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_host.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:	1.21
Committed:	2009-08-17T20:42:26Z (15 years, 3 months ago) by asvitkine
Branch:	MAIN
Changes since 1.20:	+33 -6 lines
Log Message:	[Charles Srstka] Attached is a set of patches to port the precise timer that is currently used in the Linux and BeOS builds of SheepShaver to Mac OS X (and any other Mach-based operating systems). Currently, the Linux build uses the clock_gettime() function to get nanosecond-precision time, and falls back on gettimeofday() if it is not present. Unfortunately, Mac OS X does not currently support clock_gettime(), and gettimeofday() has only microsecond granularity. The Mach kernel, however, has a clock_get_time() function that does very nearly the same thing as clock_gettime(). The patches to BasiliskII cause the timing functions such as timer_current_time() to use clock_get_time() instead of gettimeofday() on Mach-based systems that do not support clock_gettime(). The changes to SheepShaver involve the precise timer. The existing code for Linux uses pthreads and real-time signals to handle the timing. Mac OS X unfortunately does not seem to support real-time signals, so Mach calls are again used to suspend and resume the timer thread in order to attempt to duplicate the Linux and BeOS versions of the timer. The code is somewhat ugly right now, as I decided to leave alone the pre-existing style of the source file, which unfortunately involves #ifdefs scattered throughout the file and some duplication of code. A future patch may want to clean this up to separate out the OS-specific code and put it all together at the top of the file. However, for the time being, this seems to work. This has not been extensively tested, because I have not been able to get my hands on a good test-case app for the classic Mac OS that would run inside the emulator and try out the timer. However, performance does seem to be better than with the pre-existing code, and nothing seems to have blown up as far as I can tell. I did find a game via a Google search - Cap'n Magneto - that is known to have problems with Basilisk/SheepShaver's legacy 60 Hz timer, and the opening fade-to-color for this game appears to run much more smoothly with the precise timer code in place.
#	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_host.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	}