[dpdk-dev] [PATCH v9 4/4] examples: add pthread_shim example to performance thread

[Ian Betts <ian.betts@intel.com>]

This commit adds an example that illustrates how to implement
a pthread shim with the lthread subsystem included in the
performance thread example application.

Signed-off-by: Ian Betts <ian.betts@intel.com>
---
 examples/performance-thread/Makefile               |   2 +
 examples/performance-thread/pthread_shim/Makefile  |  60 ++
 examples/performance-thread/pthread_shim/main.c    | 284 ++++++++
 .../performance-thread/pthread_shim/pthread_shim.c | 714 +++++++++++++++++++++
 .../performance-thread/pthread_shim/pthread_shim.h | 113 ++++
 5 files changed, 1173 insertions(+)
 create mode 100644 examples/performance-thread/pthread_shim/Makefile
 create mode 100644 examples/performance-thread/pthread_shim/main.c
 create mode 100644 examples/performance-thread/pthread_shim/pthread_shim.c
 create mode 100644 examples/performance-thread/pthread_shim/pthread_shim.h

diff --git a/examples/performance-thread/Makefile b/examples/performance-thread/Makefile
index 0a02e90..75389d7 100644
--- a/examples/performance-thread/Makefile
+++ b/examples/performance-thread/Makefile
@@ -39,5 +39,7 @@ RTE_TARGET ?= x86_64-native-linuxapp-gcc
 include $(RTE_SDK)/mk/rte.vars.mk
 
 DIRS-y += l3fwd-thread
+DIRS-y += pthread_shim
+
 
 include $(RTE_SDK)/mk/rte.extsubdir.mk
diff --git a/examples/performance-thread/pthread_shim/Makefile b/examples/performance-thread/pthread_shim/Makefile
new file mode 100644
index 0000000..9cf32e3
--- /dev/null
+++ b/examples/performance-thread/pthread_shim/Makefile
@@ -0,0 +1,60 @@
+#   BSD LICENSE
+#
+#   Copyright(c) 2015 Intel Corporation. All rights reserved.
+#   All rights reserved.
+#
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+ifeq ($(RTE_SDK),)
+$(error "Please define RTE_SDK environment variable")
+endif
+
+# Default target, can be overridden by command line or environment
+RTE_TARGET ?= x86_64-native-linuxapp-gcc
+
+include $(RTE_SDK)/mk/rte.vars.mk
+
+# binary name
+APP = lthread_pthread_shim
+
+# all source are stored in SRCS-y
+SRCS-y := main.c  pthread_shim.c
+INCLUDES := -I$(RTE_SDK)/$(RTE_TARGET)/include -I$(SRCDIR)
+include $(RTE_SDK)/examples/performance-thread/common/common.mk
+
+CFLAGS=    -g -O3 $(USER_FLAGS) $(INCLUDES)
+CFLAGS += $(WERROR_FLAGS)
+
+LDFLAGS += -lpthread
+
+# workaround for a gcc bug with noreturn attribute
+# http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12603
+ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y)
+CFLAGS_main.o += -Wno-return-type
+endif
+
+include $(RTE_SDK)/mk/rte.extapp.mk
diff --git a/examples/performance-thread/pthread_shim/main.c b/examples/performance-thread/pthread_shim/main.c
new file mode 100644
index 0000000..2f67c1b
--- /dev/null
+++ b/examples/performance-thread/pthread_shim/main.c
@@ -0,0 +1,284 @@
+
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <sys/types.h>
+#include <string.h>
+#include <sys/queue.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <getopt.h>
+#include <unistd.h>
+#include <sched.h>
+#include <pthread.h>
+
+#include <rte_config.h>
+#include <rte_common.h>
+#include <rte_lcore.h>
+#include <rte_per_lcore.h>
+#include <rte_timer.h>
+
+#include "lthread_api.h"
+#include "lthread_diag_api.h"
+#include "pthread_shim.h"
+
+#define DEBUG_APP 0
+#define HELLOW_WORLD_MAX_LTHREADS 10
+
+__thread int print_count;
+__thread pthread_mutex_t print_lock;
+
+__thread pthread_mutex_t exit_lock;
+__thread pthread_cond_t exit_cond;
+
+/*
+ * A simple thread that demonstrates use of a mutex, a condition
+ * variable, thread local storage, explicit yield, and thread exit.
+ *
+ * The thread uses a mutex to protect a shared counter which is incremented
+ * and then it waits on condition variable before exiting.
