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+/******************************************************
+The wait array used in synchronization primitives
+
+(c) 1995 Innobase Oy
+
+Created 9/5/1995 Heikki Tuuri
+*******************************************************/
+
+#ifndef sync0arr_h
+#define sync0arr_h
+
+#include "univ.i"
+#include "ut0lst.h"
+#include "ut0mem.h"
+#include "os0thread.h"
+
+typedef struct sync_cell_struct sync_cell_t;
+typedef struct sync_array_struct sync_array_t;
+
+#define SYNC_ARRAY_OS_MUTEX 1
+#define SYNC_ARRAY_MUTEX 2
+
+/***********************************************************************
+Creates a synchronization wait array. It is protected by a mutex
+which is automatically reserved when the functions operating on it
+are called. */
+
+sync_array_t*
+sync_array_create(
+/*==============*/
+ /* out, own: created wait array */
+ ulint n_cells, /* in: number of cells in the array
+ to create */
+ ulint protection); /* in: either SYNC_ARRAY_OS_MUTEX or
+ SYNC_ARRAY_MUTEX: determines the type
+ of mutex protecting the data structure */
+/**********************************************************************
+Frees the resources in a wait array. */
+
+void
+sync_array_free(
+/*============*/
+ sync_array_t* arr); /* in, own: sync wait array */
+/**********************************************************************
+Reserves a wait array cell for waiting for an object.
+The event of the cell is reset to nonsignalled state. */
+
+void
+sync_array_reserve_cell(
+/*====================*/
+ sync_array_t* arr, /* in: wait array */
+ void* object, /* in: pointer to the object to wait for */
+ ulint type, /* in: lock request type */
+ const char* file, /* in: file where requested */
+ ulint line, /* in: line where requested */
+ ulint* index); /* out: index of the reserved cell */
+/**********************************************************************
+This function should be called when a thread starts to wait on
+a wait array cell. In the debug version this function checks
+if the wait for a semaphore will result in a deadlock, in which
+case prints info and asserts. */
+
+void
+sync_array_wait_event(
+/*==================*/
+ sync_array_t* arr, /* in: wait array */
+ ulint index); /* in: index of the reserved cell */
+/**********************************************************************
+Frees the cell. NOTE! sync_array_wait_event frees the cell
+automatically! */
+
+void
+sync_array_free_cell(
+/*=================*/
+ sync_array_t* arr, /* in: wait array */
+ ulint index); /* in: index of the cell in array */
+/**************************************************************************
+Looks for the cells in the wait array which refer
+to the wait object specified,
+and sets their corresponding events to the signaled state. In this
+way releases the threads waiting for the object to contend for the object.
+It is possible that no such cell is found, in which case does nothing. */
+
+void
+sync_array_signal_object(
+/*=====================*/
+ sync_array_t* arr, /* in: wait array */
+ void* object);/* in: wait object */
+/**************************************************************************
+If the wakeup algorithm does not work perfectly at semaphore relases,
+this function will do the waking (see the comment in mutex_exit). This
+function should be called about every 1 second in the server. */
+
+void
+sync_arr_wake_threads_if_sema_free(void);
+/*====================================*/
+/**************************************************************************
+Prints warnings of long semaphore waits to stderr. */
+
+ibool
+sync_array_print_long_waits(void);
+/*=============================*/
+ /* out: TRUE if fatal semaphore wait threshold
+ was exceeded */
+/************************************************************************
+Validates the integrity of the wait array. Checks
+that the number of reserved cells equals the count variable. */
+
+void
+sync_array_validate(
+/*================*/
+ sync_array_t* arr); /* in: sync wait array */
+/**************************************************************************
+Prints info of the wait array. */
+
+void
+sync_array_print_info(
+/*==================*/
+ FILE* file, /* in: file where to print */
+ sync_array_t* arr); /* in: wait array */
+
+
+#ifndef UNIV_NONINL
+#include "sync0arr.ic"
+#endif
+
+#endif