[PATCH v5 2/6] eal: add thread lifetime management

[Tyler Retzlaff <roretzla@linux.microsoft.com>]

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>
Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
---
 lib/eal/include/rte_thread.h    |  75 ++++++++++++++
 lib/eal/unix/rte_thread.c       | 135 +++++++++++++++++++++++++
 lib/eal/version.map             |   3 +
 lib/eal/windows/include/sched.h |   2 +-
 lib/eal/windows/rte_thread.c    | 213 ++++++++++++++++++++++++++++++++--------
 5 files changed, 387 insertions(+), 41 deletions(-)

diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
index a3802de..65cdcfa 100644
--- a/lib/eal/include/rte_thread.h
+++ b/lib/eal/include/rte_thread.h
@@ -31,6 +31,18 @@
 } rte_thread_t;
 
 /**
+ * Thread function
+ *
+ * Function pointer to thread start routine.
+ *
+ * @param arg
+ *   Argument passed to rte_thread_create().
+ * @return
+ *   Thread function exit value.
+ */
+typedef uint32_t (*rte_thread_func) (void *arg);
+
+/**
  * Thread priority values.
  */
 enum rte_thread_priority {
@@ -57,6 +69,69 @@ enum rte_thread_priority {
  * @warning
  * @b EXPERIMENTAL: this API may change without prior notice.
  *
+ * 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 arg
+ *    Argument 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 *arg);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * 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, uint32_t *value_ptr);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * 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);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
  * Get the id of the calling thread.
  *
  * @return
diff --git a/lib/eal/unix/rte_thread.c b/lib/eal/unix/rte_thread.c
index 9126595..d4c1a7f 100644
--- a/lib/eal/unix/rte_thread.c
+++ b/lib/eal/unix/rte_thread.c
@@ -16,6 +16,11 @@ struct eal_tls_key {
 	pthread_key_t thread_index;
 };
 
+struct thread_routine_ctx {
+	rte_thread_func thread_func;
+	void *routine_args;
+};
+
 static int
 thread_map_priority_to_os_value(enum rte_thread_priority eal_pri, int *os_pri,
 	int *pol)
@@ -75,6 +80,136 @@ struct eal_tls_key {
 	return 0;
 }
 
+static void *
+thread_func_wrapper(void *arg)
+{
+	struct thread_routine_ctx ctx = *(struct thread_routine_ctx *)arg;
+
+	free(arg);
+
+	return (void *)(uintptr_t)ctx.thread_func(ctx.routine_args);
+}
+
+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 thread_routine_ctx *ctx;
+	struct sched_param param = {
+		.sched_priority = 0,
+	};
+	int policy = SCHED_OTHER;
+
+	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;
+
+	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;
+
+		/*
+		 * 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;
+		}
+
+
+		if (thread_attr->priority ==
+				RTE_THREAD_PRIORITY_REALTIME_CRITICAL) {
+			ret = ENOTSUP;
+			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;
+		}
+	}
+
+	ret = pthread_create((pthread_t *)&thread_id->opaque_id, attrp,
+		thread_func_wrapper, ctx);
+	if (ret != 0) {
+		RTE_LOG(DEBUG, EAL, "pthread_create failed\n");
+		goto cleanup;
+	}
+
+	if (thread_attr != NULL && CPU_COUNT(&thread_attr->cpuset) > 0) {
+		ret = rte_thread_set_affinity_by_id(*thread_id,
+			&thread_attr->cpuset);
+		if (ret != 0) {
+			RTE_LOG(DEBUG, EAL, "rte_thread_set_affinity_by_id failed\n");
+			goto cleanup;
+		}
+	}
+
+	ctx = NULL;
+cleanup:
+	free(ctx);
+	if (attrp != NULL)
+		pthread_attr_destroy(&attr);
+
+	return ret;
+}
+
+int
+rte_thread_join(rte_thread_t thread_id, uint32_t *value_ptr)
+{
+	int ret = 0;
+	void *res = (void *)(uintptr_t)0;
+	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 (value_ptr != NULL)
+		*value_ptr = (uint32_t)(uintptr_t)res;
+
+	return 0;
+}
+
+int
+rte_thread_detach(rte_thread_t thread_id)
+{
+	return pthread_detach((pthread_t)thread_id.opaque_id);
+}
+
 rte_thread_t
 rte_thread_self(void)
 {
diff --git a/lib/eal/version.map b/lib/eal/version.map
index e9df18d..5fd84b6 100644
--- a/lib/eal/version.map
+++ b/lib/eal/version.map
@@ -436,6 +436,9 @@ EXPERIMENTAL {
 	rte_thread_attr_init;
 	rte_thread_attr_set_affinity;
 	rte_thread_attr_set_priority;
+	rte_thread_create;
+	rte_thread_detach;
+	rte_thread_join;
 };
 