+ *
+ * The thread argument is stored in and retrieved from TLS, using
+ * the pthread key create, get and set specific APIs.
+ *
+ * The thread yields while holding the mutex, to provide opportunity
+ * for other threads to contend.
+ *
+ * All of the pthread API functions used by this thread are actually
+ * resolved to corresponding lthread functions by the pthread shim
+ * implemented in pthread_shim.c
+ */
+void *helloworld_pthread(void *arg);
+void *helloworld_pthread(void *arg)
+{
+	pthread_key_t key;
+
+	/* create a key for TLS */
+	pthread_key_create(&key, NULL);
+
+	/* store the arg in TLS */
+	pthread_setspecific(key, arg);
+
+	/* grab lock and increment shared counter */
+	pthread_mutex_lock(&print_lock);
+	print_count++;
+
+	/* yield thread to give opportunity for lock contention */
+	pthread_yield();
+
+	/* retrieve arg from TLS */
+	uint64_t thread_no = (uint64_t) pthread_getspecific(key);
+
+	printf("Hello - lcore = %d count = %d thread_no = %d thread_id = %p\n",
+			sched_getcpu(),
+			print_count,
+			(int) thread_no,
+			(void *)pthread_self());
+
+	/* release the lock */
+	pthread_mutex_unlock(&print_lock);
+
+	/*
+	 * wait on condition variable
+	 * before exiting
+	 */
+	pthread_mutex_lock(&exit_lock);
+	pthread_cond_wait(&exit_cond, &exit_lock);
+	pthread_mutex_unlock(&exit_lock);
+
+	/* exit */
+	pthread_exit((void *) thread_no);
+}
+
+
+/*
+ * This is the initial thread
+ *
+ * It demonstrates pthread, mutex and condition variable creation,
+ * broadcast and pthread join APIs.
+ *
+ * This initial thread must always start life as an lthread.
+ *
+ * This thread creates many more threads then waits a short time
+ * before signalling them to exit using a broadcast.
+ *
+ * All of the pthread API functions used by this thread are actually
+ * resolved to corresponding lthread functions by the pthread shim
+ * implemented in pthread_shim.c
+ *
+ * After all threads have finished the lthread scheduler is shutdown
+ * and normal pthread operation is restored
+ */
+__thread pthread_t tid[HELLOW_WORLD_MAX_LTHREADS];
+
+static void initial_lthread(void *args);
+static void initial_lthread(void *args __attribute__((unused)))
+{
+	int lcore = (int) rte_lcore_id();
+	/*
+	 *
+	 * We can now enable pthread API override
+	 * and start to use the pthread APIs
+	 */
+	pthread_override_set(1);
+
+	uint64_t i;
+
+	/* initialize mutex for shared counter */
+	print_count = 0;
+	pthread_mutex_init(&print_lock, NULL);
+
+	/* initialize mutex and condition variable controlling thread exit */
+	pthread_mutex_init(&exit_lock, NULL);
+	pthread_cond_init(&exit_cond, NULL);
+
+	/* spawn a number of threads */
+	for (i = 0; i < HELLOW_WORLD_MAX_LTHREADS; i++) {
+
+		/*
+		 * Not strictly necessary but
+		 * for the sake of this example
+		 * use an attribute to pass the desired lcore
+		 */
+		pthread_attr_t attr;
+		cpu_set_t cpuset;
+
+		CPU_ZERO(&cpuset);
+		CPU_SET(lcore, &cpuset);
+		pthread_attr_init(&attr);
+		pthread_attr_setaffinity_np(&attr, sizeof(cpu_set_t), &cpuset);
+
+		/* create the thread */
+		pthread_create(&tid[i], &attr, helloworld_pthread, (void *) i);
+	}
+
+	/* wait for 1s to allow threads
+	 * to block on the condition variable
+	 * N.B. nanosleep() is resolved to lthread_sleep()
+	 * by the shim.
