#include <side/trace.h>
#include <string.h>
+#include <assert.h>
-#include "tracer.h"
#include "rcu.h"
#include "list.h"
void *priv;
};
+struct side_callback {
+ union {
+ void (*call)(const struct side_event_description *desc,
+ const struct side_arg_vec *side_arg_vec,
+ void *priv);
+ void (*call_variadic)(const struct side_event_description *desc,
+ const struct side_arg_vec *side_arg_vec,
+ const struct side_arg_dynamic_struct *var_struct,
+ void *priv);
+ } u;
+ void *priv;
+ void *key;
+};
+
static struct side_rcu_gp_state rcu_gp;
/*
*/
static bool finalized;
-static pthread_mutex_t side_lock = PTHREAD_MUTEX_INITIALIZER;
+/*
+ * Recursive mutex to allow tracer callbacks to use the side API.
+ */
+static pthread_mutex_t side_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP;
static DEFINE_SIDE_LIST_HEAD(side_events_list);
static DEFINE_SIDE_LIST_HEAD(side_tracer_list);
* The empty callback has a NULL function callback pointer, which stops
* iteration on the array of callbacks immediately.
*/
-const struct side_callback side_empty_callback;
+const char side_empty_callback[sizeof(struct side_callback)];
-void side_init(void) __attribute__((constructor));
-void side_exit(void) __attribute__((destructor));
-
-void side_call(const struct side_event_description *desc, const struct side_arg_vec_description *sav_desc)
+void side_call_key(const struct side_event_state *event_state, const struct side_arg_vec *side_arg_vec, void *key)
{
+ struct side_rcu_read_state rcu_read_state;
+ const struct side_event_state_0 *es0;
const struct side_callback *side_cb;
- unsigned int rcu_period;
uintptr_t enabled;
if (side_unlikely(finalized))
return;
if (side_unlikely(!initialized))
side_init();
- if (side_unlikely(desc->flags & SIDE_EVENT_FLAG_VARIADIC)) {
- printf("ERROR: unexpected variadic event description\n");
+ if (side_unlikely(event_state->version != 0))
abort();
- }
- enabled = __atomic_load_n(desc->enabled, __ATOMIC_RELAXED);
+ es0 = side_container_of(event_state, const struct side_event_state_0, parent);
+ assert(!(es0->desc->flags & SIDE_EVENT_FLAG_VARIADIC));
+ enabled = __atomic_load_n(&es0->enabled, __ATOMIC_RELAXED);
if (side_unlikely(enabled & SIDE_EVENT_ENABLED_KERNEL_USER_EVENT_MASK)) {
// TODO: call kernel write.
}
- if (side_unlikely(!(enabled & SIDE_EVENT_ENABLED_USER_MASK)))
- return;
+ side_rcu_read_begin(&rcu_gp, &rcu_read_state);
+ for (side_cb = side_rcu_dereference(es0->callbacks); side_cb->u.call != NULL; side_cb++) {
+ /* A NULL key is always a match. */
+ if (key && side_cb->key && side_cb->key != key)
+ continue;
+ side_cb->u.call(es0->desc, side_arg_vec, side_cb->priv);
+ }
+ side_rcu_read_end(&rcu_gp, &rcu_read_state);
+}
- rcu_period = side_rcu_read_begin(&rcu_gp);
- for (side_cb = side_rcu_dereference(desc->callbacks); side_cb->u.call != NULL; side_cb++)
- side_cb->u.call(desc, sav_desc, side_cb->priv);
- side_rcu_read_end(&rcu_gp, rcu_period);
+void side_call(const struct side_event_state *event_state, const struct side_arg_vec *side_arg_vec)
+{
+ side_call_key(event_state, side_arg_vec, NULL);
}
-void side_call_variadic(const struct side_event_description *desc,
- const struct side_arg_vec_description *sav_desc,
- const struct side_arg_dynamic_event_struct *var_struct)
+void side_call_variadic_key(const struct side_event_state *event_state,
+ const struct side_arg_vec *side_arg_vec,
+ const struct side_arg_dynamic_struct *var_struct,
+ void *key)
{
+ struct side_rcu_read_state rcu_read_state;
+ const struct side_event_state_0 *es0;
const struct side_callback *side_cb;
- unsigned int rcu_period;
uintptr_t enabled;
if (side_unlikely(finalized))
return;
if (side_unlikely(!initialized))
side_init();
- if (side_unlikely(!(desc->flags & SIDE_EVENT_FLAG_VARIADIC))) {
- printf("ERROR: unexpected non-variadic event description\n");
+ if (side_unlikely(event_state->version != 0))
abort();
- }
- enabled = __atomic_load_n(desc->enabled, __ATOMIC_RELAXED);
+ es0 = side_container_of(event_state, const struct side_event_state_0, parent);
+ assert(es0->desc->flags & SIDE_EVENT_FLAG_VARIADIC);
+ enabled = __atomic_load_n(&es0->enabled, __ATOMIC_RELAXED);
if (side_unlikely(enabled & SIDE_EVENT_ENABLED_KERNEL_USER_EVENT_MASK)) {
// TODO: call kernel write.
