Changeset e9c0b4c

Timestamp:

Apr 24, 2021, 9:05:30 PM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

adaee12

Parents:

28d426a

Message:

I/O drain now keeps the schedlock for the duration of the call.
(Rather than locking/unlocking for each thread).

Location:

libcfa/src/concurrency

Files:

• io.cfa (modified) (4 diffs)
• kernel.cfa (modified) (4 diffs)

libcfa/src/concurrency/io.cfa

@@ -40 +40 @@
         #include "kernel.hfa"
         #include "kernel/fwd.hfa"
+        #include "kernel_private.hfa"
         #include "io/types.hfa"
 
@@ -89 +90 @@
         static inline unsigned __flush( struct $io_context & );
         static inline __u32 __release_sqes( struct $io_context & );
+        extern void __kernel_unpark( $thread * thrd );
 
         bool __cfa_io_drain( processor * proc ) {
                 /* paranoid */ verify( ! __preemption_enabled() );
+                /* paranoid */ verify( ready_schedule_islocked() );
                 /* paranoid */ verify( proc );
                 /* paranoid */ verify( proc->io.ctx );
@@ -115 +118 @@
                         __cfadbg_print_safe( io, "Kernel I/O : Syscall completed : cqe %p, result %d for %p\n", &cqe, cqe.res, future );
 
-                        fulfil( *future, cqe.res );
+                        __kernel_unpark( fulfil( *future, cqe.res, false ) );
                 }
 
@@ -124 +127 @@
                 __atomic_store_n( ctx->cq.head, head + count, __ATOMIC_SEQ_CST );
 
+                /* paranoid */ verify( ready_schedule_islocked() );
                 /* paranoid */ verify( ! __preemption_enabled() );
 

libcfa/src/concurrency/kernel.cfa

@@ -551 +551 @@
 // Scheduler routines
 // KERNEL ONLY
-void __schedule_thread( $thread * thrd ) {
+static void __schedule_thread( $thread * thrd ) {
         /* paranoid */ verify( ! __preemption_enabled() );
         /* paranoid */ verify( kernelTLS().this_proc_id );
@@ -659 +659 @@
 }
 
+void __kernel_unpark( $thread * thrd ) {
+        /* paranoid */ verify( ! __preemption_enabled() );
+        /* paranoid */ verify( ready_schedule_islocked());
+
+        if( !thrd ) return;
+
+        if(__must_unpark(thrd)) {
+                // Wake lost the race,
+                __schedule_thread( thrd );
+        }
+
+        /* paranoid */ verify( ready_schedule_islocked());
+        /* paranoid */ verify( ! __preemption_enabled() );
+}
+
 void unpark( $thread * thrd ) {
         if( !thrd ) return;
@@ -871 +886 @@
 
 static inline bool __maybe_io_drain( processor * proc ) {
+        bool ret = false;
         #if defined(CFA_HAVE_LINUX_IO_URING_H)
                 __cfadbg_print_safe(runtime_core, "Kernel : core %p checking io for ring %d\n", proc, proc->io.ctx->fd);
@@ -879 +895 @@
                 unsigned tail = *ctx->cq.tail;
                 if(head == tail) return false;
-                return __cfa_io_drain( proc );
+                ret = __cfa_io_drain( proc );
         #endif
+        return ret;
 }