* src/mm/gc-boehm.cpp: Define GC_SOLARIS_THREADS on Solaris.
[cacao.git] / src / threads / posix / thread-posix.cpp
index 6db5dfdab5e7d79f6b3ade281e7675469e8ce54c..a68cede39cf91c405bd86f2180fd3f137c519e65 100644 (file)
@@ -1,6 +1,6 @@
 /* src/threads/posix/thread-posix.cpp - POSIX thread functions
 
-   Copyright (C) 1996-2005, 2006, 2007, 2008
+   Copyright (C) 1996-2005, 2006, 2007, 2008, 2010
    CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO
 
    This file is part of CACAO.
@@ -27,6 +27,8 @@
 
 /* XXX cleanup these includes */
 
+#define __STDC_LIMIT_MACROS
+
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
 #include "arch.h"
 
 #include "mm/gc.hpp"
-#include "mm/memory.h"
+#include "mm/memory.hpp"
 
 #if defined(ENABLE_GC_CACAO)
 # include "mm/cacao-gc/gc.h"
 #endif
 
-#include "native/jni.h"
 #include "native/llni.h"
-#include "native/native.h"
+#include "native/native.hpp"
 
 #include "threads/condition.hpp"
-#include "threads/lock-common.h"
+#include "threads/lock.hpp"
 #include "threads/mutex.hpp"
-#include "threads/threadlist.h"
+#include "threads/threadlist.hpp"
 #include "threads/thread.hpp"
 
-#include "toolbox/logging.h"
+#include "toolbox/logging.hpp"
 
-#include "vm/builtin.h"
+#include "vm/jit/builtin.hpp"
 #include "vm/exceptions.hpp"
 #include "vm/global.h"
-#include "vm/signallocal.h"
+#include "vm/globals.hpp"
+#include "vm/hook.hpp"
+#include "vm/javaobjects.hpp"
+#include "vm/options.h"
+#include "vm/os.hpp"
+#include "vm/signallocal.hpp"
 #include "vm/string.hpp"
 #include "vm/vm.hpp"
 
+#if defined(ENABLE_STATISTICS)
+# include "vm/statistics.h"
+#endif
+
 #include "vm/jit/asmpart.h"
 
-#include "vmcore/globals.hpp"
-#include "vmcore/javaobjects.hpp"
-#include "vmcore/options.h"
+#if defined(__DARWIN__)
 
-#if defined(ENABLE_STATISTICS)
-# include "vmcore/statistics.h"
-#endif
+typedef struct {
+       Mutex* mutex;
+       Condition* cond;
+       int value;
+} sem_t;
 
-#if !defined(__DARWIN__)
+#else
 # include <semaphore.h>
 #endif
 
@@ -88,6 +98,8 @@
 # define GC_IRIX_THREADS
 #elif defined(__DARWIN__)
 # define GC_DARWIN_THREADS
+#elif defined(__SOLARIS__)
+# define GC_SOLARIS_THREADS
 #endif
 
 #if defined(ENABLE_GC_BOEHM)
 # include "mm/boehm-gc/include/gc.h"
 #endif
 
-#if defined(ENABLE_JVMTI)
-#include "native/jvmti/cacaodbg.h"
-#endif
-
-
-// FIXME For now we export everything as C functions.
-extern "C" {
 
 #if defined(__DARWIN__)
 /* Darwin has no working semaphore implementation.  This one is taken
@@ -434,33 +439,6 @@ void threads_startworld(void)
 #endif
 
 
-/* threads_impl_thread_init ****************************************************
-
-   Initialize OS-level locking constructs in threadobject.
-
-   IN:
-      t....the threadobject
-
-*******************************************************************************/
-
-void threads_impl_thread_init(threadobject *t)
-{
-       /* initialize the mutex and the condition */
-
-       t->flc_lock = new Mutex();
-       t->flc_cond = new Condition();
-
-       t->waitmutex = new Mutex();
-       t->waitcond = new Condition();
-
-       t->suspendmutex = new Mutex();
-       t->suspendcond = new Condition();
-
-#if defined(ENABLE_TLH)
-       tlh_init(&(t->tlh));
-#endif
-}
-
 /* threads_impl_thread_clear ***************************************************
 
