Added support for simple binary semaphores in addition to the high

power binary/mutex style semaphores already supported by RTEMS.  This
was done at the request of Eric Norum <eric@cls.usask.ca> in support
of his effort to port EPICS to RTEMS.  This change consisted of
changing the nesting_allowed boolean into a lock_nesting_behavior
enumerated value as well as allowing the core mutex object to optionally
support ensuring that the holder of a binary semaphore released it.
Finally, a more subtle enhancement was to allow the non-holder to release
a priority inheritance/ceiling mutex and still allow the holding task
to return to its original priority.

8 files changed, 92 insertions, 47 deletions

diff --git a/cpukit/rtems/include/rtems/rtems/attr.h b/cpukit/rtems/include/rtems/rtems/attr.h
index 20d8eebe01..b054bd6684 100644
--- a/cpukit/rtems/include/rtems/rtems/attr.h
+++ b/cpukit/rtems/include/rtems/rtems/attr.h
@@ -37,17 +37,16 @@ typedef unsigned32 rtems_attribute;
 #define RTEMS_FIFO                0x00000000 /* process RTEMS_FIFO */
 #define RTEMS_PRIORITY            0x00000004 /* process by priority */
 
-#define RTEMS_COUNTING_SEMAPHORE  0x00000000
-#define RTEMS_BINARY_SEMAPHORE    0x00000010
+#define RTEMS_SEMAPHORE_CLASS         0x00000030 /* mask */
+#define RTEMS_COUNTING_SEMAPHORE      0x00000000
+#define RTEMS_BINARY_SEMAPHORE        0x00000010
+#define RTEMS_SIMPLE_BINARY_SEMAPHORE 0x00000020
 
 #define RTEMS_NO_INHERIT_PRIORITY 0x00000000
-#define RTEMS_INHERIT_PRIORITY    0x00000020
+#define RTEMS_INHERIT_PRIORITY    0x00000040
 
 #define RTEMS_NO_PRIORITY_CEILING 0x00000000
-#define RTEMS_PRIORITY_CEILING    0x00000040
-
-#define RTEMS_NESTING_ALLOWED     0x00000000
-#define RTEMS_NO_NESTING_ALLOWED  0x00000080
+#define RTEMS_PRIORITY_CEILING    0x00000080
 
 #define RTEMS_APPLICATION_TASK    0x00000000
 #define RTEMS_SYSTEM_TASK         0x00000100
diff --git a/cpukit/rtems/inline/rtems/rtems/attr.inl b/cpukit/rtems/inline/rtems/rtems/attr.inl
index 94a8052648..d35be0dca4 100644
--- a/cpukit/rtems/inline/rtems/rtems/attr.inl
+++ b/cpukit/rtems/inline/rtems/rtems/attr.inl
@@ -119,58 +119,76 @@ RTEMS_INLINE_ROUTINE boolean _Attributes_Is_binary_semaphore(
   rtems_attribute attribute_set
 )
 {
-  return ( attribute_set & RTEMS_BINARY_SEMAPHORE );
+  return ((attribute_set & RTEMS_SEMAPHORE_CLASS) == RTEMS_BINARY_SEMAPHORE);
 }
 
 /*PAGE
  *
- *  _Attributes_Is_inherit_priority
+ *  _Attributes_Is_simple_binary_semaphore
  *
  *  DESCRIPTION:
  *
- *  This function returns TRUE if the priority inheritance attribute
- *  is enabled in the attribute_set and FALSE otherwise.
+ *  This function returns TRUE if the simple binary semaphore attribute is
+ *  enabled in the attribute_set and FALSE otherwise.
  */
 
-RTEMS_INLINE_ROUTINE boolean _Attributes_Is_inherit_priority(
+RTEMS_INLINE_ROUTINE boolean _Attributes_Is_simple_binary_semaphore(
+  rtems_attribute attribute_set
+) 
+{
+  return
+    ((attribute_set & RTEMS_SEMAPHORE_CLASS) == RTEMS_SIMPLE_BINARY_SEMAPHORE);
+}  
+
+/*PAGE
+ *
+ *  _Attributes_Is_counting_semaphore
+ *
+ *  DESCRIPTION:
+ *
+ *  This function returns TRUE if the counting semaphore attribute is
+ *  enabled in the attribute_set and FALSE otherwise.
+ */
+
+RTEMS_INLINE_ROUTINE boolean _Attributes_Is_counting_semaphore(
   rtems_attribute attribute_set
 )
 {
-   return ( attribute_set & RTEMS_INHERIT_PRIORITY );
+  return ((attribute_set & RTEMS_SEMAPHORE_CLASS) == RTEMS_COUNTING_SEMAPHORE);
 }
 
