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-rw-r--r--src/common/compat_pthreads.c1
-rw-r--r--src/common/workqueue.c206
-rw-r--r--src/common/workqueue.h10
-rw-r--r--src/or/cpuworker.c15
-rw-r--r--src/test/test_workqueue.c23
5 files changed, 141 insertions, 114 deletions
diff --git a/src/common/compat_pthreads.c b/src/common/compat_pthreads.c
index 848bfe0973..f43480539f 100644
--- a/src/common/compat_pthreads.c
+++ b/src/common/compat_pthreads.c
@@ -5,6 +5,7 @@
#include "orconfig.h"
#include <pthread.h>
+#include <signal.h>
#include "compat.h"
#include "torlog.h"
diff --git a/src/common/workqueue.c b/src/common/workqueue.c
index 7fa8967580..5ba29e3b26 100644
--- a/src/common/workqueue.c
+++ b/src/common/workqueue.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013, The Tor Project, Inc. */
+/* Copyright (c) 2013-2015, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "orconfig.h"
@@ -13,8 +13,23 @@ struct threadpool_s {
/** An array of pointers to workerthread_t: one for each running worker
* thread. */
struct workerthread_s **threads;
- /** Index of the next thread that we'll give work to.*/
- int next_for_work;
+
+ /** Condition variable that we wait on when we have no work, and which
+ * gets signaled when our queue becomes nonempty. */
+ tor_cond_t condition;
+ /** Queue of pending work that we have to do. */
+ TOR_TAILQ_HEAD(, workqueue_entry_s) work;
+
+ /** The current 'update generation' of the threadpool. Any thread that is
+ * at an earlier generation needs to run the update function. */
+ unsigned generation;
+
+ /** Function that should be run for updates on each thread. */
+ int (*update_fn)(void *, void *);
+ /** Function to free update arguments if they can't be run. */
+ void (*free_update_arg_fn)(void *);
+ /** Array of n_threads update arguments. */
+ void **update_args;
/** Number of elements in threads. */
int n_threads;
@@ -34,10 +49,10 @@ struct workqueue_entry_s {
/** The next workqueue_entry_t that's pending on the same thread or
* reply queue. */
TOR_TAILQ_ENTRY(workqueue_entry_s) next_work;
- /** The thread to which this workqueue_entry_t was assigned. This field
+ /** The threadpool to which this workqueue_entry_t was assigned. This field
* is set when the workqueue_entry_t is created, and won't be cleared until
* after it's handled in the main thread. */
- struct workerthread_s *on_thread;
+ struct threadpool_s *on_pool;
/** True iff this entry is waiting for a worker to start processing it. */
uint8_t pending;
/** Function to run in the worker thread. */
@@ -62,13 +77,10 @@ struct replyqueue_s {
* contention, each gets its own queue. This breaks the guarantee that that
* queued work will get executed strictly in order. */
typedef struct workerthread_s {
- /** Lock to protect all fields of this thread and its queue. */
- tor_mutex_t lock;
- /** Condition variable that we wait on when we have no work, and which
- * gets signaled when our queue becomes nonempty. */
- tor_cond_t condition;
- /** Queue of pending work that we have to do. */
- TOR_TAILQ_HEAD(, workqueue_entry_s) work;
+ /** Which thread it this? In range 0..in_pool->n_threads-1 */
+ int index;
+ /** The pool this thread is a part of. */
+ struct threadpool_s *in_pool;
/** True iff this thread is currently in its loop. (Not currently used.) */
unsigned is_running;
/** True iff this thread has crashed or is shut down for some reason. (Not
@@ -81,6 +93,8 @@ typedef struct workerthread_s {
void *state;
/** Reply queue to which we pass our results. */
replyqueue_t *reply_queue;
+ /** The current update generation of this thread */
+ unsigned generation;
} workerthread_t;
static void queue_reply(replyqueue_t *queue, workqueue_entry_t *work);
@@ -132,13 +146,13 @@ workqueue_entry_cancel(workqueue_entry_t *ent)
{
int cancelled = 0;
void *result = NULL;
- tor_mutex_acquire(&ent->on_thread->lock);
+ tor_mutex_acquire(&ent->on_pool->lock);
if (ent->pending) {
- TOR_TAILQ_REMOVE(&ent->on_thread->work, ent, next_work);
+ TOR_TAILQ_REMOVE(&ent->on_pool->work, ent, next_work);
cancelled = 1;
result = ent->arg;
}
- tor_mutex_release(&ent->on_thread->lock);
+ tor_mutex_release(&ent->on_pool->lock);
if (cancelled) {
tor_free(ent);
@@ -146,6 +160,16 @@ workqueue_entry_cancel(workqueue_entry_t *ent)
return result;
}
+/**DOCDOC
+
+ must hold lock */
+static int
+worker_thread_has_work(workerthread_t *thread)
+{
+ return !TOR_TAILQ_EMPTY(&thread->in_pool->work) ||
+ thread->generation != thread->in_pool->generation;
+}
+
/**
* Main function for the worker thread.