}
- if (side_unlikely(!(enabled & SIDE_EVENT_ENABLED_USER_MASK)))
- return;
+ side_rcu_read_begin(&rcu_gp, &rcu_read_state);
+ for (side_cb = side_rcu_dereference(es0->callbacks); side_cb->u.call_variadic != NULL; side_cb++) {
+ /* A NULL key is always a match. */
+ if (key && side_cb->key && side_cb->key != key)
+ continue;
+ side_cb->u.call_variadic(es0->desc, side_arg_vec, var_struct, side_cb->priv);
+ }
+ side_rcu_read_end(&rcu_gp, &rcu_read_state);
+}
- rcu_period = side_rcu_read_begin(&rcu_gp);
- for (side_cb = side_rcu_dereference(desc->callbacks); side_cb->u.call_variadic != NULL; side_cb++)
- side_cb->u.call_variadic(desc, sav_desc, var_struct, side_cb->priv);
- side_rcu_read_end(&rcu_gp, rcu_period);
+void side_call_variadic(const struct side_event_state *event_state,
+ const struct side_arg_vec *side_arg_vec,
+ const struct side_arg_dynamic_struct *var_struct)
+{
+ side_call_variadic_key(event_state, side_arg_vec, var_struct, NULL);
}
static
const struct side_callback *side_tracer_callback_lookup(
const struct side_event_description *desc,
- void (*call)(), void *priv)
+ void *call, void *priv, void *key)
{
+ struct side_event_state *event_state = side_ptr_get(desc->state);
+ const struct side_event_state_0 *es0;
const struct side_callback *cb;
- for (cb = desc->callbacks; cb->u.call != NULL; cb++) {
- if (cb->u.call == call && cb->priv == priv)
+ if (side_unlikely(event_state->version != 0))
+ abort();
+ es0 = side_container_of(event_state, const struct side_event_state_0, parent);
+ for (cb = es0->callbacks; cb->u.call != NULL; cb++) {
+ if ((void *) cb->u.call == call && cb->priv == priv && cb->key == key)
return cb;
}
return NULL;
static
int _side_tracer_callback_register(struct side_event_description *desc,
- void (*call)(), void *priv)
+ void *call, void *priv, void *key)
{
+ struct side_event_state *event_state;
struct side_callback *old_cb, *new_cb;
+ struct side_event_state_0 *es0;
int ret = SIDE_ERROR_OK;
uint32_t old_nr_cb;
if (!initialized)
side_init();
pthread_mutex_lock(&side_lock);
- old_nr_cb = desc->nr_callbacks;
+ event_state = side_ptr_get(desc->state);
+ if (side_unlikely(event_state->version != 0))
+ abort();
+ es0 = side_container_of(event_state, struct side_event_state_0, parent);
+ old_nr_cb = es0->nr_callbacks;
if (old_nr_cb == UINT32_MAX) {
ret = SIDE_ERROR_INVAL;
goto unlock;
}
/* Reject duplicate (call, priv) tuples. */
- if (side_tracer_callback_lookup(desc, call, priv)) {
+ if (side_tracer_callback_lookup(desc, call, priv, key)) {
ret = SIDE_ERROR_EXIST;
goto unlock;
}
- old_cb = (struct side_callback *) desc->callbacks;
+ old_cb = (struct side_callback *) es0->callbacks;
/* old_nr_cb + 1 (new cb) + 1 (NULL) */
new_cb = (struct side_callback *) calloc(old_nr_cb + 2, sizeof(struct side_callback));
if (!new_cb) {
}
memcpy(new_cb, old_cb, old_nr_cb);
if (desc->flags & SIDE_EVENT_FLAG_VARIADIC)
- new_cb[old_nr_cb].u.call_variadic = call;
+ new_cb[old_nr_cb].u.call_variadic =
+ (side_tracer_callback_variadic_func) call;
else
- new_cb[old_nr_cb].u.call = call;
+ new_cb[old_nr_cb].u.call =
+ (side_tracer_callback_func) call;
new_cb[old_nr_cb].priv = priv;
- side_rcu_assign_pointer(desc->callbacks, new_cb);
+ new_cb[old_nr_cb].key = key;
+ /* High order bits are already zeroed. */
+ side_rcu_assign_pointer(es0->callbacks, new_cb);