    Clears all fields in threadobject the way an MZERO would have
@@ -511,7 +489,7 @@ void threads_impl_thread_clear(threadobject *t)
        t->es = NULL;
 #endif
 
-       MZERO(&t->dumpinfo, dumpinfo_t, 1);
+       // Simply reuse the existing dump memory.
 }
 
 /* threads_impl_thread_reuse ***************************************************
@@ -577,21 +555,21 @@ void threads_impl_thread_free(threadobject *t)
        result = pthread_cond_destroy(&(t->flc_cond));
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_free: pthread_cond_destroy failed");
+               os::abort_errnum(result, "threads_impl_thread_free: pthread_cond_destroy failed");
 
        delete t->waitmutex;
 
        result = pthread_cond_destroy(&(t->waitcond));
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_free: pthread_cond_destroy failed");
+               os::abort_errnum(result, "threads_impl_thread_free: pthread_cond_destroy failed");
 
        delete t->suspendmutex;
 
        result = pthread_cond_destroy(&(t->suspendcond));
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_free: pthread_cond_destroy failed");
+               os::abort_errnum(result, "threads_impl_thread_free: pthread_cond_destroy failed");
 }
 #endif
 
@@ -607,8 +585,6 @@ void threads_impl_thread_free(threadobject *t)
 
 void threads_impl_preinit(void)
 {
-       int result;
-
        stopworldlock = new Mutex();
 
        /* initialize exit mutex and condition (on exit we join all
@@ -625,9 +601,9 @@ void threads_impl_preinit(void)
 #endif
 
 #if !defined(HAVE___THREAD)
-       result = pthread_key_create(&thread_current_key, NULL);
+       int result = pthread_key_create(&thread_current_key, NULL);
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_preinit: pthread_key_create failed");
+               os::abort_errnum(result, "threads_impl_preinit: pthread_key_create failed");
 #endif
 }
 
@@ -701,12 +677,12 @@ void threads_impl_init(void)
        result = pthread_attr_init(&attr);
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_init: pthread_attr_init failed");
+               os::abort_errnum(result, "threads_impl_init: pthread_attr_init failed");
 
        result = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_init: pthread_attr_setdetachstate failed");
+               os::abort_errnum(result, "threads_impl_init: pthread_attr_setdetachstate failed");
 }
 
 
@@ -824,12 +800,8 @@ static void *threads_startup_thread(void *arg)
                thread->_global_sp = (Cell *) (intrp_thread_stack + opt_stacksize);
 #endif
 
-#if defined(ENABLE_JVMTI)
-       /* fire thread start event */
-
-       if (jvmti) 
-               jvmti_ThreadStartEnd(JVMTI_EVENT_THREAD_START);
-#endif
+       // Hook point just before the threads initial method is executed.
+       Hook::thread_start(t);
 
        DEBUGTHREADS("starting", t);
 
@@ -853,17 +825,6 @@ static void *threads_startup_thread(void *arg)
                if (m == NULL)
                        vm_abort("threads_startup_thread: run() method not found in class");
 
-               /* set ThreadMXBean variables */
-
-/*             _Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount++; */
-/*             _Jv_jvm->java_lang_management_ThreadMXBean_TotalStartedThreadCount++; */
-
-/*             if (_Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount > */
-/*                     _Jv_jvm->java_lang_management_ThreadMXBean_PeakThreadCount) */
-/*                     _Jv_jvm->java_lang_management_ThreadMXBean_PeakThreadCount = */
-/*                             _Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount; */
-#warning Move to C++
-
 #if defined(WITH_JAVA_RUNTIME_LIBRARY_GNU_CLASSPATH)
 
                // We need to start the run method of java.lang.VMThread.
@@ -883,17 +844,6 @@ static void *threads_startup_thread(void *arg)
                (void) vm_call_method(m, h);
        }
        else {
-               /* set ThreadMXBean variables */
-
-/*             _Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount++; */
-/*             _Jv_jvm->java_lang_management_ThreadMXBean_TotalStartedThreadCount++; */
-
-/*             if (_Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount > */
-/*                     _Jv_jvm->java_lang_management_ThreadMXBean_PeakThreadCount) */
-/*                     _Jv_jvm->java_lang_management_ThreadMXBean_PeakThreadCount = */
-/*                             _Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount; */
-#warning Move to C++
-
                /* call passed function, e.g. finalizer_thread */
 
