Changes in libcfa/src/concurrency/preemption.cfa [a3821fa:a33c113]

File:

• libcfa/src/concurrency/preemption.cfa (modified) (2 diffs)

libcfa/src/concurrency/preemption.cfa

@@ -315 +315 @@
         // Enable interrupts by decrementing the counter
         // If counter reaches 0, execute any pending __cfactx_switch
-        void enable_interrupts( bool poll ) {
+        void enable_interrupts( __cfaabi_dbg_ctx_param ) {
                 // Cache the processor now since interrupts can start happening after the atomic store
                 processor   * proc = __cfaabi_tls.this_processor;
-                /* paranoid */ verify( !poll || proc );
+                /* paranoid */ verify( proc );
 
                 with( __cfaabi_tls.preemption_state ){
@@ -340 +340 @@
                                 // Signal the compiler that a fence is needed but only for signal handlers
                                 __atomic_signal_fence(__ATOMIC_RELEASE);
-                                if( poll && proc->pending_preemption ) {
+                                if( proc->pending_preemption ) {
                                         proc->pending_preemption = false;
                                         force_yield( __POLL_PREEMPTION );
                                 }
                         }
+                }
+
+                // For debugging purposes : keep track of the last person to enable the interrupts
+                __cfaabi_dbg_debug_do( proc->last_enable = caller; )
+        }
+
+        // Disable interrupts by incrementint the counter
+        // Don't execute any pending __cfactx_switch even if counter reaches 0
+        void enable_interrupts_noPoll() {
+                unsigned short prev = __cfaabi_tls.preemption_state.disable_count;
+                __cfaabi_tls.preemption_state.disable_count -= 1;
+                // If this triggers someone is enabled already enabled interrupts
+                /* paranoid */ verifyf( prev != 0u, "Incremented from %u\n", prev );
+                if( prev == 1 ) {
+                        #if GCC_VERSION > 50000
+                                static_assert(__atomic_always_lock_free(sizeof(__cfaabi_tls.preemption_state.enabled), &__cfaabi_tls.preemption_state.enabled), "Must be lock-free");
+                        #endif
+                        // Set enabled flag to true
+                        // should be atomic to avoid preemption in the middle of the operation.
+                        // use memory order RELAXED since there is no inter-thread on this variable requirements
+                        __atomic_store_n(&__cfaabi_tls.preemption_state.enabled, true, __ATOMIC_RELAXED);
+
+                        // Signal the compiler that a fence is needed but only for signal handlers
+                        __atomic_signal_fence(__ATOMIC_RELEASE);
                 }
         }