#endif /* ISC_PLATFORM_USETHREADS */
XTHREADTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TASK,
ISC_MSG_WORKING, "working"));
task = HEAD(manager->ready_tasks);
if (task != NULL) {
unsigned int dispatch_count = 0;
isc_boolean_t done = ISC_FALSE;
isc_boolean_t requeue = ISC_FALSE;
isc_boolean_t finished = ISC_FALSE;
isc_event_t *event;
INSIST(VALID_TASK(task));
/*
* Note we only unlock the manager lock if we actually
* have a task to do. We must reacquire the manager
* lock before exiting the 'if (task != NULL)' block.
*/
DEQUEUE(manager->ready_tasks, task, ready_link);
manager->tasks_running++;
UNLOCK(&manager->lock);
LOCK(&task->lock);
INSIST(task->state == task_state_ready);
task->state = task_state_running;
XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_RUNNING, "running"));
isc_stdtime_get(&task->now);
do {
if (!EMPTY(task->events)) {
event = HEAD(task->events);
DEQUEUE(task->events, event, ev_link);
/*
* Execute the event action.
*/
XTRACE(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TASK,
ISC_MSG_EXECUTE,
"execute action"));
if (event->ev_action != NULL) {
UNLOCK(&task->lock);
(event->ev_action)(task,event);
LOCK(&task->lock);
}
dispatch_count++;
#ifndef ISC_PLATFORM_USETHREADS
total_dispatch_count++;
#endif /* ISC_PLATFORM_USETHREADS */
}
if (task->references == 0 &&
EMPTY(task->events) &&
!TASK_SHUTTINGDOWN(task)) {
isc_boolean_t was_idle;
/*
* There are no references and no
* pending events for this task,
* which means it will not become
* runnable again via an external
* action (such as sending an event
* or detaching).
*
* We initiate shutdown to prevent
* it from becoming a zombie.
*
* We do this here instead of in
* the "if EMPTY(task->events)" block
* below because:
*
* If we post no shutdown events,
* we want the task to finish.
*
* If we did post shutdown events,
* will still want the task's
* quantum to be applied.
*/
was_idle = task_shutdown(task);
INSIST(!was_idle);
}
if (EMPTY(task->events)) {
/*
* Nothing else to do for this task
* right now.
*/
XTRACE(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TASK,
ISC_MSG_EMPTY,
"empty"));
if (task->references == 0 &&
TASK_SHUTTINGDOWN(task)) {
/*
* The task is done.
*/
XTRACE(isc_msgcat_get(
isc_msgcat,
ISC_MSGSET_TASK,
ISC_MSG_DONE,
"done"));
finished = ISC_TRUE;
task->state = task_state_done;
} else
task->state = task_state_idle;
done = ISC_TRUE;
} else if (dispatch_count >= task->quantum) {
/*
* Our quantum has expired, but
* there is more work to be done.
* We'll requeue it to the ready
* queue later.
*
* We don't check quantum until
* dispatching at least one event,
* so the minimum quantum is one.
*/
XTRACE(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TASK,
ISC_MSG_QUANTUM,
"quantum"));
task->state = task_state_ready;
requeue = ISC_TRUE;
done = ISC_TRUE;
}
} while (!done);
UNLOCK(&task->lock);
if (finished)
task_finished(task);
LOCK(&manager->lock);
manager->tasks_running--;
#ifdef ISC_PLATFORM_USETHREADS
if (manager->exclusive_requested &&
manager->tasks_running == 1) {
SIGNAL(&manager->exclusive_granted);
}
#endif /* ISC_PLATFORM_USETHREADS */
if (requeue) {
/*
* We know we're awake, so we don't have
* to wakeup any sleeping threads if the
* ready queue is empty before we requeue.
*
* A possible optimization if the queue is
* empty is to 'goto' the 'if (task != NULL)'
* block, avoiding the ENQUEUE of the task
* and the subsequent immediate DEQUEUE
* (since it is the only executable task).