                (function)();
@@ -901,22 +851,13 @@ static void *threads_startup_thread(void *arg)
 
        DEBUGTHREADS("stopping", t);
 
-#if defined(ENABLE_JVMTI)
-       /* fire thread end event */
-
-       if (jvmti)
-               jvmti_ThreadStartEnd(JVMTI_EVENT_THREAD_END);
-#endif
+       // Hook point just after the threads initial method returned.
+       Hook::thread_end(t);
 
        /* We ignore the return value. */
 
        (void) thread_detach_current_thread();
 
-       /* set ThreadMXBean variables */
-
-/*     _Jv_jvm->java_lang_management_ThreadMXBean_ThreadCount--; */
-#warning Move to C++
-
        return NULL;
 }
 
@@ -957,33 +898,33 @@ void threads_impl_thread_start(threadobject *thread, functionptr f)
        result = pthread_attr_init(&attr);
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_start: pthread_attr_init failed");
+               os::abort_errnum(result, "threads_impl_thread_start: pthread_attr_init failed");
 
     result = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 
     if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_start: pthread_attr_setdetachstate failed");
+               os::abort_errnum(result, "threads_impl_thread_start: pthread_attr_setdetachstate failed");
 
        /* initialize thread stacksize */
 
        result = pthread_attr_setstacksize(&attr, opt_stacksize);
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_start: pthread_attr_setstacksize failed");
+               os::abort_errnum(result, "threads_impl_thread_start: pthread_attr_setstacksize failed");
 
        /* create the thread */
 
        result = pthread_create(&(thread->tid), &attr, threads_startup_thread, &startup);
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_start: pthread_create failed");
+               os::abort_errnum(result, "threads_impl_thread_start: pthread_create failed");
 
        /* destroy the thread attributes */
 
        result = pthread_attr_destroy(&attr);
 
        if (result != 0)
-               vm_abort_errnum(result, "threads_impl_thread_start: pthread_attr_destroy failed");
+               os::abort_errnum(result, "threads_impl_thread_start: pthread_attr_destroy failed");
 
        /* signal that pthread_create has returned, so thread->tid is valid */
 
@@ -1168,134 +1109,146 @@ bool thread_detach_current_thread(void)
 }
 
 
-/* threads_suspend_thread ******************************************************
-
-   Suspend the passed thread. Execution stops until the thread
-   is explicitly resumend again.
-
-   IN:
-     reason.....Reason for suspending this thread.
-
-*******************************************************************************/
-
-bool threads_suspend_thread(threadobject *thread, s4 reason)
+/**
+ * Internal helper function which suspends the current thread. This is
+ * the core method of the suspension mechanism actually blocking the
+ * execution until the suspension reason is cleared again. Note that
+ * the current thread needs to hold the suspension mutex while calling
+ * this function.
+ */
+static void threads_suspend_self()
 {
-       /* acquire the suspendmutex */
-       thread->suspendmutex->lock();
-
-       if (thread->suspended) {
-               thread->suspendmutex->unlock();
-               return false;
-       }
+       threadobject* thread = THREADOBJECT;
 
-       /* set the reason for the suspension */
-       thread->suspend_reason = reason;
+       DEBUGTHREADS("suspending", thread);
 
-       /* send the suspend signal to the thread */
-       assert(thread != THREADOBJECT);
-       if (pthread_kill(thread->tid, SIGUSR1) != 0)
-               vm_abort("threads_suspend_thread: pthread_kill failed: %s",
-                                strerror(errno));
+       // Mark thread as suspended.
+       assert(!thread->suspended);
+       assert(thread->suspend_reason != SUSPEND_REASON_NONE);
+       thread->suspended = true;
 
-       /* REMEMBER: do not release the suspendmutex, this is done
-          by the thread itself in threads_suspend_ack().  */
+       // Acknowledge the suspension.
+       thread->suspendcond->broadcast();
 
