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Fix Lua scripting synchronization

For several years now, the lua script lock has been completely broken.
This commit fixes the main issue (creation of a temporary rather than
scoped object), and fixes a subsequent deadlock issue caused by
nested script API calls by adding support for recursive mutexes.
This commit is contained in:
kwolekr 2015-10-31 16:31:43 -04:00
parent d198e420ec
commit 52e5b513ed
5 changed files with 57 additions and 17 deletions

View file

@ -32,28 +32,50 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#ifdef SCRIPTAPI_LOCK_DEBUG
#include "debug.h" // assert()
class LockChecker {
public:
LockChecker(bool *variable) {
assert(*variable == false);
LockChecker(int *recursion_counter, threadid_t *owning_thread)
{
m_lock_recursion_counter = recursion_counter;
m_owning_thread = owning_thread;
m_original_level = *recursion_counter;
m_variable = variable;
*m_variable = true;
if (*m_lock_recursion_counter > 0)
assert(thr_is_current_thread(*m_owning_thread));
else
*m_owning_thread = thr_get_current_thread_id();
(*m_lock_recursion_counter)++;
}
~LockChecker() {
*m_variable = false;
~LockChecker()
{
assert(thr_is_current_thread(*m_owning_thread));
assert(*m_lock_recursion_counter > 0);
(*m_lock_recursion_counter)--;
assert(*m_lock_recursion_counter == m_original_level);
}
private:
bool *m_variable;
int *m_lock_recursion_counter;
int m_original_level;
threadid_t *m_owning_thread;
};
#define SCRIPTAPI_LOCK_CHECK LockChecker(&(this->m_locked))
#define SCRIPTAPI_LOCK_CHECK \
LockChecker scriptlock_checker( \
&this->m_lock_recursion_count, \
&this->m_owning_thread)
#else
#define SCRIPTAPI_LOCK_CHECK while(0)
#define SCRIPTAPI_LOCK_CHECK while(0)
#endif
#define SCRIPTAPI_PRECHECKHEADER \
MutexAutoLock(this->m_luastackmutex); \
MutexAutoLock scriptlock(this->m_luastackmutex); \
SCRIPTAPI_LOCK_CHECK; \
realityCheck(); \
lua_State *L = getStack(); \