* We don't do this because then we'd be
* skipping the exit_requested check. The
* cost of ENQUEUE is low anyway, especially
* when you consider that we'd have to do
* an extra EMPTY check to see if we could
* do the optimization. If the ready queue
* were usually nonempty, the 'optimization'
* might even hurt rather than help.
*/
#ifdef ISC_PLATFORM_USETHREADS
ENQUEUE(manager->ready_tasks, task,
ready_link);
#else
ENQUEUE(ready_tasks, task, ready_link);
#endif
}
}
}
#ifndef ISC_PLATFORM_USETHREADS
ISC_LIST_APPENDLIST(manager->ready_tasks, ready_tasks, ready_link);
#endif
UNLOCK(&manager->lock);
}
isc_result_t
isc_taskmgr_create(isc_mem_t *mctx, unsigned int workers,
unsigned int default_quantum, isc_taskmgr_t **managerp)
{
isc_result_t result;
unsigned int i, started = 0;
isc_taskmgr_t *manager;
/*
* Create a new task manager.
*/
REQUIRE(workers > 0);
REQUIRE(managerp != NULL && *managerp == NULL);
#ifndef ISC_PLATFORM_USETHREADS
UNUSED(i);
UNUSED(started);
UNUSED(workers);
if (taskmgr != NULL) {
taskmgr->refs++;
*managerp = taskmgr;
return (ISC_R_SUCCESS);
}
#endif /* ISC_PLATFORM_USETHREADS */
manager = isc_mem_get(mctx, sizeof(*manager));
if (manager == NULL)
return (ISC_R_NOMEMORY);
manager->magic = TASK_MANAGER_MAGIC;
manager->mctx = NULL;
result = isc_mutex_init(&manager->lock);
if (result != ISC_R_SUCCESS)
goto cleanup_mgr;
#ifdef ISC_PLATFORM_USETHREADS
manager->workers = 0;
manager->threads = isc_mem_allocate(mctx,
workers * sizeof(isc_thread_t));
if (manager->threads == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup_lock;
}
if (isc_condition_init(&manager->work_available) != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_condition_init() %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
result = ISC_R_UNEXPECTED;
goto cleanup_threads;
}
if (isc_condition_init(&manager->exclusive_granted) != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_condition_init() %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
result = ISC_R_UNEXPECTED;
goto cleanup_workavailable;
}
#endif /* ISC_PLATFORM_USETHREADS */
if (default_quantum == 0)
default_quantum = DEFAULT_DEFAULT_QUANTUM;
manager->default_quantum = default_quantum;
INIT_LIST(manager->tasks);
INIT_LIST(manager->ready_tasks);
manager->tasks_running = 0;
manager->exclusive_requested = ISC_FALSE;
manager->exiting = ISC_FALSE;
isc_mem_attach(mctx, &manager->mctx);
#ifdef ISC_PLATFORM_USETHREADS
LOCK(&manager->lock);
/*
* Start workers.
*/
for (i = 0; i < workers; i++) {
if (isc_thread_create(run, manager,
&manager->threads[manager->workers]) ==
ISC_R_SUCCESS) {
manager->workers++;
started++;
}
}
UNLOCK(&manager->lock);
if (started == 0) {
manager_free(manager);
return (ISC_R_NOTHREADS);
}
isc_thread_setconcurrency(workers);
#else /* ISC_PLATFORM_USETHREADS */
manager->refs = 1;
taskmgr = manager;
#endif /* ISC_PLATFORM_USETHREADS */
*managerp = manager;
return (ISC_R_SUCCESS);
#ifdef ISC_PLATFORM_USETHREADS
cleanup_workavailable:
(void)isc_condition_destroy(&manager->work_available);
cleanup_threads:
isc_mem_free(mctx, manager->threads);
cleanup_lock:
DESTROYLOCK(&manager->lock);
#endif
cleanup_mgr:
isc_mem_put(mctx, manager, sizeof(*manager));
return (result);
}
ISC_TIMERFUNC_SCOPE void
isc__timermgr_destroy(isc_timermgr_t **managerp) {
isc__timermgr_t *manager;
isc_mem_t *mctx;
/*
* Destroy a timer manager.