+	 */
+	struct timespec time;
+
+	time.tv_sec = 1;
+	time.tv_nsec = 0;
+	nanosleep(&time, NULL);
+
+	/* wake up all the threads */
+	pthread_cond_broadcast(&exit_cond);
+
+	/* wait for them to finish */
+	for (i = 0; i < HELLOW_WORLD_MAX_LTHREADS; i++) {
+
+		uint64_t thread_no;
+
+		pthread_join(tid[i], (void *) &thread_no);
+		if (thread_no != i)
+			printf("error on thread exit\n");
+	}
+
+	/* shutdown the lthread scheduler */
+	lthread_scheduler_shutdown(rte_lcore_id());
+	lthread_detach();
+}
+
+
+
+/* This thread creates a single initial lthread
+ * and then runs the scheduler
+ * An instance of this thread is created on each thread
+ * in the core mask
+ */
+static int
+lthread_scheduler(void *args);
+static int
+lthread_scheduler(void *args __attribute__((unused)))
+{
+	/* create initial thread  */
+	struct lthread *lt;
+
+	lthread_create(&lt, -1, initial_lthread, (void *) NULL);
+
+	/* run the lthread scheduler */
+	lthread_run();
+
+	/* restore genuine pthread operation */
+	pthread_override_set(0);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int num_sched = 0;
+
+	/* basic DPDK initialization is all that is necessary to run lthreads*/
+	int ret = rte_eal_init(argc, argv);
+
+	if (ret < 0)
+		rte_exit(EXIT_FAILURE, "Invalid EAL parameters\n");
+
+	/* enable timer subsystem */
+	rte_timer_subsystem_init();
+
+#if DEBUG_APP
+	lthread_diagnostic_set_mask(LT_DIAG_ALL);
+#endif
+
+	/* create a scheduler on every core in the core mask
+	 * and launch an initial lthread that will spawn many more.
+	 */
+	unsigned lcore_id;
+
+	for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++) {
+		if (rte_lcore_is_enabled(lcore_id))
+			num_sched++;
+	}
+
+	/* set the number of schedulers, this forces all schedulers synchronize
+	 * before entering their main loop
+	 */
+	lthread_num_schedulers_set(num_sched);
+
+	/* launch all threads */
+	rte_eal_mp_remote_launch(lthread_scheduler, (void *)NULL, CALL_MASTER);
+
+	/* wait for threads to stop */
+	RTE_LCORE_FOREACH_SLAVE(lcore_id) {
+		rte_eal_wait_lcore(lcore_id);
+	}
+	return 0;
+}
diff --git a/examples/performance-thread/pthread_shim/pthread_shim.c b/examples/performance-thread/pthread_shim/pthread_shim.c
new file mode 100644
index 0000000..e55077e
--- /dev/null
+++ b/examples/performance-thread/pthread_shim/pthread_shim.c
@@ -0,0 +1,714 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <errno.h>
+#define __USE_GNU
+#include <sched.h>
+#include <dlfcn.h>
+
+#include <rte_config.h>
+#include <rte_log.h>
+
+#include "lthread_api.h"
+#include "pthread_shim.h"
+
+#define RTE_LOGTYPE_PTHREAD_SHIM RTE_LOGTYPE_USER3
+
+#define POSIX_ERRNO(x)  (x)
+
+/*
+ * this flag determines at run time if we override pthread
+ * calls and map then to equivalent lthread calls
+ * or of we call the standard pthread function
+ */
+static __thread int override;
+
+
+/*
+ * this structures contains function pointers that will be
+ * initialised to the loaded address of the real
+ * pthread library API functions
+ */
+struct pthread_lib_funcs {
+int (*f_pthread_barrier_destroy)
+	(pthread_barrier_t *);
+int (*f_pthread_barrier_init)
+	(pthread_barrier_t *, const pthread_barrierattr_t *, unsigned);
+int (*f_pthread_barrier_wait)
