~drizzle-trunk/drizzle/development

/******************************************************

The interface to the operating system 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"

#include "os0sync.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_HPUX10

	/* In HP-UX-10.20 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, or NULL */

{

#ifdef __WIN__

	os_thread_t	thread;

	DWORD		win_thread_id;

	os_mutex_enter(os_sync_mutex);

	os_thread_count++;

	os_mutex_exit(os_sync_mutex);

	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));

	}

	if (thread_id) {

		*thread_id = win_thread_id;

	}

	return(thread);

#else

	int		ret;

	os_thread_t	pthread;

	pthread_attr_t	attr;

#if !(defined(UNIV_HOTBACKUP) && defined(UNIV_HPUX10))

	pthread_attr_init(&attr);

#endif

#ifdef UNIV_AIX

	/* We must make sure a thread stack is at least 32 kB, otherwise

	InnoDB might crash; we do not know if the default stack size on

	AIX is always big enough. An empirical test on AIX-4.3 suggested

	the size was 96 kB, though. */

	ret = pthread_attr_setstacksize(&attr,

					(size_t)(PTHREAD_STACK_MIN

						 + 32 * 1024));

	if (ret) {

		fprintf(stderr,

			"InnoDB: Error: pthread_attr_setstacksize"

			" returned %d\n", ret);

		exit(1);

	}

#endif

#ifdef __NETWARE__

	ret = pthread_attr_setstacksize(&attr,

					(size_t) NW_THD_STACKSIZE);

	if (ret) {

		fprintf(stderr,

			"InnoDB: Error: pthread_attr_setstacksize"

			" returned %d\n", ret);

		exit(1);

	}

#endif

	os_mutex_enter(os_sync_mutex);

	os_thread_count++;

	os_mutex_exit(os_sync_mutex);

#if defined(UNIV_HOTBACKUP) && defined(UNIV_HPUX10)

	ret = pthread_create(&pthread, pthread_attr_default, start_f, arg);

#else

	ret = pthread_create(&pthread, &attr, start_f, arg);

#endif

	if (ret) {

		fprintf(stderr,

			"InnoDB: Error: pthread_create returned %d\n", ret);

		exit(1);

	}

#if !(defined(UNIV_HOTBACKUP) && defined(UNIV_HPUX10))

	pthread_attr_destroy(&attr);

#endif

	if (srv_set_thread_priorities) {

                  struct sched_param tmp_sched_param;

                  memset(&tmp_sched_param, 0, sizeof(tmp_sched_param));

                  tmp_sched_param.sched_priority= srv_query_thread_priority;

                  (void)pthread_setschedparam(pthread, SCHED_OTHER, &tmp_sched_param);

	}

	if (thread_id) {

		*thread_id = pthread;

	}

	return(pthread);

#endif

}

/*********************************************************************

Exits the current thread. */

void

os_thread_exit(

/*===========*/

	void*	exit_value)	/* in: exit value; in Windows this void*

				is cast as a DWORD */

{

#ifdef UNIV_DEBUG_THREAD_CREATION

	fprintf(stderr, "Thread exits, id %lu\n",

		os_thread_pf(os_thread_get_curr_id()));

#endif

	os_mutex_enter(os_sync_mutex);

	os_thread_count--;

	os_mutex_exit(os_sync_mutex);

#ifdef __WIN__

	ExitThread((DWORD)exit_value);

#else

	pthread_exit(exit_value);

#endif

}

#ifdef HAVE_PTHREAD_JOIN

int

os_thread_join(

/*===========*/

  os_thread_id_t  thread_id)	/* in: id of the thread to join */

{

	return(pthread_join(thread_id, NULL));

}

#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((DWORD) tm / 1000);

#elif defined(__NETWARE__)

	delay(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 __attribute__((unused)))

				/* 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

}