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