rtems: Avoid Giant lock for signals

Update #2555.

1 files changed, 45 insertions, 34 deletions

diff --git a/cpukit/rtems/src/signalmp.c b/cpukit/rtems/src/signalmp.c
index 8c63c2f790..cd89e9f0dd 100644
--- a/cpukit/rtems/src/signalmp.c
+++ b/cpukit/rtems/src/signalmp.c
@@ -24,13 +24,36 @@
 #include <rtems/score/threadimpl.h>
 #include <rtems/score/threadqimpl.h>
 
+/**
+ *  The following enumerated type defines the list of
+ *  remote signal operations.
+ */
+typedef enum {
+  SIGNAL_MP_SEND_REQUEST  = 0,
+  SIGNAL_MP_SEND_RESPONSE = 1
+}   Signal_MP_Remote_operations;
+
+/**
+ *  The following data structure defines the packet used to perform
+ *  remote signal operations.
+ */
+typedef struct {
+  rtems_packet_prefix          Prefix;
+  Signal_MP_Remote_operations  operation;
+  rtems_signal_set             signal_set;
+}   Signal_MP_Packet;
+
 RTEMS_STATIC_ASSERT(
   sizeof(Signal_MP_Packet) <= MP_PACKET_MINIMUM_PACKET_SIZE,
   Signal_MP_Packet
 );
 
-static Signal_MP_Packet *_Signal_MP_Get_packet( void )
+static Signal_MP_Packet *_Signal_MP_Get_packet( Objects_Id id )
 {
+  if ( !_Thread_MP_Is_remote( id ) ) {
+    return NULL;
+  }
+
   return (Signal_MP_Packet *) _MPCI_Get_packet();
 }
 
@@ -42,43 +65,31 @@ static Signal_MP_Packet *_Signal_MP_Get_packet( void )
  *
  */
 
-rtems_status_code _Signal_MP_Send_request_packet (
-  Signal_MP_Remote_operations operation,
-  Objects_Id                  task_id,
-  rtems_signal_set            signal_in
+rtems_status_code _Signal_MP_Send(
+  rtems_id         id,
+  rtems_signal_set signal_set
 )
 {
   Signal_MP_Packet *the_packet;
 
-  switch ( operation ) {
-
-    case SIGNAL_MP_SEND_REQUEST:
-
-      the_packet                    = _Signal_MP_Get_packet();
-      the_packet->Prefix.the_class  = MP_PACKET_SIGNAL;
-      the_packet->Prefix.length     = sizeof ( Signal_MP_Packet );
-      the_packet->Prefix.to_convert = sizeof ( Signal_MP_Packet );
-      the_packet->operation         = operation;
-      the_packet->Prefix.id         = task_id;
-      the_packet->signal_in         = signal_in;
-
-      return _MPCI_Send_request_packet(
-        _Objects_Get_node( task_id ),
-        &the_packet->Prefix,
-        STATES_READY,  /* Not used */
-        RTEMS_TIMEOUT
-      );
-      break;
-
-    case SIGNAL_MP_SEND_RESPONSE:
-      break;
-
+  the_packet = _Signal_MP_Get_packet( id );
+  if ( the_packet == NULL ) {
+    return RTEMS_INVALID_ID;
   }
-  /*
-   *  The following line is included to satisfy compilers which
-   *  produce warnings when a function does not end with a return.
-   */
-  return RTEMS_INTERNAL_ERROR;
+
+  the_packet->Prefix.the_class  = MP_PACKET_SIGNAL;
+  the_packet->Prefix.length     = sizeof( *the_packet );
+  the_packet->Prefix.to_convert = sizeof( *the_packet );
+  the_packet->operation         = SIGNAL_MP_SEND_REQUEST;
+  the_packet->Prefix.id         = id;
+  the_packet->signal_set        = signal_set;
+
+  return (rtems_status_code) _MPCI_Send_request_packet(
+    _Objects_Get_node( id ),
+    &the_packet->Prefix,
+    STATES_READY,
+    RTEMS_TIMEOUT
+  );
 }
 
 static void _Signal_MP_Send_response_packet (
@@ -127,7 +138,7 @@ void _Signal_MP_Process_packet (
 
       the_packet->Prefix.return_code = rtems_signal_send(
         the_packet->Prefix.id,
-        the_packet->signal_in
+        the_packet->signal_set
       );
 
       _Signal_MP_Send_response_packet(