Skip to content

Commit 124df6f

Browse files
dpgeorgedpgeorge
committed
py: Add mp_pending_exception global variable, for VM soft interrupt.
This allows to implement KeyboardInterrupt on unix, and a much safer ctrl-C in stmhal port. First ctrl-C is a soft one, with hope that VM will notice it; second ctrl-C is a hard one that kills anything (for both unix and stmhal). One needs to check for a pending exception in the VM only for jump opcodes. Others can't produce an infinite loop (infinite recursion is caught by stack check).
1 parent d7353fe commit 124df6f

File tree

10 files changed

+71
-14
lines changed

10 files changed

+71
-14
lines changed

‎py/obj.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -330,6 +330,7 @@ extern const mp_obj_type_t mp_type_GeneratorExit;
330330
extern const mp_obj_type_t mp_type_ImportError;
331331
extern const mp_obj_type_t mp_type_IndentationError;
332332
extern const mp_obj_type_t mp_type_IndexError;
333+
extern const mp_obj_type_t mp_type_KeyboardInterrupt;
333334
extern const mp_obj_type_t mp_type_KeyError;
334335
extern const mp_obj_type_t mp_type_LookupError;
335336
extern const mp_obj_type_t mp_type_MemoryError;

‎py/objexcept.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -211,7 +211,7 @@ const mp_obj_type_t mp_type_ ## exc_name = { \
211211
// http://docs.python.org/3/library/exceptions.html
212212
MP_DEFINE_EXCEPTION_BASE(BaseException)
213213
MP_DEFINE_EXCEPTION(SystemExit, BaseException)
214-
//MP_DEFINE_EXCEPTION(KeyboardInterrupt, BaseException)
214+
MP_DEFINE_EXCEPTION(KeyboardInterrupt, BaseException)
215215
MP_DEFINE_EXCEPTION(GeneratorExit, BaseException)
216216
MP_DEFINE_EXCEPTION(Exception, BaseException)
217217
MP_DEFINE_EXCEPTION_BASE(Exception)

‎py/qstrdefs.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -108,6 +108,7 @@ Q(GeneratorExit)
108108
Q(ImportError)
109109
Q(IndentationError)
110110
Q(IndexError)
111+
Q(KeyboardInterrupt)
111112
Q(KeyError)
112113
Q(LookupError)
113114
Q(MemoryError)

‎py/runtime.c‎

Lines changed: 6 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -62,6 +62,9 @@
6262
#define DEBUG_OP_printf(...) (void)0
6363
#endif
6464

65+
// pending exception object (MP_OBJ_NULL if not pending)
66+
mp_obj_t mp_pending_exception;
67+
6568
// locals and globals need to be pointers because they can be the same in outer module scope
6669
STATIC mp_obj_dict_t *dict_locals;
6770
STATIC mp_obj_dict_t *dict_globals;
@@ -79,6 +82,9 @@ void mp_init(void) {
7982
qstr_init();
8083
mp_stack_ctrl_init();
8184

85+
// no pending exceptions to start with
86+
mp_pending_exception = MP_OBJ_NULL;
87+
8288
#if MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF
8389
mp_init_emergency_exception_buf();
8490
#endif

‎py/runtime.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -116,6 +116,7 @@ mp_obj_t mp_convert_native_to_obj(mp_uint_t val, mp_uint_t type);
116116
mp_obj_t mp_native_call_function_n_kw(mp_obj_t fun_in, mp_uint_t n_args_kw, const mp_obj_t *args);
117117
NORETURN void mp_native_raise(mp_obj_t o);
118118

119+
extern mp_obj_t mp_pending_exception;
119120
extern struct _mp_obj_list_t mp_sys_path_obj;
120121
extern struct _mp_obj_list_t mp_sys_argv_obj;
121122
#define mp_sys_path ((mp_obj_t)&mp_sys_path_obj)