side_rcu_wait_grace_period(&rcu_gp);
if (old_nr_cb)
free(old_cb);
- desc->nr_callbacks++;
+ es0->nr_callbacks++;
/* Increment concurrently with kernel setting the top bits. */
if (!old_nr_cb)
- (void) __atomic_add_fetch(desc->enabled, 1, __ATOMIC_RELAXED);
+ (void) __atomic_add_fetch(&es0->enabled, 1, __ATOMIC_RELAXED);
unlock:
pthread_mutex_unlock(&side_lock);
return ret;
}
int side_tracer_callback_register(struct side_event_description *desc,
- void (*call)(const struct side_event_description *desc,
- const struct side_arg_vec_description *sav_desc,
- void *priv),
- void *priv)
+ side_tracer_callback_func call,
+ void *priv, void *key)
{
if (desc->flags & SIDE_EVENT_FLAG_VARIADIC)
return SIDE_ERROR_INVAL;
- return _side_tracer_callback_register(desc, call, priv);
+ return _side_tracer_callback_register(desc, (void *) call, priv, key);
}
int side_tracer_callback_variadic_register(struct side_event_description *desc,
- void (*call_variadic)(const struct side_event_description *desc,
- const struct side_arg_vec_description *sav_desc,
- const struct side_arg_dynamic_event_struct *var_struct,
- void *priv),
- void *priv)
+ side_tracer_callback_variadic_func call_variadic,
+ void *priv, void *key)
{
if (!(desc->flags & SIDE_EVENT_FLAG_VARIADIC))
return SIDE_ERROR_INVAL;
- return _side_tracer_callback_register(desc, call_variadic, priv);
+ return _side_tracer_callback_register(desc, (void *) call_variadic, priv, key);
}
-int _side_tracer_callback_unregister(struct side_event_description *desc,
- void (*call)(), void *priv)
+static int _side_tracer_callback_unregister(struct side_event_description *desc,
+ void *call, void *priv, void *key)
{
+ struct side_event_state *event_state;
struct side_callback *old_cb, *new_cb;
const struct side_callback *cb_pos;
+ struct side_event_state_0 *es0;
uint32_t pos_idx;
int ret = SIDE_ERROR_OK;
uint32_t old_nr_cb;
if (!initialized)
side_init();
pthread_mutex_lock(&side_lock);
- cb_pos = side_tracer_callback_lookup(desc, call, priv);
+ event_state = side_ptr_get(desc->state);
+ if (side_unlikely(event_state->version != 0))
+ abort();
+ es0 = side_container_of(event_state, struct side_event_state_0, parent);
+ cb_pos = side_tracer_callback_lookup(desc, call, priv, key);
if (!cb_pos) {
ret = SIDE_ERROR_NOENT;
goto unlock;
}
- old_nr_cb = desc->nr_callbacks;
- old_cb = (struct side_callback *) desc->callbacks;
+ old_nr_cb = es0->nr_callbacks;
+ old_cb = (struct side_callback *) es0->callbacks;
if (old_nr_cb == 1) {
new_cb = (struct side_callback *) &side_empty_callback;
} else {
- pos_idx = cb_pos - desc->callbacks;
+ pos_idx = cb_pos - es0->callbacks;
/* Remove entry at pos_idx. */
/* old_nr_cb - 1 (removed cb) + 1 (NULL) */
new_cb = (struct side_callback *) calloc(old_nr_cb, sizeof(struct side_callback));
memcpy(new_cb, old_cb, pos_idx);
memcpy(&new_cb[pos_idx], &old_cb[pos_idx + 1], old_nr_cb - pos_idx - 1);
}
- side_rcu_assign_pointer(desc->callbacks, new_cb);
+ /* High order bits are already zeroed. */
+ side_rcu_assign_pointer(es0->callbacks, new_cb);
side_rcu_wait_grace_period(&rcu_gp);
free(old_cb);
- desc->nr_callbacks--;
+ es0->nr_callbacks--;
/* Decrement concurrently with kernel setting the top bits. */
if (old_nr_cb == 1)
- (void) __atomic_add_fetch(desc->enabled, -1, __ATOMIC_RELAXED);
