src/Unix/timer_unix.cpp

/*
 *  timer_unix.cpp - Time Manager emulation, Unix specific stuff
 *
 *  Basilisk II (C) 1997-2008 Christian Bauer
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "sysdeps.h"
#include "macos_util.h"
#include "timer.h"

#include <errno.h>

#define DEBUG 0
#include "debug.h"

// For NetBSD with broken pthreads headers
#ifndef CLOCK_REALTIME
#define CLOCK_REALTIME 0
#endif

#if defined(__MACH__)
#include <mach/mach.h>
#include <mach/clock.h>

static clock_serv_t host_clock;
static bool host_clock_inited = false;

static inline void mach_current_time(tm_time_t &t) {
        if(!host_clock_inited) {
                host_get_clock_service(mach_host_self(), SYSTEM_CLOCK, &host_clock);
                host_clock_inited = true;
        }
        
        clock_get_time(host_clock, &t);
}
#endif


/*
 *  Return microseconds since boot (64 bit)
 */

void Microseconds(uint32 &hi, uint32 &lo)
{
        D(bug("Microseconds\n"));
#if defined(HAVE_CLOCK_GETTIME)
        struct timespec t;
        clock_gettime(CLOCK_REALTIME, &t);
        uint64 tl = (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
#elif defined(__MACH__)
        tm_time_t t;
        mach_current_time(t);
        uint64 tl = (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
#else
        struct timeval t;
        gettimeofday(&t, NULL);
        uint64 tl = (uint64)t.tv_sec * 1000000 + t.tv_usec;
#endif
        hi = tl >> 32;
        lo = tl;
}


/*
 *  Return local date/time in Mac format (seconds since 1.1.1904)
 */

uint32 TimerDateTime(void)
{
        return TimeToMacTime(time(NULL));
}


/*
 *  Get current time
 */

void timer_current_time(tm_time_t &t)
{
#ifdef HAVE_CLOCK_GETTIME
        clock_gettime(CLOCK_REALTIME, &t);
#elif defined(__MACH__)
        mach_current_time(t);
#else
        gettimeofday(&t, NULL);
#endif
}


/*
 *  Add times
 */

void timer_add_time(tm_time_t &res, tm_time_t a, tm_time_t b)
{
#if defined(HAVE_CLOCK_GETTIME) || defined(__MACH__)
        res.tv_sec = a.tv_sec + b.tv_sec;
        res.tv_nsec = a.tv_nsec + b.tv_nsec;
        if (res.tv_nsec >= 1000000000) {
                res.tv_sec++;
                res.tv_nsec -= 1000000000;
        }
#else
        res.tv_sec = a.tv_sec + b.tv_sec;
        res.tv_usec = a.tv_usec + b.tv_usec;
        if (res.tv_usec >= 1000000) {
                res.tv_sec++;
                res.tv_usec -= 1000000;
        }
#endif
}


/*
 *  Subtract times
 */

void timer_sub_time(tm_time_t &res, tm_time_t a, tm_time_t b)
{
#if defined(HAVE_CLOCK_GETTIME) || defined(__MACH__)
        res.tv_sec = a.tv_sec - b.tv_sec;
        res.tv_nsec = a.tv_nsec - b.tv_nsec;
        if (res.tv_nsec < 0) {
                res.tv_sec--;
                res.tv_nsec += 1000000000;
        }
#else
        res.tv_sec = a.tv_sec - b.tv_sec;
        res.tv_usec = a.tv_usec - b.tv_usec;
        if (res.tv_usec < 0) {
                res.tv_sec--;
                res.tv_usec += 1000000;
        }
#endif
}


/*
 *  Compare times (<0: a < b, =0: a = b, >0: a > b)
 */

int timer_cmp_time(tm_time_t a, tm_time_t b)
{
#if defined(HAVE_CLOCK_GETTIME) || defined(__MACH__)
        if (a.tv_sec == b.tv_sec)
                return a.tv_nsec - b.tv_nsec;
        else
                return a.tv_sec - b.tv_sec;
#else
        if (a.tv_sec == b.tv_sec)
                return a.tv_usec - b.tv_usec;
        else
                return a.tv_sec - b.tv_sec;
#endif
}


