[PATCH 7/8] score: Add self-contained futex implementation
Sebastian Huber
sebastian.huber at embedded-brains.de
Thu Jul 23 12:54:47 UTC 2015
---
cpukit/libmisc/monitor/mon-prmisc.c | 1 +
cpukit/score/Makefile.am | 1 +
cpukit/score/include/rtems/score/statesimpl.h | 3 +
cpukit/score/src/futex.c | 174 +++++++++++++++++++++++++
testsuites/sptests/spsyslock01/init.c | 41 ++++++
testsuites/sptests/spsyslock01/spsyslock01.doc | 5 +
6 files changed, 225 insertions(+)
create mode 100644 cpukit/score/src/futex.c
diff --git a/cpukit/libmisc/monitor/mon-prmisc.c b/cpukit/libmisc/monitor/mon-prmisc.c
index 4656ed2..14ba173 100644
--- a/cpukit/libmisc/monitor/mon-prmisc.c
+++ b/cpukit/libmisc/monitor/mon-prmisc.c
@@ -134,6 +134,7 @@ static const rtems_assoc_t rtems_monitor_state_assoc[] = {
{ "Wseg", STATES_WAITING_FOR_SEGMENT, 0 },
{ "Wsem", STATES_WAITING_FOR_SEMAPHORE, 0 },
{ "Wsig", STATES_WAITING_FOR_SIGNAL, 0 },
+ { "Wslftx", STATES_WAITING_FOR_SYS_LOCK_FUTEX, 0 },
{ "Wslmtx", STATES_WAITING_FOR_SYS_LOCK_MUTEX, 0 },
{ "Wslsem", STATES_WAITING_FOR_SYS_LOCK_SEMAPHORE, 0 },
{ "Wsysev", STATES_WAITING_FOR_SYSTEM_EVENT, 0 },
diff --git a/cpukit/score/Makefile.am b/cpukit/score/Makefile.am
index 3223470..6f0c4db 100644
--- a/cpukit/score/Makefile.am
+++ b/cpukit/score/Makefile.am
@@ -344,6 +344,7 @@ libscore_a_SOURCES += src/apiext.c src/chain.c src/chainappend.c \
src/interr.c src/isr.c src/wkspace.c src/wkstringduplicate.c
libscore_a_SOURCES += src/isrisinprogress.c
libscore_a_SOURCES += src/debugisownerofallocator.c
+libscore_a_SOURCES += src/futex.c
libscore_a_SOURCES += src/profilingisrentryexit.c
libscore_a_SOURCES += src/mutex.c
libscore_a_SOURCES += src/once.c
diff --git a/cpukit/score/include/rtems/score/statesimpl.h b/cpukit/score/include/rtems/score/statesimpl.h
index 7805ca4..82d222c 100644
--- a/cpukit/score/include/rtems/score/statesimpl.h
+++ b/cpukit/score/include/rtems/score/statesimpl.h
@@ -90,6 +90,8 @@ extern "C" {
#define STATES_WAITING_FOR_SYS_LOCK_MUTEX 0x2000000
/** This macro corresponds to a task waiting for a <sys/lock.h> semaphore. */
#define STATES_WAITING_FOR_SYS_LOCK_SEMAPHORE 0x4000000
+/** This macro corresponds to a task waiting for a <sys/lock.h> futex. */
+#define STATES_WAITING_FOR_SYS_LOCK_FUTEX 0x8000000
/** This macro corresponds to a task which is in an interruptible
* blocking state.
@@ -109,6 +111,7 @@ extern "C" {
STATES_WAITING_FOR_BSD_WAKEUP | \
STATES_WAITING_FOR_SYS_LOCK_MUTEX | \
STATES_WAITING_FOR_SYS_LOCK_SEMAPHORE | \
+ STATES_WAITING_FOR_SYS_LOCK_FUTEX | \
STATES_WAITING_FOR_RWLOCK )
/** This macro corresponds to a task waiting which is blocked. */
diff --git a/cpukit/score/src/futex.c b/cpukit/score/src/futex.c
new file mode 100644
index 0000000..f1dfd80
--- /dev/null
+++ b/cpukit/score/src/futex.c
@@ -0,0 +1,174 @@
+/*
+ * Copyright (c) 2015 embedded brains GmbH. All rights reserved.
+ *
+ * embedded brains GmbH
+ * Dornierstr. 4
+ * 82178 Puchheim
+ * Germany
+ * <rtems at embedded-brains.de>
+ *
+ * The license and distribution terms for this file may be
+ * found in the file LICENSE in this distribution or at
+ * http://www.rtems.org/license/LICENSE.