‎py/vm.c‎

Lines changed: 17 additions & 6 deletions
Original file line numberDiff line numberDiff line change
@@ -110,10 +110,12 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state *code_state, volatile mp_o
110110
code_state->ip = ip; \
111111
goto *entry_table[*ip++]; \
112112
} while(0)
113+
#define DISPATCH_WITH_PEND_EXC_CHECK() goto pending_exception_check
113114
#define ENTRY(op) entry_##op
114115
#define ENTRY_DEFAULT entry_default
115116
#else
116117
#define DISPATCH() break
118+
#define DISPATCH_WITH_PEND_EXC_CHECK() goto pending_exception_check
117119
#define ENTRY(op) case op
118120
#define ENTRY_DEFAULT default
119121
#endif
@@ -372,21 +374,21 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state *code_state, volatile mp_o
372374
ENTRY(MP_BC_JUMP):
373375
DECODE_SLABEL;
374376
ip += unum;
375-
DISPATCH();
377+
DISPATCH_WITH_PEND_EXC_CHECK();
376378

377379
ENTRY(MP_BC_POP_JUMP_IF_TRUE):
378380
DECODE_SLABEL;
379381
if (mp_obj_is_true(POP())) {
380382
ip += unum;
381383
}
382-
DISPATCH();
384+
DISPATCH_WITH_PEND_EXC_CHECK();
383385

384386
ENTRY(MP_BC_POP_JUMP_IF_FALSE):
385387
DECODE_SLABEL;
386388
if (!mp_obj_is_true(POP())) {
387389
ip += unum;
388390
}
389-
DISPATCH();
391+
DISPATCH_WITH_PEND_EXC_CHECK();
390392

391393
ENTRY(MP_BC_JUMP_IF_TRUE_OR_POP):
392394
DECODE_SLABEL;
@@ -395,7 +397,7 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state *code_state, volatile mp_o
395397
} else {
396398
sp--;
397399
}
398-
DISPATCH();
400+
DISPATCH_WITH_PEND_EXC_CHECK();
399401

400402
ENTRY(MP_BC_JUMP_IF_FALSE_OR_POP):
401403
DECODE_SLABEL;
@@ -404,7 +406,7 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state *code_state, volatile mp_o
404406
} else {
405407
ip += unum;
406408
}
407-
DISPATCH();
409+
DISPATCH_WITH_PEND_EXC_CHECK();
408410

409411
ENTRY(MP_BC_SETUP_WITH): {
410412
mp_obj_t obj = TOP();
@@ -502,7 +504,7 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state *code_state, volatile mp_o
502504
if (unum != 0) {
503505
sp--;
504506
}
505-
DISPATCH();
507+
DISPATCH_WITH_PEND_EXC_CHECK();
506508

507509
// matched against: POP_BLOCK or POP_EXCEPT (anything else?)
508510
ENTRY(MP_BC_SETUP_EXCEPT):
@@ -909,6 +911,15 @@ mp_vm_return_kind_t mp_execute_bytecode(mp_code_state *code_state, volatile mp_o
909911
#if !MICROPY_OPT_COMPUTED_GOTO
910912
} // switch
911913
#endif
914+
915+
pending_exception_check:
916+
if (mp_pending_exception != MP_OBJ_NULL) {
917+
mp_obj_t obj = mp_pending_exception;
918+
mp_pending_exception = MP_OBJ_NULL;
919+
RAISE(obj);
920+
}
921+
DISPATCH();
922+
912923
} // for loop
913924

914925
} else {

‎stmhal/pendsv.c‎

Lines changed: 16 additions & 5 deletions
Original file line numberDiff line numberDiff line change
@@ -31,6 +31,7 @@
3131
#include "misc.h"
3232
#include "qstr.h"
3333
#include "obj.h"
34+
#include "runtime.h"
3435
#include "pendsv.h"
3536

3637
static void *pendsv_object = NULL;
@@ -40,12 +41,22 @@ void pendsv_init(void) {
4041
HAL_NVIC_SetPriority(PendSV_IRQn, 0xf, 0xf);
4142
}
4243

43-
// call this function to raise a pending exception during an interrupt
44-
// it will wait until all interrupts are finished then raise the given
45-
// exception object using nlr_jump in the context of the top-level thread
44+
// Call this function to raise a pending exception during an interrupt.
45+
// It will first try to raise the exception "softly" by setting the
46+
// mp_pending_exception variable and hoping that the VM will notice it.
47+
// If this function is called a second time (ie with the mp_pending_exception
48+
// variable already set) then it will force the exception by using the hardware
49+
// PENDSV feature. This will wait until all interrupts are finished then raise
50+
// the given exception object using nlr_jump in the context of the top-level
51+
// thread.
4652
void pendsv_nlr_jump(void *o) {
47-
pendsv_object = o;
48-
SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
53+
if (mp_pending_exception == MP_OBJ_NULL) {
54+
mp_pending_exception = o;
55+
} else {
56+
mp_pending_exception = MP_OBJ_NULL;
57+
pendsv_object = o;
58+
SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
59+
}
4960
}
5061

