Merge pull request #2339 from MartinNowak/merge_stable

Merge remote-tracking branch 'upstream/stable' into merge_stable

Author: wilzbach

src/core/thread.d

@@ -596,7 +596,10 @@ class Thread
      */
     ~this() nothrow @nogc
     {
-        if ( m_addr == m_addr.init )
+        bool no_context = m_addr == m_addr.init;
+        bool not_registered = !next && !prev && (sm_tbeg !is this);
+
+        if (no_context || not_registered)
         {
             return;
         }
@@ -1856,8 +1859,9 @@ private:
     do
     {
         // Thread was already removed earlier, might happen b/c of thread_detachInstance
-        if (!t.next && !t.prev)
+        if (!t.next && !t.prev && (sm_tbeg !is t))
             return;
+
         slock.lock_nothrow();
         {
             // NOTE: When a thread is removed from the global thread list its

src/gc/impl/conservative/gc.d

@@ -2384,6 +2384,14 @@ struct Gcx
      */
     size_t fullcollect(bool nostack = false) nothrow
     {
+        // It is possible that `fullcollect` will be called from a thread which
+        // is not yet registered in runtime (because allocating `new Thread` is
+        // part of `thread_attachThis` implementation). In that case it is
+        // better not to try actually collecting anything
+
+        if (Thread.getThis() is null)
+            return 0;
+
         MonoTime start, stop, begin;
 
         if (config.profile)

test/thread/Makefile

@@ -1,6 +1,6 @@
 include ../common.mak
 
-TESTS:=fiber_guard_page
+TESTS:=fiber_guard_page external_threads
 
 .PHONY: all clean
 all: $(addprefix $(ROOT)/,$(addsuffix .done,$(TESTS)))
@@ -11,6 +11,11 @@ $(ROOT)/fiber_guard_page.done: $(ROOT)/%.done : $(ROOT)/%
 	$(QUIET)$(TIMELIMIT)$(ROOT)/$* $(RUN_ARGS); rc=$$?; [ $$rc -eq 139 ] || [ $$rc -eq 138 ]
 	@touch $@
 
+$(ROOT)/external_threads.done: $(ROOT)/%.done : $(ROOT)/%
+	@echo Testing $*
+	$(QUIET)$(TIMELIMIT)$(ROOT)/$*
+	@touch $@
+
 $(ROOT)/%: $(SRC)/%.d
 	$(QUIET)$(DMD) $(DFLAGS) -of$@ $<
 

test/thread/src/external_threads.d

@@ -0,0 +1,50 @@
+import core.sys.posix.pthread;
+import core.memory;
+import core.thread;
+
+extern (C) void  rt_moduleTlsCtor();
+extern (C) void  rt_moduleTlsDtor();
+
+extern(C)
+void* entry_point1(void*)
+{
+    // try collecting - GC must ignore this call because this thread
+    // is not registered in runtime
+    GC.collect();
+    return null;
+}
+
+extern(C)
+void* entry_point2(void*)
+{
+    // This thread gets registered in druntime, does some work and gets
+    // unregistered to be cleaned up manually
+    thread_attachThis();
+    rt_moduleTlsCtor();
+
+    auto x = new int[10];
+
+    rt_moduleTlsDtor();
+    thread_detachThis();
+    return null;
+}
+
+void main()
+{
+    // allocate some garbage
+    auto x = new int[1000];
+
+    {
+        pthread_t thread;
+        auto status = pthread_create(&thread, null, &entry_point1, null);
+        assert(status == 0);
+        pthread_join(thread, null);
+    }
+
+    {
+        pthread_t thread;
+        auto status = pthread_create(&thread, null, &entry_point2, null);
+        assert(status == 0);
+        pthread_join(thread, null);
+    }
+}