Applications can use recursive locks to avoid deadlock from single
thread acquiring the same lock multiple times. Recursive locks
are commonly used by legacy applications.
Signed-off-by: Petri Savolainen <petri.savolai...@nokia.com>
---
include/odp.h | 1 +
include/odp/api/reclock.h | 82 ++++++++++++++++++++++
platform/linux-generic/Makefile.am | 4 ++
.../linux-generic/include/odp/plat/reclock_types.h | 46 ++++++++++++
platform/linux-generic/include/odp/reclock.h | 28 ++++++++
platform/linux-generic/odp_reclock.c | 70 ++++++++++++++++++
6 files changed, 231 insertions(+)
create mode 100644 include/odp/api/reclock.h
create mode 100644 platform/linux-generic/include/odp/plat/reclock_types.h
create mode 100644 platform/linux-generic/include/odp/reclock.h
create mode 100644 platform/linux-generic/odp_reclock.c
diff --git a/include/odp.h b/include/odp.h
index fe1dc74..9acd1c4 100644
--- a/include/odp.h
+++ b/include/odp.h
@@ -54,6 +54,7 @@ extern "C" {
#include <odp/random.h>
#include <odp/errno.h>
#include <odp/thrmask.h>
+#include <odp/reclock.h>
#ifdef __cplusplus
}
diff --git a/include/odp/api/reclock.h b/include/odp/api/reclock.h
new file mode 100644
index 0000000..06ea702
--- /dev/null
+++ b/include/odp/api/reclock.h
@@ -0,0 +1,82 @@
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * ODP recursive lock
+ */
+
+#ifndef ODP_API_RECLOCK_H_
+#define ODP_API_RECLOCK_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @addtogroup odp_synchronizers
+ * Operations on recursive locks.
+ * @{
+ */
+
+/**
+ * @typedef odp_reclock_t
+ * Recursive lock
+ *
+ * A thread can acquire the lock multiple times without a deadlock. To release
+ * the lock, the thread must unlock it the same number of times.
+ */
+
+/**
+ * Initialize recursive lock.
+ *
+ * @param lock Pointer to a lock
+ */
+void odp_reclock_init(odp_reclock_t *lock);
+
+/**
+ * Acquire recursive lock.
+ *
+ * @param lock Pointer to a lock
+ */
+void odp_reclock_lock(odp_reclock_t *lock);
+
+/**
+ * Try to acquire recursive lock.
+ *
+ * @param lock Pointer to a lock
+ *
+ * @retval 1 lock acquired
+ * @retval 0 lock not acquired
+ */
+int odp_reclock_trylock(odp_reclock_t *lock);
+
+/**
+ * Release recursive lock.
+ *
+ * @param lock Pointer to a lock
+ */
+void odp_reclock_unlock(odp_reclock_t *lock);
+
+/**
+ * Check if recursive lock is locked.
+ *
+ * @param lock Pointer to a lock
+ *
+ * @retval 1 lock is locked
+ * @retval 0 lock is not locked
+ */
+int odp_reclock_is_locked(odp_reclock_t *lock);
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/platform/linux-generic/Makefile.am
b/platform/linux-generic/Makefile.am
index 765db34..b6fd611 100644
--- a/platform/linux-generic/Makefile.am
+++ b/platform/linux-generic/Makefile.am
@@ -32,6 +32,7 @@ odpinclude_HEADERS = \
$(top_srcdir)/platform/linux-generic/include/odp/pool.h \
$(top_srcdir)/platform/linux-generic/include/odp/queue.h \
$(top_srcdir)/platform/linux-generic/include/odp/random.h \
+ $(top_srcdir)/platform/linux-generic/include/odp/reclock.h \
$(top_srcdir)/platform/linux-generic/include/odp/rwlock.h \
$(top_srcdir)/platform/linux-generic/include/odp/schedule.h \
$(top_srcdir)/platform/linux-generic/include/odp/shared_memory.h \
@@ -60,6 +61,7 @@ odpplatinclude_HEADERS = \
$(top_srcdir)/platform/linux-generic/include/odp/plat/packet_io_types.h \
$(top_srcdir)/platform/linux-generic/include/odp/plat/pool_types.h \
$(top_srcdir)/platform/linux-generic/include/odp/plat/queue_types.h \
+
$(top_srcdir)/platform/linux-generic/include/odp/plat/reclock_types.h \
