Squashed 'third_party/allwpilib_2019/' content from commit bd05dfa1c
Change-Id: I2b1c2250cdb9b055133780c33593292098c375b7
git-subtree-dir: third_party/allwpilib_2019
git-subtree-split: bd05dfa1c7cca74c4fac451e7b9d6a37e7b53447
diff --git a/wpiutil/src/main/native/libuv/threadpool.cpp b/wpiutil/src/main/native/libuv/threadpool.cpp
new file mode 100644
index 0000000..3b4b7cf
--- /dev/null
+++ b/wpiutil/src/main/native/libuv/threadpool.cpp
@@ -0,0 +1,318 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "uv-common.h"
+
+#if !defined(_WIN32)
+# include "unix/internal.h"
+#endif
+
+#include <stdlib.h>
+
+#define MAX_THREADPOOL_SIZE 128
+
+static uv_once_t once = UV_ONCE_INIT;
+static uv_cond_t cond;
+static uv_mutex_t mutex;
+static unsigned int idle_threads;
+static unsigned int nthreads;
+static uv_thread_t* threads;
+static uv_thread_t default_threads[4];
+static QUEUE exit_message;
+static QUEUE wq;
+
+
+static void uv__cancelled(struct uv__work* w) {
+ abort();
+}
+
+
+/* To avoid deadlock with uv_cancel() it's crucial that the worker
+ * never holds the global mutex and the loop-local mutex at the same time.
+ */
+static void worker(void* arg) {
+ struct uv__work* w;
+ QUEUE* q;
+
+ uv_sem_post((uv_sem_t*) arg);
+ arg = NULL;
+
+ for (;;) {
+ uv_mutex_lock(&mutex);
+
+ while (QUEUE_EMPTY(&wq)) {
+ idle_threads += 1;
+ uv_cond_wait(&cond, &mutex);
+ idle_threads -= 1;
+ }
+
+ q = QUEUE_HEAD(&wq);
+
+ if (q == &exit_message)
+ uv_cond_signal(&cond);
+ else {
+ QUEUE_REMOVE(q);
+ QUEUE_INIT(q); /* Signal uv_cancel() that the work req is
+ executing. */
+ }
+
+ uv_mutex_unlock(&mutex);
+
+ if (q == &exit_message)
+ break;
+
+ w = QUEUE_DATA(q, struct uv__work, wq);
+ w->work(w);
+
+ uv_mutex_lock(&w->loop->wq_mutex);
+ w->work = NULL; /* Signal uv_cancel() that the work req is done
+ executing. */
+ QUEUE_INSERT_TAIL(&w->loop->wq, &w->wq);
+ uv_async_send(&w->loop->wq_async);
+ uv_mutex_unlock(&w->loop->wq_mutex);
+ }
+}
+
+
+static void post(QUEUE* q) {
+ uv_mutex_lock(&mutex);
+ QUEUE_INSERT_TAIL(&wq, q);
+ if (idle_threads > 0)
+ uv_cond_signal(&cond);
+ uv_mutex_unlock(&mutex);
+}
+
+
+#ifndef _WIN32
+UV_DESTRUCTOR(static void cleanup(void)) {
+ unsigned int i;
+
+ if (nthreads == 0)
+ return;
+
+ post(&exit_message);
+
+ for (i = 0; i < nthreads; i++)
+ if (uv_thread_join(threads + i))
+ abort();
+
+ if (threads != default_threads)
+ uv__free(threads);
+
+ uv_mutex_destroy(&mutex);
+ uv_cond_destroy(&cond);
+
+ threads = NULL;
+ nthreads = 0;
+}
+#endif
+
+
+static void init_threads(void) {
+ unsigned int i;
+ const char* val;
+ uv_sem_t sem;
+
+ nthreads = ARRAY_SIZE(default_threads);
+ val = getenv("UV_THREADPOOL_SIZE");
+ if (val != NULL)
+ nthreads = atoi(val);
+ if (nthreads == 0)
+ nthreads = 1;
+ if (nthreads > MAX_THREADPOOL_SIZE)
+ nthreads = MAX_THREADPOOL_SIZE;
+
+ threads = default_threads;
+ if (nthreads > ARRAY_SIZE(default_threads)) {
+ threads = (uv_thread_t*)uv__malloc(nthreads * sizeof(threads[0]));
+ if (threads == NULL) {
+ nthreads = ARRAY_SIZE(default_threads);
+ threads = default_threads;
+ }
+ }
+
+ if (uv_cond_init(&cond))
+ abort();
+
+ if (uv_mutex_init(&mutex))
+ abort();
+
+ QUEUE_INIT(&wq);
+
+ if (uv_sem_init(&sem, 0))
+ abort();
+
+ for (i = 0; i < nthreads; i++)
+ if (uv_thread_create(threads + i, worker, &sem))
+ abort();
+
+ for (i = 0; i < nthreads; i++)
+ uv_sem_wait(&sem);
+
+ uv_sem_destroy(&sem);
+}
+
+
+#ifndef _WIN32
+static void reset_once(void) {
+ uv_once_t child_once = UV_ONCE_INIT;
+ memcpy(&once, &child_once, sizeof(child_once));
+}
+#endif
+
+
+static void init_once(void) {
+#ifndef _WIN32
+ /* Re-initialize the threadpool after fork.