-       return true;
-}
+#if defined(ENABLE_GC_CACAO)
+       // If we are stopping the world, we should send a global ack.
+       if (thread->suspend_reason == SUSPEND_REASON_STOPWORLD)
+               threads_sem_post(&suspend_ack);
+#endif
 
+       // Release the suspension mutex and wait till we are resumed.
+       thread->suspendcond->wait(thread->suspendmutex);
 
-/* threads_suspend_ack *********************************************************
+#if defined(ENABLE_GC_CACAO)
+       // XXX This is propably not ok!
+       // If we are starting the world, we should send a global ack.
+       if (thread->suspend_reason == SUSPEND_REASON_STOPWORLD)
+               threads_sem_post(&suspend_ack);
+#endif
 
-   Acknowledges the suspension of the current thread.
+       // Mark thread as not suspended.
+       assert(thread->suspended);
+       assert(thread->suspend_reason == SUSPEND_REASON_NONE);
+       thread->suspended = false;
 
-   IN:
-     pc.....The PC where the thread suspended its execution.
-     sp.....The SP before the thread suspended its execution.
+       DEBUGTHREADS("resuming", thread);
+}
 
-*******************************************************************************/
 
-#if defined(ENABLE_GC_CACAO)
-void threads_suspend_ack(u1* pc, u1* sp)
+/**
+ * Suspend the passed thread. Execution of that thread stops until the thread
+ * is explicitly resumend again.
+ *
+ * @param thread The thread to be suspended.
+ * @param reason Reason for suspending the given thread.
+ * @return True of operation was successful, false otherwise.
+ */
+bool threads_suspend_thread(threadobject *thread, int32_t reason)
 {
-       threadobject *thread;
-
-       thread = THREADOBJECT;
+       // Sanity check.
+       assert(reason != SUSPEND_REASON_NONE);
 
-       assert(thread->suspend_reason != 0);
+       // Guard this with the suspension mutex.
+       MutexLocker ml(*thread->suspendmutex);
 
-       /* TODO: remember dump memory size */
-
-       /* inform the GC about the suspension */
-       if (thread->suspend_reason == SUSPEND_REASON_STOPWORLD && gc_pending) {
+       // Check if thread is already suspended.
+       if (thread->suspended)
+               return false;
 
-               /* check if the GC wants to leave the thread running */
-               if (!gc_suspend(thread, pc, sp)) {
+       // Check if thread is in the process of suspending.
+       if (thread->suspend_reason != SUSPEND_REASON_NONE)
+               return false;
 
-                       /* REMEMBER: we do not unlock the suspendmutex because the thread
-                          will suspend itself again at a later time */
-                       return;
+       // Set the reason for suspending the thread.
+       thread->suspend_reason = reason;
 
-               }
+       if (thread == THREADOBJECT) {
+               // We already hold the suspension mutex and can suspend ourselves
+               // immediately without using signals at all.
+               threads_suspend_self();
        }
-
-       /* mark this thread as suspended and remember the PC */
-       thread->pc        = pc;
-       thread->suspended = true;
-
-       /* if we are stopping the world, we should send a global ack */
-       if (thread->suspend_reason == SUSPEND_REASON_STOPWORLD) {
-               threads_sem_post(&suspend_ack);
+       else {
+               // Send the suspend signal to the other thread.
+               if (pthread_kill(thread->tid, SIGUSR1) != 0)
+                       os::abort_errno("threads_suspend_thread: pthread_kill failed");
+
+               // Wait for the thread to acknowledge the suspension.
+               // XXX A possible optimization would be to not wait here, but you
+               //     better think this through twice before trying it!
+               thread->suspendcond->wait(thread->suspendmutex);
        }
 
-       DEBUGTHREADS("suspending", thread);
+       return true;
+}
 
-       /* release the suspension mutex and wait till we are resumed */
-       thread->suspendcond->wait(thread->suspendmutex);
 