*/
@@ -153,20 +177,39 @@ static void
worker_thread_main(void *thread_)
{
workerthread_t *thread = thread_;
+ threadpool_t *pool = thread->in_pool;
workqueue_entry_t *work;
int result;
- tor_mutex_acquire(&thread->lock);
thread->is_running = 1;
+
+ tor_mutex_acquire(&pool->lock);
while (1) {
/* lock must be held at this point. */
- while (!TOR_TAILQ_EMPTY(&thread->work)) {
+ while (worker_thread_has_work(thread)) {
/* lock must be held at this point. */
-
- work = TOR_TAILQ_FIRST(&thread->work);
- TOR_TAILQ_REMOVE(&thread->work, work, next_work);
+ if (thread->in_pool->generation != thread->generation) {
+ void *arg = thread->in_pool->update_args[thread->index];
+ thread->in_pool->update_args[thread->index] = NULL;
+ int (*update_fn)(void*,void*) = thread->in_pool->update_fn;
+ thread->generation = thread->in_pool->generation;
+ tor_mutex_release(&pool->lock);
+
+ int r = update_fn(thread->state, arg);
+
+ if (r < 0) {
+ thread->is_running = 0;
+ thread->is_shut_down = 1;
+ return;
+ }
+
+ tor_mutex_acquire(&pool->lock);
+ continue;
+ }
+ work = TOR_TAILQ_FIRST(&pool->work);
+ TOR_TAILQ_REMOVE(&pool->work, work, next_work);
work->pending = 0;
- tor_mutex_release(&thread->lock);
+ tor_mutex_release(&pool->lock);
/* We run the work function without holding the thread lock. This
* is the main thread's first opportunity to give us more work. */
@@ -175,25 +218,23 @@ worker_thread_main(void *thread_)
/* Queue the reply for the main thread. */
queue_reply(thread->reply_queue, work);
- tor_mutex_acquire(&thread->lock);
/* We may need to exit the thread. */
if (result >= WQ_RPL_ERROR) {
thread->is_running = 0;
thread->is_shut_down = 1;
- tor_mutex_release(&thread->lock);
return;
}
+ tor_mutex_acquire(&pool->lock);
}
/* At this point the lock is held, and there is no work in this thread's
* queue. */
- /* TODO: Try work-stealing. */
/* TODO: support an idle-function */
/* Okay. Now, wait till somebody has work for us. */
/* XXXX we could just omit waiting and instead */
thread->waiting = 1;
- if (tor_cond_wait(&thread->condition, &thread->lock, NULL) < 0) {
+ if (tor_cond_wait(&pool->condition, &pool->lock, NULL) < 0) {
/* XXXX ERROR */
}
thread->waiting = 0;
@@ -221,14 +262,12 @@ queue_reply(replyqueue_t *queue, workqueue_entry_t *work)
/** Allocate and start a new worker thread to use state object <b>state</b>,
* and send responses to <b>replyqueue</b>. */
static workerthread_t *
-workerthread_new(void *state, replyqueue_t *replyqueue)
+workerthread_new(void *state, threadpool_t *pool, replyqueue_t *replyqueue)
{
workerthread_t *thr = tor_malloc_zero(sizeof(workerthread_t));
- tor_mutex_init_for_cond(&thr->lock);
- tor_cond_init(&thr->condition);
- TOR_TAILQ_INIT(&thr->work);
thr->state = state;
thr->reply_queue = replyqueue;
+ thr->in_pool = pool;
if (spawn_func(worker_thread_main, thr) < 0) {
log_err(LD_GENERAL, "Can't launch worker thread.");
@@ -239,30 +278,6 @@ workerthread_new(void *state, replyqueue_t *replyqueue)
}
/**
- * Add an item of work to a single worker thread. See threadpool_queue_work(*)
- * for arguments.
