-/*
- * sgen-thread-pool.c: Threadpool for all concurrent GC work.
+/**
+ * \file
+ * Threadpool for all concurrent GC work.
*
* Copyright (C) 2015 Xamarin Inc
*
#include "mono/sgen/sgen-gc.h"
#include "mono/sgen/sgen-thread-pool.h"
-#include "mono/sgen/sgen-pointer-queue.h"
+#include "mono/sgen/sgen-client.h"
#include "mono/utils/mono-os-mutex.h"
-#ifndef SGEN_WITHOUT_MONO
-#include "mono/utils/mono-threads.h"
-#endif
-
-#define MAX_NUM_THREADS 8
static mono_mutex_t lock;
static mono_cond_t work_cond;
static mono_cond_t done_cond;
-static int threads_num = 0;
-static MonoNativeThreadId threads [MAX_NUM_THREADS];
-
-/* Only accessed with the lock held. */
-static SgenPointerQueue job_queue;
-
-static SgenThreadPoolThreadInitFunc thread_init_func;
-static SgenThreadPoolIdleJobFunc idle_job_func;
-static SgenThreadPoolContinueIdleJobFunc continue_idle_job_func;
+static int threads_num;
+static MonoNativeThreadId threads [SGEN_THREADPOOL_MAX_NUM_THREADS];
+static int threads_context [SGEN_THREADPOOL_MAX_NUM_THREADS];
static volatile gboolean threadpool_shutdown;
-static volatile int threads_finished = 0;
+static volatile int threads_finished;
+
+static int contexts_num;
+static SgenThreadPoolContext pool_contexts [SGEN_THREADPOOL_MAX_NUM_CONTEXTS];
enum {
STATE_WAITING,
/* Assumes that the lock is held. */
static SgenThreadPoolJob*
-get_job_and_set_in_progress (void)
+get_job_and_set_in_progress (SgenThreadPoolContext *context)
{
- for (size_t i = 0; i < job_queue.next_slot; ++i) {
- SgenThreadPoolJob *job = (SgenThreadPoolJob *)job_queue.data [i];
+ for (size_t i = 0; i < context->job_queue.next_slot; ++i) {
+ SgenThreadPoolJob *job = (SgenThreadPoolJob *)context->job_queue.data [i];
if (job->state == STATE_WAITING) {
job->state = STATE_IN_PROGRESS;
return job;
/* Assumes that the lock is held. */
static ssize_t
-find_job_in_queue (SgenThreadPoolJob *job)
+find_job_in_queue (SgenThreadPoolContext *context, SgenThreadPoolJob *job)
{
- for (ssize_t i = 0; i < job_queue.next_slot; ++i) {
- if (job_queue.data [i] == job)
+ for (ssize_t i = 0; i < context->job_queue.next_slot; ++i) {
+ if (context->job_queue.data [i] == job)
return i;
}
return -1;
/* Assumes that the lock is held. */
static void
-remove_job (SgenThreadPoolJob *job)
+remove_job (SgenThreadPoolContext *context, SgenThreadPoolJob *job)
{
ssize_t index;
SGEN_ASSERT (0, job->state == STATE_DONE, "Why are we removing a job that's not done?");
- index = find_job_in_queue (job);
+ index = find_job_in_queue (context, job);
SGEN_ASSERT (0, index >= 0, "Why is the job we're trying to remove not in the queue?");
- job_queue.data [index] = NULL;
- sgen_pointer_queue_remove_nulls (&job_queue);
+ context->job_queue.data [index] = NULL;
+ sgen_pointer_queue_remove_nulls (&context->job_queue);
sgen_thread_pool_job_free (job);
}
static gboolean
-continue_idle_job (void *thread_data)
+continue_idle_job (SgenThreadPoolContext *context, void *thread_data)
{
- if (!continue_idle_job_func)
+ if (!context->continue_idle_job_func)
return FALSE;
- return continue_idle_job_func (thread_data);
+ return context->continue_idle_job_func (thread_data, context - pool_contexts);
+}
+
+static gboolean
+should_work (SgenThreadPoolContext *context, void *thread_data)
+{
+ if (!context->should_work_func)
+ return TRUE;
+ return context->should_work_func (thread_data);
+}
+
+/*
+ * Tells whether we should lock and attempt to get work from
+ * a higher priority context.
+ */
+static gboolean
+has_priority_work (int worker_index, int current_context)
+{
+ int i;
+
+ for (i = 0; i < current_context; i++) {
+ SgenThreadPoolContext *context = &pool_contexts [i];
+ void *thread_data;
+
+ if (worker_index >= context->num_threads)
+ continue;
+ thread_data = (context->thread_datas) ? context->thread_datas [worker_index] : NULL;
+ if (!should_work (context, thread_data))
+ continue;
+ if (context->job_queue.next_slot > 0)
+ return TRUE;
+ if (continue_idle_job (context, thread_data))
+ return TRUE;
+ }
+
+ /* Return if job enqueued on current context. Jobs have priority over idle work */
+ if (pool_contexts [current_context].job_queue.next_slot > 0)
+ return TRUE;
+
+ return FALSE;
+}
+
+/*
+ * Gets the highest priority work. If there is none, it waits
+ * for work_cond. Should always be called with lock held.
