| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed |
| * with this work for additional information regarding copyright |
| * ownership. The ASF licenses this file to you under the Apache |
| * License, Version 2.0 (the "License"); you may not use this file |
| * except in compliance with the License. You may obtain a copy of |
| * the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| * implied. See the License for the specific language governing |
| * permissions and limitations under the License. |
| */ |
| |
| #ifndef APU_THREAD_POOL_H |
| #define APU_THREAD_POOL_H |
| |
| #include "apr_thread_proc.h" |
| |
| /** |
| * @file apr_thread_pool.h |
| * @brief APR Thread Pool Library |
| |
| * @remarks This library implements a thread pool using apr_thread_t. A thread |
| * pool is a set of threads that can be created in advance or on demand until a |
| * maximum number. When a task is scheduled, the thread pool will find an idle |
| * thread to handle the task. In case all existing threads are busy and the |
| * number of tasks in the queue is higher than the adjustable threshold, the |
| * pool will try to create a new thread to serve the task if the maximum number |
| * has not been reached. Otherwise, the task will be put into a queue based on |
| * priority, which can be valued from 0 to 255, with higher values being served |
| * first. If there are tasks with the same priority, the new task might be put at |
| * the top or at the bottom - it depends on which function is used to put the task. |
| * |
| * @remarks There may be the case where the thread pool can use up to the maximum |
| * number of threads at peak load, but having those threads idle afterwards. A |
| * maximum number of idle threads can be set so that the extra idling threads will |
| * be terminated to save system resources. |
| */ |
| #if APR_HAS_THREADS |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif /* __cplusplus */ |
| |
| /** |
| * @defgroup APR_Util_TP Thread Pool routines |
| * @ingroup APR_Util |
| * @{ |
| */ |
| |
| /** Opaque Thread Pool structure. */ |
| typedef struct apr_thread_pool apr_thread_pool_t; |
| |
| #define APR_THREAD_TASK_PRIORITY_LOWEST 0 |
| #define APR_THREAD_TASK_PRIORITY_LOW 63 |
| #define APR_THREAD_TASK_PRIORITY_NORMAL 127 |
| #define APR_THREAD_TASK_PRIORITY_HIGH 191 |
| #define APR_THREAD_TASK_PRIORITY_HIGHEST 255 |
| |
| /** |
| * Create a thread pool |
| * @param me The pointer in which to return the newly created apr_thread_pool |
| * object, or NULL if thread pool creation fails. |
| * @param init_threads The number of threads to be created initially, this number |
| * will also be used as the initial value for the maximum number of idle threads. |
| * @param max_threads The maximum number of threads that can be created |
| * @param pool The pool to use |
| * @return APR_SUCCESS if the thread pool was created successfully. Otherwise, |
| * the error code. |
| */ |
| apr_status_t etch_apr_thread_pool_create(apr_thread_pool_t **me, |
| apr_size_t init_threads, |
| apr_size_t max_threads, |
| apr_pool_t *pool); |
| |
| /** |
| * Destroy the thread pool and stop all the threads |
| * @return APR_SUCCESS if all threads are stopped. |
| */ |
| apr_status_t etch_apr_thread_pool_destroy(apr_thread_pool_t *me); |
| |
| /** |
| * Schedule a task to the bottom of the tasks of same priority. |
| * @param me The thread pool |
| * @param func The task function |
| * @param param The parameter for the task function |
| * @param priority The priority of the task. |
| * @param owner Owner of this task. |
| * @return APR_SUCCESS if the task had been scheduled successfully |
| */ |
| apr_status_t etch_apr_thread_pool_push(apr_thread_pool_t *me, |
| apr_thread_start_t func, |
| void *param, |
| apr_byte_t priority, |
| void *owner); |
| /** |
| * Schedule a task to be run after a delay |
| * @param me The thread pool |
| * @param func The task function |
| * @param param The parameter for the task function |
| * @param time Time in microseconds |
| * @param owner Owner of this task. |
| * @return APR_SUCCESS if the task had been scheduled successfully |
| */ |
| apr_status_t etch_apr_thread_pool_schedule(apr_thread_pool_t *me, |
| apr_thread_start_t func, |
| void *param, |
| apr_interval_time_t time, |
| void *owner); |
| |
| /** |
| * Schedule a task to the top of the tasks of same priority. |
| * @param me The thread pool |
| * @param func The task function |
| * @param param The parameter for the task function |
| * @param priority The priority of the task. |
| * @param owner Owner of this task. |
| * @return APR_SUCCESS if the task had been scheduled successfully |
| */ |
| apr_status_t etch_apr_thread_pool_top(apr_thread_pool_t *me, |
| apr_thread_start_t func, |
| void *param, |
| apr_byte_t priority, |
| void *owner); |
| |
| /** |
| * Cancel tasks submitted by the owner. If there is any task from the owner that |
| * is currently running, the function will spin until the task finished. |
| * @param me The thread pool |
| * @param owner Owner of the task |
| * @return APR_SUCCESS if the task has been cancelled successfully |
| * @note The task function should not be calling cancel, otherwise the function |
