py: Add emergency exception object for when heap allocation fails.

This commit is contained in:
Damien George 2014-04-10 14:38:25 +01:00
parent 6f355fd3b9
commit f0954e3fac
3 changed files with 54 additions and 20 deletions

View File

@ -53,6 +53,20 @@ void *m_malloc(int num_bytes) {
return ptr;
}
void *m_malloc_maybe(int num_bytes) {
void *ptr = malloc(num_bytes);
if (ptr == NULL) {
return NULL;
}
#if MICROPY_MEM_STATS
total_bytes_allocated += num_bytes;
current_bytes_allocated += num_bytes;
UPDATE_PEAK();
#endif
DEBUG_printf("malloc %d : %p\n", num_bytes, ptr);
return ptr;
}
#if MICROPY_ENABLE_FINALISER
void *m_malloc_with_finaliser(int num_bytes) {
if (num_bytes == 0) {

View File

@ -38,6 +38,7 @@ typedef unsigned int uint;
#define m_del_var(obj_type, var_type, var_num, ptr) (m_free(ptr, sizeof(obj_type) + sizeof(var_type) * (var_num)))
void *m_malloc(int num_bytes);
void *m_malloc_maybe(int num_bytes);
void *m_malloc_with_finaliser(int num_bytes);
void *m_malloc0(int num_bytes);
void *m_realloc(void *ptr, int old_num_bytes, int new_num_bytes);

View File

@ -20,6 +20,9 @@ typedef struct _mp_obj_exception_t {
// Instance of MemoryError exception - needed by mp_malloc_fail
const mp_obj_exception_t mp_const_MemoryError_obj = {{&mp_type_MemoryError}, MP_OBJ_NULL, {{&mp_type_tuple}, 0}};
// Local non-heap memory for allocating an exception when we run out of RAM
STATIC mp_obj_exception_t mp_emergency_exception_obj;
// Instance of GeneratorExit exception - needed by generator.close()
// This would belong to objgenerator.c, but to keep mp_obj_exception_t
// definition module-private so far, have it here.
@ -51,7 +54,13 @@ STATIC mp_obj_t mp_obj_exception_make_new(mp_obj_t type_in, uint n_args, uint n_
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "%s does not take keyword arguments", mp_obj_get_type_str(type_in)));
}
mp_obj_exception_t *o = m_new_obj_var(mp_obj_exception_t, mp_obj_t, n_args);
mp_obj_exception_t *o = m_malloc_maybe(sizeof(mp_obj_exception_t) + n_args * sizeof(mp_obj_t));
if (o == NULL) {
// Couldn't allocate heap memory; use local data instead.
o = &mp_emergency_exception_obj;
// We can't store any args.
n_args = 0;
}
o->base.type = type;
o->traceback = MP_OBJ_NULL;
o->args.base.type = &mp_type_tuple;
@ -196,25 +205,35 @@ mp_obj_t mp_obj_new_exception_msg_varg(const mp_obj_type_t *exc_type, const char
assert(exc_type->make_new == mp_obj_exception_make_new);
// make exception object
mp_obj_exception_t *o = m_new_obj_var(mp_obj_exception_t, mp_obj_t, 1);
o->base.type = exc_type;
o->traceback = MP_OBJ_NULL;
o->args.base.type = &mp_type_tuple;
o->args.len = 1;
if (fmt == NULL) {
// no message
assert(0);
mp_obj_exception_t *o = m_malloc_maybe(sizeof(mp_obj_exception_t) + 1 * sizeof(mp_obj_t));
if (o == NULL) {
// Couldn't allocate heap memory; use local data instead.
// Unfortunately, we won't be able to format the string...
o = &mp_emergency_exception_obj;
o->base.type = exc_type;
o->traceback = MP_OBJ_NULL;
o->args.base.type = &mp_type_tuple;
o->args.len = 0;
} else {
// render exception message and store as .args[0]
// TODO: optimize bufferbloat
vstr_t *vstr = vstr_new();
va_list ap;
va_start(ap, fmt);
vstr_vprintf(vstr, fmt, ap);
va_end(ap);
o->args.items[0] = mp_obj_new_str((byte*)vstr->buf, vstr->len, false);
vstr_free(vstr);
o->base.type = exc_type;
o->traceback = MP_OBJ_NULL;
o->args.base.type = &mp_type_tuple;
o->args.len = 1;
if (fmt == NULL) {
// no message
assert(0);
} else {
// render exception message and store as .args[0]
// TODO: optimize bufferbloat
vstr_t *vstr = vstr_new();
va_list ap;
va_start(ap, fmt);
vstr_vprintf(vstr, fmt, ap);
va_end(ap);
o->args.items[0] = mp_obj_new_str((byte*)vstr->buf, vstr->len, false);
vstr_free(vstr);
}
}
return o;
@ -259,7 +278,7 @@ void mp_obj_exception_clear_traceback(mp_obj_t self_in) {
void mp_obj_exception_add_traceback(mp_obj_t self_in, qstr file, machine_uint_t line, qstr block) {
// make sure self_in is an exception instance
// TODO add traceback information to user-defined exceptions (need proper builtin subclassing for that)
if (mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new) {
if (mp_obj_get_type(self_in)->make_new == mp_obj_exception_make_new && self_in != &mp_emergency_exception_obj) {
mp_obj_exception_t *self = self_in;
// for traceback, we are just using the list object for convenience, it's not really a list of Python objects