+ */
+static void
+get_work (int worker_index, int *work_context, int *do_idle, SgenThreadPoolJob **job)
+{
+ while (!threadpool_shutdown) {
+ int i;
+
+ for (i = 0; i < contexts_num; i++) {
+ SgenThreadPoolContext *context = &pool_contexts [i];
+ void *thread_data;
+
+ if (worker_index >= context->num_threads)
+ continue;
+ thread_data = (context->thread_datas) ? context->thread_datas [worker_index] : NULL;
+
+ if (!should_work (context, thread_data))
+ continue;
+
+ /*
+ * It's important that we check the continue idle flag with the lock held.
+ * Suppose we didn't check with the lock held, and the result is FALSE. The
+ * main thread might then set continue idle and signal us before we can take
+ * the lock, and we'd lose the signal.
+ */
+ *do_idle = continue_idle_job (context, thread_data);
+ *job = get_job_and_set_in_progress (context);
+
+ if (*job || *do_idle) {
+ *work_context = i;
+ return;
+ }
+ }
+
+ /*
+ * Nothing to do on any context
+ * pthread_cond_wait() can return successfully despite the condition
+ * not being signalled, so we have to run this in a loop until we
+ * really have work to do.
+ */
+ mono_os_cond_wait (&work_cond, &lock);
+ }
}
static mono_native_thread_return_t
-thread_func (void *thread_data)
+thread_func (int worker_index)
{
- thread_init_func (thread_data);
+ int current_context;
+ void *thread_data = NULL;
+
+ sgen_client_thread_register_worker ();
+
+ for (current_context = 0; current_context < contexts_num; current_context++) {
+ if (worker_index >= pool_contexts [current_context].num_threads ||
+ !pool_contexts [current_context].thread_init_func)
+ break;
+
+ thread_data = (pool_contexts [current_context].thread_datas) ? pool_contexts [current_context].thread_datas [worker_index] : NULL;
+ pool_contexts [current_context].thread_init_func (thread_data);
+ }
+
+ current_context = 0;
mono_os_mutex_lock (&lock);
for (;;) {
- /*
- * It's important that we check the continue idle flag with the lock held.
- * Suppose we didn't check with the lock held, and the result is FALSE. The
- * main thread might then set continue idle and signal us before we can take
- * the lock, and we'd lose the signal.
- */
- gboolean do_idle = continue_idle_job (thread_data);
- SgenThreadPoolJob *job = get_job_and_set_in_progress ();
+ gboolean do_idle = FALSE;
+ SgenThreadPoolJob *job = NULL;
+ SgenThreadPoolContext *context = NULL;
- if (!job && !do_idle && !threadpool_shutdown) {
- /*
- * pthread_cond_wait() can return successfully despite the condition
- * not being signalled, so we have to run this in a loop until we
- * really have work to do.
- */
- mono_os_cond_wait (&work_cond, &lock);
- continue;
+ threads_context [worker_index] = -1;
+ get_work (worker_index, ¤t_context, &do_idle, &job);
+ threads_context [worker_index] = current_context;
+
+ if (!threadpool_shutdown) {
+ context = &pool_contexts [current_context];
+ thread_data = (context->thread_datas) ? context->thread_datas [worker_index] : NULL;
}
mono_os_mutex_unlock (&lock);
SGEN_ASSERT (0, job->state == STATE_IN_PROGRESS, "The job should still be in progress.");
job->state = STATE_DONE;
- remove_job (job);
+ remove_job (context, job);
/*
* Only the main GC thread will ever wait on the done condition, so we don't
* have to broadcast.
