Showing with 68 additions and 54 deletions.
  1. +68 −54 src/core/thread.d
122 changes: 68 additions & 54 deletions src/core/thread.d
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Original file line number Diff line number Diff line change
Expand Up @@ -385,15 +385,10 @@ else version( Posix )
// NOTE: Since registers are being pushed and popped from the
// stack, any other stack data used by this function should
// be gone before the stack cleanup code is called below.
Thread obj = Thread.getThis();

// NOTE: The thread reference returned by getThis is set within
// the thread startup code, so it is possible that this
// handler may be called before the reference is set. In
// this case it is safe to simply suspend and not worry
// about the stack pointers as the thread will not have
// any references to GC-managed data.
if( obj && !obj.m_lock )
Thread obj = Thread.getThis();
assert(obj !is null);

if( !obj.m_lock )
{
obj.m_curr.tstack = getStackTop();
}
Expand All @@ -407,13 +402,13 @@ else version( Posix )
status = sigdelset( &sigres, resumeSignalNumber );
assert( status == 0 );

version (FreeBSD) Thread.sm_suspendagain = false;
version (FreeBSD) obj.m_suspendagain = false;
status = sem_post( &suspendCount );
assert( status == 0 );

sigsuspend( &sigres );

if( obj && !obj.m_lock )
if( !obj.m_lock )
{
obj.m_curr.tstack = obj.m_curr.bstack;
}
Expand All @@ -422,9 +417,10 @@ else version( Posix )
// avoid deadlocks on FreeBSD, see Issue 13416
version (FreeBSD)
{
if (THR_IN_CRITICAL(pthread_self()))
auto obj = Thread.getThis();
if (THR_IN_CRITICAL(obj.m_addr))
{
Thread.sm_suspendagain = true;
obj.m_suspendagain = true;
if (sem_post(&suspendCount)) assert(0);
return;
}
Expand Down Expand Up @@ -1400,7 +1396,7 @@ private:
version (FreeBSD)
{
// set when suspend failed and should be retried, see Issue 13416
static shared bool sm_suspendagain;
shared bool m_suspendagain;
}


Expand Down Expand Up @@ -2381,17 +2377,35 @@ private __gshared uint suspendDepth = 0;
*
* Throws:
* ThreadError if the suspend operation fails for a running thread.
* Returns:
* Whether the thread is now suspended (true) or terminated (false).
*/
private void suspend( Thread t ) nothrow
private bool suspend( Thread t ) nothrow
{
Duration waittime = dur!"usecs"(10);
Lagain:
if (!t.isRunning)
{
Thread.remove(t);
return false;
}
else if (t.m_isInCriticalRegion)
{
Thread.criticalRegionLock.unlock_nothrow();
Thread.sleep(waittime);
if (waittime < dur!"msecs"(10)) waittime *= 2;
Thread.criticalRegionLock.lock_nothrow();
goto Lagain;
}

version( Windows )
{
if( t.m_addr != GetCurrentThreadId() && SuspendThread( t.m_hndl ) == 0xFFFFFFFF )
{
if( !t.isRunning )
{
Thread.remove( t );
return;
return false;
}
onThreadError( "Unable to suspend thread" );
}
Expand Down Expand Up @@ -2450,7 +2464,7 @@ private void suspend( Thread t ) nothrow
if( !t.isRunning )
{
Thread.remove( t );
return;
return false;
}
onThreadError( "Unable to suspend thread" );
}
Expand Down Expand Up @@ -2511,33 +2525,22 @@ private void suspend( Thread t ) nothrow
{
if( t.m_addr != pthread_self() )
{
Lagain:
if( pthread_kill( t.m_addr, suspendSignalNumber ) != 0 )
{
if( !t.isRunning )
{
Thread.remove( t );
return;
return false;
}
onThreadError( "Unable to suspend thread" );
}
while (sem_wait(&suspendCount) != 0)
{
if (errno != EINTR)
onThreadError( "Unable to wait for semaphore" );
errno = 0;
}
version (FreeBSD)
{
// avoid deadlocks, see Issue 13416
if (Thread.sm_suspendagain) goto Lagain;
}
}
else if( !t.m_lock )
{
t.m_curr.tstack = getStackTop();
}
}
return true;
}

/**
Expand Down Expand Up @@ -2577,40 +2580,51 @@ extern (C) void thread_suspendAll() nothrow
if( ++suspendDepth > 1 )
return;

// NOTE: I'd really prefer not to check isRunning within this loop but
// not doing so could be problematic if threads are terminated
// abnormally and a new thread is created with the same thread
// address before the next GC run. This situation might cause
// the same thread to be suspended twice, which would likely
// cause the second suspend to fail, the garbage collection to
// abort, and Bad Things to occur.

Thread.criticalRegionLock.lock_nothrow();
scope (exit) Thread.criticalRegionLock.unlock_nothrow();
size_t cnt;
auto t = Thread.sm_tbeg;
while (t)
{
auto tn = t.next;
Duration waittime = dur!"usecs"(10);
if (suspend(t))
++cnt;
t = tn;
}

version (OSX)
{}
else version (Posix)
{
// subtract own thread
assert(cnt >= 1);
--cnt;
Lagain:
if (!t.isRunning)
// wait for semaphore notifications
for (; cnt; --cnt)
{
Thread.remove(t);
}
else if (t.m_isInCriticalRegion)
{
Thread.criticalRegionLock.unlock_nothrow();
Thread.sleep(waittime);
if (waittime < dur!"msecs"(10)) waittime *= 2;
Thread.criticalRegionLock.lock_nothrow();
goto Lagain;
while (sem_wait(&suspendCount) != 0)
{
if (errno != EINTR)
onThreadError("Unable to wait for semaphore");
errno = 0;
}
}
else
version (FreeBSD)
{
suspend(t);
}
t = tn;
// avoid deadlocks, see Issue 13416
t = Thread.sm_tbeg;
while (t)
{
auto tn = t.next;
if (t.m_suspendagain && suspend(t))
++cnt;
t = tn;
}
if (cnt)
goto Lagain;
}
}
Thread.criticalRegionLock.unlock_nothrow();
}
}

Expand Down