/*
 *  Convert Mac time value (>0: microseconds, <0: microseconds) to tm_time_t
 */

void timer_mac2host_time(tm_time_t &res, int32 mactime)
{
#if defined(HAVE_CLOCK_GETTIME) || defined(__MACH__)
        if (mactime > 0) {
                // Time in milliseconds
                res.tv_sec = mactime / 1000;
                res.tv_nsec = (mactime % 1000) * 1000000;
        } else {
                // Time in negative microseconds
                res.tv_sec = -mactime / 1000000;
                res.tv_nsec = (-mactime % 1000000) * 1000;
        }
#else
        if (mactime > 0) {
                // Time in milliseconds
                res.tv_sec = mactime / 1000;
                res.tv_usec = (mactime % 1000) * 1000;
        } else {
                // Time in negative microseconds
                res.tv_sec = -mactime / 1000000;
                res.tv_usec = -mactime % 1000000;
        }
#endif
}


/*
 *  Convert positive tm_time_t to Mac time value (>0: microseconds, <0: microseconds)
 *  A negative input value for hosttime results in a zero return value
 *  As long as the microseconds value fits in 32 bit, it must not be converted to milliseconds!
 */

int32 timer_host2mac_time(tm_time_t hosttime)
{
        if (hosttime.tv_sec < 0)
                return 0;
        else {
#if defined(HAVE_CLOCK_GETTIME) || defined(__MACH__)
                uint64 t = (uint64)hosttime.tv_sec * 1000000 + hosttime.tv_nsec / 1000;
#else
                uint64 t = (uint64)hosttime.tv_sec * 1000000 + hosttime.tv_usec;
#endif
                if (t > 0x7fffffff)
                        return t / 1000;        // Time in milliseconds
                else
                        return -t;                      // Time in negative microseconds
        }
}


/*
 *  Get current value of microsecond timer
 */

uint64 GetTicks_usec(void)
{
#ifdef HAVE_CLOCK_GETTIME
        struct timespec t;
        clock_gettime(CLOCK_REALTIME, &t);
        return (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
#elif defined(__MACH__)
        tm_time_t t;
        mach_current_time(t);
        return (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
#else
        struct timeval t;
        gettimeofday(&t, NULL);
        return (uint64)t.tv_sec * 1000000 + t.tv_usec;
#endif
}


/*
 *  Delay by specified number of microseconds (<1 second)
 *  (adapted from SDL_Delay() source; this function is designed to provide
 *  the highest accuracy possible)
 */

#if defined(linux)
// Linux select() changes its timeout parameter upon return to contain
// the remaining time. Most other unixen leave it unchanged or undefined.
#define SELECT_SETS_REMAINING
#elif defined(__FreeBSD__) || defined(__sun__) || (defined(__MACH__) && defined(__APPLE__))
#define USE_NANOSLEEP
#elif defined(HAVE_PTHREADS) && defined(sgi)
// SGI pthreads has a bug when using pthreads+signals+nanosleep,
// so instead of using nanosleep, wait on a CV which is never signalled.
#include <pthread.h>
#define USE_COND_TIMEDWAIT
#endif

void Delay_usec(uint32 usec)
{
        int was_error;

#if defined(USE_NANOSLEEP)
        struct timespec elapsed, tv;
#elif defined(USE_COND_TIMEDWAIT)
        // Use a local mutex and cv, so threads remain independent
        pthread_cond_t delay_cond = PTHREAD_COND_INITIALIZER;
        pthread_mutex_t delay_mutex = PTHREAD_MUTEX_INITIALIZER;
        struct timespec elapsed;
        uint64 future;
#else
        struct timeval tv;
#ifndef SELECT_SETS_REMAINING
        uint64 then, now, elapsed;
#endif
#endif

        // Set the timeout interval - Linux only needs to do this once
#if defined(SELECT_SETS_REMAINING)
    tv.tv_sec = 0;
    tv.tv_usec = usec;
#elif defined(USE_NANOSLEEP)
    elapsed.tv_sec = 0;
    elapsed.tv_nsec = usec * 1000;
#elif defined(USE_COND_TIMEDWAIT)
        future = GetTicks_usec() + usec;
        elapsed.tv_sec = future / 1000000;
        elapsed.tv_nsec = (future % 1000000) * 1000;
#else
    then = GetTicks_usec();
#endif