+ (void) __atomic_add_fetch(&es0->enabled, -1, __ATOMIC_RELAXED);
unlock:
pthread_mutex_unlock(&side_lock);
return ret;
}
int side_tracer_callback_unregister(struct side_event_description *desc,
- void (*call)(const struct side_event_description *desc,
- const struct side_arg_vec_description *sav_desc,
- void *priv),
- void *priv)
+ side_tracer_callback_func call,
+ void *priv, void *key)
{
if (desc->flags & SIDE_EVENT_FLAG_VARIADIC)
return SIDE_ERROR_INVAL;
- return _side_tracer_callback_unregister(desc, call, priv);
+ return _side_tracer_callback_unregister(desc, (void *) call, priv, key);
}
int side_tracer_callback_variadic_unregister(struct side_event_description *desc,
- void (*call_variadic)(const struct side_event_description *desc,
- const struct side_arg_vec_description *sav_desc,
- const struct side_arg_dynamic_event_struct *var_struct,
- void *priv),
- void *priv)
+ side_tracer_callback_variadic_func call_variadic,
+ void *priv, void *key)
{
if (!(desc->flags & SIDE_EVENT_FLAG_VARIADIC))
return SIDE_ERROR_INVAL;
- return _side_tracer_callback_unregister(desc, call_variadic, priv);
+ return _side_tracer_callback_unregister(desc, (void *) call_variadic, priv, key);
}
struct side_events_register_handle *side_events_register(struct side_event_description **events, uint32_t nr_events)
return NULL;
if (!initialized)
side_init();
- events_handle = calloc(1, sizeof(struct side_events_register_handle));
+ events_handle = (struct side_events_register_handle *)
+ calloc(1, sizeof(struct side_events_register_handle));
if (!events_handle)
return NULL;
events_handle->events = events;
static
void side_event_remove_callbacks(struct side_event_description *desc)
{
- uint32_t nr_cb = desc->nr_callbacks;
+ struct side_event_state *event_state = side_ptr_get(desc->state);
+ struct side_event_state_0 *es0;
struct side_callback *old_cb;
+ uint32_t nr_cb;
+ if (side_unlikely(event_state->version != 0))
+ abort();
+ es0 = side_container_of(event_state, struct side_event_state_0, parent);
+ nr_cb = es0->nr_callbacks;
if (!nr_cb)
return;
- old_cb = (struct side_callback *) desc->callbacks;
- (void) __atomic_add_fetch(desc->enabled, -1, __ATOMIC_RELAXED);
+ old_cb = (struct side_callback *) es0->callbacks;
+ (void) __atomic_add_fetch(&es0->enabled, -1, __ATOMIC_RELAXED);
/*
* Setting the state back to 0 cb and empty callbacks out of
* caution. This should not matter because instrumentation is
* unreachable.
*/
- desc->nr_callbacks = 0;
- side_rcu_assign_pointer(desc->callbacks, &side_empty_callback);
+ es0->nr_callbacks = 0;
+ side_rcu_assign_pointer(es0->callbacks, &side_empty_callback);
/*
* No need to wait for grace period because instrumentation is
* unreachable.
return NULL;
if (!initialized)
side_init();
- tracer_handle = calloc(1, sizeof(struct side_tracer_handle));
+ tracer_handle = (struct side_tracer_handle *)
+ calloc(1, sizeof(struct side_tracer_handle));
if (!tracer_handle)
return NULL;
pthread_mutex_lock(&side_lock);
}
side_list_remove_node(&tracer_handle->node);
pthread_mutex_unlock(&side_lock);
+ free(tracer_handle);
}
void side_init(void)
if (finalized)
return;
- side_rcu_gp_exit(&rcu_gp);
side_list_for_each_entry_safe(handle, tmp, &side_events_list, node)
side_events_unregister(handle);
+ side_rcu_gp_exit(&rcu_gp);
finalized = true;
}
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