 /*PAGE
  *
- *  _Attributes_Is_priority_ceiling
+ *  _Attributes_Is_inherit_priority
  *
  *  DESCRIPTION:
  *
- *  This function returns TRUE if the priority ceiling attribute
+ *  This function returns TRUE if the priority inheritance attribute
  *  is enabled in the attribute_set and FALSE otherwise.
  */
- 
-RTEMS_INLINE_ROUTINE boolean _Attributes_Is_priority_ceiling(
+
+RTEMS_INLINE_ROUTINE boolean _Attributes_Is_inherit_priority(
   rtems_attribute attribute_set
 )
 {
-   return ( attribute_set & RTEMS_PRIORITY_CEILING );
+   return ( attribute_set & RTEMS_INHERIT_PRIORITY );
 }
 
 /*PAGE
  *
- *  _Attributes_Is_nesting_allowed
+ *  _Attributes_Is_priority_ceiling
  *
  *  DESCRIPTION:
  *
- *  This function returns TRUE if the nesting allowed attribute
+ *  This function returns TRUE if the priority ceiling attribute
  *  is enabled in the attribute_set and FALSE otherwise.
  */
  
-RTEMS_INLINE_ROUTINE boolean _Attributes_Is_nesting_allowed(
+RTEMS_INLINE_ROUTINE boolean _Attributes_Is_priority_ceiling(
   rtems_attribute attribute_set
 )
 {
-   return ( !(attribute_set & RTEMS_NO_NESTING_ALLOWED) );
+   return ( attribute_set & RTEMS_PRIORITY_CEILING );
 }
 
 /*PAGE
diff --git a/cpukit/rtems/macros/rtems/rtems/attr.inl b/cpukit/rtems/macros/rtems/rtems/attr.inl
index 516752b7d1..56ccac6657 100644
--- a/cpukit/rtems/macros/rtems/rtems/attr.inl
+++ b/cpukit/rtems/macros/rtems/rtems/attr.inl
@@ -68,7 +68,25 @@
  */
 
 #define _Attributes_Is_binary_semaphore( _attribute_set ) \
-  ( (_attribute_set) & RTEMS_BINARY_SEMAPHORE )
+  (((_attribute_set) & RTEMS_SEMAPHORE_CLASS) == RTEMS_BINARY_SEMAPHORE)
+
+/*PAGE
+ *
+ *  _Attributes_Is_simple_binary_semaphore
+ *
+ */
+
+#define _Attributes_Is_simple_binary_semaphore( _attribute_set ) \
+  (((_attribute_set) & RTEMS_SEMAPHORE_CLASS) == RTEMS_SIMPLE_BINARY_SEMAPHORE)
+
+/*PAGE
+ *
+ *  _Attributes_Is_counting_semaphore
+ *
+ */
+
+#define _Attributes_Is_counting_semaphore( _attribute_set ) \
+  (((_attribute_set) & RTEMS_SEMAPHORE_CLASS) == RTEMS_COUNTING_SEMAPHORE)
 
 /*PAGE
  *
@@ -90,15 +108,6 @@
 
 /*PAGE
  *
- *  _Attributes_Is_nesting_allowed
- *
- */
-
-#define _Attributes_Is_nesting_allowed( _attribute_set ) \
-   ( !((_attribute_set) & RTEMS_NO_NESTING_ALLOWED) )
-
-/*PAGE
- *
  *  _Attributes_Is_system_task
  *
  */
diff --git a/cpukit/rtems/src/semcreate.c b/cpukit/rtems/src/semcreate.c
index a63814acfe..3ffbfc39c0 100644
--- a/cpukit/rtems/src/semcreate.c
+++ b/cpukit/rtems/src/semcreate.c
@@ -96,13 +96,15 @@ rtems_status_code rtems_semaphore_create(
   if ( _Attributes_Is_inherit_priority( attribute_set ) || 
               _Attributes_Is_priority_ceiling( attribute_set ) ) {
 
-    if ( ! ( _Attributes_Is_binary_semaphore( attribute_set ) &&
+    if ( ! ( (_Attributes_Is_binary_semaphore( attribute_set ) ||
+              _Attributes_Is_simple_binary_semaphore( attribute_set )) &&
+             
              _Attributes_Is_priority( attribute_set ) ) )
       return RTEMS_NOT_DEFINED;
 
   }
 
-  if ( _Attributes_Is_binary_semaphore( attribute_set ) && ( count > 1 ) )
+  if ( !_Attributes_Is_counting_semaphore( attribute_set ) && ( count > 1 ) )
     return RTEMS_INVALID_NUMBER;
 
   _Thread_Disable_dispatch();             /* prevents deletion */
@@ -126,7 +128,13 @@ rtems_status_code rtems_semaphore_create(
 
   the_semaphore->attribute_set = attribute_set;
 
-  if ( _Attributes_Is_binary_semaphore( attribute_set ) ) {
+  /*
+   *  If it is not a counting, semaphore, then it is either a 
+   *  simple binary semaphore or a more powerful lmutex style binary
+   *  semaphore.
+   */
+
+  if ( !_Attributes_Is_counting_semaphore( attribute_set ) ) {
     if ( _Attributes_Is_inherit_priority( attribute_set ) )
       the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT;
     else if ( _Attributes_Is_priority_ceiling( attribute_set ) )
@@ -136,12 +144,24 @@ rtems_status_code rtems_semaphore_create(
     else
       the_mutex_attributes.discipline = CORE_MUTEX_DISCIPLINES_FIFO;
 
