[PATCH] posix: Use cleanup contexts on the stack
Sebastian Huber
sebastian.huber at embedded-brains.de
Fri Jul 5 14:05:32 UTC 2013
This change must be in synchronization with a Newlib <pthread.h> change.
The cleanup contexts are stored on the thread stack. This is conform to
the POSIX requirements for the pthread_cleanup_push() and
pthread_cleanup_pop() statement pair.
Passing an invalid pointer as the routine to pthread_cleanup_push() is
now a usage error and the behaviour is undefined.
---
cpukit/posix/include/rtems/posix/cancel.h | 12 ------
cpukit/posix/include/rtems/posix/threadsup.h | 6 ++-
cpukit/posix/src/cancelrun.c | 26 +++++-------
cpukit/posix/src/cleanuppop.c | 53 +++++---------------------
cpukit/posix/src/cleanuppush.c | 44 +++++++--------------
cpukit/posix/src/pthread.c | 2 +-
testsuites/psxtests/psxcleanup/psxcleanup.c | 7 ---
7 files changed, 40 insertions(+), 110 deletions(-)
diff --git a/cpukit/posix/include/rtems/posix/cancel.h b/cpukit/posix/include/rtems/posix/cancel.h
index c1fff9c..6ad53d6 100644
--- a/cpukit/posix/include/rtems/posix/cancel.h
+++ b/cpukit/posix/include/rtems/posix/cancel.h
@@ -22,18 +22,6 @@
#include <rtems/posix/threadsup.h>
/**
- * This structure is used to manage the cancelation handlers.
- */
-typedef struct {
- /** This field is the Chain Node so we can put these on lists. */
- Chain_Node Node;
- /** This field is the cancelation routine. */
- void (*routine)( void * );
- /** This field is the argument to the cancelation routine. */
- void *arg;
-} POSIX_Cancel_Handler_control;
-
-/**
* @brief POSIX run thread cancelation.
*
* This support routine runs through the chain of cancel handlers that
diff --git a/cpukit/posix/include/rtems/posix/threadsup.h b/cpukit/posix/include/rtems/posix/threadsup.h
index 80f64dc..c4d75c8 100644
--- a/cpukit/posix/include/rtems/posix/threadsup.h
+++ b/cpukit/posix/include/rtems/posix/threadsup.h
@@ -76,9 +76,11 @@ typedef struct {
int cancelability_type;
/** This indicates if a cancelation has been requested. */
int cancelation_requested;
- /** This is the set of cancelation handlers. */
- Chain_Control Cancellation_Handlers;
+ /**
+ * @brief LIFO list of cleanup contexts.
+ */
+ struct _pthread_cleanup_context *last_cleanup_context;
} POSIX_API_Control;
/**
diff --git a/cpukit/posix/src/cancelrun.c b/cpukit/posix/src/cancelrun.c
index 2d73bda..fb3e596 100644
--- a/cpukit/posix/src/cancelrun.c
+++ b/cpukit/posix/src/cancelrun.c
@@ -34,26 +34,22 @@ void _POSIX_Threads_cancel_run(
Thread_Control *the_thread
)
{
- POSIX_Cancel_Handler_control *handler;
- Chain_Control *handler_stack;
- POSIX_API_Control *thread_support;
- ISR_Level level;
+ struct _pthread_cleanup_context *context;
+ POSIX_API_Control *thread_support;
- thread_support = the_thread->API_Extensions[ THREAD_API_POSIX ];
-
- handler_stack = &thread_support->Cancellation_Handlers;
+ _Thread_Disable_dispatch();
+ thread_support = the_thread->API_Extensions[ THREAD_API_POSIX ];
thread_support->cancelability_state = PTHREAD_CANCEL_DISABLE;
- while ( !_Chain_Is_empty( handler_stack ) ) {
- _ISR_Disable( level );
- handler = (POSIX_Cancel_Handler_control *)
- _Chain_Tail( handler_stack )->previous;
- _Chain_Extract_unprotected( &handler->Node );
- _ISR_Enable( level );
+ context = thread_support->last_cleanup_context;
+ thread_support->last_cleanup_context = NULL;
+
+ _Thread_Enable_dispatch();
- (*handler->routine)( handler->arg );
+ while ( context != NULL ) {
+ ( *context->_routine )( context->_arg );
- _Workspace_Free( handler );
+ context = context->_previous;
}
}
diff --git a/cpukit/posix/src/cleanuppop.c b/cpukit/posix/src/cleanuppop.c
index bbadec5..78e2c34 100644
--- a/cpukit/posix/src/cleanuppop.c
+++ b/cpukit/posix/src/cleanuppop.c
@@ -15,67 +15,34 @@
*/
#if HAVE_CONFIG_H
-#include "config.h"
+ #include "config.h"
#endif
#include <pthread.h>
-#include <errno.h>
#include <rtems/system.h>
-#include <rtems/score/chain.h>
-#include <rtems/score/isr.h>
#include <rtems/score/thread.h>
-#include <rtems/score/wkspace.h>
-#include <rtems/posix/cancel.h>
#include <rtems/posix/pthread.h>
-#include <rtems/posix/threadsup.h>
/*
* 18.2.3.1 Establishing Cancellation Handlers, P1003.1c/Draft 10, p. 184
*/
-void pthread_cleanup_pop(
- int execute
+void _pthread_cleanup_pop(
+ struct _pthread_cleanup_context *context,
+ int execute
)
{
- POSIX_Cancel_Handler_control *handler;
- POSIX_Cancel_Handler_control tmp_handler;
- Chain_Control *handler_stack;
- POSIX_API_Control *thread_support;
- ISR_Level level;
+ POSIX_API_Control *thread_support;
- thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];
-
- handler_stack = &thread_support->Cancellation_Handlers;
-
- /*
- * We need interrupts disabled to safely check the chain and pull
- * the last element off. But we also need dispatching disabled to
- * ensure that we do not get prempted and deleted while we are holding
- * memory that needs to be freed.