-       DEBUGTHREADS("resuming", thread);
+/**
+ * Resumes execution of the passed thread.
+ *
+ * @param thread The thread to be resumed.
+ * @param reason Reason for suspending the given thread.
+ * @return True of operation was successful, false otherwise.
+ */
+bool threads_resume_thread(threadobject *thread, int32_t reason)
+{
+       // Sanity check.
+       assert(thread != THREADOBJECT);
+       assert(reason != SUSPEND_REASON_NONE);
 
-       /* if we are stopping the world, we should send a global ack */
-       if (thread->suspend_reason == SUSPEND_REASON_STOPWORLD) {
-               threads_sem_post(&suspend_ack);
-       }
+       // Guard this with the suspension mutex.
+       MutexLocker ml(*thread->suspendmutex);
 
-       /* TODO: free dump memory */
+       // Check if thread really is suspended.
+       if (!thread->suspended)
+               return false;
 
-       /* release the suspendmutex */
-       thread->suspendmutex->unlock();
-}
-#endif
+       // Threads can only be resumed for the same reason they were suspended.
+       if (thread->suspend_reason != reason)
+               return false;
 
+       // Clear the reason for suspending the thread.
+       thread->suspend_reason = SUSPEND_REASON_NONE;
 
-/* threads_resume_thread *******************************************************
+       // Tell everyone that the thread should resume.
+       thread->suspendcond->broadcast();
 
-   Resumes the execution of the passed thread.
+       return true;
+}
 
-*******************************************************************************/
 
-#if defined(ENABLE_GC_CACAO)
-bool threads_resume_thread(threadobject *thread)
+/**
+ * Acknowledges the suspension of the current thread.
+ */
+void threads_suspend_ack()
 {
-       /* acquire the suspendmutex */
-       thread->suspendmutex->lock();
+       threadobject* thread = THREADOBJECT;
 
-       if (!thread->suspended) {
-               thread->suspendmutex->unlock();
-               return false;
-       }
-
-       thread->suspended = false;
+       // Guard this with the suspension mutex.
+       MutexLocker ml(*thread->suspendmutex);
 
-       /* tell everyone that the thread should resume */
-       assert(thread != THREADOBJECT);
-       thread->suspendcond->broadcast();
-
-       /* release the suspendmutex */
-       thread->suspendmutex->unlock();
-
-       return true;
+       // Suspend ourselves while holding the suspension mutex.
+       threads_suspend_self();
 }
-#endif
 
 
 /* threads_join_all_threads ****************************************************
@@ -1324,7 +1277,7 @@ void threads_join_all_threads(void)
           compare against 1 because the current (main thread) is also a
           non-daemon thread. */
 
-       while (threadlist_get_non_daemons() > 1)
+       while (ThreadList::get_number_of_non_daemon_threads() > 1)
                cond_join->wait(mutex_join);
 
        /* leave join mutex */
@@ -1401,7 +1354,7 @@ static bool threads_current_time_is_earlier_than(const struct timespec *tv)
 
 *******************************************************************************/
 
-static void threads_wait_with_timeout(threadobject *t, struct timespec *wakeupTime)
+static void threads_wait_with_timeout(threadobject *t, struct timespec *wakeupTime, bool parking)
 {
        // Acquire the waitmutex.
        t->waitmutex->lock();
@@ -1410,10 +1363,13 @@ static void threads_wait_with_timeout(threadobject *t, struct timespec *wakeupTi
 
        if (wakeupTime->tv_sec || wakeupTime->tv_nsec) {
                /* with timeout */
-               while (!t->interrupted && !t->signaled
+               while (!t->interrupted && !(parking ? t->park_permit : t->signaled)
                           && threads_current_time_is_earlier_than(wakeupTime))
                {
-                       thread_set_state_timed_waiting(t);
+                       if (parking)
+                               thread_set_state_timed_parked(t);
+                       else
+                               thread_set_state_timed_waiting(t);
 
                        t->waitcond->timedwait(t->waitmutex, wakeupTime);
 
@@ -1422,8 +1378,11 @@ static void threads_wait_with_timeout(threadobject *t, struct timespec *wakeupTi
        }
        else {
                /* no timeout */
-               while (!t->interrupted && !t->signaled) {
-                       thread_set_state_waiting(t);
+               while (!t->interrupted && !(parking ? t->park_permit : t->signaled)) {
+                       if (parking)
+                               thread_set_state_parked(t);
+                       else
+                               thread_set_state_waiting(t);
 