-    if ( _Attributes_Is_nesting_allowed( attribute_set ) )
-      the_mutex_attributes.allow_nesting = TRUE;
-    else
-      the_mutex_attributes.allow_nesting = FALSE;
 
-    /* Add priority ceiling code here ????? */
+    if ( _Attributes_Is_binary_semaphore( attribute_set ) ) {
+      the_mutex_attributes.lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES;
+
+      switch ( the_mutex_attributes.discipline ) {
+        case CORE_MUTEX_DISCIPLINES_FIFO:
+        case CORE_MUTEX_DISCIPLINES_PRIORITY:
+          the_mutex_attributes.only_owner_release = FALSE;
+          break;
+        case CORE_MUTEX_DISCIPLINES_PRIORITY_CEILING:
+        case CORE_MUTEX_DISCIPLINES_PRIORITY_INHERIT:
+          the_mutex_attributes.only_owner_release = TRUE;
+          break;
+      }
+    } else {
+      the_mutex_attributes.lock_nesting_behavior = CORE_MUTEX_NESTING_BLOCKS;
+      the_mutex_attributes.only_owner_release = FALSE;
+    }
 
     the_mutex_attributes.priority_ceiling = priority_ceiling;
 
@@ -161,8 +181,7 @@ rtems_status_code rtems_semaphore_create(
       NULL
 #endif
     );
-  }
-  else {
+  } else {
     if ( _Attributes_Is_priority( attribute_set ) )
       the_semaphore_attributes.discipline = CORE_SEMAPHORE_DISCIPLINES_PRIORITY;
     else
@@ -178,7 +197,7 @@ rtems_status_code rtems_semaphore_create(
      *  The following are just to make Purify happy.
      */
 
-    the_mutex_attributes.allow_nesting = TRUE;
+    the_mutex_attributes.lock_nesting_behavior = CORE_MUTEX_NESTING_ACQUIRES;
     the_mutex_attributes.priority_ceiling = PRIORITY_MINIMUM;
 
     _CORE_semaphore_Initialize(
diff --git a/cpukit/rtems/src/semdelete.c b/cpukit/rtems/src/semdelete.c
index 3bbc4001a1..1e9b165c71 100644
--- a/cpukit/rtems/src/semdelete.c
+++ b/cpukit/rtems/src/semdelete.c
@@ -81,7 +81,7 @@ rtems_status_code rtems_semaphore_delete(
       return RTEMS_INVALID_ID;
 
     case OBJECTS_LOCAL:
-      if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set) ) { 
+      if ( !_Attributes_Is_counting_semaphore(the_semaphore->attribute_set) ) { 
         if ( _CORE_mutex_Is_locked( &the_semaphore->Core_control.mutex ) ) {
           _Thread_Enable_dispatch();
           return RTEMS_RESOURCE_IN_USE;
diff --git a/cpukit/rtems/src/semflush.c b/cpukit/rtems/src/semflush.c
index 43e690479a..dcdd8b1b34 100644
--- a/cpukit/rtems/src/semflush.c
+++ b/cpukit/rtems/src/semflush.c
@@ -77,7 +77,7 @@ rtems_status_code rtems_semaphore_flush(
       return RTEMS_INVALID_ID;
 
     case OBJECTS_LOCAL:
-      if ( _Attributes_Is_binary_semaphore(the_semaphore->attribute_set) ) { 
+      if ( !_Attributes_Is_counting_semaphore(the_semaphore->attribute_set) ) { 
         _CORE_mutex_Flush(
           &the_semaphore->Core_control.mutex, 
           SEND_OBJECT_WAS_DELETED,
diff --git a/cpukit/rtems/src/semobtain.c b/cpukit/rtems/src/semobtain.c
index 5c8eb400fb..fef659d3cb 100644
--- a/cpukit/rtems/src/semobtain.c
+++ b/cpukit/rtems/src/semobtain.c
@@ -92,7 +92,7 @@ rtems_status_code rtems_semaphore_obtain(
       else
         wait = TRUE;
 
-      if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set ) ) {
+      if ( !_Attributes_Is_counting_semaphore(the_semaphore->attribute_set) ) {
         _CORE_mutex_Seize(
           &the_semaphore->Core_control.mutex,
           id, 
diff --git a/cpukit/rtems/src/semrelease.c b/cpukit/rtems/src/semrelease.c
index d33c857437..2f05b6503f 100644
--- a/cpukit/rtems/src/semrelease.c
+++ b/cpukit/rtems/src/semrelease.c
@@ -85,7 +85,7 @@ rtems_status_code rtems_semaphore_release(
       return RTEMS_INVALID_ID;
 
     case OBJECTS_LOCAL:
-      if ( _Attributes_Is_binary_semaphore( the_semaphore->attribute_set ) ) {
+      if ( !_Attributes_Is_counting_semaphore(the_semaphore->attribute_set) ) {
         mutex_status = _CORE_mutex_Surrender(
                          &the_semaphore->Core_control.mutex,
                          id,