- */
+ if ( execute != 0 ) {
+ ( *context->_routine )( context->_arg );
+ }
_Thread_Disable_dispatch();
- _ISR_Disable( level );
-
- if ( _Chain_Is_empty( handler_stack ) ) {
- _Thread_Enable_dispatch();
- _ISR_Enable( level );
- return;
- }
-
- handler = (POSIX_Cancel_Handler_control *)
- _Chain_Tail( handler_stack )->previous;
- _Chain_Extract_unprotected( &handler->Node );
- _ISR_Enable( level );
-
- tmp_handler = *handler;
-
- _Workspace_Free( handler );
+ thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];
+ thread_support->last_cleanup_context = context->_previous;
_Thread_Enable_dispatch();
-
- if ( execute )
- (*tmp_handler.routine)( tmp_handler.arg );
}
diff --git a/cpukit/posix/src/cleanuppush.c b/cpukit/posix/src/cleanuppush.c
index 4fb82c2..52597e6 100644
--- a/cpukit/posix/src/cleanuppush.c
+++ b/cpukit/posix/src/cleanuppush.c
@@ -15,54 +15,38 @@
*/
#if HAVE_CONFIG_H
-#include "config.h"
+ #include "config.h"
#endif
#include <pthread.h>
-#include <errno.h>
#include <rtems/system.h>
-#include <rtems/score/chain.h>
-#include <rtems/score/isr.h>
#include <rtems/score/thread.h>
-#include <rtems/score/wkspace.h>
-#include <rtems/posix/cancel.h>
#include <rtems/posix/pthread.h>
-#include <rtems/posix/threadsup.h>
/*
* 18.2.3.1 Establishing Cancellation Handlers, P1003.1c/Draft 10, p. 184
*/
-void pthread_cleanup_push(
- void (*routine)( void * ),
- void *arg
+void _pthread_cleanup_push(
+ struct _pthread_cleanup_context *context,
+ void ( *routine )( void * ),
+ void *arg
)
{
- POSIX_Cancel_Handler_control *handler;
- Chain_Control *handler_stack;
- POSIX_API_Control *thread_support;
+ POSIX_API_Control *thread_support;
- /*
- * The POSIX standard does not address what to do when the routine
- * is NULL. It also does not address what happens when we cannot
- * allocate memory or anything else bad happens.
- */
- if ( !routine )
- return;
+ context->_routine = routine;
+ context->_arg = arg;
- _Thread_Disable_dispatch();
- handler = _Workspace_Allocate( sizeof( POSIX_Cancel_Handler_control ) );
-
- if ( handler ) {
- thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];
+ /* Use an invalid value here */
+ context->_canceltype = 13;
- handler_stack = &thread_support->Cancellation_Handlers;
+ _Thread_Disable_dispatch();
- handler->routine = routine;
- handler->arg = arg;
+ thread_support = _Thread_Executing->API_Extensions[ THREAD_API_POSIX ];
+ context->_previous = thread_support->last_cleanup_context;
+ thread_support->last_cleanup_context = context;
- _Chain_Append( handler_stack, &handler->Node );
- }
_Thread_Enable_dispatch();
}
diff --git a/cpukit/posix/src/pthread.c b/cpukit/posix/src/pthread.c
index f35a000..fc17549 100644
--- a/cpukit/posix/src/pthread.c
+++ b/cpukit/posix/src/pthread.c
@@ -198,7 +198,7 @@ static bool _POSIX_Threads_Create_extension(
api->cancelation_requested = 0;
api->cancelability_state = PTHREAD_CANCEL_ENABLE;
api->cancelability_type = PTHREAD_CANCEL_DEFERRED;
- _Chain_Initialize_empty (&api->Cancellation_Handlers);
+ api->last_cleanup_context = NULL;
/*
* If the thread is not a posix thread, then all posix signals are blocked
diff --git a/testsuites/psxtests/psxcleanup/psxcleanup.c b/testsuites/psxtests/psxcleanup/psxcleanup.c
index 568e897..123e766 100644
--- a/testsuites/psxtests/psxcleanup/psxcleanup.c
+++ b/testsuites/psxtests/psxcleanup/psxcleanup.c
@@ -250,13 +250,6 @@ void *POSIX_Init(
sleep(1);
- /*************** ERROR CASES ***************/
- puts("Call pthread_cleanup_push with NULL handler");
- pthread_cleanup_push(NULL, NULL);
-
- puts("Call pthread_cleanup_pop with no push");
- pthread_cleanup_pop(1);
-
/*************** END OF TEST *****************/
puts( "*** END OF POSIX CLEANUP TEST ***\n" );
rtems_test_exit(0);
--
1.7.7
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