From 35f66d38b8e153399b5d277b6e02ea1a98eccee1 Mon Sep 17 00:00:00 2001
From: David Lechner <david@pybricks.com>
Date: Thu, 23 Jan 2020 21:50:53 -0600
Subject: [PATCH] extmod/vfs_posix: Release GIL during system calls.

This releases the GIL during syscalls that could block.
---
 extmod/vfs_posix.c      | 20 ++++++++++++++++++--
 extmod/vfs_posix_file.c | 16 +++++++++++++++-
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/extmod/vfs_posix.c b/extmod/vfs_posix.c
index d943e0c803..22471e48f3 100644
--- a/extmod/vfs_posix.c
+++ b/extmod/vfs_posix.c
@@ -26,6 +26,7 @@
 
 #include "py/runtime.h"
 #include "py/mperrno.h"
+#include "py/mpthread.h"
 #include "extmod/vfs.h"
 #include "extmod/vfs_posix.h"
 
@@ -170,12 +171,15 @@ STATIC mp_obj_t vfs_posix_ilistdir_it_iternext(mp_obj_t self_in) {
     }
 
     for (;;) {
+        MP_THREAD_GIL_EXIT();
         struct dirent *dirent = readdir(self->dir);
         if (dirent == NULL) {
             closedir(self->dir);
+            MP_THREAD_GIL_ENTER();
             self->dir = NULL;
             return MP_OBJ_STOP_ITERATION;
         }
+        MP_THREAD_GIL_ENTER();
         const char *fn = dirent->d_name;
 
         if (fn[0] == '.' && (fn[1] == 0 || fn[1] == '.')) {
@@ -229,7 +233,9 @@ STATIC mp_obj_t vfs_posix_ilistdir(mp_obj_t self_in, mp_obj_t path_in) {
     if (path[0] == '\0') {
         path = ".";
     }
+    MP_THREAD_GIL_EXIT();
     iter->dir = opendir(path);
+    MP_THREAD_GIL_ENTER();
     if (iter->dir == NULL) {
         mp_raise_OSError(errno);
     }
@@ -245,7 +251,10 @@ typedef struct _mp_obj_listdir_t {
 
 STATIC mp_obj_t vfs_posix_mkdir(mp_obj_t self_in, mp_obj_t path_in) {
     mp_obj_vfs_posix_t *self = MP_OBJ_TO_PTR(self_in);
-    int ret = mkdir(vfs_posix_get_path_str(self, path_in), 0777);
+    const char *path = vfs_posix_get_path_str(self, path_in);
+    MP_THREAD_GIL_EXIT();
+    int ret = mkdir(path, 0777);
+    MP_THREAD_GIL_ENTER();
     if (ret != 0) {
         mp_raise_OSError(errno);
     }
@@ -262,7 +271,9 @@ STATIC mp_obj_t vfs_posix_rename(mp_obj_t self_in, mp_obj_t old_path_in, mp_obj_
     mp_obj_vfs_posix_t *self = MP_OBJ_TO_PTR(self_in);
     const char *old_path = vfs_posix_get_path_str(self, old_path_in);
     const char *new_path = vfs_posix_get_path_str(self, new_path_in);
+    MP_THREAD_GIL_EXIT();
     int ret = rename(old_path, new_path);
+    MP_THREAD_GIL_ENTER();
     if (ret != 0) {
         mp_raise_OSError(errno);
     }
@@ -278,7 +289,10 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_2(vfs_posix_rmdir_obj, vfs_posix_rmdir);
 STATIC mp_obj_t vfs_posix_stat(mp_obj_t self_in, mp_obj_t path_in) {
     mp_obj_vfs_posix_t *self = MP_OBJ_TO_PTR(self_in);
     struct stat sb;
-    int ret = stat(vfs_posix_get_path_str(self, path_in), &sb);
+    const char *path = vfs_posix_get_path_str(self, path_in);
+    MP_THREAD_GIL_EXIT();
+    int ret = stat(path, &sb);
+    MP_THREAD_GIL_ENTER();
     if (ret != 0) {
         mp_raise_OSError(errno);
     }
@@ -321,7 +335,9 @@ STATIC mp_obj_t vfs_posix_statvfs(mp_obj_t self_in, mp_obj_t path_in) {
     mp_obj_vfs_posix_t *self = MP_OBJ_TO_PTR(self_in);
     STRUCT_STATVFS sb;
     const char *path = vfs_posix_get_path_str(self, path_in);
+    MP_THREAD_GIL_EXIT();
     int ret = STATVFS(path, &sb);
+    MP_THREAD_GIL_ENTER();
     if (ret != 0) {
         mp_raise_OSError(errno);
     }
diff --git a/extmod/vfs_posix_file.c b/extmod/vfs_posix_file.c
index 87c202e3b0..c817e51b8b 100644
--- a/extmod/vfs_posix_file.c
+++ b/extmod/vfs_posix_file.c
@@ -24,6 +24,7 @@
  * THE SOFTWARE.
  */
 