- */
-static workqueue_entry_t *
-workerthread_queue_work(workerthread_t *worker,
- int (*fn)(void *, void *),
- void (*reply_fn)(void *),
- void *arg)
-{
- workqueue_entry_t *ent = workqueue_entry_new(fn, reply_fn, arg);
-
- tor_mutex_acquire(&worker->lock);
- ent->on_thread = worker;
- ent->pending = 1;
- TOR_TAILQ_INSERT_TAIL(&worker->work, ent, next_work);
-
- if (worker->waiting) /* XXXX inside or outside of lock?? */
- tor_cond_signal_one(&worker->condition);
-
- tor_mutex_release(&worker->lock);
- return ent;
-}
-
-/**
* Queue an item of work for a thread in a thread pool. The function
* <b>fn</b> will be run in a worker thread, and will receive as arguments the
* thread's state object, and the provided object <b>arg</b>. It must return
@@ -285,20 +300,19 @@ threadpool_queue_work(threadpool_t *pool,
void (*reply_fn)(void *),
void *arg)
{
- workerthread_t *worker;
+ workqueue_entry_t *ent = workqueue_entry_new(fn, reply_fn, arg);
+ ent->on_pool = pool;
+ ent->pending = 1;
tor_mutex_acquire(&pool->lock);
- /* Pick the next thread in random-access order. */
- worker = pool->threads[pool->next_for_work++];
- if (!worker) {
- tor_mutex_release(&pool->lock);
- return NULL;
- }
- if (pool->next_for_work >= pool->n_threads)
- pool->next_for_work = 0;
+
+ TOR_TAILQ_INSERT_TAIL(&pool->work, ent, next_work);
+
tor_mutex_release(&pool->lock);
- return workerthread_queue_work(worker, fn, reply_fn, arg);
+ tor_cond_signal_one(&pool->condition);
+
+ return ent;
}
/**
@@ -309,30 +323,56 @@ threadpool_queue_work(threadpool_t *pool,
* <b>arg</b> value is passed to <b>dup_fn</b> once per each thread to
* make a copy of it.
*
+ * UPDATE FUNCTIONS MUST BE IDEMPOTENT. We do not guarantee that every update
+ * will be run. If a new update is scheduled before the old update finishes
+ * running, then the new will replace the old in any threads that haven't run
+ * it yet.
+ *
* Return 0 on success, -1 on failure.
*/
int
-threadpool_queue_for_all(threadpool_t *pool,
+threadpool_queue_update(threadpool_t *pool,
void *(*dup_fn)(void *),
int (*fn)(void *, void *),
- void (*reply_fn)(void *),
+ void (*free_fn)(void *),
void *arg)
{
- int i = 0;
- workerthread_t *worker;
- void *arg_copy;
- while (1) {
- tor_mutex_acquire(&pool->lock);
- if (i >= pool->n_threads) {
- tor_mutex_release(&pool->lock);
- return 0;
- }
- worker = pool->threads[i++];
- tor_mutex_release(&pool->lock);
+ int i, n_threads;
+ void (*old_args_free_fn)(void *arg);
+ void **old_args;
+ void **new_args;
+
+ tor_mutex_acquire(&pool->lock);
+ n_threads = pool->n_threads;
+ old_args = pool->update_args;
+ old_args_free_fn = pool->free_update_arg_fn;
+
+ new_args = tor_calloc(n_threads, sizeof(void*));
+ for (i = 0; i < n_threads; ++i) {
+ if (dup_fn)
+ new_args[i] = dup_fn(arg);
+ else
+ new_args[i] = arg;
+ }
+
+ pool->update_args = new_args;
+ pool->free_update_arg_fn = free_fn;
+ pool->update_fn = fn;
+ ++pool->generation;
- arg_copy = dup_fn ? dup_fn(arg) : arg;
- /* CHECK*/ workerthread_queue_work(worker, fn, reply_fn, arg_copy);
+ tor_mutex_release(&pool->lock);
+
+ tor_cond_signal_all(&pool->condition);
+
+ if (old_args) {
+ for (i = 0; i < n_threads; ++i) {
+ if (old_args[i] && old_args_free_fn)
+ old_args_free_fn(old_args[i]);
+ }
+ tor_free(old_args);
}
+
+ return 0;
}
/** Launch threads until we have <b>n</b>. */
@@ -346,7 +386,8 @@ threadpool_start_threads(threadpool_t *pool, int n)
while (pool->n_threads < n) {
void *state = pool->new_thread_state_fn(pool->new_thread_state_arg);
- workerthread_t *thr = workerthread_new(state, pool->reply_queue);
+ workerthread_t *thr = workerthread_new(state, pool, pool->reply_queue);
+ thr->index = pool->n_threads;
if (!thr) {
tor_mutex_release(&pool->lock);
@@ -375,7 +416,10 @@ threadpool_new(int n_threads,
{
threadpool_t *pool;
pool = tor_malloc_zero(sizeof(threadpool_t));
- tor_mutex_init(&pool->lock);
+ tor_mutex_init_nonrecursive(&pool->lock);
+ tor_cond_init(&pool->condition);
+ TOR_TAILQ_INIT(&pool->work);