+	(pthread_barrier_t *);
+int (*f_pthread_cond_broadcast)
+	(pthread_cond_t *);
+int (*f_pthread_cond_destroy)
+	(pthread_cond_t *);
+int (*f_pthread_cond_init)
+	(pthread_cond_t *, const pthread_condattr_t *);
+int (*f_pthread_cond_signal)
+	(pthread_cond_t *);
+int (*f_pthread_cond_timedwait)
+	(pthread_cond_t *, pthread_mutex_t *, const struct timespec *);
+int (*f_pthread_cond_wait)
+	(pthread_cond_t *, pthread_mutex_t *);
+int (*f_pthread_create)
+	(pthread_t *, const pthread_attr_t *, void *(*)(void *), void *);
+int (*f_pthread_detach)
+	(pthread_t);
+int (*f_pthread_equal)
+	(pthread_t, pthread_t);
+void (*f_pthread_exit)
+	(void *);
+void * (*f_pthread_getspecific)
+	(pthread_key_t);
+int (*f_pthread_getcpuclockid)
+	(pthread_t, clockid_t *);
+int (*f_pthread_join)
+	(pthread_t, void **);
+int (*f_pthread_key_create)
+	(pthread_key_t *, void (*) (void *));
+int (*f_pthread_key_delete)
+	(pthread_key_t);
+int (*f_pthread_mutex_destroy)
+	(pthread_mutex_t *__mutex);
+int (*f_pthread_mutex_init)
+	(pthread_mutex_t *__mutex, const pthread_mutexattr_t *);
+int (*f_pthread_mutex_lock)
+	(pthread_mutex_t *__mutex);
+int (*f_pthread_mutex_trylock)
+	(pthread_mutex_t *__mutex);
+int (*f_pthread_mutex_timedlock)
+	(pthread_mutex_t *__mutex, const struct timespec *);
+int (*f_pthread_mutex_unlock)
+	(pthread_mutex_t *__mutex);
+int (*f_pthread_once)
+	(pthread_once_t *, void (*) (void));
+int (*f_pthread_rwlock_destroy)
+	(pthread_rwlock_t *__rwlock);
+int (*f_pthread_rwlock_init)
+	(pthread_rwlock_t *__rwlock, const pthread_rwlockattr_t *);
+int (*f_pthread_rwlock_rdlock)
+	(pthread_rwlock_t *__rwlock);
+int (*f_pthread_rwlock_timedrdlock)
+	(pthread_rwlock_t *__rwlock, const struct timespec *);
+int (*f_pthread_rwlock_timedwrlock)
+	(pthread_rwlock_t *__rwlock, const struct timespec *);
+int (*f_pthread_rwlock_tryrdlock)
+	(pthread_rwlock_t *__rwlock);
+int (*f_pthread_rwlock_trywrlock)
+	(pthread_rwlock_t *__rwlock);
+int (*f_pthread_rwlock_unlock)
+	(pthread_rwlock_t *__rwlock);
+int (*f_pthread_rwlock_wrlock)
+	(pthread_rwlock_t *__rwlock);
+pthread_t (*f_pthread_self)
+	(void);
+int (*f_pthread_setspecific)
+	(pthread_key_t, const void *);
+int (*f_pthread_spin_init)
+	(pthread_spinlock_t *__spin, int);
+int (*f_pthread_spin_destroy)
+	(pthread_spinlock_t *__spin);
+int (*f_pthread_spin_lock)
+	(pthread_spinlock_t *__spin);
+int (*f_pthread_spin_trylock)
+	(pthread_spinlock_t *__spin);
+int (*f_pthread_spin_unlock)
+	(pthread_spinlock_t *__spin);
+int (*f_pthread_cancel)
+	(pthread_t);
+int (*f_pthread_setcancelstate)
+	(int, int *);
+int (*f_pthread_setcanceltype)
+	(int, int *);
+void (*f_pthread_testcancel)
+	(void);
+int (*f_pthread_getschedparam)
+	(pthread_t pthread, int *, struct sched_param *);
+int (*f_pthread_setschedparam)
+	(pthread_t, int, const struct sched_param *);
+int (*f_pthread_yield)
+	(void);
+int (*f_pthread_setaffinity_np)
+	(pthread_t thread, size_t cpusetsize, const cpu_set_t *cpuset);
+int (*f_nanosleep)
+	(const struct timespec *req, struct timespec *rem);
+} _sys_pthread_funcs = {
+	.f_pthread_barrier_destroy = NULL,
+};
+
+
+/*
+ * this macro obtains the loaded address of a library function
+ * and saves it.