        do {
                errno = 0;
#if defined(USE_NANOSLEEP)
                tv.tv_sec = elapsed.tv_sec;
                tv.tv_nsec = elapsed.tv_nsec;
                was_error = nanosleep(&tv, &elapsed);
#elif defined(USE_COND_TIMEDWAIT)
                was_error = pthread_mutex_lock(&delay_mutex);
                was_error = pthread_cond_timedwait(&delay_cond, &delay_mutex, &elapsed);
                was_error = pthread_mutex_unlock(&delay_mutex);
#else
#ifndef SELECT_SETS_REMAINING
                // Calculate the time interval left (in case of interrupt)
                now = GetTicks_usec();
                elapsed = now - then;
                then = now;
                if (elapsed >= usec)
                        break;
                usec -= elapsed;
                tv.tv_sec = 0;
                tv.tv_usec = usec;
#endif
                was_error = select(0, NULL, NULL, NULL, &tv);
#endif
        } while (was_error && (errno == EINTR));
}


/*
 *  Suspend emulator thread, virtual CPU in idle mode
 */

#ifdef HAVE_PTHREADS
#if defined(HAVE_PTHREAD_COND_INIT)
#define IDLE_USES_COND_WAIT 1
static pthread_mutex_t idle_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t idle_cond = PTHREAD_COND_INITIALIZER;
#elif defined(HAVE_SEM_INIT)
#define IDLE_USES_SEMAPHORE 1
#include <semaphore.h>
#ifdef HAVE_SPINLOCKS
static spinlock_t idle_lock = SPIN_LOCK_UNLOCKED;
#define LOCK_IDLE spin_lock(&idle_lock)
#define UNLOCK_IDLE spin_unlock(&idle_lock)
#else
static pthread_mutex_t idle_lock = PTHREAD_MUTEX_INITIALIZER;
#define LOCK_IDLE pthread_mutex_lock(&idle_lock)
#define UNLOCK_IDLE pthread_mutex_unlock(&idle_lock)
#endif
static sem_t idle_sem;
static int idle_sem_ok = -1;
#endif
#endif

void idle_wait(void)
{
#ifdef IDLE_USES_COND_WAIT
        pthread_mutex_lock(&idle_lock);
        pthread_cond_wait(&idle_cond, &idle_lock);
        pthread_mutex_unlock(&idle_lock);
#else
#ifdef IDLE_USES_SEMAPHORE
        LOCK_IDLE;
        if (idle_sem_ok < 0)
                idle_sem_ok = (sem_init(&idle_sem, 0, 0) == 0);
        if (idle_sem_ok > 0) {
                idle_sem_ok++;
                UNLOCK_IDLE;
                sem_wait(&idle_sem);
                return;
        }
        UNLOCK_IDLE;
#endif

