From e355c83f59ace15850d4de6935e9fb6512a6afb5 Mon Sep 17 00:00:00 2001
From: gbeauche <>
Date: Thu, 30 Jun 2005 10:20:18 +0000
Subject: [PATCH] Add system-specific implementations of idle_{wait,resume}
 functions.

---
 BasiliskII/src/BeOS/timer_beos.cpp       | 19 +++++++
 BasiliskII/src/Unix/configure.ac         |  1 +
 BasiliskII/src/Unix/timer_unix.cpp       | 69 ++++++++++++++++++++++++
 BasiliskII/src/Windows/timer_windows.cpp | 19 +++++++
 BasiliskII/src/include/timer.h           |  4 ++
 5 files changed, 112 insertions(+)

diff --git a/BasiliskII/src/BeOS/timer_beos.cpp b/BasiliskII/src/BeOS/timer_beos.cpp
index df941900..f3998ee6 100644
--- a/BasiliskII/src/BeOS/timer_beos.cpp
+++ b/BasiliskII/src/BeOS/timer_beos.cpp
@@ -130,3 +130,22 @@ void Delay_usec(uint32 usec)
 {
 	snooze(usec);
 }
+
+
+/*
+ *  Suspend emulator thread, virtual CPU in idle mode
+ */
+
+void idle_wait(void)
+{
+	sleep(16667);
+}
+
+
+/*
+ *  Resume execution of emulator thread, events just arrived
+ */
+
+void idle_resume(void)
+{
+}
diff --git a/BasiliskII/src/Unix/configure.ac b/BasiliskII/src/Unix/configure.ac
index 16a2d4b7..f2e2e398 100644
--- a/BasiliskII/src/Unix/configure.ac
+++ b/BasiliskII/src/Unix/configure.ac
@@ -202,6 +202,7 @@ AC_CHECK_LIB(pthread, pthread_create, , [
 if [[ "x$HAVE_PTHREADS" = "xyes" ]]; then
   AC_DEFINE(HAVE_PTHREADS, 1, [Define if pthreads are available.])
 fi
+AC_CHECK_FUNCS(pthread_cond_init)
 AC_CHECK_FUNCS(pthread_cancel pthread_testcancel)
 AC_CHECK_FUNCS(pthread_mutexattr_setprotocol)
 AC_CHECK_FUNCS(pthread_mutexattr_settype)
diff --git a/BasiliskII/src/Unix/timer_unix.cpp b/BasiliskII/src/Unix/timer_unix.cpp
index f2f91bcc..11587433 100644
--- a/BasiliskII/src/Unix/timer_unix.cpp
+++ b/BasiliskII/src/Unix/timer_unix.cpp
@@ -297,3 +297,72 @@ void Delay_usec(uint32 usec)
 #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_cond_wait(&idle_cond, &idle_lock);
+#else
+#ifdef IDLE_USES_SEMAPHORE
+	if (idle_sem_ok < 0)
+		idle_sem_ok = (sem_init(&idle_sem, 0, 0) == 0);
+	if (idle_sem_ok > 0) {
+		LOCK_IDLE;
+		idle_sem_ok++;
+		UNLOCK_IDLE;
+		sem_wait(&idle_sem);
+		return;
+	}
+#endif
+	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
+	if (idle_sem_ok > 1) {
+		LOCK_IDLE;
+		idle_sem_ok--;
+		UNLOCK_IDLE;
+		sem_post(&idle_sem);
+		return;
+	}
+#endif
+#endif
+}
diff --git a/BasiliskII/src/Windows/timer_windows.cpp b/BasiliskII/src/Windows/timer_windows.cpp
index 39ad61dd..3ed729bf 100755
--- a/BasiliskII/src/Windows/timer_windows.cpp
+++ b/BasiliskII/src/Windows/timer_windows.cpp
@@ -195,3 +195,22 @@ void Delay_usec(uint32 usec)
 	// millisecond resolution anyway
 	Sleep(usec / 1000);
 }
+
+
+/*
+ *  Suspend emulator thread, virtual CPU in idle mode
+ */
+
+void idle_wait(void)
+{
+	Delay_usec(10000);
+}
+
+
+/*
+ *  Resume execution of emulator thread, events just arrived
+ */
+
+void idle_resume(void)
+{
+}
diff --git a/BasiliskII/src/include/timer.h b/BasiliskII/src/include/timer.h
index c9105620..cd99ef34 100644
--- a/BasiliskII/src/include/timer.h
+++ b/BasiliskII/src/include/timer.h
@@ -42,4 +42,8 @@ extern int timer_cmp_time(tm_time_t a, tm_time_t b);
 extern void timer_mac2host_time(tm_time_t &res, int32 mactime);
 extern int32 timer_host2mac_time(tm_time_t hosttime);
 
+// Suspend execution of emulator thread and resume it on events
+extern void idle_wait(void);
+extern void idle_resume(void);
+
 #endif