 INTERNAL {
diff --git a/lib/eal/windows/include/sched.h b/lib/eal/windows/include/sched.h
index bc31cc8..912fed1 100644
--- a/lib/eal/windows/include/sched.h
+++ b/lib/eal/windows/include/sched.h
@@ -44,7 +44,7 @@
 	(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 63442ec..e153278 100644
--- a/lib/eal/windows/rte_thread.c
+++ b/lib/eal/windows/rte_thread.c
@@ -15,6 +15,11 @@ 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)
@@ -116,6 +121,174 @@ struct eal_tls_key {
 	return 0;
 }
 
+static int
+convert_cpuset_to_affinity(const rte_cpuset_t *cpuset,
+		PGROUP_AFFINITY affinity)
+{
+	int ret = 0;
+	PGROUP_AFFINITY cpu_affinity = NULL;
+	unsigned int cpu_idx;
+
+	memset(affinity, 0, sizeof(GROUP_AFFINITY));
+	affinity->Group = (USHORT)-1;
+
+	/* Check that all cpus of the set belong to the same processor group and
+	 * accumulate thread affinity to be applied.
+	 */
+	for (cpu_idx = 0; cpu_idx < CPU_SETSIZE; cpu_idx++) {
+		if (!CPU_ISSET(cpu_idx, cpuset))
+			continue;
+
+		cpu_affinity = eal_get_cpu_affinity(cpu_idx);
+
+		if (affinity->Group == (USHORT)-1) {
+			affinity->Group = cpu_affinity->Group;
+		} else if (affinity->Group != cpu_affinity->Group) {
+			RTE_LOG(DEBUG, EAL, "All processors must belong to the same processor group\n");
+			ret = ENOTSUP;
+			goto cleanup;
+		}
+
+		affinity->Mask |= cpu_affinity->Mask;
+	}
+
+	if (affinity->Mask == 0) {
+		ret = EINVAL;
+		goto cleanup;
+	}
+
+cleanup:
+	return ret;
+}
+
+static DWORD
+thread_func_wrapper(void *arg)
+{
+	struct thread_routine_ctx ctx = *(struct thread_routine_ctx *)arg;
+
+	free(arg);
+
+	return (DWORD)ctx.thread_func(ctx.routine_args);
+}
+
+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;
+
+	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()");
+		goto cleanup;
+	}
+	thread_id->opaque_id = tid;
+
+	if (thread_attr != NULL) {
+		if (CPU_COUNT(&thread_attr->cpuset) > 0) {
+			ret = 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;
+			}
+		}
+		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;
+	}
+
+	ctx = NULL;
+cleanup:
+	free(ctx);
+	if (thread_handle != NULL) {
+		CloseHandle(thread_handle);
+		thread_handle = NULL;
+	}
+
+	return ret;
+}
+
+int
+rte_thread_join(rte_thread_t thread_id, uint32_t *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;
+}
+
 rte_thread_t
 rte_thread_self(void)
 {
@@ -280,46 +453,6 @@ struct eal_tls_key {
 	return output;
 }
 
-static int
-convert_cpuset_to_affinity(const rte_cpuset_t *cpuset,
-		PGROUP_AFFINITY affinity)
-{
-	int ret = 0;
-	PGROUP_AFFINITY cpu_affinity = NULL;
-	unsigned int cpu_idx;
-
-	memset(affinity, 0, sizeof(GROUP_AFFINITY));
-	affinity->Group = (USHORT)-1;
-
-	/* Check that all cpus of the set belong to the same processor group and
-	 * accumulate thread affinity to be applied.
-	 */
-	for (cpu_idx = 0; cpu_idx < CPU_SETSIZE; cpu_idx++) {
-		if (!CPU_ISSET(cpu_idx, cpuset))
-			continue;
-
-		cpu_affinity = eal_get_cpu_affinity(cpu_idx);
-
-		if (affinity->Group == (USHORT)-1) {
-			affinity->Group = cpu_affinity->Group;
-		} else if (affinity->Group != cpu_affinity->Group) {
-			RTE_LOG(DEBUG, EAL, "All processors must belong to the same processor group\n");
-			ret = ENOTSUP;
-			goto cleanup;
-		}
-
-		affinity->Mask |= cpu_affinity->Mask;
-	}
-
-	if (affinity->Mask == 0) {
-		ret = EINVAL;
-		goto cleanup;
-	}
-
-cleanup:
-	return ret;
-}
-
 int
 rte_thread_set_affinity_by_id(rte_thread_t thread_id,
 		const rte_cpuset_t *cpuset)
-- 
1.8.3.1