        // Fallback: sleep 10 ms
        Delay_usec(10000);
#endif
}


/*
 *  Resume execution of emulator thread, events just arrived
 */

void idle_resume(void)
{
#ifdef IDLE_USES_COND_WAIT
        pthread_cond_signal(&idle_cond);
#else
#ifdef IDLE_USES_SEMAPHORE
        LOCK_IDLE;
        if (idle_sem_ok > 1) {
                idle_sem_ok--;
                UNLOCK_IDLE;
                sem_post(&idle_sem);
                return;
        }
        UNLOCK_IDLE;
#endif
#endif
}
Revision:	1.22
Committed:	2009-08-21T17:39:58Z (15 years, 3 months ago) by asvitkine
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.21:	+1 -1 lines
Log Message:	Change #include <mach/mach_host.h> to #include <mach/mach.h>
#	Content
1	/*
2	* timer_unix.cpp - Time Manager emulation, Unix specific stuff
3	*
4	* Basilisk II (C) 1997-2008 Christian Bauer
5	*
6	* This program is free software; you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation; either version 2 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program; if not, write to the Free Software
18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19	*/
20
21	#include "sysdeps.h"
22	#include "macos_util.h"
23	#include "timer.h"
24
25	#include <errno.h>
26
27	#define DEBUG 0
28	#include "debug.h"
29
30	// For NetBSD with broken pthreads headers
31	#ifndef CLOCK_REALTIME
32	#define CLOCK_REALTIME 0
33	#endif
34
35	#if defined(__MACH__)
36	#include <mach/mach.h>
37	#include <mach/clock.h>
38
39	static clock_serv_t host_clock;
40	static bool host_clock_inited = false;
41
42	static inline void mach_current_time(tm_time_t &t) {
43	if(!host_clock_inited) {
44	host_get_clock_service(mach_host_self(), SYSTEM_CLOCK, &host_clock);
45	host_clock_inited = true;
46	}
47
48	clock_get_time(host_clock, &t);
49	}
50	#endif
51
52
53	/*
54	* Return microseconds since boot (64 bit)
55	*/
56
57	void Microseconds(uint32 &hi, uint32 &lo)
58	{
59	D(bug("Microseconds\n"));
60	#if defined(HAVE_CLOCK_GETTIME)
61	struct timespec t;
62	clock_gettime(CLOCK_REALTIME, &t);
63	uint64 tl = (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
64	#elif defined(__MACH__)
65	tm_time_t t;
66	mach_current_time(t);
67	uint64 tl = (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
68	#else
69	struct timeval t;
70	gettimeofday(&t, NULL);
71	uint64 tl = (uint64)t.tv_sec * 1000000 + t.tv_usec;
72	#endif
73	hi = tl >> 32;
74	lo = tl;
75	}
76
77
78	/*
79	* Return local date/time in Mac format (seconds since 1.1.1904)
80	*/
81
82	uint32 TimerDateTime(void)
83	{
84	return TimeToMacTime(time(NULL));
85	}
86
87
88	/*
89	* Get current time
90	*/
91
92	void timer_current_time(tm_time_t &t)
93	{
94	#ifdef HAVE_CLOCK_GETTIME
95	clock_gettime(CLOCK_REALTIME, &t);
96	#elif defined(__MACH__)
97	mach_current_time(t);
98	#else
99	gettimeofday(&t, NULL);
100	#endif
101	}
102
103
104	/*
105	* Add times
106	*/
107
108	void timer_add_time(tm_time_t &res, tm_time_t a, tm_time_t b)
109	{
110	#if defined(HAVE_CLOCK_GETTIME) \|\| defined(__MACH__)
111	res.tv_sec = a.tv_sec + b.tv_sec;
112	res.tv_nsec = a.tv_nsec + b.tv_nsec;
113	if (res.tv_nsec >= 1000000000) {
114	res.tv_sec++;
115	res.tv_nsec -= 1000000000;
116	}
117	#else
118	res.tv_sec = a.tv_sec + b.tv_sec;
119	res.tv_usec = a.tv_usec + b.tv_usec;
120	if (res.tv_usec >= 1000000) {
121	res.tv_sec++;
122	res.tv_usec -= 1000000;
123	}
124	#endif
125	}
126
127
128	/*
129	* Subtract times
130	*/
131
132	void timer_sub_time(tm_time_t &res, tm_time_t a, tm_time_t b)
133	{
134	#if defined(HAVE_CLOCK_GETTIME) \|\| defined(__MACH__)
135	res.tv_sec = a.tv_sec - b.tv_sec;