*/
mono_os_cond_signal (&done_cond);
} else if (do_idle) {
- SGEN_ASSERT (0, idle_job_func, "Why do we have idle work when there's no idle job function?");
+ SGEN_ASSERT (0, context->idle_job_func, "Why do we have idle work when there's no idle job function?");
do {
- idle_job_func (thread_data);
- do_idle = continue_idle_job (thread_data);
- } while (do_idle && !job_queue.next_slot);
+ context->idle_job_func (thread_data);
+ do_idle = continue_idle_job (context, thread_data);
+ } while (do_idle && !has_priority_work (worker_index, current_context));
mono_os_mutex_lock (&lock);
return (mono_native_thread_return_t)0;
}
+int
+sgen_thread_pool_create_context (int num_threads, SgenThreadPoolThreadInitFunc init_func, SgenThreadPoolIdleJobFunc idle_func, SgenThreadPoolContinueIdleJobFunc continue_idle_func, SgenThreadPoolShouldWorkFunc should_work_func, void **thread_datas)
+{
+ int context_id = contexts_num;
+
+ SGEN_ASSERT (0, contexts_num < SGEN_THREADPOOL_MAX_NUM_CONTEXTS, "Maximum sgen thread pool contexts reached");
+
+ pool_contexts [context_id].thread_init_func = init_func;
+ pool_contexts [context_id].idle_job_func = idle_func;
+ pool_contexts [context_id].continue_idle_job_func = continue_idle_func;
+ pool_contexts [context_id].should_work_func = should_work_func;
+ pool_contexts [context_id].thread_datas = thread_datas;
+
+ SGEN_ASSERT (0, num_threads <= SGEN_THREADPOOL_MAX_NUM_THREADS, "Maximum sgen thread pool threads exceeded");
+
+ pool_contexts [context_id].num_threads = num_threads;
+
+ sgen_pointer_queue_init (&pool_contexts [contexts_num].job_queue, 0);
+
+ contexts_num++;
+
+ return context_id;
+}
+
void
-sgen_thread_pool_init (int num_threads, SgenThreadPoolThreadInitFunc init_func, SgenThreadPoolIdleJobFunc idle_func, SgenThreadPoolContinueIdleJobFunc continue_idle_func, void **thread_datas)
+sgen_thread_pool_start (void)
{
int i;
- threads_num = (num_threads < MAX_NUM_THREADS) ? num_threads : MAX_NUM_THREADS;
+ for (i = 0; i < contexts_num; i++) {
+ if (threads_num < pool_contexts [i].num_threads)
+ threads_num = pool_contexts [i].num_threads;
+ }
+
+ if (!threads_num)
+ return;
mono_os_mutex_init (&lock);
mono_os_cond_init (&work_cond);
mono_os_cond_init (&done_cond);
- thread_init_func = init_func;
- idle_job_func = idle_func;
- continue_idle_job_func = continue_idle_func;
+ threads_finished = 0;
+ threadpool_shutdown = FALSE;
- for (i = 0; i < threads_num; i++)
- mono_native_thread_create (&threads [i], thread_func, thread_datas ? thread_datas [i] : NULL);
+ for (i = 0; i < threads_num; i++) {
+ mono_native_thread_create (&threads [i], thread_func, (void*)(gsize)i);
+ }
}
void
}
void
-sgen_thread_pool_job_enqueue (SgenThreadPoolJob *job)
+sgen_thread_pool_job_enqueue (int context_id, SgenThreadPoolJob *job)
{
mono_os_mutex_lock (&lock);
- sgen_pointer_queue_add (&job_queue, job);
- mono_os_cond_signal (&work_cond);
+ sgen_pointer_queue_add (&pool_contexts [context_id].job_queue, job);
+ mono_os_cond_broadcast (&work_cond);
mono_os_mutex_unlock (&lock);
}
void
-sgen_thread_pool_job_wait (SgenThreadPoolJob *job)
+sgen_thread_pool_job_wait (int context_id, SgenThreadPoolJob *job)
{
SGEN_ASSERT (0, job, "Where's the job?");
mono_os_mutex_lock (&lock);
- while (find_job_in_queue (job) >= 0)
+ while (find_job_in_queue (&pool_contexts [context_id], job) >= 0)
mono_os_cond_wait (&done_cond, &lock);
mono_os_mutex_unlock (&lock);
}
void
-sgen_thread_pool_idle_signal (void)
+sgen_thread_pool_idle_signal (int context_id)
{
- SGEN_ASSERT (0, idle_job_func, "Why are we signaling idle without an idle function?");
+ SGEN_ASSERT (0, pool_contexts [context_id].idle_job_func, "Why are we signaling idle without an idle function?");
mono_os_mutex_lock (&lock);
- if (continue_idle_job_func (NULL))
+ if (pool_contexts [context_id].continue_idle_job_func (NULL, context_id))
mono_os_cond_broadcast (&work_cond);
mono_os_mutex_unlock (&lock);
}
void
-sgen_thread_pool_idle_wait (void)
+sgen_thread_pool_idle_wait (int context_id, SgenThreadPoolContinueIdleWaitFunc continue_wait)
{
- SGEN_ASSERT (0, idle_job_func, "Why are we waiting for idle without an idle function?");
+ SGEN_ASSERT (0, pool_contexts [context_id].idle_job_func, "Why are we waiting for idle without an idle function?");
mono_os_mutex_lock (&lock);
- while (continue_idle_job_func (NULL))
+ while (continue_wait (context_id, threads_context))
mono_os_cond_wait (&done_cond, &lock);
mono_os_mutex_unlock (&lock);
}
void
-sgen_thread_pool_wait_for_all_jobs (void)
+sgen_thread_pool_wait_for_all_jobs (int context_id)
{
mono_os_mutex_lock (&lock);
- while (!sgen_pointer_queue_is_empty (&job_queue))
+ while (!sgen_pointer_queue_is_empty (&pool_contexts [context_id].job_queue))
mono_os_cond_wait (&done_cond, &lock);
mono_os_mutex_unlock (&lock);
}
-gboolean
+/* Return 0 if is not a thread pool thread or the thread number otherwise */
+int
sgen_thread_pool_is_thread_pool_thread (MonoNativeThreadId some_thread)
{
int i;
for (i = 0; i < threads_num; i++) {
if (some_thread == threads [i])
- return TRUE;
+ return i + 1;
}
- return FALSE;
+ return 0;
}
#endif