5162
// since we play tricks with the stack, the compiler must not generate a

‎stmhal/usb.c‎

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -50,7 +50,7 @@ STATIC mp_obj_t mp_const_vcp_interrupt = MP_OBJ_NULL;
5050

5151
void pyb_usb_init0(void) {
5252
// create an exception object for interrupting by VCP
53-
mp_const_vcp_interrupt = mp_obj_new_exception_msg(&mp_type_OSError, "VCPInterrupt");
53+
mp_const_vcp_interrupt = mp_obj_new_exception(&mp_type_KeyboardInterrupt);
5454
USBD_CDC_SetInterrupt(VCP_CHAR_NONE, mp_const_vcp_interrupt);
5555
}
5656

‎stmhal/usbd_cdc_interface.c‎

Lines changed: 0 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -374,7 +374,6 @@ static int8_t CDC_Itf_Receive(uint8_t* Buf, uint32_t *Len) {
374374

375375
if (char_found) {
376376
// raise exception when interrupts are finished
377-
user_interrupt_char = VCP_CHAR_NONE;
378377
pendsv_nlr_jump(user_interrupt_data);
379378
}
380379

‎unix/main.c‎

Lines changed: 27 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -34,6 +34,7 @@
3434
#include <sys/stat.h>
3535
#include <sys/types.h>
3636
#include <errno.h>
37+
#include <signal.h>
3738

3839
#include "mpconfig.h"
3940
#include "nlr.h"
@@ -64,6 +65,20 @@ mp_uint_t mp_verbose_flag = 0;
6465
long heap_size = 128*1024 * (sizeof(mp_uint_t) / 4);
6566
#endif
6667

68+
STATIC mp_obj_t keyboard_interrupt_obj;
69+
70+
STATIC void sighandler(int signum) {
71+
if (signum == SIGINT) {
72+
mp_obj_exception_clear_traceback(keyboard_interrupt_obj);
73+
mp_pending_exception = keyboard_interrupt_obj;
74+
// disable our handler so next we really die
75+
struct sigaction sa;
76+
sa.sa_handler = SIG_DFL;
77+
sigemptyset(&sa.sa_mask);
78+
sigaction(SIGINT, &sa, NULL);
79+
}
80+
}
81+
6782
#define FORCED_EXIT (0x100)
6883
// returns standard error codes: 0 for success, 1 for all other errors
6984
// if FORCED_EXIT bit is set then script raised SystemExit and the
@@ -119,14 +134,23 @@ STATIC int execute_from_lexer(mp_lexer_t *lex, mp_parse_input_kind_t input_kind,
119134
return 0;
120135
}
121136

137+
// enable signal handler
138+
struct sigaction sa;
139+
sa.sa_handler = sighandler;
140+
sigemptyset(&sa.sa_mask);
141+
sigaction(SIGINT, &sa, NULL);
142+
sa.sa_handler = SIG_DFL;
143+
122144
// execute it
123145
nlr_buf_t nlr;
124146
if (nlr_push(&nlr) == 0) {
125147
mp_call_function_0(module_fun);
148+
sigaction(SIGINT, &sa, NULL);
126149
nlr_pop();
127150
return 0;
128151
} else {
129152
// uncaught exception
153+
sigaction(SIGINT, &sa, NULL);
130154
// check for SystemExit
131155
mp_obj_t exc = (mp_obj_t)nlr.ret_val;
132156
if (mp_obj_is_subclass_fast(mp_obj_get_type(exc), &mp_type_SystemExit)) {
@@ -305,6 +329,9 @@ int main(int argc, char **argv) {
305329

306330
mp_init();
307331

332+
// create keyboard interrupt object
333+
keyboard_interrupt_obj = mp_obj_new_exception(&mp_type_KeyboardInterrupt);
334+
308335
char *home = getenv("HOME");
309336
char *path = getenv("MICROPYPATH");
310337
if (path == NULL) {

0 commit comments

Comments
 (0)