136	res.tv_nsec = a.tv_nsec - b.tv_nsec;
137	if (res.tv_nsec < 0) {
138	res.tv_sec--;
139	res.tv_nsec += 1000000000;
140	}
141	#else
142	res.tv_sec = a.tv_sec - b.tv_sec;
143	res.tv_usec = a.tv_usec - b.tv_usec;
144	if (res.tv_usec < 0) {
145	res.tv_sec--;
146	res.tv_usec += 1000000;
147	}
148	#endif
149	}
150
151
152	/*
153	* Compare times (<0: a < b, =0: a = b, >0: a > b)
154	*/
155
156	int timer_cmp_time(tm_time_t a, tm_time_t b)
157	{
158	#if defined(HAVE_CLOCK_GETTIME) \|\| defined(__MACH__)
159	if (a.tv_sec == b.tv_sec)
160	return a.tv_nsec - b.tv_nsec;
161	else
162	return a.tv_sec - b.tv_sec;
163	#else
164	if (a.tv_sec == b.tv_sec)
165	return a.tv_usec - b.tv_usec;
166	else
167	return a.tv_sec - b.tv_sec;
168	#endif
169	}
170
171
172	/*
173	* Convert Mac time value (>0: microseconds, <0: microseconds) to tm_time_t
174	*/
175
176	void timer_mac2host_time(tm_time_t &res, int32 mactime)
177	{
178	#if defined(HAVE_CLOCK_GETTIME) \|\| defined(__MACH__)
179	if (mactime > 0) {
180	// Time in milliseconds
181	res.tv_sec = mactime / 1000;
182	res.tv_nsec = (mactime % 1000) * 1000000;
183	} else {
184	// Time in negative microseconds
185	res.tv_sec = -mactime / 1000000;
186	res.tv_nsec = (-mactime % 1000000) * 1000;
187	}
188	#else
189	if (mactime > 0) {
190	// Time in milliseconds
191	res.tv_sec = mactime / 1000;
192	res.tv_usec = (mactime % 1000) * 1000;
193	} else {
194	// Time in negative microseconds
195	res.tv_sec = -mactime / 1000000;
196	res.tv_usec = -mactime % 1000000;
197	}
198	#endif
199	}
200
201
202	/*
203	* Convert positive tm_time_t to Mac time value (>0: microseconds, <0: microseconds)
204	* A negative input value for hosttime results in a zero return value
205	* As long as the microseconds value fits in 32 bit, it must not be converted to milliseconds!
206	*/
207
208	int32 timer_host2mac_time(tm_time_t hosttime)
209	{
210	if (hosttime.tv_sec < 0)
211	return 0;
212	else {
213	#if defined(HAVE_CLOCK_GETTIME) \|\| defined(__MACH__)
214	uint64 t = (uint64)hosttime.tv_sec * 1000000 + hosttime.tv_nsec / 1000;
215	#else
216	uint64 t = (uint64)hosttime.tv_sec * 1000000 + hosttime.tv_usec;
217	#endif
218	if (t > 0x7fffffff)
219	return t / 1000; // Time in milliseconds
220	else
221	return -t; // Time in negative microseconds
222	}
223	}
224
225
226	/*
227	* Get current value of microsecond timer
228	*/
229
230	uint64 GetTicks_usec(void)
231	{
232	#ifdef HAVE_CLOCK_GETTIME
233	struct timespec t;
234	clock_gettime(CLOCK_REALTIME, &t);
235	return (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
236	#elif defined(__MACH__)
237	tm_time_t t;
238	mach_current_time(t);
239	return (uint64)t.tv_sec * 1000000 + t.tv_nsec / 1000;
240	#else
241	struct timeval t;
242	gettimeofday(&t, NULL);
243	return (uint64)t.tv_sec * 1000000 + t.tv_usec;
244	#endif
245	}
246
247
248	/*
249	* Delay by specified number of microseconds (<1 second)
250	* (adapted from SDL_Delay() source; this function is designed to provide
251	* the highest accuracy possible)
252	*/
253
254	#if defined(linux)
255	// Linux select() changes its timeout parameter upon return to contain
256	// the remaining time. Most other unixen leave it unchanged or undefined.
257	#define SELECT_SETS_REMAINING
258	#elif defined(__FreeBSD__) \|\| defined(__sun__) \|\| (defined(__MACH__) && defined(__APPLE__))
259	#define USE_NANOSLEEP
260	#elif defined(HAVE_PTHREADS) && defined(sgi)
261	// SGI pthreads has a bug when using pthreads+signals+nanosleep,
262	// so instead of using nanosleep, wait on a CV which is never signalled.
263	#include <pthread.h>
