[dpdk-dev] [PATCH v10 6/9] eal: add thread lifetime management

[Narcisa Ana Maria Vasile <navasile@linux.microsoft.com>]

From: Narcisa Vasile <navasile@microsoft.com>

Add functions for thread creation, joining, detaching.

The *rte_thread_create()* function can optionally receive
an rte_thread_attr_t object that will cause the thread to be
created with the affinity and priority described by the
attributes object. If no rte_thread_attr_t is passed (parameter is NULL),
the default affinity and priority are used.

On Windows, the function executed by a thread when the thread starts is
represeneted by a function pointer of type DWORD (*func) (void*).
On other platforms, the function pointer is a void* (*func) (void*).

Performing a cast between these two types of function pointers to
uniformize the API on all platforms may result in undefined behavior.
TO fix this issue, a wrapper that respects the signature required by
CreateThread() has been created on Windows.

Signed-off-by: Narcisa Vasile <navasile@microsoft.com>
---
 lib/eal/common/rte_thread.c     | 107 +++++++++++++++++++++++++
 lib/eal/include/rte_thread.h    |  55 +++++++++++++
 lib/eal/version.map             |   3 +
 lib/eal/windows/include/sched.h |   2 +-
 lib/eal/windows/rte_thread.c    | 138 ++++++++++++++++++++++++++++++++
 5 files changed, 304 insertions(+), 1 deletion(-)

diff --git a/lib/eal/common/rte_thread.c b/lib/eal/common/rte_thread.c
index fcebf7097c..a0a51bc190 100644
--- a/lib/eal/common/rte_thread.c
+++ b/lib/eal/common/rte_thread.c
@@ -144,6 +144,113 @@ rte_thread_attr_set_priority(rte_thread_attr_t *thread_attr,
 	return 0;
 }
 
+int
+rte_thread_create(rte_thread_t *thread_id,
+		const rte_thread_attr_t *thread_attr,
+		rte_thread_func thread_func, void *args)
+{
+	int ret = 0;
+	pthread_attr_t attr;
+	pthread_attr_t *attrp = NULL;
+	struct sched_param param = {
+		.sched_priority = 0,
+	};
+	int policy = SCHED_OTHER;
+
+	if (thread_attr != NULL) {
+		ret = pthread_attr_init(&attr);
+		if (ret != 0) {
+			RTE_LOG(DEBUG, EAL, "pthread_attr_init failed\n");
+			goto cleanup;
+		}
+
+		attrp = &attr;
+
+		if (thread_attr->priority != RTE_THREAD_PRIORITY_UNDEFINED) {
+			/*
+			 * Set the inherit scheduler parameter to explicit,
+			 * otherwise the priority attribute is ignored.
+			 */
+			ret = pthread_attr_setinheritsched(attrp,
+					PTHREAD_EXPLICIT_SCHED);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL, "pthread_attr_setinheritsched failed\n");
+				goto cleanup;
+			}
+
+			ret = thread_map_priority_to_os_value(
+					thread_attr->priority,
+					&param.sched_priority, &policy
+					);
+			if (ret != 0)
+				goto cleanup;
+
+			ret = pthread_attr_setschedpolicy(attrp, policy);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL, "pthread_attr_setschedpolicy failed\n");
+				goto cleanup;
+			}
+
+			ret = pthread_attr_setschedparam(attrp, &param);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL, "pthread_attr_setschedparam failed\n");
+				goto cleanup;
+			}
+		}
+
+		if (CPU_COUNT(&thread_attr->cpuset) > 0) {
+			ret = pthread_attr_setaffinity_np(attrp,
+					sizeof(thread_attr->cpuset),
+					&thread_attr->cpuset);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL, "pthread_attr_setaffinity_np failed\n");
+				goto cleanup;
+			}
+		}
+	}
+
+	ret = pthread_create((pthread_t *)&thread_id->opaque_id, attrp,
+		thread_func, args);
+	if (ret != 0) {
+		RTE_LOG(DEBUG, EAL, "pthread_create failed\n");
+		goto cleanup;
+	}
+
+cleanup:
+	if (attrp != NULL)
+		pthread_attr_destroy(&attr);
+
+	return ret;
+}
+
+int
+rte_thread_join(rte_thread_t thread_id, unsigned long *value_ptr)
+{
+	int ret = 0;
+	void *res = NULL;
+	void **pres = NULL;
+
+	if (value_ptr != NULL)
+		pres = &res;
+
+	ret = pthread_join((pthread_t)thread_id.opaque_id, pres);
+	if (ret != 0) {
+		RTE_LOG(DEBUG, EAL, "pthread_join failed\n");
+		return ret;
+	}
+
+	if (pres != NULL)
+		*value_ptr = *(unsigned long *)(*pres);
+
+	return 0;
+}
+
+int
+rte_thread_detach(rte_thread_t thread_id)
+{
+	return pthread_detach((pthread_t)thread_id.opaque_id);
+}
+
 int
 rte_thread_key_create(rte_thread_key *key, void (*destructor)(void *))
 {
diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
index 5514b2f57f..098c3ba343 100644
--- a/lib/eal/include/rte_thread.h
+++ b/lib/eal/include/rte_thread.h
@@ -31,6 +31,7 @@ typedef struct rte_thread_tag {
 	uintptr_t opaque_id; /**< thread identifier */
 } rte_thread_t;
 
