Try not to cause a MemoryError when raising an exception during nterrupt handling.

Step 1 fixes #732

1 files changed, 4 insertions, 0 deletions

diff --git a/py/gc.c b/py/gc.c
index 65bfea0b35..7aa5bc326e 100644
--- a/py/gc.c
+++ b/py/gc.c
@@ -172,6 +172,10 @@ void gc_unlock(void) {
     gc_lock_depth--;
 }
 
+bool gc_is_locked(void) {
+    return gc_lock_depth != 0;
+}
+
 #define VERIFY_PTR(ptr) ( \
         (ptr & (BYTES_PER_BLOCK - 1)) == 0          /* must be aligned on a block */ \
         && ptr >= (machine_uint_t)gc_pool_start     /* must be above start of pool */ \