Generalize futex observers for the compare_exchanges in lockless_queue
This is necessary to get lockless_queue_death_test running on aarch64.
Change-Id: I621fe55fac4d43a8e40d053d4f069d618e738f7d
Signed-off-by: Austin Schuh <austin.schuh@bluerivertech.com>
diff --git a/aos/ipc_lib/aos_sync.cc b/aos/ipc_lib/aos_sync.cc
index 6407a57..861a6fe 100644
--- a/aos/ipc_lib/aos_sync.cc
+++ b/aos/ipc_lib/aos_sync.cc
@@ -20,6 +20,8 @@
#include <cstdint>
#include <cstring>
+#include "aos/ipc_lib/shm_observers.h"
+
#ifdef AOS_SANITIZER_thread
#include <sanitizer/tsan_interface_atomic.h>
#endif
@@ -33,7 +35,7 @@
#include "aos/util/compiler_memory_barrier.h"
#include "glog/logging.h"
-using ::aos::linux_code::ipc_lib::FutexAccessorObserver;
+using ::aos::linux_code::ipc_lib::RunShmObservers;
// This code was originally based on
// <https://www.akkadia.org/drepper/futex.pdf>, but is has since evolved a lot.
@@ -680,34 +682,6 @@
my_robust_list::Init();
}
-FutexAccessorObserver before_observer = nullptr, after_observer = nullptr;
-
-// RAII class which runs before_observer during construction and after_observer
-// during destruction.
-class RunObservers {
- public:
- template <class T>
- RunObservers(T *address, bool write)
- : address_(static_cast<void *>(
- const_cast<typename ::std::remove_cv<T>::type *>(address))),
- write_(write) {
- if (__builtin_expect(before_observer != nullptr, false)) {
- before_observer(address_, write_);
- }
- }
- ~RunObservers() {
- if (__builtin_expect(after_observer != nullptr, false)) {
- after_observer(address_, write_);
- }
- }
-
- private:
- void *const address_;
- const bool write_;
-
- DISALLOW_COPY_AND_ASSIGN(RunObservers);
-};
-
// Finishes the locking of a mutex by potentially clearing FUTEX_OWNER_DIED in
// the futex and returning the correct value.
inline int mutex_finish_lock(aos_mutex *m) {
@@ -726,7 +700,7 @@
// own my_robust_list::Adder.
inline int mutex_do_get(aos_mutex *m, bool signals_fail,
const struct timespec *timeout, uint32_t tid) {
- RunObservers run_observers(m, true);
+ RunShmObservers run_observers(m, true);
if (kPrintOperations) {
printf("%" PRId32 ": %p do_get\n", tid, m);
}
@@ -794,7 +768,7 @@
// number_requeue is the number of waiters to requeue (probably INT_MAX or 0). 1
// will always be woken.
void condition_wake(aos_condition *c, aos_mutex *m, int number_requeue) {
- RunObservers run_observers(c, true);
+ RunShmObservers run_observers(c, true);
// Make it so that anybody just going to sleep won't.
// This is where we might accidentally wake more than just 1 waiter with 1
// signal():
@@ -838,7 +812,7 @@
int mutex_grab(aos_mutex *m) { return mutex_get(m, false, NULL); }
void mutex_unlock(aos_mutex *m) {
- RunObservers run_observers(m, true);
+ RunShmObservers run_observers(m, true);
const uint32_t tid = get_tid();
if (kPrintOperations) {
printf("%" PRId32 ": %p unlock\n", tid, m);
@@ -874,7 +848,7 @@
}
int mutex_trylock(aos_mutex *m) {
- RunObservers run_observers(m, true);
+ RunShmObservers run_observers(m, true);
const uint32_t tid = get_tid();
if (kPrintOperations) {
printf("%" PRId32 ": %p trylock\n", tid, m);
@@ -929,14 +903,14 @@
}
my_robust_list::Adder adder(m);
{
- RunObservers run_observers(m, true);
+ RunShmObservers run_observers(m, true);
CHECK(compare_and_swap(&m->futex, 0, tid));
}
adder.Add();
}
void death_notification_release(aos_mutex *m) {
- RunObservers run_observers(m, true);
+ RunShmObservers run_observers(m, true);
#ifndef NDEBUG
// Verify it's "locked", like it should be.
@@ -961,7 +935,7 @@
}
int condition_wait(aos_condition *c, aos_mutex *m, struct timespec *end_time) {
- RunObservers run_observers(c, false);
+ RunShmObservers run_observers(c, false);
const uint32_t tid = get_tid();
const uint32_t wait_start = __atomic_load_n(c, __ATOMIC_SEQ_CST);
@@ -1041,7 +1015,7 @@
}
int futex_wait_timeout(aos_futex *m, const struct timespec *timeout) {
- RunObservers run_observers(m, false);
+ RunShmObservers run_observers(m, false);
const int ret = sys_futex_wait(FUTEX_WAIT, m, 0, timeout);
if (ret != 0) {
if (ret == -EINTR) {
@@ -1060,7 +1034,7 @@
int futex_wait(aos_futex *m) { return futex_wait_timeout(m, NULL); }
int futex_set_value(aos_futex *m, uint32_t value) {
- RunObservers run_observers(m, false);
+ RunShmObservers run_observers(m, false);
ANNOTATE_HAPPENS_BEFORE(m);
__atomic_store_n(m, value, __ATOMIC_SEQ_CST);
const int r = sys_futex_wake(m, INT_MAX - 4096);
@@ -1084,15 +1058,6 @@
namespace linux_code {
namespace ipc_lib {
-// Sets functions to run befor eand after all futex operations.
-// This is important when doing robustness testing because the memory has to be
-// made writable for the whole futex operation, otherwise it never succeeds.
-void SetFutexAccessorObservers(FutexAccessorObserver before,
- FutexAccessorObserver after) {
- before_observer = before;
- after_observer = after;
-}
-
// Sets an extra offset between mutexes and the value we use for them in the
// robust list (only the forward pointers). This is used to work around a kernel
// bug by keeping a second set of mutexes which is always writable so the kernel