+#include "py/mpthread.h"
 #include "py/runtime.h"
 #include "py/stream.h"
 #include "extmod/vfs_posix.h"
@@ -100,7 +101,9 @@ mp_obj_t mp_vfs_posix_file_open(const mp_obj_type_t *type, mp_obj_t file_in, mp_
     }
 
     const char *fname = mp_obj_str_get_str(fid);
+    MP_THREAD_GIL_EXIT();
     int fd = open(fname, mode_x | mode_rw, 0644);
+    MP_THREAD_GIL_ENTER();
     if (fd == -1) {
         mp_raise_OSError(errno);
     }
@@ -135,7 +138,9 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(vfs_posix_file___exit___obj, 4, 4, vf
 STATIC mp_uint_t vfs_posix_file_read(mp_obj_t o_in, void *buf, mp_uint_t size, int *errcode) {
     mp_obj_vfs_posix_file_t *o = MP_OBJ_TO_PTR(o_in);
     check_fd_is_open(o);
+    MP_THREAD_GIL_EXIT();
     mp_int_t r = read(o->fd, buf, size);
+    MP_THREAD_GIL_ENTER();
     if (r == -1) {
         *errcode = errno;
         return MP_STREAM_ERROR;
@@ -159,7 +164,9 @@ STATIC mp_uint_t vfs_posix_file_write(mp_obj_t o_in, const void *buf, mp_uint_t
             MP_STATE_VM(mp_pending_exception) = MP_OBJ_NULL;
             nlr_raise(obj);
         }
+        MP_THREAD_GIL_EXIT();
         r = write(o->fd, buf, size);
+        MP_THREAD_GIL_ENTER();
     }
     if (r == -1) {
         *errcode = errno;
@@ -173,14 +180,19 @@ STATIC mp_uint_t vfs_posix_file_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_
     check_fd_is_open(o);
     switch (request) {
         case MP_STREAM_FLUSH:
-            if (fsync(o->fd) < 0) {
+            MP_THREAD_GIL_EXIT();
+            int ret = fsync(o->fd);
+            MP_THREAD_GIL_ENTER();
+            if (ret == -1) {
                 *errcode = errno;
                 return MP_STREAM_ERROR;
             }
             return 0;
         case MP_STREAM_SEEK: {
             struct mp_stream_seek_t *s = (struct mp_stream_seek_t*)arg;
+            MP_THREAD_GIL_EXIT();
             off_t off = lseek(o->fd, s->offset, s->whence);
+            MP_THREAD_GIL_ENTER();
             if (off == (off_t)-1) {
                 *errcode = errno;
                 return MP_STREAM_ERROR;
@@ -189,7 +201,9 @@ STATIC mp_uint_t vfs_posix_file_ioctl(mp_obj_t o_in, mp_uint_t request, uintptr_
             return 0;
         }
         case MP_STREAM_CLOSE:
+            MP_THREAD_GIL_EXIT();
             close(o->fd);
+            MP_THREAD_GIL_ENTER();
             #ifdef MICROPY_CPYTHON_COMPAT
             o->fd = -1;
             #endif