os0thread.c 7.57 KB
Newer Older
osku's avatar
osku committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342
/******************************************************
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 */
{
#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));
	}

	*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
	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) {
	
	        my_pthread_setprio(pthread, srv_query_thread_priority);
	}

	*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
}