1 files changed, 118 insertions, 0 deletions
diff --git a/src/mercury/include/mercury_thread_pool.h b/src/mercury/include/mercury_thread_pool.h
new file mode 100644
index 0000000..db973d1
--- /dev/null
+++ b/src/mercury/include/mercury_thread_pool.h
@@ -0,0 +1,118 @@
+/*
+ * Copyright (C) 2013-2020 Argonne National Laboratory, Department of Energy,
+ *                    UChicago Argonne, LLC and The HDF Group.
+ * All rights reserved.
+ *
+ * The full copyright notice, including terms governing use, modification,
+ * and redistribution, is contained in the COPYING file that can be
+ * found at the root of the source code distribution tree.
+ */
+
+#ifndef MERCURY_THREAD_POOL_H
+#define MERCURY_THREAD_POOL_H
+
+#include "mercury_queue.h"
+#include "mercury_thread.h"
+#include "mercury_thread_condition.h"
+
+/*************************************/
+/* Public Type and Struct Definition */
+/*************************************/
+
+typedef struct hg_thread_pool hg_thread_pool_t;
+
+struct hg_thread_pool {
+    unsigned int sleeping_worker_count;
+    HG_QUEUE_HEAD(hg_thread_work) queue;
+    int               shutdown;
+    hg_thread_mutex_t mutex;
+    hg_thread_cond_t  cond;
+};
+
+struct hg_thread_work {
+    hg_thread_func_t func;
+    void *           args;
+    HG_QUEUE_ENTRY(hg_thread_work) entry; /* Internal */
+};
+
+/*****************/
+/* Public Macros */
+/*****************/
+
+/*********************/
+/* Public Prototypes */
+/*********************/
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Initialize the thread pool.
+ *
+ * \param thread_count [IN]     number of threads that will be created at
+ *                              initialization
+ * \param pool [OUT]            pointer to pool object
+ *
+ * \return Non-negative on success or negative on failure
+ */
+HG_UTIL_PUBLIC int hg_thread_pool_init(unsigned int thread_count, hg_thread_pool_t **pool);
+
+/**
+ * Destroy the thread pool.
+ *
+ * \param pool [IN/OUT]         pointer to pool object
+ *
+ * \return Non-negative on success or negative on failure
+ */
+HG_UTIL_PUBLIC int hg_thread_pool_destroy(hg_thread_pool_t *pool);
+
+/**
+ * Post work to the pool. Note that the operation may be queued depending on
+ * the number of threads and number of tasks already running.
+ *
+ * \param pool [IN/OUT]         pointer to pool object
+ * \param work [IN]             pointer to work struct
+ *
+ * \return Non-negative on success or negative on failure
+ */
+static HG_UTIL_INLINE int hg_thread_pool_post(hg_thread_pool_t *pool, struct hg_thread_work *work);
+
+/*---------------------------------------------------------------------------*/
+static HG_UTIL_INLINE int
+hg_thread_pool_post(hg_thread_pool_t *pool, struct hg_thread_work *work)
+{
+    int ret = HG_UTIL_SUCCESS;
+
+    if (!pool || !work)
+        return HG_UTIL_FAIL;
+
+    if (!work->func)
+        return HG_UTIL_FAIL;
+
+    hg_thread_mutex_lock(&pool->mutex);
+
+    /* Are we shutting down ? */
+    if (pool->shutdown) {
+        ret = HG_UTIL_FAIL;
+        goto unlock;
+    }
+
+    /* Add task to task queue */
+    HG_QUEUE_PUSH_TAIL(&pool->queue, work, entry);
+
+    /* Wake up sleeping worker */
+    if (pool->sleeping_worker_count && (hg_thread_cond_signal(&pool->cond) != HG_UTIL_SUCCESS))
+        ret = HG_UTIL_FAIL;
+
+unlock:
+    hg_thread_mutex_unlock(&pool->mutex);
+
+    return ret;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* MERCURY_THREAD_POOL_H */