+ */
+
+#if HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include <sys/lock.h>
+#include <errno.h>
+
+#include <rtems/score/chainimpl.h>
+#include <rtems/score/threadimpl.h>
+#include <rtems/score/threadqimpl.h>
+
+#if HAVE_STRUCT__THREAD_QUEUE_QUEUE
+
+#define FUTEX_TQ_OPERATIONS &_Thread_queue_Operations_FIFO
+
+static Thread_queue_Queue *_Futex_Get_thread_queue(
+ struct _Futex_Control *futex
+)
+{
+ return (Thread_queue_Queue *) &futex->_Queue;
+}
+
+static Thread_Control *_Futex_Queue_acquire(
+ struct _Futex_Control *futex,
+ ISR_lock_Context *lock_context
+)
+{
+ Thread_Control *executing;
+
+ _ISR_lock_ISR_disable( lock_context );
+ executing = _Thread_Executing;
+ _Thread_queue_Queue_acquire_critical(
+ _Futex_Get_thread_queue( futex ),
+ &executing->Potpourri_stats,
+ lock_context
+ );
+
+ return executing;
+}
+
+static void _Futex_Queue_release(
+ struct _Futex_Control *futex,
+ ISR_lock_Context *lock_context
+)
+{
+ _Thread_queue_Queue_release(
+ _Futex_Get_thread_queue( futex ),
+ lock_context
+ );
+}
+
+int _Futex_Wait( struct _Futex_Control *futex, int *uaddr, int val )
+{
+ ISR_lock_Context lock_context;
+ Thread_Control *executing;
+ int eno;
+
+ executing = _Futex_Queue_acquire( futex, &lock_context );
+
+ if ( *uaddr == val ) {
+ _Thread_queue_Enqueue_critical(
+ _Futex_Get_thread_queue( futex ),
+ FUTEX_TQ_OPERATIONS,
+ executing,
+ STATES_WAITING_FOR_SYS_LOCK_FUTEX,
+ 0,
+ 0,
+ &lock_context
+ );
+ eno = 0;
+ } else {
+ _Futex_Queue_release( futex, &lock_context );
+ eno = EWOULDBLOCK;
+ }
+
+ return eno;
+}
+
+int _Futex_Wake( struct _Futex_Control *futex, int count )
+{
+ ISR_lock_Context lock_context;
+ Thread_queue_Heads *heads;
+ Chain_Control unblock;
+ Chain_Node *node;
+ Chain_Node *tail;
+ int woken;
+
+ _Futex_Queue_acquire( futex, &lock_context );
+
+ /*
+ * For some synchronization objects like barriers the _Futex_Wake() must be
+ * called in the fast path. Normally there are no threads on the queue, so
+ * check this condition early.
+ */
+ heads = _Futex_Get_thread_queue( futex )->heads;
+ if ( heads == NULL ) {
+ _Futex_Queue_release( futex, &lock_context );
+
+ return 0;
+ }
+
+ woken = 0;
+ _Chain_Initialize_empty( &unblock );
+
+ while ( count > 0 ) {
+
+ if ( heads != NULL ) {
+ const Thread_queue_Operations *operations;
+ Thread_Control *first;
+ bool do_unblock;
+
+ operations = FUTEX_TQ_OPERATIONS;
+ first = ( *operations->first )( heads );
+
+ do_unblock = _Thread_queue_Extract_locked(
+ _Futex_Get_thread_queue( futex ),
+ operations,
+ first
+ );
+ if (do_unblock) {
+ _Chain_Append_unprotected( &unblock, &first->Wait.Node.Chain );
+ }
+
+ heads = _Futex_Get_thread_queue( futex )->heads;
+ ++woken;
+ } else {
+ break;
+ }
+
+ --count;
+ }
+
+ node = _Chain_First( &unblock );
+ tail = _Chain_Tail( &unblock );
+ if ( node != tail ) {
+ Per_CPU_Control *cpu_self;
+
+ cpu_self = _Thread_Dispatch_disable_critical( &lock_context );
+ _Futex_Queue_release( futex, &lock_context );
+
+ do {
+ Thread_Control *thread;
+ Chain_Node *next;
+
+ next = _Chain_Next( node );
+ thread = THREAD_CHAIN_NODE_TO_THREAD( node );
+ _Thread_Unblock( thread );
+
+ node = next;
+ } while ( node != tail );
+
+ _Thread_Dispatch_enable( cpu_self );
+ } else {
+ _Futex_Queue_release( futex, &lock_context );
+ }
+
+ return woken;
+}
+
+#endif /* HAVE_STRUCT__THREAD_QUEUE_QUEUE */