264	#define USE_COND_TIMEDWAIT
265	#endif
266
267	void Delay_usec(uint32 usec)
268	{
269	int was_error;
270
271	#if defined(USE_NANOSLEEP)
272	struct timespec elapsed, tv;
273	#elif defined(USE_COND_TIMEDWAIT)
274	// Use a local mutex and cv, so threads remain independent
275	pthread_cond_t delay_cond = PTHREAD_COND_INITIALIZER;
276	pthread_mutex_t delay_mutex = PTHREAD_MUTEX_INITIALIZER;
277	struct timespec elapsed;
278	uint64 future;
279	#else
280	struct timeval tv;
281	#ifndef SELECT_SETS_REMAINING
282	uint64 then, now, elapsed;
283	#endif
284	#endif
285
286	// Set the timeout interval - Linux only needs to do this once
287	#if defined(SELECT_SETS_REMAINING)
288	tv.tv_sec = 0;
289	tv.tv_usec = usec;
290	#elif defined(USE_NANOSLEEP)
291	elapsed.tv_sec = 0;
292	elapsed.tv_nsec = usec * 1000;
293	#elif defined(USE_COND_TIMEDWAIT)
294	future = GetTicks_usec() + usec;
295	elapsed.tv_sec = future / 1000000;
296	elapsed.tv_nsec = (future % 1000000) * 1000;
297	#else
298	then = GetTicks_usec();
299	#endif
300
301	do {
302	errno = 0;
303	#if defined(USE_NANOSLEEP)
304	tv.tv_sec = elapsed.tv_sec;
305	tv.tv_nsec = elapsed.tv_nsec;
306	was_error = nanosleep(&tv, &elapsed);
307	#elif defined(USE_COND_TIMEDWAIT)
308	was_error = pthread_mutex_lock(&delay_mutex);
309	was_error = pthread_cond_timedwait(&delay_cond, &delay_mutex, &elapsed);
310	was_error = pthread_mutex_unlock(&delay_mutex);
311	#else
312	#ifndef SELECT_SETS_REMAINING
313	// Calculate the time interval left (in case of interrupt)
314	now = GetTicks_usec();
315	elapsed = now - then;
316	then = now;
317	if (elapsed >= usec)
318	break;
319	usec -= elapsed;
320	tv.tv_sec = 0;
321	tv.tv_usec = usec;
322	#endif
323	was_error = select(0, NULL, NULL, NULL, &tv);
324	#endif
325	} while (was_error && (errno == EINTR));
326	}
327
328
329	/*
330	* Suspend emulator thread, virtual CPU in idle mode
331	*/
332
333	#ifdef HAVE_PTHREADS
334	#if defined(HAVE_PTHREAD_COND_INIT)
335	#define IDLE_USES_COND_WAIT 1
336	static pthread_mutex_t idle_lock = PTHREAD_MUTEX_INITIALIZER;
337	static pthread_cond_t idle_cond = PTHREAD_COND_INITIALIZER;
338	#elif defined(HAVE_SEM_INIT)
339	#define IDLE_USES_SEMAPHORE 1
340	#include <semaphore.h>
341	#ifdef HAVE_SPINLOCKS
342	static spinlock_t idle_lock = SPIN_LOCK_UNLOCKED;
343	#define LOCK_IDLE spin_lock(&idle_lock)
344	#define UNLOCK_IDLE spin_unlock(&idle_lock)
345	#else
346	static pthread_mutex_t idle_lock = PTHREAD_MUTEX_INITIALIZER;
347	#define LOCK_IDLE pthread_mutex_lock(&idle_lock)
348	#define UNLOCK_IDLE pthread_mutex_unlock(&idle_lock)
349	#endif
350	static sem_t idle_sem;
351	static int idle_sem_ok = -1;
352	#endif
353	#endif
354
355	void idle_wait(void)
356	{
357	#ifdef IDLE_USES_COND_WAIT
358	pthread_mutex_lock(&idle_lock);
359	pthread_cond_wait(&idle_cond, &idle_lock);
360	pthread_mutex_unlock(&idle_lock);
361	#else
362	#ifdef IDLE_USES_SEMAPHORE
363	LOCK_IDLE;
364	if (idle_sem_ok < 0)
365	idle_sem_ok = (sem_init(&idle_sem, 0, 0) == 0);
366	if (idle_sem_ok > 0) {
367	idle_sem_ok++;
368	UNLOCK_IDLE;
369	sem_wait(&idle_sem);
370	return;
371	}
372	UNLOCK_IDLE;
373	#endif
374
375	// Fallback: sleep 10 ms
376	Delay_usec(10000);
377	#endif
378	}
379
380
381	/*
382	* Resume execution of emulator thread, events just arrived
383	*/
384
385	void idle_resume(void)
386	{
387	#ifdef IDLE_USES_COND_WAIT
388	pthread_cond_signal(&idle_cond);
389	#else
390	#ifdef IDLE_USES_SEMAPHORE
391	LOCK_IDLE;
392	if (idle_sem_ok > 1) {
393	idle_sem_ok--;
394	UNLOCK_IDLE;
395	sem_post(&idle_sem);
396	return;
397	}
398	UNLOCK_IDLE;
399	#endif
400	#endif
401	}