*/
REQUIRE(managerp != NULL);
manager = (isc__timermgr_t *)*managerp;
REQUIRE(VALID_MANAGER(manager));
LOCK(&manager->lock);
#ifdef USE_SHARED_MANAGER
manager->refs--;
if (manager->refs > 0) {
UNLOCK(&manager->lock);
*managerp = NULL;
return;
}
timermgr = NULL;
#endif /* USE_SHARED_MANAGER */
#ifndef USE_TIMER_THREAD
isc__timermgr_dispatch((isc_timermgr_t *)manager);
#endif
REQUIRE(EMPTY(manager->timers));
manager->done = ISC_TRUE;
#ifdef USE_TIMER_THREAD
XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
ISC_MSG_SIGNALDESTROY, "signal (destroy)"));
SIGNAL(&manager->wakeup);
#endif /* USE_TIMER_THREAD */
UNLOCK(&manager->lock);
#ifdef USE_TIMER_THREAD
/*
* Wait for thread to exit.
*/
if (isc_thread_join(manager->thread, NULL) != ISC_R_SUCCESS)
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_thread_join() %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
#endif /* USE_TIMER_THREAD */
/*
* Clean up.
*/
#ifdef USE_TIMER_THREAD
(void)isc_condition_destroy(&manager->wakeup);
#endif /* USE_TIMER_THREAD */
DESTROYLOCK(&manager->lock);
isc_heap_destroy(&manager->heap);
manager->common.impmagic = 0;
manager->common.magic = 0;
mctx = manager->mctx;
isc_mem_put(mctx, manager, sizeof(*manager));
isc_mem_detach(&mctx);
*managerp = NULL;
#ifdef USE_SHARED_MANAGER
timermgr = NULL;
#endif
}
ISC_TIMERFUNC_SCOPE isc_result_t
isc__timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp) {
isc__timermgr_t *manager;
isc_result_t result;
/*
* Create a timer manager.
*/
REQUIRE(managerp != NULL && *managerp == NULL);
#ifdef USE_SHARED_MANAGER
if (timermgr != NULL) {
timermgr->refs++;
*managerp = (isc_timermgr_t *)timermgr;
return (ISC_R_SUCCESS);
}
#endif /* USE_SHARED_MANAGER */
manager = isc_mem_get(mctx, sizeof(*manager));
if (manager == NULL)
return (ISC_R_NOMEMORY);
manager->common.impmagic = TIMER_MANAGER_MAGIC;
manager->common.magic = ISCAPI_TIMERMGR_MAGIC;
manager->common.methods = (isc_timermgrmethods_t *)&timermgrmethods;
manager->mctx = NULL;
manager->done = ISC_FALSE;
INIT_LIST(manager->timers);
manager->nscheduled = 0;
isc_time_settoepoch(&manager->due);
manager->heap = NULL;
result = isc_heap_create(mctx, sooner, set_index, 0, &manager->heap);
if (result != ISC_R_SUCCESS) {
INSIST(result == ISC_R_NOMEMORY);
isc_mem_put(mctx, manager, sizeof(*manager));
return (ISC_R_NOMEMORY);
}
result = isc_mutex_init(&manager->lock);
if (result != ISC_R_SUCCESS) {
isc_heap_destroy(&manager->heap);
isc_mem_put(mctx, manager, sizeof(*manager));
return (result);
}
isc_mem_attach(mctx, &manager->mctx);
#ifdef USE_TIMER_THREAD
if (isc_condition_init(&manager->wakeup) != ISC_R_SUCCESS) {
isc_mem_detach(&manager->mctx);
DESTROYLOCK(&manager->lock);
isc_heap_destroy(&manager->heap);
isc_mem_put(mctx, manager, sizeof(*manager));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_condition_init() %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
return (ISC_R_UNEXPECTED);
}
if (isc_thread_create(run, manager, &manager->thread) !=
ISC_R_SUCCESS) {
isc_mem_detach(&manager->mctx);
(void)isc_condition_destroy(&manager->wakeup);
DESTROYLOCK(&manager->lock);
isc_heap_destroy(&manager->heap);
isc_mem_put(mctx, manager, sizeof(*manager));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_thread_create() %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"));
