Functionality for disabling garbage collection

Being able to disable garbage collection over context
switches vastly simplifies implementation of yielding
native code that builds large or complex data structures
on the heap. This since the heap can be left in an
inconsistent state over the context switch.

1 files changed, 12 insertions, 1 deletions

diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c
index 8ba94d89e9..da254286c4 100644
--- a/erts/emulator/beam/erl_gc.c
+++ b/erts/emulator/beam/erl_gc.c
@@ -400,10 +400,16 @@ erts_garbage_collect(Process* p, int need, Eterm* objv, int nobj)
     Uint reclaimed_now = 0;
     int done = 0;
     Uint ms1, s1, us1;
-    ErtsSchedulerData *esdp = erts_get_scheduler_data();
+    ErtsSchedulerData *esdp;
 #ifdef USE_VM_PROBES
     DTRACE_CHARBUF(pidbuf, DTRACE_TERM_BUF_SIZE);
 #endif
+
+    if (p->flags & F_DISABLE_GC)
+	return 1;
+
+    esdp = erts_get_scheduler_data();
+
     if (IS_TRACED_FL(p, F_TRACE_GC)) {
         trace_gc(p, am_gc_start);
     }
@@ -532,6 +538,9 @@ erts_garbage_collect_hibernate(Process* p)
     Uint area_size;
     Sint offs;
 
+    if (p->flags & F_DISABLE_GC)
+	ERTS_INTERNAL_ERROR("GC disabled");
+
     /*
      * Preliminaries.
      */
@@ -667,6 +676,8 @@ erts_garbage_collect_literals(Process* p, Eterm* literals,
     Uint n;
     struct erl_off_heap_header** prev;
 
+    if (p->flags & F_DISABLE_GC)
+	return;
     /*
      * Set GC state.
      */