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/******************************************************
The interface to the operating system
process and thread control primitives
(c) 1995 Innobase Oy
Created 9/8/1995 Heikki Tuuri
*******************************************************/
#include "os0thread.h"
#ifdef UNIV_NONINL
#include "os0thread.ic"
#endif
#ifdef __WIN__
#include <windows.h>
#endif
#include "srv0srv.h"
/*******************************************************************
Compares two thread ids for equality. */
ibool
os_thread_eq(
/*=========*/
/* out: TRUE if equal */
os_thread_id_t a, /* in: OS thread or thread id */
os_thread_id_t b) /* in: OS thread or thread id */
{
#ifdef __WIN__
if (a == b) {
return(TRUE);
}
return(FALSE);
#else
if (pthread_equal(a, b)) {
return(TRUE);
}
return(FALSE);
#endif
}
/********************************************************************
Converts an OS thread id to a ulint. It is NOT guaranteed that the ulint is
unique for the thread though! */
ulint
os_thread_pf(
/*=========*/
os_thread_id_t a)
{
#ifdef UNIV_HPUX
/* In HP-UX a pthread_t is a struct of 3 fields: field1, field2,
field3. We do not know if field1 determines the thread uniquely. */
return((ulint)(a.field1));
#else
return((ulint)a);
#endif
}
/*********************************************************************
Returns the thread identifier of current thread. Currently the thread
identifier in Unix is the thread handle itself. Note that in HP-UX
pthread_t is a struct of 3 fields. */
os_thread_id_t
os_thread_get_curr_id(void)
/*=======================*/
{
#ifdef __WIN__
return(GetCurrentThreadId());
#else
return(pthread_self());
#endif
}
/********************************************************************
Creates a new thread of execution. The execution starts from
the function given. The start function takes a void* parameter
and returns an ulint. */
os_thread_t
os_thread_create(
/*=============*/
/* out: handle to the thread */
#ifndef __WIN__
os_posix_f_t start_f,
#else
ulint (*start_f)(void*), /* in: pointer to function
from which to start */
#endif
void* arg, /* in: argument to start
function */
os_thread_id_t* thread_id) /* out: id of the created
thread */
{
#ifdef __WIN__
os_thread_t thread;
ulint win_thread_id;
thread = CreateThread(NULL, /* no security attributes */
0, /* default size stack */
(LPTHREAD_START_ROUTINE)start_f,
arg,
0, /* thread runs immediately */
&win_thread_id);
if (srv_set_thread_priorities) {
/* Set created thread priority the same as a normal query
in MYSQL: we try to prevent starvation of threads by
assigning same priority QUERY_PRIOR to all */
ut_a(SetThreadPriority(thread, srv_query_thread_priority));
}
*thread_id = win_thread_id;
return(thread);
#else
int ret;
os_thread_t pthread;
pthread_attr_t attr;
pthread_attr_init(&attr);
ret = pthread_create(&pthread, &attr, start_f, arg);
pthread_attr_destroy(&attr);
if (srv_set_thread_priorities) {
my_pthread_setprio(pthread, srv_query_thread_priority);
}
*thread_id = pthread;
return(pthread);
#endif
}
/*********************************************************************
Returns handle to the current thread. */
os_thread_t
os_thread_get_curr(void)
/*====================*/
{
#ifdef __WIN__
return(GetCurrentThread());
#else
return(pthread_self());
#endif
}
/*********************************************************************
Advises the os to give up remainder of the thread's time slice. */
void
os_thread_yield(void)
/*=================*/
{
#if defined(__WIN__)
Sleep(0);
#elif (defined(HAVE_SCHED_YIELD) && defined(HAVE_SCHED_H))
sched_yield();
#elif defined(HAVE_PTHREAD_YIELD_ZERO_ARG)
pthread_yield();
#elif defined(HAVE_PTHREAD_YIELD_ONE_ARG)
pthread_yield(0);
#else
os_thread_sleep(0);
#endif
}
/*********************************************************************
The thread sleeps at least the time given in microseconds. */
void
os_thread_sleep(
/*============*/
ulint tm) /* in: time in microseconds */
{
#ifdef __WIN__
Sleep(tm / 1000);
#else
struct timeval t;
t.tv_sec = tm / 1000000;
t.tv_usec = tm % 1000000;
select(0, NULL, NULL, NULL, &t);
#endif
}
/**********************************************************************
Sets a thread priority. */
void
os_thread_set_priority(
/*===================*/
os_thread_t handle, /* in: OS handle to the thread */
ulint pri) /* in: priority */
{
#ifdef __WIN__
int os_pri;
if (pri == OS_THREAD_PRIORITY_BACKGROUND) {
os_pri = THREAD_PRIORITY_BELOW_NORMAL;
} else if (pri == OS_THREAD_PRIORITY_NORMAL) {
os_pri = THREAD_PRIORITY_NORMAL;
} else if (pri == OS_THREAD_PRIORITY_ABOVE_NORMAL) {
os_pri = THREAD_PRIORITY_HIGHEST;
} else {
ut_error;
}
ut_a(SetThreadPriority(handle, os_pri));
#else
UT_NOT_USED(handle);
UT_NOT_USED(pri);
#endif
}
/**********************************************************************
Gets a thread priority. */
ulint
os_thread_get_priority(
/*===================*/
/* out: priority */
os_thread_t handle) /* in: OS handle to the thread */
{
#ifdef __WIN__
int os_pri;
ulint pri;
os_pri = GetThreadPriority(handle);
if (os_pri == THREAD_PRIORITY_BELOW_NORMAL) {
pri = OS_THREAD_PRIORITY_BACKGROUND;
} else if (os_pri == THREAD_PRIORITY_NORMAL) {
pri = OS_THREAD_PRIORITY_NORMAL;
} else if (os_pri == THREAD_PRIORITY_HIGHEST) {
pri = OS_THREAD_PRIORITY_ABOVE_NORMAL;
} else {
ut_error;
}
return(pri);
#else
return(0);
#endif
}
/**********************************************************************
Gets the last operating system error code for the calling thread. */
ulint
os_thread_get_last_error(void)
/*==========================*/
{
#ifdef __WIN__
return(GetLastError());
#else
return(0);
#endif
}
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