gdk_system.c

这个是内存数据库中的一个管理工具

#line 219 "/export/scratch0/monet/monet.GNU.64.64.d.14791/MonetDB/src/gdk/gdk_system.mx"
#include "monetdb_config.h"
#include "gdk.h"

size_t _MT_pagesize = 0;	/* variable holding memory size */
size_t _MT_npages = 0;		/* variable holding page size */

MT_Lock MT_system_lock = PTHREAD_MUTEX_INITIALIZER;

void
MT_init(void)
{
#ifdef HAVE_GETSYSTEMINFO
	{
		SYSTEM_INFO sysInfo;

		GetSystemInfo(&sysInfo);
		_MT_pagesize = sysInfo.dwPageSize;
	}
#else
#if defined(HAVE_SYSCONF) && defined(_SC_PAGESIZE)
	_MT_pagesize = sysconf(_SC_PAGESIZE);
#endif
#endif
	if (_MT_pagesize <= 0)
		_MT_pagesize = 4096;	/* default */

#ifdef HAVE_GLOBALMEMORYSTATUSEX
	{
		MEMORYSTATUSEX memStatEx;

		memStatEx.dwLength = sizeof(memStatEx);
		if (GlobalMemoryStatusEx(&memStatEx))
			_MT_npages = (size_t) (memStatEx.ullTotalPhys / _MT_pagesize);
	}
#endif
#ifdef HAVE_GLOBALMEMORYSTATUS
	if (_MT_npages <= 0) {
		MEMORYSTATUS memStat;

		GlobalMemoryStatus(&memStat);
		_MT_npages = memStat.dwTotalPhys / _MT_pagesize;
	}
#endif
#if defined(HAVE_SYSCONF) && defined(_SC_PHYS_PAGES)
	_MT_npages = sysconf(_SC_PHYS_PAGES);
#else
#ifdef HAVE_GETRLIMIT
	{
		struct rlimit rl;

		getrlimit(RLIMIT_RSS, &rl);
		_MT_npages = rl.rlim_cur / _MT_pagesize;
	}
#endif
#endif
}

#ifdef HAVE_PTHREAD_SIGMASK
void
MT_thread_sigmask(sigset_t * new_mask, sigset_t * orig_mask)
{
	(void) sigdelset(new_mask, SIGQUIT);
	(void) sigdelset(new_mask, SIGALRM);	/* else sleep doesn't work */
	(void) pthread_sigmask(SIG_SETMASK, new_mask, orig_mask);
}
#endif

int
MT_create_thread(MT_Id *t, void (*f) (void *), void *arg)
{
#ifdef HAVE_PTHREAD_SIGMASK
	sigset_t new_mask, orig_mask;
#endif
	pthread_attr_t attr;
	pthread_t newt;
	int ret;

#ifdef HAVE_PTHREAD_SIGMASK
	(void) sigfillset(&new_mask);
	MT_thread_sigmask(&new_mask, &orig_mask);
#endif
	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	pthread_attr_setstacksize(&attr, 4 * THREAD_STACK_SIZE);
	ret = pthread_create(&newt, &attr, (void *(*)(void *)) f, arg);
	if (ret == 0)
#ifdef PTW32
		*t = (MT_Id) (((size_t) newt.p) + 1);	/* use pthread-id + 1 */
#else
		*t = (MT_Id) (((size_t) newt) + 1);	/* use pthread-id + 1 */
#endif
#ifdef HAVE_PTHREAD_SIGMASK
	MT_thread_sigmask(&orig_mask, NULL);
#endif
	return ret;
}

void
MT_global_exit(int s)
{
	exit(s);
}


void
MT_exit_thread(int s)
{
	int st = s;
	pthread_exit(&st);
}


int
MT_kill_thread(MT_Id t)
{
#ifdef HAVE_PTHREAD_KILL
	thread_t id = (thread_t) (t - 1);

	return pthread_kill((pthread_t) id, SIGHUP);
#else
	(void) t;
	return -1;		/* XXX */
#endif
}
#if defined(_AIX) || defined(__APPLE_CC__)
void
pthread_sema_init(pthread_sema_t *s, int flag, int nresources)
{
	(void) flag;
	s->cnt = nresources;
	pthread_mutex_init(&(s->mutex), 0);
	pthread_cond_init(&(s->cond), 0);
}

void
pthread_sema_destroy(pthread_sema_t *s)
{
	pthread_mutex_destroy(&(s->mutex));
	pthread_cond_destroy(&(s->cond));
}

void
pthread_sema_up(pthread_sema_t *s)
{
	int status = pthread_mutex_lock(&(s->mutex));

	if (s->cnt++ < 0) {
		/* wackup sleeping thread */
		status = pthread_cond_signal(&(s->cond));
	}
	status = pthread_mutex_unlock(&(s->mutex));
}

void
pthread_sema_down(pthread_sema_t *s)
{
	int status = pthread_mutex_lock(&(s->mutex));

	if (--s->cnt < 0) {
		/* thread goes to sleep */
		status = pthread_cond_wait(&(s->cond), &(s->mutex));
	}
	status = pthread_mutex_unlock(&(s->mutex));
}
#endif

MT_Id
MT_getpid(void)
{
#ifdef PTW32
	return (MT_Id) (((size_t) pthread_self().p) + 1);
#else
	return (MT_Id) (((size_t) pthread_self()) + 1);
#endif
}

int
MT_alive(int pid)
{
#ifdef HAVE_KILL
	return kill(pid, 0) == 0;
#else
	(void)pid;
	return 0;
#endif
}


#line 406 "/export/scratch0/monet/monet.GNU.64.64.d.14791/MonetDB/src/gdk/gdk_system.mx"