return (ISC_R_UNEXPECTED);
}
#endif
#ifdef USE_SHARED_MANAGER
manager->refs = 1;
timermgr = manager;
#endif /* USE_SHARED_MANAGER */
*managerp = (isc_timermgr_t *)manager;
return (ISC_R_SUCCESS);
}
isc_result_t
isc_rwlock_unlock(isc_rwlock_t *rwl, isc_rwlocktype_t type) {
isc_int32_t prev_cnt;
REQUIRE(VALID_RWLOCK(rwl));
#ifdef ISC_RWLOCK_TRACE
print_lock(isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_PREUNLOCK, "preunlock"), rwl, type);
#endif
if (type == isc_rwlocktype_read) {
prev_cnt = isc_atomic_xadd(&rwl->cnt_and_flag, -READER_INCR);
/*
* If we're the last reader and any writers are waiting, wake
* them up. We need to wake up all of them to ensure the
* FIFO order.
*/
if (prev_cnt == READER_INCR &&
rwl->write_completions != rwl->write_requests) {
LOCK(&rwl->lock);
BROADCAST(&rwl->writeable);
UNLOCK(&rwl->lock);
}
} else {
isc_boolean_t wakeup_writers = ISC_TRUE;
/*
* Reset the flag, and (implicitly) tell other writers
* we are done.
*/
(void)isc_atomic_xadd(&rwl->cnt_and_flag, -WRITER_ACTIVE);
(void)isc_atomic_xadd(&rwl->write_completions, 1);
if (rwl->write_granted >= rwl->write_quota ||
rwl->write_requests == rwl->write_completions ||
(rwl->cnt_and_flag & ~WRITER_ACTIVE) != 0) {
/*
* We have passed the write quota, no writer is
* waiting, or some readers are almost ready, pending
* possible writers. Note that the last case can
* happen even if write_requests != write_completions
* (which means a new writer in the queue), so we need
* to catch the case explicitly.
*/
LOCK(&rwl->lock);
if (rwl->readers_waiting > 0) {
wakeup_writers = ISC_FALSE;
BROADCAST(&rwl->readable);
}
UNLOCK(&rwl->lock);
}
if (rwl->write_requests != rwl->write_completions &&
wakeup_writers) {
LOCK(&rwl->lock);
BROADCAST(&rwl->writeable);
UNLOCK(&rwl->lock);
}
}
#ifdef ISC_RWLOCK_TRACE
print_lock(isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_POSTUNLOCK, "postunlock"),
rwl, type);
#endif
return (ISC_R_SUCCESS);
}
static void
dispatch(isc__timermgr_t *manager, isc_time_t *now) {
isc_boolean_t done = ISC_FALSE, post_event, need_schedule;
isc_timerevent_t *event;
isc_eventtype_t type = 0;
isc__timer_t *timer;
isc_result_t result;
isc_boolean_t idle;
/*!
* The caller must be holding the manager lock.
*/
while (manager->nscheduled > 0 && !done) {
timer = isc_heap_element(manager->heap, 1);
INSIST(timer->type != isc_timertype_inactive);
if (isc_time_compare(now, &timer->due) >= 0) {
if (timer->type == isc_timertype_ticker) {
type = ISC_TIMEREVENT_TICK;
post_event = ISC_TRUE;
need_schedule = ISC_TRUE;
} else if (timer->type == isc_timertype_limited) {
int cmp;
cmp = isc_time_compare(now, &timer->expires);
if (cmp >= 0) {
type = ISC_TIMEREVENT_LIFE;
post_event = ISC_TRUE;
need_schedule = ISC_FALSE;
} else {
type = ISC_TIMEREVENT_TICK;
post_event = ISC_TRUE;
need_schedule = ISC_TRUE;
}
} else if (!isc_time_isepoch(&timer->expires) &&
isc_time_compare(now,
&timer->expires) >= 0) {
type = ISC_TIMEREVENT_LIFE;
post_event = ISC_TRUE;
need_schedule = ISC_FALSE;
} else {
idle = ISC_FALSE;
LOCK(&timer->lock);
if (!isc_time_isepoch(&timer->idle) &&
isc_time_compare(now,
&timer->idle) >= 0) {
idle = ISC_TRUE;
}
UNLOCK(&timer->lock);
if (idle) {
type = ISC_TIMEREVENT_IDLE;
post_event = ISC_TRUE;
need_schedule = ISC_FALSE;
} else {
/*
* Idle timer has been touched;
* reschedule.