+ */
+static void *__libc_dl_handle = RTLD_NEXT;
+
+#define get_addr_of_loaded_symbol(name) do {				\
+	char *error_str;						\
+	_sys_pthread_funcs.f_##name = dlsym(__libc_dl_handle, (#name));	\
+	error_str = dlerror();						\
+	if (error_str != NULL) {					\
+		fprintf(stderr, "%s\n", error_str);			\
+		*((int *)0) = 0;                                        \
+	}								\
+} while (0)
+
+
+/*
+ * The constructor function initialises the
+ * function pointers for pthread library functions
+ */
+void
+pthread_intercept_ctor(void)__attribute__((constructor));
+void
+pthread_intercept_ctor(void)
+{
+	override = 0;
+	/*
+	 * Get the original functions
+	 */
+	get_addr_of_loaded_symbol(pthread_barrier_destroy);
+	get_addr_of_loaded_symbol(pthread_barrier_init);
+	get_addr_of_loaded_symbol(pthread_barrier_wait);
+	get_addr_of_loaded_symbol(pthread_cond_broadcast);
+	get_addr_of_loaded_symbol(pthread_cond_destroy);
+	get_addr_of_loaded_symbol(pthread_cond_init);
+	get_addr_of_loaded_symbol(pthread_cond_signal);
+	get_addr_of_loaded_symbol(pthread_cond_timedwait);
+	get_addr_of_loaded_symbol(pthread_cond_wait);
+	get_addr_of_loaded_symbol(pthread_create);
+	get_addr_of_loaded_symbol(pthread_detach);
+	get_addr_of_loaded_symbol(pthread_equal);
+	get_addr_of_loaded_symbol(pthread_exit);
+	get_addr_of_loaded_symbol(pthread_getspecific);
+	get_addr_of_loaded_symbol(pthread_getcpuclockid);
+	get_addr_of_loaded_symbol(pthread_join);
+	get_addr_of_loaded_symbol(pthread_key_create);
+	get_addr_of_loaded_symbol(pthread_key_delete);
+	get_addr_of_loaded_symbol(pthread_mutex_destroy);
+	get_addr_of_loaded_symbol(pthread_mutex_init);
+	get_addr_of_loaded_symbol(pthread_mutex_lock);
+	get_addr_of_loaded_symbol(pthread_mutex_trylock);
+	get_addr_of_loaded_symbol(pthread_mutex_timedlock);
+	get_addr_of_loaded_symbol(pthread_mutex_unlock);
+	get_addr_of_loaded_symbol(pthread_once);
+	get_addr_of_loaded_symbol(pthread_rwlock_destroy);
+	get_addr_of_loaded_symbol(pthread_rwlock_init);
+	get_addr_of_loaded_symbol(pthread_rwlock_rdlock);
+	get_addr_of_loaded_symbol(pthread_rwlock_timedrdlock);
+	get_addr_of_loaded_symbol(pthread_rwlock_timedwrlock);
+	get_addr_of_loaded_symbol(pthread_rwlock_tryrdlock);
+	get_addr_of_loaded_symbol(pthread_rwlock_trywrlock);
+	get_addr_of_loaded_symbol(pthread_rwlock_unlock);
+	get_addr_of_loaded_symbol(pthread_rwlock_wrlock);
+	get_addr_of_loaded_symbol(pthread_self);
+	get_addr_of_loaded_symbol(pthread_setspecific);
+	get_addr_of_loaded_symbol(pthread_spin_init);
+	get_addr_of_loaded_symbol(pthread_spin_destroy);
+	get_addr_of_loaded_symbol(pthread_spin_lock);
+	get_addr_of_loaded_symbol(pthread_spin_trylock);
+	get_addr_of_loaded_symbol(pthread_spin_unlock);
+	get_addr_of_loaded_symbol(pthread_cancel);
+	get_addr_of_loaded_symbol(pthread_setcancelstate);
+	get_addr_of_loaded_symbol(pthread_setcanceltype);
+	get_addr_of_loaded_symbol(pthread_testcancel);
+	get_addr_of_loaded_symbol(pthread_getschedparam);
+	get_addr_of_loaded_symbol(pthread_setschedparam);
+	get_addr_of_loaded_symbol(pthread_yield);
+	get_addr_of_loaded_symbol(pthread_setaffinity_np);
+	get_addr_of_loaded_symbol(nanosleep);
+}
+
+
+/*
+ * Enable/Disable pthread override
+ * state
+ *  0 disable
+ *  1 enable
+ */
+void pthread_override_set(int state)
+{
+	override = state;
+}
+
+
+/*
+ * Return pthread override state
+ * return
+ *  0 disable
+ *  1 enable
+ */
+int pthread_override_get(void)
+{
+	return override;
+}
+
+/*
+ * This macro is used to catch and log
+ * invocation of stubs for unimplemented pthread
+ * API functions.
+ */
+#define NOT_IMPLEMENTED do {				\
+	if (override) {					\
+		RTE_LOG(WARNING,			\
+			PTHREAD_SHIM,			\
+			"WARNING %s NOT IMPLEMENTED\n",	\
+			__func__);			\
+	}						\
+} while (0)
+
+/*
+ * pthread API override functions follow
+ * Note in this example code only a subset of functions are
+ * implemented.
