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by brian
clean slate |
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/******************************************************
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Server query execution
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(c) 1996 Innobase Oy
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Created 6/5/1996 Heikki Tuuri
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*******************************************************/
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#include "srv0que.h" |
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#include "srv0srv.h" |
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#include "sync0sync.h" |
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#include "os0thread.h" |
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#include "usr0sess.h" |
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#include "que0que.h" |
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/**************************************************************************
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Checks if there is work to do in the server task queue. If there is, the
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thread starts processing a task. Before leaving, it again checks the task
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queue and picks a new task if any exists. This is called by a SRV_WORKER
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thread. */
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void
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srv_que_task_queue_check(void) |
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/*==========================*/
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{
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que_thr_t* thr; |
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for (;;) { |
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mutex_enter(&kernel_mutex); |
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thr = UT_LIST_GET_FIRST(srv_sys->tasks); |
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if (thr == NULL) { |
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mutex_exit(&kernel_mutex); |
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return; |
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}
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UT_LIST_REMOVE(queue, srv_sys->tasks, thr); |
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mutex_exit(&kernel_mutex); |
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que_run_threads(thr); |
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}
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}
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/**************************************************************************
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Performs round-robin on the server tasks. This is called by a SRV_WORKER
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thread every second or so. */
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que_thr_t* |
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srv_que_round_robin( |
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/*================*/
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/* out: the new (may be == thr) query thread |
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to run */ |
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que_thr_t* thr) /* in: query thread */ |
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{
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que_thr_t* new_thr; |
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ut_ad(thr); |
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ut_ad(thr->state == QUE_THR_RUNNING); |
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mutex_enter(&kernel_mutex); |
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UT_LIST_ADD_LAST(queue, srv_sys->tasks, thr); |
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new_thr = UT_LIST_GET_FIRST(srv_sys->tasks); |
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mutex_exit(&kernel_mutex); |
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return(new_thr); |
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}
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/**************************************************************************
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Enqueues a task to server task queue and releases a worker thread, if there
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is a suspended one. */
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void
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srv_que_task_enqueue_low( |
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/*=====================*/
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que_thr_t* thr) /* in: query thread */ |
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{
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ut_ad(thr); |
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ut_ad(mutex_own(&kernel_mutex)); |
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UT_LIST_ADD_LAST(queue, srv_sys->tasks, thr); |
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srv_release_threads(SRV_WORKER, 1); |
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}
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/**************************************************************************
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Enqueues a task to server task queue and releases a worker thread, if there
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is a suspended one. */
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void
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srv_que_task_enqueue( |
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/*=================*/
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que_thr_t* thr) /* in: query thread */ |
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{
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ut_ad(thr); |
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ut_a(0); /* Under MySQL this is never called */ |
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mutex_enter(&kernel_mutex); |
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srv_que_task_enqueue_low(thr); |
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mutex_exit(&kernel_mutex); |
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}
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