*/
XTRACEID(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TIMER,
ISC_MSG_IDLERESCHED,
"idle reschedule"),
timer);
post_event = ISC_FALSE;
need_schedule = ISC_TRUE;
}
}
if (post_event) {
XTRACEID(isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TIMER,
ISC_MSG_POSTING,
"posting"), timer);
/*
* XXX We could preallocate this event.
*/
event = (isc_timerevent_t *)isc_event_allocate(manager->mctx,
timer,
type,
timer->action,
timer->arg,
sizeof(*event));
if (event != NULL) {
event->due = timer->due;
isc_task_send(timer->task,
ISC_EVENT_PTR(&event));
} else
UNEXPECTED_ERROR(__FILE__, __LINE__, "%s",
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TIMER,
ISC_MSG_EVENTNOTALLOC,
"couldn't "
"allocate event"));
}
timer->index = 0;
isc_heap_delete(manager->heap, 1);
manager->nscheduled--;
if (need_schedule) {
result = schedule(timer, now, ISC_FALSE);
if (result != ISC_R_SUCCESS)
UNEXPECTED_ERROR(__FILE__, __LINE__,
"%s: %u",
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_TIMER,
ISC_MSG_SCHEDFAIL,
"couldn't schedule "
"timer"),
result);
}
} else {
manager->due = timer->due;
done = ISC_TRUE;
}
}
}
static inline isc_result_t
schedule(isc__timer_t *timer, isc_time_t *now, isc_boolean_t signal_ok) {
isc_result_t result;
isc__timermgr_t *manager;
isc_time_t due;
int cmp;
#ifdef USE_TIMER_THREAD
isc_boolean_t timedwait;
#endif
/*!
* Note: the caller must ensure locking.
*/
REQUIRE(timer->type != isc_timertype_inactive);
#ifndef USE_TIMER_THREAD
UNUSED(signal_ok);
#endif /* USE_TIMER_THREAD */
manager = timer->manager;
#ifdef USE_TIMER_THREAD
/*!
* If the manager was timed wait, we may need to signal the
* manager to force a wakeup.
*/
timedwait = ISC_TF(manager->nscheduled > 0 &&
isc_time_seconds(&manager->due) != 0);
#endif
/*
* Compute the new due time.
*/
if (timer->type != isc_timertype_once) {
result = isc_time_add(now, &timer->interval, &due);
if (result != ISC_R_SUCCESS)
return (result);
if (timer->type == isc_timertype_limited &&
isc_time_compare(&timer->expires, &due) < 0)
due = timer->expires;
} else {
if (isc_time_isepoch(&timer->idle))
due = timer->expires;
else if (isc_time_isepoch(&timer->expires))
due = timer->idle;
else if (isc_time_compare(&timer->idle, &timer->expires) < 0)
due = timer->idle;
else
due = timer->expires;
}
/*
* Schedule the timer.
*/
if (timer->index > 0) {
/*
* Already scheduled.