+ *
+ * The stub functions provided will issue a warning log
+ * message if an unimplemented function is invoked
+ *
+ */
+
+int pthread_barrier_destroy(pthread_barrier_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_barrier_destroy(a);
+}
+
+int
+pthread_barrier_init(pthread_barrier_t *a,
+		     const pthread_barrierattr_t *b, unsigned c)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_barrier_init(a, b, c);
+}
+
+int pthread_barrier_wait(pthread_barrier_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_barrier_wait(a);
+}
+
+int pthread_cond_broadcast(pthread_cond_t *cond)
+{
+	if (override) {
+
+		lthread_cond_broadcast(*(struct lthread_cond **)cond);
+		return 0;
+	}
+	return _sys_pthread_funcs.f_pthread_cond_broadcast(cond);
+}
+
+int pthread_cond_destroy(pthread_cond_t *cond)
+{
+	if (override)
+		return -lthread_cond_destroy(*(struct lthread_cond **)cond);
+	return _sys_pthread_funcs.f_pthread_cond_destroy(cond);
+}
+
+int pthread_cond_init(pthread_cond_t *cond, const pthread_condattr_t *attr)
+{
+	if (override)
+		return -lthread_cond_init(NULL,
+				(struct lthread_cond **)cond,
+				(const struct lthread_condattr *) attr);
+	return _sys_pthread_funcs.f_pthread_cond_init(cond, attr);
+}
+
+int pthread_cond_signal(pthread_cond_t *cond)
+{
+	if (override) {
+		lthread_cond_signal(*(struct lthread_cond **)cond);
+		return 0;
+	}
+	return _sys_pthread_funcs.f_pthread_cond_signal(cond);
+}
+
+int
+pthread_cond_timedwait(pthread_cond_t *__restrict cond,
+		       pthread_mutex_t *__restrict mutex,
+		       const struct timespec *__restrict time)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_cond_timedwait(cond, mutex, time);
+}
+
+int pthread_cond_wait(pthread_cond_t *cond, pthread_mutex_t *mutex)
+{
+	if (override) {
+		pthread_mutex_unlock(mutex);
+		int rv = lthread_cond_wait(*(struct lthread_cond **)cond, 0);
+
+		pthread_mutex_lock(mutex);
+		return rv;
+	}
+	return _sys_pthread_funcs.f_pthread_cond_wait(cond, mutex);
+}
+
+int
+pthread_create(pthread_t *__restrict tid,
+		const pthread_attr_t *__restrict attr,
+		void *(func) (void *),
+	       void *__restrict arg)
+{
+	if (override) {
+		int lcore = -1;
+
+		if (attr != NULL) {
+			/* determine CPU being requested */
+			cpu_set_t cpuset;
+
+			CPU_ZERO(&cpuset);
+			pthread_attr_getaffinity_np(attr,
+						sizeof(cpu_set_t),
+						&cpuset);
+
+			if (CPU_COUNT(&cpuset) != 1)
+				return POSIX_ERRNO(EINVAL);
+
+			for (lcore = 0; lcore < LTHREAD_MAX_LCORES; lcore++) {
+				if (!CPU_ISSET(lcore, &cpuset))
+					continue;
+				break;
+			}
+		}
+		return lthread_create((struct lthread **)tid, lcore,
+				      (void (*)(void *))func, arg);
+	}
+	return _sys_pthread_funcs.f_pthread_create(tid, attr, func, arg);
+}
+
+int pthread_detach(pthread_t tid)
+{
+	if (override) {
+		struct lthread *lt = (struct lthread *)tid;
+
+		if (lt == lthread_current())
+			lthread_detach();
+			return 0;
+		NOT_IMPLEMENTED;
+	}
+	return _sys_pthread_funcs.f_pthread_detach(tid);
+}
+
+int pthread_equal(pthread_t a, pthread_t b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_equal(a, b);
+}
+
+void pthread_exit_override(void *v)
+{
+	if (override) {
+		lthread_exit(v);
+		return;
+	}
+	_sys_pthread_funcs.f_pthread_exit(v);
+}
+
+void
+*pthread_getspecific(pthread_key_t key)
+{
+	if (override)
+		return lthread_getspecific((unsigned int) key);
+	return _sys_pthread_funcs.f_pthread_getspecific(key);
+}
+
+int pthread_getcpuclockid(pthread_t a, clockid_t *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_getcpuclockid(a, b);
+}
+
+int pthread_join(pthread_t tid, void **val)
+{
+	if (override)
+		return lthread_join((struct lthread *)tid, val);
+	return _sys_pthread_funcs.f_pthread_join(tid, val);
+}
+
+int pthread_key_create(pthread_key_t *keyptr, void (*dtor) (void *))
+{
+	if (override)
+		return lthread_key_create((unsigned int *)keyptr, dtor);
+	return _sys_pthread_funcs.f_pthread_key_create(keyptr, dtor);
+}
+
+int pthread_key_delete(pthread_key_t key)
+{
+	if (override) {
+		lthread_key_delete((unsigned int) key);
+		return 0;
+	}