| * may get stuck forever. The function assert if it detect such a case. |
| */ |
| apr_status_t etch_apr_thread_pool_tasks_cancel(apr_thread_pool_t *me, |
| void *owner); |
| |
| /** |
| * Get the current number of tasks waiting in the queue |
| * @param me The thread pool |
| * @return Number of tasks in the queue |
| */ |
| apr_size_t etch_apr_thread_pool_tasks_count(apr_thread_pool_t *me); |
| |
| /** |
| * Get the current number of scheduled tasks waiting in the queue |
| * @param me The thread pool |
| * @return Number of scheduled tasks in the queue |
| */ |
| apr_size_t etch_apr_thread_pool_scheduled_tasks_count(apr_thread_pool_t *me); |
| |
| /** |
| * Get the current number of threads |
| * @param me The thread pool |
| * @return Total number of threads |
| */ |
| apr_size_t etch_apr_thread_pool_threads_count(apr_thread_pool_t *me); |
| |
| /** |
| * Get the current number of busy threads |
| * @param me The thread pool |
| * @return Number of busy threads |
| */ |
| apr_size_t etch_apr_thread_pool_busy_count(apr_thread_pool_t *me); |
| |
| /** |
| * Get the current number of idle threads |
| * @param me The thread pool |
| * @return Number of idle threads |
| */ |
| apr_size_t etch_apr_thread_pool_idle_count(apr_thread_pool_t *me); |
| |
| /** |
| * Access function for the maximum number of idle threads. Number of current |
| * idle threads will be reduced to the new limit. |
| * @param me The thread pool |
| * @param cnt The number |
| * @return The number of threads that were stopped. |
| */ |
| apr_size_t etch_apr_thread_pool_idle_max_set(apr_thread_pool_t *me, |
| apr_size_t cnt); |
| |
| /** |
| * Get number of tasks that have run |
| * @param me The thread pool |
| * @return Number of tasks that have run |
| */ |
| apr_size_t |
| etch_apr_thread_pool_tasks_run_count(apr_thread_pool_t * me); |
| |
| /** |
| * Get high water mark of the number of tasks waiting to run |
| * @param me The thread pool |
| * @return High water mark of tasks waiting to run |
| */ |
| apr_size_t |
| etch_apr_thread_pool_tasks_high_count(apr_thread_pool_t * me); |
| |
| /** |
| * Get high water mark of the number of threads |
| * @param me The thread pool |
| * @return High water mark of threads in thread pool |
| */ |
| apr_size_t |
| etch_apr_thread_pool_threads_high_count(apr_thread_pool_t * me); |
| |
| /** |
| * Get the number of idle threads that were destroyed after timing out |
| * @param me The thread pool |
| * @return Number of idle threads that timed out |
| */ |
| apr_size_t |
| etch_apr_thread_pool_threads_idle_timeout_count(apr_thread_pool_t * me); |
| |
| /** |
| * Access function for the maximum number of idle threads |
| * @param me The thread pool |
| * @return The current maximum number |
| */ |
| apr_size_t etch_apr_thread_pool_idle_max_get(apr_thread_pool_t *me); |
| |
| /** |
| * Access function for the maximum number of threads. |
| * @param me The thread pool |
| * @param cnt Number of threads |
| * @return The original maximum number of threads |
| */ |
| apr_size_t etch_apr_thread_pool_thread_max_set(apr_thread_pool_t *me, |
| apr_size_t cnt); |
| |
| /** |
| * Access function for the maximum wait time (in microseconds) of an |
| * idling thread that exceeds the maximum number of idling threads. |
| * A non-zero value allows for the reaping of idling threads to shrink |
| * over time. Which helps reduce thrashing. |
| * @param me The thread pool |
| * @param timeout The number of microseconds an idle thread should wait |
| * till it reaps itself |
| * @return The original maximum wait time |
| */ |
| apr_interval_time_t |
| etch_apr_thread_pool_idle_wait_set(apr_thread_pool_t * me, |
| apr_interval_time_t timeout); |
| |
| /** |
| * Access function for the maximum wait time (in microseconds) of an |
| * idling thread that exceeds the maximum number of idling threads |
| * @param me The thread pool |
| * @return The current maximum wait time |
| */ |
| apr_interval_time_t |
| etch_apr_thread_pool_idle_wait_get(apr_thread_pool_t * me); |
| |
| /** |
| * Access function for the maximum number of threads |
| * @param me The thread pool |
| * @return The current maximum number |
| */ |
| apr_size_t etch_apr_thread_pool_thread_max_get(apr_thread_pool_t *me); |
| |
| /** |
| * Access function for the threshold of tasks in queue to trigger a new thread. |
| * @param me The thread pool |
| * @param cnt The new threshold |
| * @return The original threshold |
| */ |
| apr_size_t etch_apr_thread_pool_threshold_set(apr_thread_pool_t *me, |
| apr_size_t val); |
| |
| /** |
| * Access function for the threshold of tasks in queue to trigger a new thread. |
| * @param me The thread pool |
| * @return The current threshold |
| */ |
| apr_size_t etch_apr_thread_pool_threshold_get(apr_thread_pool_t * me); |
| |
| /** |
| * Get owner of the task currently been executed by the thread. |
| * @param thd The thread is executing a task |
| * @param owner Pointer to receive owner of the task. |
| * @return APR_SUCCESS if the owner is retrieved successfully |
| */ |
| apr_status_t etch_apr_thread_pool_task_owner_get(apr_thread_t *thd, |
| void **owner); |
| |
| /** @} */ |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* APR_HAS_THREADS */ |
| #endif /* !APR_THREAD_POOL_H */ |
