From edbb73a411919af954619dcee02bc448912c9e27 Mon Sep 17 00:00:00 2001
From: David Lechner <david@pybricks.com>
Date: Wed, 22 Jan 2020 11:19:37 -0600
Subject: [PATCH] py/qstr: Don't include or init qstr_mutex when GIL is
 enabled.

When threads and the GIL are enabled, then the qstr mutex is not needed.
The qstr_mutex field is never used in this case because of:

    #if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
    #define QSTR_ENTER() mp_thread_mutex_lock(&MP_STATE_VM(qstr_mutex), 1)
    #define QSTR_EXIT() mp_thread_mutex_unlock(&MP_STATE_VM(qstr_mutex))
    #else
    #define QSTR_ENTER()
    #define QSTR_EXIT()
    #endif

So, we can completely remove qstr_mutex everywhere when MICROPY_PY_THREAD
&& !MICROPY_PY_THREAD_GIL.
---
 py/mpstate.h | 2 +-
 py/qstr.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/py/mpstate.h b/py/mpstate.h
index 9bb87f0ba..5f6cf5593 100644
--- a/py/mpstate.h
+++ b/py/mpstate.h
@@ -203,7 +203,7 @@ typedef struct _mp_state_vm_t {
     size_t qstr_last_alloc;
     size_t qstr_last_used;
 
-    #if MICROPY_PY_THREAD
+    #if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
     // This is a global mutex used to make qstr interning thread-safe.
     mp_thread_mutex_t qstr_mutex;
     #endif
diff --git a/py/qstr.c b/py/qstr.c
index 29ffcae40..940d09ea4 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -125,7 +125,7 @@ void qstr_init(void) {
     MP_STATE_VM(last_pool) = (qstr_pool_t*)&CONST_POOL; // we won't modify the const_pool since it has no allocated room left
     MP_STATE_VM(qstr_last_chunk) = NULL;
 
-    #if MICROPY_PY_THREAD
+    #if MICROPY_PY_THREAD && !MICROPY_PY_THREAD_GIL
     mp_thread_mutex_init(&MP_STATE_VM(qstr_mutex));
     #endif
 }