Changeset fbb930e for libcfa/src

Timestamp:

Aug 30, 2022, 4:57:46 PM (2 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, ast-experimental, master, pthread-emulation

Children:

01ba701

Parents:

cefd0b9

Message:

Added option to explicitly poll interrupts.
Usefull in cases using nopreempt sections

Location:

libcfa/src

Files:

• bits/locks.hfa (modified) (1 diff)
• concurrency/preemption.cfa (modified) (1 diff)
• startup.cfa (modified) (1 diff)

libcfa/src/bits/locks.hfa

@@ -32 +32 @@
                 extern void disable_interrupts() OPTIONAL_THREAD;
                 extern void enable_interrupts( bool poll = true ) OPTIONAL_THREAD;
+                extern bool poll_interrupts() OPTIONAL_THREAD;
                 #define __cfaabi_dbg_record_lock(x, y)
         }

libcfa/src/concurrency/preemption.cfa

@@ -357 +357 @@
                         }
                 }
+        }
+
+        // Check whether or not there is pending preemption
+        // force_yield( __POLL_PREEMPTION ) if appropriate
+        // return true if the thread was in an interruptable state
+        // i.e. on a real processor and not in the kernel
+        // (can return true even if no preemption was pending)
+        bool poll_interrupts() libcfa_public {
+                // Cache the processor now since interrupts can start happening after the atomic store
+                processor   * proc = publicTLS_get( this_processor );
+                if ( ! proc ) return false;
+                if ( ! __preemption_enabled() ) return false;
+
+                with( __cfaabi_tls.preemption_state ){
+                        // Signal the compiler that a fence is needed but only for signal handlers
+                        __atomic_signal_fence(__ATOMIC_RELEASE);
+                        if( proc->pending_preemption ) {
+                                proc->pending_preemption = false;
+                                force_yield( __POLL_PREEMPTION );
+                        }
+                }
+
+                return true;
         }
 }

libcfa/src/startup.cfa

@@ -43 +43 @@
         void disable_interrupts() __attribute__(( weak )) libcfa_public {}
         void enable_interrupts() __attribute__(( weak )) libcfa_public {}
+        bool poll_interrupts() __attribute__(( weak )) libcfa_public { return false; }