From 1f54ad2aed0dc8f2d868ccd89ccf639a475e8022 Mon Sep 17 00:00:00 2001
From: Damien George <damien.p.george@gmail.com>
Date: Thu, 26 May 2016 09:06:46 +0000
Subject: [PATCH] py: Make interning of qstrs thread safe.
---
py/mpstate.h | 5 +++++
py/qstr.c | 33 +++++++++++++++++++++++++++++++--
2 files changed, 36 insertions(+), 2 deletions(-)
diff --git a/py/mpstate.h b/py/mpstate.h
index f1f8fd9c5..3ee243dff 100644
--- a/py/mpstate.h
+++ b/py/mpstate.h
@@ -164,6 +164,11 @@ typedef struct _mp_state_vm_t {
size_t qstr_last_alloc;
size_t qstr_last_used;
+ #if MICROPY_PY_THREAD
+ // This is a global mutex used to make qstr interning thread-safe.
+ mp_thread_mutex_t qstr_mutex;
+ #endif
+
mp_uint_t mp_optimise_value;
// size of the emergency exception buf, if it's dynamically allocated
diff --git a/py/qstr.c b/py/qstr.c
index 61202fb4a..39eb696c7 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -72,6 +72,14 @@
#error unimplemented qstr length decoding
#endif
+#if MICROPY_PY_THREAD
+#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
+
// this must match the equivalent function in makeqstrdata.py
mp_uint_t qstr_compute_hash(const byte *data, size_t len) {
// djb2 algorithm; see http://www.cse.yorku.ca/~oz/hash.html
@@ -111,6 +119,10 @@ extern const qstr_pool_t MICROPY_QSTR_EXTRA_POOL;
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
+ mp_thread_mutex_init(&MP_STATE_VM(qstr_mutex));
+ #endif
}
STATIC const byte *find_qstr(qstr q) {
@@ -125,12 +137,17 @@ STATIC const byte *find_qstr(qstr q) {
return 0;
}
+// qstr_mutex must be taken while in this function
STATIC qstr qstr_add(const byte *q_ptr) {
DEBUG_printf("QSTR: add hash=%d len=%d data=%.*s\n", Q_GET_HASH(q_ptr), Q_GET_LENGTH(q_ptr), Q_GET_LENGTH(q_ptr), Q_GET_DATA(q_ptr));
// make sure we have room in the pool for a new qstr
if (MP_STATE_VM(last_pool)->len >= MP_STATE_VM(last_pool)->alloc) {
- qstr_pool_t *pool = m_new_obj_var(qstr_pool_t, const char*, MP_STATE_VM(last_pool)->alloc * 2);
+ qstr_pool_t *pool = m_new_obj_var_maybe(qstr_pool_t, const char*, MP_STATE_VM(last_pool)->alloc * 2);
+ if (pool == NULL) {
+ QSTR_EXIT();
+ m_malloc_fail(MP_STATE_VM(last_pool)->alloc * 2);
+ }
pool->prev = MP_STATE_VM(last_pool);
pool->total_prev_len = MP_STATE_VM(last_pool)->total_prev_len + MP_STATE_VM(last_pool)->len;
pool->alloc = MP_STATE_VM(last_pool)->alloc * 2;
@@ -169,6 +186,7 @@ qstr qstr_from_str(const char *str) {
qstr qstr_from_strn(const char *str, size_t len) {
assert(len < (1 << (8 * MICROPY_QSTR_BYTES_IN_LEN)));
+ QSTR_ENTER();
qstr q = qstr_find_strn(str, len);
if (q == 0) {
// qstr does not exist in interned pool so need to add it
@@ -198,7 +216,11 @@ qstr qstr_from_strn(const char *str, size_t len) {
MP_STATE_VM(qstr_last_chunk) = m_new_maybe(byte, al);
if (MP_STATE_VM(qstr_last_chunk) == NULL) {
// failed to allocate a large chunk so try with exact size
- MP_STATE_VM(qstr_last_chunk) = m_new(byte, n_bytes);
+ MP_STATE_VM(qstr_last_chunk) = m_new_maybe(byte, n_bytes);
+ if (MP_STATE_VM(qstr_last_chunk) == NULL) {
+ QSTR_EXIT();
+ m_malloc_fail(n_bytes);
+ }
al = n_bytes;
}
MP_STATE_VM(qstr_last_alloc) = al;
@@ -217,6 +239,7 @@ qstr qstr_from_strn(const char *str, size_t len) {
q_ptr[MICROPY_QSTR_BYTES_IN_HASH + MICROPY_QSTR_BYTES_IN_LEN + len] = '\0';
q = qstr_add(q_ptr);
}
+ QSTR_EXIT();
return q;
}
@@ -228,6 +251,7 @@ byte *qstr_build_start(size_t len, byte **q_ptr) {
}
qstr qstr_build_end(byte *q_ptr) {
+ QSTR_ENTER();
qstr q = qstr_find_strn((const char*)Q_GET_DATA(q_ptr), Q_GET_LENGTH(q_ptr));
if (q == 0) {
size_t len = Q_GET_LENGTH(q_ptr);
@@ -238,6 +262,7 @@ qstr qstr_build_end(byte *q_ptr) {
} else {
m_del(byte, q_ptr, Q_GET_ALLOC(q_ptr));
}
+ QSTR_EXIT();
return q;
}
@@ -263,6 +288,7 @@ const byte *qstr_data(qstr q, size_t *len) {
}
void qstr_pool_info(size_t *n_pool, size_t *n_qstr, size_t *n_str_data_bytes, size_t *n_total_bytes) {
+ QSTR_ENTER();
*n_pool = 0;
*n_qstr = 0;
*n_str_data_bytes = 0;
@@ -280,14 +306,17 @@ void qstr_pool_info(size_t *n_pool, size_t *n_qstr, size_t *n_str_data_bytes, si
#endif
}
*n_total_bytes += *n_str_data_bytes;
+ QSTR_EXIT();
}
#if MICROPY_PY_MICROPYTHON_MEM_INFO
void qstr_dump_data(void) {
+ QSTR_ENTER();
for (qstr_pool_t *pool = MP_STATE_VM(last_pool); pool != NULL && pool != &CONST_POOL; pool = pool->prev) {
for (const byte **q = pool->qstrs, **q_top = pool->qstrs + pool->len; q < q_top; q++) {
mp_printf(&mp_plat_print, "Q(%s)\n", Q_GET_DATA(*q));
}
}
+ QSTR_EXIT();
}
#endif
--
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