*/
cmp = isc_time_compare(&due, &timer->due);
timer->due = due;
switch (cmp) {
case -1:
isc_heap_increased(manager->heap, timer->index);
break;
case 1:
isc_heap_decreased(manager->heap, timer->index);
break;
case 0:
/* Nothing to do. */
break;
}
} else {
timer->due = due;
result = isc_heap_insert(manager->heap, timer);
if (result != ISC_R_SUCCESS) {
INSIST(result == ISC_R_NOMEMORY);
return (ISC_R_NOMEMORY);
}
manager->nscheduled++;
}
XTRACETIMER(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
ISC_MSG_SCHEDULE, "schedule"), timer, due);
/*
* If this timer is at the head of the queue, we need to ensure
* that we won't miss it if it has a more recent due time than
* the current "next" timer. We do this either by waking up the
* run thread, or explicitly setting the value in the manager.
*/
#ifdef USE_TIMER_THREAD
/*
* This is a temporary (probably) hack to fix a bug on tru64 5.1
* and 5.1a. Sometimes, pthread_cond_timedwait() doesn't actually
* return when the time expires, so here, we check to see if
* we're 15 seconds or more behind, and if we are, we signal
* the dispatcher. This isn't such a bad idea as a general purpose
* watchdog, so perhaps we should just leave it in here.
*/
if (signal_ok && timedwait) {
isc_interval_t fifteen;
isc_time_t then;
isc_interval_set(&fifteen, 15, 0);
result = isc_time_add(&manager->due, &fifteen, &then);
if (result == ISC_R_SUCCESS &&
isc_time_compare(&then, now) < 0) {
SIGNAL(&manager->wakeup);
signal_ok = ISC_FALSE;
isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
ISC_LOGMODULE_TIMER, ISC_LOG_WARNING,
"*** POKED TIMER ***");
}
}
if (timer->index == 1 && signal_ok) {
XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
ISC_MSG_SIGNALSCHED,
"signal (schedule)"));
SIGNAL(&manager->wakeup);
}
#else /* USE_TIMER_THREAD */
if (timer->index == 1 &&
isc_time_compare(&timer->due, &manager->due) < 0)
manager->due = timer->due;
#endif /* USE_TIMER_THREAD */
return (ISC_R_SUCCESS);
}
static isc_result_t
doit(isc_rwlock_t *rwl, isc_rwlocktype_t type, isc_boolean_t nonblock) {
isc_boolean_t skip = ISC_FALSE;
isc_boolean_t done = ISC_FALSE;
isc_result_t result = ISC_R_SUCCESS;
REQUIRE(VALID_RWLOCK(rwl));
LOCK(&rwl->lock);
#ifdef ISC_RWLOCK_TRACE
print_lock(isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_PRELOCK, "prelock"), rwl, type);
#endif
if (type == isc_rwlocktype_read) {
if (rwl->readers_waiting != 0)
skip = ISC_TRUE;
while (!done) {
if (!skip &&
((rwl->active == 0 ||
(rwl->type == isc_rwlocktype_read &&
(rwl->writers_waiting == 0 ||
rwl->granted < rwl->read_quota)))))
{
rwl->type = isc_rwlocktype_read;
rwl->active++;
rwl->granted++;
done = ISC_TRUE;
} else if (nonblock) {
result = ISC_R_LOCKBUSY;
done = ISC_TRUE;
} else {
skip = ISC_FALSE;
rwl->readers_waiting++;
WAIT(&rwl->readable, &rwl->lock);
rwl->readers_waiting--;
}
}
} else {
if (rwl->writers_waiting != 0)
skip = ISC_TRUE;
while (!done) {
if (!skip && rwl->active == 0) {
rwl->type = isc_rwlocktype_write;
rwl->active = 1;
rwl->granted++;
done = ISC_TRUE;
} else if (nonblock) {
result = ISC_R_LOCKBUSY;
done = ISC_TRUE;
} else {
skip = ISC_FALSE;
rwl->writers_waiting++;
WAIT(&rwl->writeable, &rwl->lock);
rwl->writers_waiting--;
}
}
}
#ifdef ISC_RWLOCK_TRACE
print_lock(isc_msgcat_get(isc_msgcat, ISC_MSGSET_RWLOCK,
ISC_MSG_POSTLOCK, "postlock"), rwl, type);
#endif
UNLOCK(&rwl->lock);
return (result);
}
isc_result_t
isc_rwlock_init(isc_rwlock_t *rwl, unsigned int read_quota,
unsigned int write_quota)
{
isc_result_t result;
REQUIRE(rwl != NULL);
/*
* In case there's trouble initializing, we zero magic now. If all
* goes well, we'll set it to RWLOCK_MAGIC.