+typedef void* (*rte_thread_func) (void *);
 /**
  * Thread priority values.
  */
@@ -213,6 +214,60 @@ int rte_thread_set_affinity(rte_cpuset_t *cpusetp);
  */
 void rte_thread_get_affinity(rte_cpuset_t *cpusetp);
 
+/**
+ * Create a new thread that will invoke the 'thread_func' routine.
+ *
+ * @param thread_id
+ *    A pointer that will store the id of the newly created thread.
+ *
+ * @param thread_attr
+ *    Attributes that are used at the creation of the new thread.
+ *
+ * @param thread_func
+ *    The routine that the new thread will invoke when starting execution.
+ *
+ * @param args
+ *    Arguments to be passed to the 'thread_func' routine.
+ *
+ * @return
+ *   On success, return 0.
+ *   On failure, return a positive errno-style error number.
+ */
+__rte_experimental
+int rte_thread_create(rte_thread_t *thread_id,
+		const rte_thread_attr_t *thread_attr,
+		rte_thread_func thread_func, void *args);
+
+/**
+ * Waits for the thread identified by 'thread_id' to terminate
+ *
+ * @param thread_id
+ *    The identifier of the thread.
+ *
+ * @param value_ptr
+ *    Stores the exit status of the thread.
+ *
+ * @return
+ *   On success, return 0.
+ *   On failure, return a positive errno-style error number.
+ */
+__rte_experimental
+int rte_thread_join(rte_thread_t thread_id, unsigned long *value_ptr);
+
+/**
+ * Indicate that the return value of the thread is not needed and
+ * all thread resources should be release when the thread terminates.
+ *
+ * @param thread_id
+ *    The id of the thread to be detached.
+ *
+ * @return
+ *   On success, return 0.
+ *   On failure, return a positive errno-style error number.
+ */
+__rte_experimental
+int rte_thread_detach(rte_thread_t thread_id);
+
 #endif /* RTE_HAS_CPUSET */
 
 /**
diff --git a/lib/eal/version.map b/lib/eal/version.map
index d091aacc47..b6d7028d94 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -433,6 +433,9 @@ EXPERIMENTAL {
 	rte_thread_get_affinity_by_id;
 	rte_thread_set_affinity_by_id;
 	rte_thread_set_priority;
+	rte_thread_create;
+	rte_thread_join;
+	rte_thread_detach;
 };
 
 INTERNAL {
diff --git a/lib/eal/windows/include/sched.h b/lib/eal/windows/include/sched.h
index ff572b5dcb..8f0b3cb71e 100644
--- a/lib/eal/windows/include/sched.h
+++ b/lib/eal/windows/include/sched.h
@@ -44,7 +44,7 @@ typedef struct _rte_cpuset_s {
 	(1LL << _WHICH_BIT(b))) != 0LL)
 
 static inline int
-count_cpu(rte_cpuset_t *s)
+count_cpu(const rte_cpuset_t *s)
 {
 	unsigned int _i;
 	int count = 0;
diff --git a/lib/eal/windows/rte_thread.c b/lib/eal/windows/rte_thread.c
index fb04718f58..e5e420fadd 100644
--- a/lib/eal/windows/rte_thread.c
+++ b/lib/eal/windows/rte_thread.c
@@ -14,6 +14,11 @@ struct eal_tls_key {
 	DWORD thread_index;
 };
 
+struct thread_routine_ctx {
+	rte_thread_func thread_func;
+	void *routine_args;
+};
+
 /* Translates the most common error codes related to threads */
 static int
 thread_translate_win32_error(DWORD error)
@@ -309,6 +314,139 @@ rte_thread_attr_set_priority(rte_thread_attr_t *thread_attr,
 	return 0;
 }
 