+ * Note that this discards the global mutex and condition as well
+ * as the work queue.
+ */
+ if (pthread_atfork(NULL, NULL, &reset_once))
+ abort();
+#endif
+ init_threads();
+}
+
+
+void uv__work_submit(uv_loop_t* loop,
+ struct uv__work* w,
+ void (*work)(struct uv__work* w),
+ void (*done)(struct uv__work* w, int status)) {
+ uv_once(&once, init_once);
+ w->loop = loop;
+ w->work = work;
+ w->done = done;
+ post(&w->wq);
+}
+
+
+static int uv__work_cancel(uv_loop_t* loop, uv_req_t* req, struct uv__work* w) {
+ int cancelled;
+
+ uv_mutex_lock(&mutex);
+ uv_mutex_lock(&w->loop->wq_mutex);
+
+ cancelled = !QUEUE_EMPTY(&w->wq) && w->work != NULL;
+ if (cancelled)
+ QUEUE_REMOVE(&w->wq);
+
+ uv_mutex_unlock(&w->loop->wq_mutex);
+ uv_mutex_unlock(&mutex);
+
+ if (!cancelled)
+ return UV_EBUSY;
+
+ w->work = uv__cancelled;
+ uv_mutex_lock(&loop->wq_mutex);
+ QUEUE_INSERT_TAIL(&loop->wq, &w->wq);
+ uv_async_send(&loop->wq_async);
+ uv_mutex_unlock(&loop->wq_mutex);
+
+ return 0;
+}
+
+
+void uv__work_done(uv_async_t* handle) {
+ struct uv__work* w;
+ uv_loop_t* loop;
+ QUEUE* q;
+ QUEUE wq;
+ int err;
+
+ loop = container_of(handle, uv_loop_t, wq_async);
+ uv_mutex_lock(&loop->wq_mutex);
+ QUEUE_MOVE(&loop->wq, &wq);
+ uv_mutex_unlock(&loop->wq_mutex);
+
+ while (!QUEUE_EMPTY(&wq)) {
+ q = QUEUE_HEAD(&wq);
+ QUEUE_REMOVE(q);
+
+ w = container_of(q, struct uv__work, wq);
+ err = (w->work == uv__cancelled) ? UV_ECANCELED : 0;
+ w->done(w, err);
+ }
+}
+
+
+static void uv__queue_work(struct uv__work* w) {
+ uv_work_t* req = container_of(w, uv_work_t, work_req);
+
+ req->work_cb(req);
+}
+
+
+static void uv__queue_done(struct uv__work* w, int err) {
+ uv_work_t* req;
+
+ req = container_of(w, uv_work_t, work_req);
+ uv__req_unregister(req->loop, req);
+
+ if (req->after_work_cb == NULL)
+ return;
+
+ req->after_work_cb(req, err);
+}
+
+
+int uv_queue_work(uv_loop_t* loop,
+ uv_work_t* req,
+ uv_work_cb work_cb,
+ uv_after_work_cb after_work_cb) {
+ if (work_cb == NULL)
+ return UV_EINVAL;
+
+ uv__req_init(loop, req, UV_WORK);
+ req->loop = loop;
+ req->work_cb = work_cb;
+ req->after_work_cb = after_work_cb;
+ uv__work_submit(loop, &req->work_req, uv__queue_work, uv__queue_done);
+ return 0;
+}
+
+
+int uv_cancel(uv_req_t* req) {
+ struct uv__work* wreq;
+ uv_loop_t* loop;
+
+ switch (req->type) {
+ case UV_FS:
+ loop = ((uv_fs_t*) req)->loop;
+ wreq = &((uv_fs_t*) req)->work_req;
+ break;
+ case UV_GETADDRINFO:
+ loop = ((uv_getaddrinfo_t*) req)->loop;
+ wreq = &((uv_getaddrinfo_t*) req)->work_req;
+ break;
+ case UV_GETNAMEINFO:
+ loop = ((uv_getnameinfo_t*) req)->loop;
+ wreq = &((uv_getnameinfo_t*) req)->work_req;
+ break;
+ case UV_WORK:
+ loop = ((uv_work_t*) req)->loop;
+ wreq = &((uv_work_t*) req)->work_req;
+ break;
+ default:
+ return UV_EINVAL;
+ }
+
+ return uv__work_cancel(loop, req, wreq);
+}