unix: Allow the GIL to be enabled.

The unix port can now be built with the GIL enabled, by passing
MICROPY_PY_THREAD_GIL=1 on the make command line.

Signed-off-by: Damien George <damien@micropython.org>

ports/unix/Makefile

@@ -132,7 +132,11 @@ ifeq ($(MICROPY_PY_SOCKET),1)
 CFLAGS += -DMICROPY_PY_SOCKET=1
 endif
 ifeq ($(MICROPY_PY_THREAD),1)
+ifeq ($(MICROPY_PY_THREAD_GIL),1)
+CFLAGS += -DMICROPY_PY_THREAD=1 -DMICROPY_PY_THREAD_GIL=1
+else
 CFLAGS += -DMICROPY_PY_THREAD=1 -DMICROPY_PY_THREAD_GIL=0
+endif
 LDFLAGS += $(LIBPTHREAD)
 endif
 

ports/unix/mpconfigport.h

@@ -137,6 +137,9 @@ typedef long mp_off_t;
 #define MICROPY_STACKLESS_STRICT    (0)
 #endif
 
+// Recursive mutex is needed when threading is enabled, regardless of GIL setting.
+#define MICROPY_PY_THREAD_RECURSIVE_MUTEX (MICROPY_PY_THREAD)
+
 // Implementation of the machine module.
 #define MICROPY_PY_MACHINE_INCLUDEFILE "ports/unix/modmachine.c"
 

ports/unix/mpconfigport.mk

@@ -13,6 +13,7 @@ MICROPY_PY_BTREE = 1
 
 # _thread module using pthreads
 MICROPY_PY_THREAD = 1
+MICROPY_PY_THREAD_GIL = 0
 
 # Subset of CPython termios module
 MICROPY_PY_TERMIOS = 1

ports/unix/mphalport.h

@@ -40,7 +40,12 @@
 //
 // Note that we don't delay for the full TIMEOUT_MS, as execution
 // can't be woken from the delay.
-#define MICROPY_INTERNAL_WFE(TIMEOUT_MS) mp_hal_delay_us(500)
+#define MICROPY_INTERNAL_WFE(TIMEOUT_MS) \
+    do { \
+        MP_THREAD_GIL_EXIT(); \
+        mp_hal_delay_us(500); \
+        MP_THREAD_GIL_ENTER(); \
+    } while (0)
 
 void mp_hal_set_interrupt_char(char c);
 

ports/unix/variants/mpconfigvariant_common.h

@@ -29,7 +29,7 @@
 
 // Send raise KeyboardInterrupt directly from the signal handler rather than
 // scheduling it into the VM.
-#define MICROPY_ASYNC_KBD_INTR         (1)
+#define MICROPY_ASYNC_KBD_INTR         (!MICROPY_PY_THREAD_GIL)
 
 // Enable helpers for printing debugging information.
 #ifndef MICROPY_DEBUG_PRINTERS