+static DWORD
+thread_func_wrapper(void *args)
+{
+	struct thread_routine_ctx *pctx = args;
+	unsigned long *func_ret = NULL;
+	struct thread_routine_ctx ctx;
+
+	ctx.thread_func = pctx->thread_func;
+	ctx.routine_args = pctx->routine_args;
+
+	free(pctx);
+
+	func_ret = (unsigned long *)ctx.thread_func(ctx.routine_args);
+	return *func_ret;
+}
+
+int
+rte_thread_create(rte_thread_t *thread_id,
+		  const rte_thread_attr_t *thread_attr,
+		  rte_thread_func thread_func, void *args)
+{
+	int ret = 0;
+	DWORD tid;
+	HANDLE thread_handle = NULL;
+	GROUP_AFFINITY thread_affinity;
+	struct thread_routine_ctx *ctx = NULL;
+
+	ctx = calloc(1, sizeof(*ctx));
+	if (ctx == NULL) {
+		RTE_LOG(DEBUG, EAL, "Insufficient memory for thread context allocations\n");
+		ret = ENOMEM;
+		goto cleanup;
+	}
+	ctx->routine_args = args;
+	ctx->thread_func = thread_func;
+
+	thread_handle = CreateThread(NULL, 0, thread_func_wrapper, ctx,
+		CREATE_SUSPENDED, &tid);
+	if (thread_handle == NULL) {
+		ret = thread_log_last_error("CreateThread()");
+		free(ctx);
+		goto cleanup;
+	}
+	thread_id->opaque_id = tid;
+
+	if (thread_attr != NULL) {
+		if (CPU_COUNT(&thread_attr->cpuset) > 0) {
+			ret = rte_convert_cpuset_to_affinity(
+							&thread_attr->cpuset,
+							&thread_affinity
+							);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL, "Unable to convert cpuset to thread affinity\n");
+				goto cleanup;
+			}
+
+			if (!SetThreadGroupAffinity(thread_handle,
+						    &thread_affinity, NULL)) {
+				ret = thread_log_last_error("SetThreadGroupAffinity()");
+				goto cleanup;
+			}
+		}
+		if (thread_attr->priority != RTE_THREAD_PRIORITY_UNDEFINED) {
+			ret = rte_thread_set_priority(*thread_id,
+						      thread_attr->priority);
+			if (ret != 0) {
+				RTE_LOG(DEBUG, EAL, "Unable to set thread priority\n");
+				goto cleanup;
+			}
+		}
+	}
+
+	if (ResumeThread(thread_handle) == (DWORD)-1) {
+		ret = thread_log_last_error("ResumeThread()");
+		goto cleanup;
+	}
+
+cleanup:
+	if (thread_handle != NULL) {
+		CloseHandle(thread_handle);
+		thread_handle = NULL;
+	}
+	return ret;
+}
+
+int
+rte_thread_join(rte_thread_t thread_id, unsigned long *value_ptr)
+{
+	HANDLE thread_handle;
+	DWORD result;
+	DWORD exit_code = 0;
+	BOOL err;
+	int ret = 0;
+
+	thread_handle = OpenThread(SYNCHRONIZE | THREAD_QUERY_INFORMATION,
+				   FALSE, thread_id.opaque_id);
+	if (thread_handle == NULL) {
+		ret = thread_log_last_error("OpenThread()");
+		goto cleanup;
+	}
+
+	result = WaitForSingleObject(thread_handle, INFINITE);
+	if (result != WAIT_OBJECT_0) {
+		ret = thread_log_last_error("WaitForSingleObject()");
+		goto cleanup;
+	}
+
+	if (value_ptr != NULL) {
+		err = GetExitCodeThread(thread_handle, &exit_code);
+		if (err == 0) {
+			ret = thread_log_last_error("GetExitCodeThread()");
+			goto cleanup;
+		}
+		*value_ptr = exit_code;
+	}
+
+cleanup:
+	if (thread_handle != NULL) {
+		CloseHandle(thread_handle);
+		thread_handle = NULL;
+	}
+
+	return ret;
+}
+
+int
+rte_thread_detach(rte_thread_t thread_id)
+{
+	/* No resources that need to be released. */
+	RTE_SET_USED(thread_id);
+	return 0;
+}
+
 int
 rte_thread_key_create(rte_thread_key *key,
 		__rte_unused void (*destructor)(void *))
-- 
2.31.0.vfs.0.1