+	return _sys_pthread_funcs.f_pthread_key_delete(key);
+}
+
+
+int
+pthread_mutex_init(pthread_mutex_t *mutex, const pthread_mutexattr_t *attr)
+{
+	if (override)
+		return lthread_mutex_init(NULL,
+				(struct lthread_mutex **)mutex,
+				(const struct lthread_mutexattr *)attr);
+	return _sys_pthread_funcs.f_pthread_mutex_init(mutex, attr);
+}
+
+int pthread_mutex_lock(pthread_mutex_t *mutex)
+{
+	if (override)
+		return lthread_mutex_lock(*(struct lthread_mutex **)mutex);
+	return _sys_pthread_funcs.f_pthread_mutex_lock(mutex);
+}
+
+int pthread_mutex_trylock(pthread_mutex_t *mutex)
+{
+	if (override)
+		return lthread_mutex_trylock(*(struct lthread_mutex **)mutex);
+	return _sys_pthread_funcs.f_pthread_mutex_trylock(mutex);
+}
+
+int pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_mutex_timedlock(mutex, b);
+}
+
+int pthread_mutex_unlock(pthread_mutex_t *mutex)
+{
+	if (override)
+		return lthread_mutex_unlock(*(struct lthread_mutex **)mutex);
+	return _sys_pthread_funcs.f_pthread_mutex_unlock(mutex);
+}
+
+int pthread_once(pthread_once_t *a, void (b) (void))
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_once(a, b);
+}
+
+int pthread_rwlock_destroy(pthread_rwlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_destroy(a);
+}
+
+int pthread_rwlock_init(pthread_rwlock_t *a, const pthread_rwlockattr_t *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_init(a, b);
+}
+
+int pthread_rwlock_rdlock(pthread_rwlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_rdlock(a);
+}
+
+int pthread_rwlock_timedrdlock(pthread_rwlock_t *a, const struct timespec *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_timedrdlock(a, b);
+}
+
+int pthread_rwlock_timedwrlock(pthread_rwlock_t *a, const struct timespec *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_timedwrlock(a, b);
+}
+
+int pthread_rwlock_tryrdlock(pthread_rwlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_tryrdlock(a);
+}
+
+int pthread_rwlock_trywrlock(pthread_rwlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_trywrlock(a);
+}
+
+int pthread_rwlock_unlock(pthread_rwlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_unlock(a);
+}
+
+int pthread_rwlock_wrlock(pthread_rwlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_rwlock_wrlock(a);
+}
+
+int pthread_yield(void)
+{
+	if (override) {
+		lthread_yield();
+		return 0;
+	}
+	return _sys_pthread_funcs.f_pthread_yield();
+
+}
+
+pthread_t pthread_self(void)
+{
+	if (override)
+		return (pthread_t) lthread_current();
+	return _sys_pthread_funcs.f_pthread_self();
+}
+
+int pthread_setspecific(pthread_key_t key, const void *data)
+{
+	if (override) {
+		int rv =  lthread_setspecific((unsigned int)key, data);
+		return rv;
+	}
+	return _sys_pthread_funcs.f_pthread_setspecific(key, data);
+}
+
+int pthread_spin_init(pthread_spinlock_t *a, int b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_spin_init(a, b);
+}
+
+int pthread_spin_destroy(pthread_spinlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_spin_destroy(a);
+}
+
+int pthread_spin_lock(pthread_spinlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_spin_lock(a);
+}
+
+int pthread_spin_trylock(pthread_spinlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_spin_trylock(a);
+}
+
+int pthread_spin_unlock(pthread_spinlock_t *a)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_spin_unlock(a);
+}
+
+int pthread_cancel(pthread_t tid)
+{
+	if (override) {
+		lthread_cancel(*(struct lthread **)tid);
+		return 0;
+	}
+	return _sys_pthread_funcs.f_pthread_cancel(tid);
+}
+
+int pthread_setcancelstate(int a, int *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_setcancelstate(a, b);
+}
+
+int pthread_setcanceltype(int a, int *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_setcanceltype(a, b);
+}
+
+void pthread_testcancel(void)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_testcancel();
+}
+
+
+int pthread_getschedparam(pthread_t tid, int *a, struct sched_param *b)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_getschedparam(tid, a, b);
+}
+
+int pthread_setschedparam(pthread_t a, int b, const struct sched_param *c)