*/
rwl->magic = 0;
rwl->spins = 0;
#if defined(ISC_PLATFORM_HAVEXADD) && defined(ISC_PLATFORM_HAVECMPXCHG)
rwl->write_requests = 0;
rwl->write_completions = 0;
rwl->cnt_and_flag = 0;
rwl->readers_waiting = 0;
rwl->write_granted = 0;
if (read_quota != 0) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"read quota is not supported");
}
if (write_quota == 0)
write_quota = RWLOCK_DEFAULT_WRITE_QUOTA;
rwl->write_quota = write_quota;
#else
rwl->type = isc_rwlocktype_read;
rwl->original = isc_rwlocktype_none;
rwl->active = 0;
rwl->granted = 0;
rwl->readers_waiting = 0;
rwl->writers_waiting = 0;
if (read_quota == 0)
read_quota = RWLOCK_DEFAULT_READ_QUOTA;
rwl->read_quota = read_quota;
if (write_quota == 0)
write_quota = RWLOCK_DEFAULT_WRITE_QUOTA;
rwl->write_quota = write_quota;
#endif
result = isc_mutex_init(&rwl->lock);
if (result != ISC_R_SUCCESS)
return (result);
result = isc_condition_init(&rwl->readable);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_condition_init(readable) %s: %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"),
isc_result_totext(result));
result = ISC_R_UNEXPECTED;
goto destroy_lock;
}
result = isc_condition_init(&rwl->writeable);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_condition_init(writeable) %s: %s",
isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
ISC_MSG_FAILED, "failed"),
isc_result_totext(result));
result = ISC_R_UNEXPECTED;
goto destroy_rcond;
}
rwl->magic = RWLOCK_MAGIC;
return (ISC_R_SUCCESS);
destroy_rcond:
(void)isc_condition_destroy(&rwl->readable);
destroy_lock:
DESTROYLOCK(&rwl->lock);
return (result);
}
static void
try_ipv6only(void) {
#ifdef IPV6_V6ONLY
SOCKET s;
int on;
char strbuf[ISC_STRERRORSIZE];
#endif
isc_result_t result;
result = isc_net_probeipv6();
if (result != ISC_R_SUCCESS) {
ipv6only_result = result;
return;
}
#ifndef IPV6_V6ONLY
ipv6only_result = ISC_R_NOTFOUND;
return;
#else
/* check for TCP sockets */
s = socket(PF_INET6, SOCK_STREAM, 0);
if (s == INVALID_SOCKET) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"socket() %s: %s",
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_GENERAL,
ISC_MSG_FAILED,
"failed"),
strbuf);
ipv6only_result = ISC_R_UNEXPECTED;
return;
}
on = 1;
if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (const char *)&on,
sizeof(on)) < 0) {
ipv6only_result = ISC_R_NOTFOUND;
goto close;
}
closesocket(s);
/* check for UDP sockets */
s = socket(PF_INET6, SOCK_DGRAM, 0);
if (s == INVALID_SOCKET) {
isc__strerror(errno, strbuf, sizeof(strbuf));
UNEXPECTED_ERROR(__FILE__, __LINE__,
"socket() %s: %s",
isc_msgcat_get(isc_msgcat,
ISC_MSGSET_GENERAL,
ISC_MSG_FAILED,
"failed"),
strbuf);
ipv6only_result = ISC_R_UNEXPECTED;
return;
}
on = 1;
if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (const char *)&on,
sizeof(on)) < 0) {
ipv6only_result = ISC_R_NOTFOUND;
goto close;
}
ipv6only_result = ISC_R_SUCCESS;
close:
closesocket(s);
return;
#endif /* IPV6_V6ONLY */
}