diff --git a/testsuites/sptests/spsyslock01/init.c b/testsuites/sptests/spsyslock01/init.c
index f6a2d3f..57f6d35 100644
--- a/testsuites/sptests/spsyslock01/init.c
+++ b/testsuites/sptests/spsyslock01/init.c
@@ -19,6 +19,8 @@
#include "tmacros.h"
#include <sys/lock.h>
+#include <errno.h>
+#include <limits.h>
#include <string.h>
const char rtems_test_name[] = "SPSYSLOCK 1";
@@ -39,6 +41,8 @@ const char rtems_test_name[] = "SPSYSLOCK 1";
#define EVENT_SEM_WAIT RTEMS_EVENT_7
+#define EVENT_FUTEX_WAIT RTEMS_EVENT_8
+
typedef struct {
rtems_id high;
rtems_id mid;
@@ -46,6 +50,9 @@ typedef struct {
struct _Mutex_Control mtx;
struct _Mutex_recursive_Control rec_mtx;
struct _Semaphore_Control sem;
+ struct _Futex_Control futex;
+ int val;
+ int eno;
bool flag;
} test_context;
@@ -64,18 +71,22 @@ static void test_initialization(test_context *ctx)
struct _Mutex_Control mtx = _MUTEX_INITIALIZER;
struct _Mutex_recursive_Control rec_mtx = _MUTEX_RECURSIVE_INITIALIZER;
struct _Semaphore_Control sem = _SEMAPHORE_INITIALIZER(1);
+ struct _Futex_Control futex = _FUTEX_INITIALIZER;
_Mutex_Initialize(&ctx->mtx);
_Mutex_recursive_Initialize(&ctx->rec_mtx);
_Semaphore_Initialize(&ctx->sem, 1);
+ _Futex_Initialize(&ctx->futex);
rtems_test_assert(memcmp(&mtx, &ctx->mtx, sizeof(mtx)) == 0);
rtems_test_assert(memcmp(&rec_mtx, &ctx->rec_mtx, sizeof(rec_mtx)) == 0);
rtems_test_assert(memcmp(&sem, &ctx->sem, sizeof(sem)) == 0);
+ rtems_test_assert(memcmp(&futex, &ctx->futex, sizeof(futex)) == 0);
_Mutex_Destroy(&mtx);
_Mutex_recursive_Destroy(&rec_mtx);
_Semaphore_Destroy(&sem);
+ _Futex_Destroy(&futex);
}
static void test_recursive_acquire_normal(test_context *ctx)
@@ -173,6 +184,31 @@ static void test_sem(test_context *ctx)
_Semaphore_Post(sem);
}
+static void test_futex(test_context *ctx)
+{
+ struct _Futex_Control *futex = &ctx->futex;
+ int eno;
+ int woken;
+
+ eno = _Futex_Wait(futex, &ctx->val, 1);
+ rtems_test_assert(eno == EWOULDBLOCK);
+
+ woken = _Futex_Wake(futex, 0);
+ rtems_test_assert(woken == 0);
+
+ woken = _Futex_Wake(futex, 1);
+ rtems_test_assert(woken == 0);
+
+ ctx->val = 1;
+ ctx->eno = -1;
+ send_events(ctx, EVENT_FUTEX_WAIT);
+ rtems_test_assert(ctx->eno == -1);
+
+ woken = _Futex_Wake(futex, INT_MAX);
+ rtems_test_assert(woken == 1);
+ rtems_test_assert(ctx->eno == 0);
+}
+
static void mid_task(rtems_task_argument arg)
{
rtems_test_assert(0);
@@ -251,6 +287,10 @@ static void high_task(rtems_task_argument arg)
_Semaphore_Wait(&ctx->sem);
ctx->flag = true;
}
+
+ if ((events & EVENT_FUTEX_WAIT) != 0) {
+ ctx->eno = _Futex_Wait(&ctx->futex, &ctx->val, 1);
+ }
}
}
@@ -291,6 +331,7 @@ static void test(void)
test_prio_inv_normal(ctx);
test_prio_inv_recursive(ctx);
test_sem(ctx);
+ test_futex(ctx);
send_events(ctx, EVENT_MTX_DEADLOCK);
diff --git a/testsuites/sptests/spsyslock01/spsyslock01.doc b/testsuites/sptests/spsyslock01/spsyslock01.doc
index 1a7384c..bf59ceb 100644
--- a/testsuites/sptests/spsyslock01/spsyslock01.doc
+++ b/testsuites/sptests/spsyslock01/spsyslock01.doc
@@ -18,8 +18,13 @@ directives:
- _Semaphore_Wait()
- _Semaphore_Post()
- _Semaphore_Destroy()
+ - _Futex_Initialize()
+ - _Futex_Wait()
+ - _Futex_Wake()
+ - _Futex_Destroy()
concepts:
- Ensure that self-contained mutexes and recursive mutexes work.
- Ensure that self-contained semaphores work.
+ - Ensure that self-contained futexes work.
--
1.8.4.5
More information about the devel
mailing list