+
pool->new_thread_state_fn = new_thread_state_fn;
pool->new_thread_state_arg = arg;
pool->free_thread_state_fn = free_thread_state_fn;
@@ -447,7 +491,7 @@ replyqueue_process(replyqueue_t *queue)
workqueue_entry_t *work = TOR_TAILQ_FIRST(&queue->answers);
TOR_TAILQ_REMOVE(&queue->answers, work, next_work);
tor_mutex_release(&queue->lock);
- work->on_thread = NULL;
+ work->on_pool = NULL;
work->reply_fn(work->arg);
workqueue_entry_free(work);
diff --git a/src/common/workqueue.h b/src/common/workqueue.h
index aa1bcc518a..92e82b8a48 100644
--- a/src/common/workqueue.h
+++ b/src/common/workqueue.h
@@ -27,11 +27,11 @@ workqueue_entry_t *threadpool_queue_work(threadpool_t *pool,
int (*fn)(void *, void *),
void (*reply_fn)(void *),
void *arg);
-int threadpool_queue_for_all(threadpool_t *pool,
- void *(*dup_fn)(void *),
- int (*fn)(void *, void *),
- void (*reply_fn)(void *),
- void *arg);
+int threadpool_queue_update(threadpool_t *pool,
+ void *(*dup_fn)(void *),
+ int (*fn)(void *, void *),
+ void (*free_fn)(void *),
+ void *arg);
void *workqueue_entry_cancel(workqueue_entry_t *pending_work);
threadpool_t *threadpool_new(int n_threads,
replyqueue_t *replyqueue,
diff --git a/src/or/cpuworker.c b/src/or/cpuworker.c
index 36ca505fe3..3f129ded99 100644
--- a/src/or/cpuworker.c
+++ b/src/or/cpuworker.c
@@ -170,11 +170,6 @@ update_state_threadfn(void *state_, void *work_)
++state->generation;
return WQ_RPL_REPLY;
}
-static void
-update_state_replyfn(void *work_)
-{
- tor_free(work_);
-}
/** Called when the onion key has changed and we need to spawn new
* cpuworkers. Close all currently idle cpuworkers, and mark the last
@@ -183,11 +178,11 @@ update_state_replyfn(void *work_)
void
cpuworkers_rotate_keyinfo(void)
{
- if (threadpool_queue_for_all(threadpool,
- worker_state_new,
- update_state_threadfn,
- update_state_replyfn,
- NULL)) {
+ if (threadpool_queue_update(threadpool,
+ worker_state_new,
+ update_state_threadfn,
+ worker_state_free,
+ NULL)) {
log_warn(LD_OR, "Failed to queue key update for worker threads.");
}
}
diff --git a/src/test/test_workqueue.c b/src/test/test_workqueue.c
index 410f43cce4..8ce4405062 100644
--- a/src/test/test_workqueue.c
+++ b/src/test/test_workqueue.c
@@ -132,7 +132,6 @@ new_state(void *arg)
/* Every thread gets its own keys. not a problem for benchmarking */
st->rsa = crypto_pk_new();
if (crypto_pk_generate_key_with_bits(st->rsa, 1024) < 0) {
- puts("keygen failed");
crypto_pk_free(st->rsa);
tor_free(st);
return NULL;
@@ -213,7 +212,6 @@ add_n_work_items(threadpool_t *tp, int n)
while (n_queued++ < n) {
ent = add_work(tp);
if (! ent) {
- puts("Couldn't add work.");
tor_event_base_loopexit(tor_libevent_get_base(), NULL);
return -1;
}
@@ -238,18 +236,6 @@ add_n_work_items(threadpool_t *tp, int n)
}
static int shutting_down = 0;
-static int n_shutdowns_done = 0;
-
-static void
-shutdown_reply(void *arg)
-{
- (void)arg;
- tor_assert(shutting_down);
- ++n_shutdowns_done;
- if (n_shutdowns_done == opt_n_threads) {
- tor_event_base_loopexit(tor_libevent_get_base(), NULL);
- }
-}
static void
replysock_readable_cb(tor_socket_t sock, short what, void *arg)
@@ -297,8 +283,8 @@ replysock_readable_cb(tor_socket_t sock, short what, void *arg)
n_received+n_successful_cancel == n_sent &&
n_sent >= opt_n_items) {
shutting_down = 1;
- threadpool_queue_for_all(tp, NULL,
- workqueue_do_shutdown, shutdown_reply, NULL);
+ threadpool_queue_update(tp, NULL,
+ workqueue_do_shutdown, NULL, NULL);
}
}
@@ -410,8 +396,9 @@ main(int argc, char **argv)
event_base_loop(tor_libevent_get_base(), 0);
- if (n_sent != opt_n_items || n_received+n_successful_cancel != n_sent ||
- n_shutdowns_done != opt_n_threads) {
+ if (n_sent != opt_n_items || n_received+n_successful_cancel != n_sent) {
+ printf("%d vs %d\n", n_sent, opt_n_items);
+ printf("%d+%d vs %d\n", n_received, n_successful_cancel, n_sent);
puts("FAIL");
return 1;
} else {
7apu2bq3rhoylwmucxizk54afw5jyda7pho4j5zdcqpwkufke7zdzwad.onion