                        t->waitcond->wait(t->waitmutex);
 
@@ -1431,6 +1390,9 @@ static void threads_wait_with_timeout(threadobject *t, struct timespec *wakeupTi
                }
        }
 
+       if (parking)
+               t->park_permit = false;
+
        // Release the waitmutex.
        t->waitmutex->unlock();
 }
@@ -1459,7 +1421,7 @@ void threads_wait_with_timeout_relative(threadobject *thread, s8 millis,
 
        /* wait */
 
-       threads_wait_with_timeout(thread, &wakeupTime);
+       threads_wait_with_timeout(thread, &wakeupTime, false);
 }
 
 
@@ -1478,20 +1440,26 @@ void threads_wait_with_timeout_relative(threadobject *thread, s8 millis,
 
 static void threads_calc_absolute_time(struct timespec *tm, s8 millis, s4 nanos)
 {
-       if ((millis != 0x7fffffffffffffffLLU) && (millis || nanos)) {
+       // (at least with GNU classpath) we know that 0 <= nanos <= 999999
+       do {
+               if (!millis && !nanos)
+                       break;
                struct timeval tv;
-               long nsec;
                gettimeofday(&tv, NULL);
-               tv.tv_sec += millis / 1000;
+               s8 secs = tv.tv_sec + millis / 1000;
+               if (secs > INT32_MAX)   // integer overflow
+                       break;
+               tv.tv_sec = secs;
                millis %= 1000;
-               nsec = tv.tv_usec * 1000 + (s4) millis * 1000000 + nanos;
+               long nsec = tv.tv_usec * 1000 + (s4) millis * 1000000 + nanos;
                tm->tv_sec = tv.tv_sec + nsec / 1000000000;
+               if (tm->tv_sec < tv.tv_sec) // integer overflow
+                       break;
                tm->tv_nsec = nsec % 1000000000;
-       }
-       else {
-               tm->tv_sec = 0;
-               tm->tv_nsec = 0;
-       }
+               return;
+       } while (0);
+       tm->tv_sec = 0;
+       tm->tv_nsec = 0;
 }
 
 
@@ -1570,7 +1538,7 @@ void threads_sleep(int64_t millis, int32_t nanos)
        else {
                threads_calc_absolute_time(&wakeupTime, millis, nanos);
 
-               threads_wait_with_timeout(t, &wakeupTime);
+               threads_wait_with_timeout(t, &wakeupTime, false);
 
                interrupted = thread_is_interrupted(t);
 
@@ -1585,6 +1553,47 @@ void threads_sleep(int64_t millis, int32_t nanos)
        }
 }
 
+/**
+ * Park the current thread for the specified amount of time or until a
+ * specified deadline.
+ *
+ * @param absolute Is the time in nanos a deadline or a duration?
+ * @param nanos    Nanoseconds to park (absolute=false)
+ *                 or deadline in milliseconds (absolute=true)
+ */
+void threads_park(bool absolute, int64_t nanos)
+{
+       threadobject    *t;
+       struct timespec  wakeupTime;
+
+       t = thread_get_current();
+
+       if (absolute) {
+               wakeupTime.tv_nsec = 0;
+               wakeupTime.tv_sec = nanos / 1000; /* milliseconds */
+       }
+       else
+               threads_calc_absolute_time(&wakeupTime, nanos / 1000000, nanos % 1000000);
+
+       threads_wait_with_timeout(t, &wakeupTime, true);
+}
+
+/**
+ * Unpark the specified thread.
+ *
+ * @param t The thread to unpark.
+ */
+void threads_unpark(threadobject *t)
+{
+       t->waitmutex->lock();
+
+       t->waitcond->signal();
+
+       t->park_permit = true;
+
+       t->waitmutex->unlock();
+}
+
 
 /* threads_yield ***************************************************************
 
@@ -1609,8 +1618,6 @@ void threads_tlh_remove_frame() {
 
 #endif
 
-} // extern "C"
-
 
 /*
  * These are local overrides for various environment variables in Emacs.