Changeset fece3d9 for libcfa/src/concurrency/locks.cfa

Timestamp:

May 10, 2023, 2:46:05 PM (16 months ago)

Author:

caparsons <caparson@…>

Branches:

ADT, ast-experimental, master

Children:

8fd1b7c

Parents:

e50fce1

Message:

Added fix for cond var timeout handling race. Cleanup of locks.hfa/cfa changes is an ongoing TODO

File:

• libcfa/src/concurrency/locks.cfa (modified) (8 diffs)

libcfa/src/concurrency/locks.cfa

@@ -171 +171 @@
 }
 
-size_t on_wait( blocking_lock & this ) with( this ) {
+size_t on_wait( blocking_lock & this, __cfa_pre_park pp_fn, void * pp_datum ) with( this ) {
         lock( lock __cfaabi_dbg_ctx2 );
         /* paranoid */ verifyf( owner != 0p, "Attempt to release lock %p that isn't held", &this );
@@ -184 +184 @@
         unlock( lock );
 
-    park();
+    pre_park_then_park( pp_fn, pp_datum );
 
         return ret;
@@ -396 +396 @@
         }
 
-    static size_t block_and_get_recursion( info_thread(L) & i ) {
+    static size_t block_and_get_recursion( info_thread(L) & i, __cfa_pre_park pp_fn, void * pp_datum ) {
         size_t recursion_count = 0;
                 if ( i.lock ) {
                         // if lock was passed get recursion count to reset to after waking thread
-                        recursion_count = on_wait( *i.lock ); // this call blocks
-                } else park( );
+                        recursion_count = on_wait( *i.lock, pp_fn, pp_datum ); // this call blocks
+                } else pre_park_then_park( pp_fn, pp_datum );
         return recursion_count;
     }
+    static size_t block_and_get_recursion( info_thread(L) & i ) { return block_and_get_recursion( i, pre_park_noop, 0p ); }
 
         // helper for wait()'s' with no timeout
@@ -424 +425 @@
                 queue_info_thread( this, i );
 
+    static void cond_alarm_register( void * node_ptr ) { register_self( (alarm_node_t *)node_ptr ); }
+
         // helper for wait()'s' with a timeout
         static void queue_info_thread_timeout( condition_variable(L) & this, info_thread(L) & info, Duration t, Alarm_Callback callback ) with(this) {
@@ -433 +436 @@
 
                 // registers alarm outside cond lock to avoid deadlock
-                register_self( &node_wrap.alarm_node );
+                // register_self( &node_wrap.alarm_node );
 
                 // blocks here
-        size_t recursion_count = block_and_get_recursion( info );
+        size_t recursion_count = block_and_get_recursion( info, cond_alarm_register, (void *)(&node_wrap.alarm_node) );
                 // park();
 
@@ -503 +506 @@
                 info_thread( L ) i = { active_thread(), info, &l };
                 insert_last( blocked_threads, i );
-                size_t recursion_count = on_wait( *i.lock ); // blocks here
+                size_t recursion_count = on_wait( *i.lock, pre_park_noop, 0p ); // blocks here
                 // park( );
                 on_wakeup(*i.lock, recursion_count);
@@ -552 +555 @@
         //      return recursion_count;
         // }
-
         
         static void queue_info_thread_timeout( pthread_cond_var(L) & this, info_thread(L) & info, Duration t, Alarm_Callback callback ) with(this) {
@@ -562 +564 @@
 
                 // registers alarm outside cond lock to avoid deadlock
-                register_self( &node_wrap.alarm_node );
+                // register_self( &node_wrap.alarm_node ); // C_TODO: fix race: registers itself and then alarm handler calls on_notify before block_and_get_recursion is run
 
                 // blocks here
-        size_t recursion_count = block_and_get_recursion( info );
+        size_t recursion_count = block_and_get_recursion( info, cond_alarm_register, (void *)(&node_wrap.alarm_node) );
                 // park();