$(top_srcdir)/platform/linux-generic/include/odp/plat/rwlock_types.h \
$(top_srcdir)/platform/linux-generic/include/odp/plat/schedule_types.h \
$(top_srcdir)/platform/linux-generic/include/odp/plat/shared_memory_types.h \
@@ -94,6 +96,7 @@ odpapiinclude_HEADERS = \
$(top_srcdir)/include/odp/api/pool.h \
$(top_srcdir)/include/odp/api/queue.h \
$(top_srcdir)/include/odp/api/random.h \
+ $(top_srcdir)/include/odp/api/reclock.h \
$(top_srcdir)/include/odp/api/rwlock.h \
$(top_srcdir)/include/odp/api/schedule.h \
$(top_srcdir)/include/odp/api/shared_memory.h \
@@ -162,6 +165,7 @@ __LIB__libodp_la_SOURCES = \
odp_pool.c \
odp_queue.c \
../../helper/ring.c \
+ odp_reclock.c \
odp_rwlock.c \
odp_schedule.c \
odp_shared_memory.c \
diff --git a/platform/linux-generic/include/odp/plat/reclock_types.h
b/platform/linux-generic/include/odp/plat/reclock_types.h
new file mode 100644
index 0000000..07ec0b9
--- /dev/null
+++ b/platform/linux-generic/include/odp/plat/reclock_types.h
@@ -0,0 +1,46 @@
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * ODP recursive lock
+ */
+
+#ifndef ODP_RECLOCK_TYPES_H_
+#define ODP_RECLOCK_TYPES_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <odp/spinlock.h>
+
+/**
+ * @internal
+ * ODP recursive lock
+ */
+struct odp_reclock_s {
+ odp_spinlock_t lock; /**< the lock */
+ int owner; /**< thread inside the lock */
+ int num; /**< number of times locked */
+};
+
+/** @addtogroup odp_synchronizers
+ * @{
+ */
+
+typedef struct odp_reclock_s odp_reclock_t;
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/platform/linux-generic/include/odp/reclock.h
b/platform/linux-generic/include/odp/reclock.h
new file mode 100644
index 0000000..3f46f51
--- /dev/null
+++ b/platform/linux-generic/include/odp/reclock.h
@@ -0,0 +1,28 @@
+/* Copyright (c) 2015, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/**
+ * @file
+ *
+ * ODP resursive lock
+ */
+
+#ifndef ODP_PLAT_RECLOCK_H_
+#define ODP_PLAT_RECLOCK_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <odp/plat/reclock_types.h>
+
+#include <odp/api/reclock.h>
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/platform/linux-generic/odp_reclock.c
b/platform/linux-generic/odp_reclock.c
new file mode 100644
index 0000000..101ebed
--- /dev/null
+++ b/platform/linux-generic/odp_reclock.c
@@ -0,0 +1,70 @@
+/* Copyright (c) 2013, Linaro Limited
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <odp/reclock.h>
+#include <odp/thread.h>
+
+#define NO_OWNER (-1)
+
+void odp_reclock_init(odp_reclock_t *reclock)
+{
+ odp_spinlock_init(&reclock->lock);
+ reclock->owner = NO_OWNER;
+ reclock->num = 0;
+}
+
+void odp_reclock_lock(odp_reclock_t *reclock)
+{
+ int thr = odp_thread_id();
+
+ if (reclock->owner == thr) {
+ reclock->num++;
+ return;
+ }
+
+ odp_spinlock_lock(&reclock->lock);
+ reclock->owner = thr;
+ reclock->num = 1;
+}
+
+int odp_reclock_trylock(odp_reclock_t *reclock)
+{
+ int thr = odp_thread_id();
+
+ if (reclock->owner == thr) {
+ reclock->num++;
+ return 1;
+ }
+
+ if (odp_spinlock_trylock(&reclock->lock)) {
+ reclock->owner = thr;
+ reclock->num = 1;
+ return 1;
+ } else {
+ return 0;
+ }
+}
+
+void odp_reclock_unlock(odp_reclock_t *reclock)
+{
+ reclock->num--;
+
+ if (reclock->num > 0)
+ return;
+
+ reclock->owner = NO_OWNER;
+ odp_spinlock_unlock(&reclock->lock);
+}
+
+int odp_reclock_is_locked(odp_reclock_t *reclock)
+{
+ int thr = odp_thread_id();
+
+ if (reclock->owner == thr)
+ return 1;
+
+ return odp_spinlock_is_locked(&reclock->lock);
+}
--
2.4.5
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