+{
+	NOT_IMPLEMENTED;
+	return _sys_pthread_funcs.f_pthread_setschedparam(a, b, c);
+}
+
+
+int nanosleep(const struct timespec *req, struct timespec *rem)
+{
+	if (override) {
+		uint64_t ns = req->tv_sec * 1000000000 + req->tv_nsec;
+
+		lthread_sleep(ns);
+		return 0;
+	}
+	return _sys_pthread_funcs.f_nanosleep(req, rem);
+}
+
+int
+pthread_setaffinity_np(pthread_t thread, size_t cpusetsize,
+		       const cpu_set_t *cpuset)
+{
+	if (override) {
+		/* we only allow affinity with a single CPU */
+		if (CPU_COUNT(cpuset) != 1)
+			return POSIX_ERRNO(EINVAL);
+
+		/* we only allow the current thread to sets its own affinity */
+		struct lthread *lt = (struct lthread *)thread;
+
+		if (lthread_current() != lt)
+			return POSIX_ERRNO(EINVAL);
+
+		/* determine the CPU being requested */
+		int i;
+
+		for (i = 0; i < LTHREAD_MAX_LCORES; i++) {
+			if (!CPU_ISSET(i, cpuset))
+				continue;
+			break;
+		}
+		/* check requested core is allowed */
+		if (i == LTHREAD_MAX_LCORES)
+			return POSIX_ERRNO(EINVAL);
+
+		/* finally we can set affinity to the requested lcore */
+		lthread_set_affinity(i);
+		return 0;
+	}
+	return _sys_pthread_funcs.f_pthread_setaffinity_np(thread, cpusetsize,
+							   cpuset);
+}
diff --git a/examples/performance-thread/pthread_shim/pthread_shim.h b/examples/performance-thread/pthread_shim/pthread_shim.h
new file mode 100644
index 0000000..78bbb5a
--- /dev/null
+++ b/examples/performance-thread/pthread_shim/pthread_shim.h
@@ -0,0 +1,113 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2015 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _PTHREAD_SHIM_H_
+#define _PTHREAD_SHIM_H_
+#include <pthread.h>
+
+/*
+ * This pthread shim is an example that demonstrates how legacy code
+ * that makes use of POSIX pthread services can make use of lthreads
+ * with reduced porting effort.
+ *
+ * N.B. The example is not a complete implementation, only a subset of
+ * pthread APIs sufficient to demonstrate the principle of operation
+ * are implemented.
+ *
+ * In general pthread attribute objects do not have equivalent functions
+ * in lthreads, and are ignored.
+ *
+ * There is one exception and that is the use of attr to specify a
+ * core affinity in calls to pthread_create.
+ *
+ * The shim operates as follows:-
+ *
+ * On initialisation a constructor function uses dlsym to obtain and
+ * save the loaded address of the full set of pthread APIs that will
+ * be overridden.
+ *
+ * For each function there is a stub provided that will invoke either
+ * the genuine pthread library function saved saved by the constructor,
+ * or else the corresponding equivalent lthread function.
+ *
+ * The stub functions are implemented in pthread_shim.c
+ *
+ * The stub will take care of adapting parameters, and any police
+ * any constraints where lthread functionality differs.
+ *
+ * The initial thread must always be a pure lthread.
+ *
+ * The decision whether to invoke the real library function or the lthread
+ * function is controlled by a per pthread flag that can be switched
+ * on of off by the pthread_override_set() API described below. Typcially
+ * this should be done as the first action of the initial lthread.
+ *
+ * N.B In general it would be poor practice to revert to invoke a real
+ * pthread function when running as an lthread, since these may block and
+ * effectively stall the lthread scheduler.
+ *
+ */
+
+
+/*
+ * An exiting lthread must not terminate the pthread it is running in
+ * since this would mean terminating the lthread scheduler.
+ * We override pthread_exit() with a macro because it is typically declared with
+ * __attribute__((noreturn))
+ */
+void pthread_exit_override(void *v);
+
+#define pthread_exit(v) do { \
+	pthread_exit_override((v));	\
+	return NULL;	\
+} while (0)
+
+/*
+ * Enable/Disable pthread override
+ * state
+ * 0 disable
+ * 1 enable
+ */
+void pthread_override_set(int state);
+
+
+/*
+ * Return pthread override state
+ * return
+ * 0 disable
+ * 1 enable
+ */
+int pthread_override_get(void);
+
+
+#endif /* _PTHREAD_SHIM_H_ */
-- 
2.1.4