Peerplays_Blockchain/peerplays-fc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Allow recursive fc::mutexes

Browse source
This commit is contained in:
Eric Frias 2014-10-12 17:28:41 -04:00
parent 4e83427df0
commit b63e6a8b81
2 changed files with 27 additions and 19 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
include/fc/thread/mutex.hpp
View file

@ -102,6 +102,7 @@ namespace fc {
private:
fc::spin_yield_lock m_blist_lock;
fc::context* m_blist;
unsigned recursive_lock_count;
};
} // namespace fc

45
src/thread/mutex.cpp
View file

@ -7,8 +7,10 @@
namespace fc {
mutex::mutex()
:m_blist(0){}
mutex::mutex() :
m_blist(0),
recursive_lock_count(0)
{}
mutex::~mutex() {
if( m_blist )
@ -134,6 +136,8 @@ namespace fc {
{
// nobody else owns the mutex, so we get it; add our context as the last and only element on the mutex's list
m_blist = current_context;
assert(recursive_lock_count == 0);
recursive_lock_count = 1;
assert(!current_context->next_blocked_mutex);
return;
}
@ -141,18 +145,14 @@ namespace fc {
// allow recusive locks
fc::context* dummy_context_to_unblock = 0;
if ( get_tail( m_blist, dummy_context_to_unblock ) == current_context ) {
// if we already have the lock (meaning we're on the tail of the list) then
// we shouldn't be trying to grab the lock again
assert(false);
// EMF: I think recursive locks are currently broken -- we need to
// keep track of how many times this mutex has been locked by the
// current context. Unlocking should decrement this count and unblock
// the next context only if the count drops to zero
assert(recursive_lock_count > 0);
++recursive_lock_count;
return;
}
// add ourselves to the head of the list
current_context->next_blocked_mutex = m_blist;
m_blist = current_context;
++recursive_lock_count;
#if 0
int cnt = 0;
@ -185,17 +185,24 @@ namespace fc {
}
}
void mutex::unlock() {
void mutex::unlock()
{
fc::context* context_to_unblock = 0;
{ fc::unique_lock<fc::spin_yield_lock> lock(m_blist_lock);
get_tail(m_blist, context_to_unblock);
if( context_to_unblock ) {
context_to_unblock->next_blocked_mutex = 0;
context_to_unblock->ctx_thread->my->unblock( context_to_unblock );
} else {
m_blist = 0;
}
}
fc::unique_lock<fc::spin_yield_lock> lock(m_blist_lock);
assert(recursive_lock_count > 0);
--recursive_lock_count;
if (recursive_lock_count != 0)
return;
get_tail(m_blist, context_to_unblock);
if( context_to_unblock )
{
context_to_unblock->next_blocked_mutex = 0;
context_to_unblock->ctx_thread->my->unblock( context_to_unblock );
}
else
m_blist = 0;
}
} // fc