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/*****************************************************************************
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Copyright (C) 1995, 2009, Innobase Oy. All Rights Reserved.
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free Software
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Foundation; version 2 of the License.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
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St, Fifth Floor, Boston, MA 02110-1301 USA
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*****************************************************************************/
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/**************************************************//**
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@file include/os0thread.h
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The interface to the operating system
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process and thread control primitives
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Created 9/8/1995 Heikki Tuuri
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*******************************************************/
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/* Maximum number of threads which can be created in the program;
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this is also the size of the wait slot array for MySQL threads which
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can wait inside InnoDB */
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#define OS_THREAD_MAX_N srv_max_n_threads
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/* Possible fixed priorities for threads */
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#define OS_THREAD_PRIORITY_NONE 100
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#define OS_THREAD_PRIORITY_BACKGROUND 1
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#define OS_THREAD_PRIORITY_NORMAL 2
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#define OS_THREAD_PRIORITY_ABOVE_NORMAL 3
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typedef void* os_thread_t;
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typedef unsigned long os_thread_id_t; /*!< In Windows the thread id
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is an unsigned long int */
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typedef pthread_t os_thread_t;
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typedef os_thread_t os_thread_id_t; /*!< In Unix we use the thread
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handle itself as the id of
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/* Define a function pointer type to use in a typecast */
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typedef void* (*os_posix_f_t) (void*);
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#ifdef HAVE_PSI_INTERFACE
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/* Define for performance schema registration key */
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typedef unsigned int mysql_pfs_key_t;
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/***************************************************************//**
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Compares two thread ids for equality.
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@return TRUE if equal */
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os_thread_id_t a, /*!< in: OS thread or thread id */
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os_thread_id_t b); /*!< in: OS thread or thread id */
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/****************************************************************//**
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Converts an OS thread id to a ulint. It is NOT guaranteed that the ulint is
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unique for the thread though!
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@return thread identifier as a number */
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os_thread_id_t a); /*!< in: OS thread identifier */
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/****************************************************************//**
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Creates a new thread of execution. The execution starts from
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the function given. The start function takes a void* parameter
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NOTE: We count the number of threads in os_thread_exit(). A created
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thread should always use that to exit and not use return() to exit.
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@return handle to the thread */
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ulint (*start_f)(void*), /*!< in: pointer to function
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from which to start */
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void* arg, /*!< in: argument to start
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os_thread_id_t* thread_id); /*!< out: id of the created
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/*****************************************************************//**
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Exits the current thread. */
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void* exit_value); /*!< in: exit value; in Windows this void*
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is cast as a DWORD */
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/*****************************************************************//**
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Returns the thread identifier of current thread.
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@return current thread identifier */
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os_thread_get_curr_id(void);
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/*========================*/
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/*****************************************************************//**
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Returns handle to the current thread.
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@return current thread handle */
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os_thread_get_curr(void);
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/*====================*/
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/*****************************************************************//**
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Advises the os to give up remainder of the thread's time slice. */
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os_thread_yield(void);
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/*=================*/
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/*****************************************************************//**
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The thread sleeps at least the time given in microseconds. */
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ulint tm); /*!< in: time in microseconds */
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/******************************************************************//**
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Gets a thread priority.
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os_thread_get_priority(
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/*===================*/
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os_thread_t handle);/*!< in: OS handle to the thread */
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/******************************************************************//**
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Sets a thread priority. */
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os_thread_set_priority(
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/*===================*/
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os_thread_t handle, /*!< in: OS handle to the thread */
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ulint pri); /*!< in: priority: one of OS_PRIORITY_... */
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/******************************************************************//**
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Gets the last operating system error code for the calling thread.
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@return last error on Windows, 0 otherwise */
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os_thread_get_last_error(void);
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/*==========================*/
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#include "os0thread.ic"