[v9,01/10] eal: add thread id and simple thread functions

Message ID 1622850274-6946-2-git-send-email-navasile@linux.microsoft.com (mailing list archive)
State Superseded, archived
Delegated to: David Marchand
Headers
Series eal: Add EAL API for threading |

Checks

Context Check Description
ci/checkpatch warning coding style issues

Commit Message

Narcisa Ana Maria Vasile June 4, 2021, 11:44 p.m. UTC
From: Narcisa Vasile <navasile@microsoft.com>

Use a portable, type-safe representation for the thread identifier.
Add functions for comparing thread ids and obtaining the thread id
for the current thread.

Signed-off-by: Narcisa Vasile <navasile@microsoft.com>
---
 lib/eal/common/rte_thread.c                   | 105 ++++++++++++++++++
 lib/eal/include/rte_thread.h                  |  53 +++++++--
 lib/eal/include/rte_thread_types.h            |  10 ++
 .../include/rte_windows_thread_types.h        |  10 ++
 lib/eal/windows/rte_thread.c                  |  17 +++
 5 files changed, 186 insertions(+), 9 deletions(-)
 create mode 100644 lib/eal/common/rte_thread.c
 create mode 100644 lib/eal/include/rte_thread_types.h
 create mode 100644 lib/eal/windows/include/rte_windows_thread_types.h
  

Comments

Dmitry Kozlyuk June 8, 2021, 11:03 p.m. UTC | #1
2021-06-04 16:44 (UTC-0700), Narcisa Ana Maria Vasile:
> From: Narcisa Vasile <navasile@microsoft.com>
> 
> Use a portable, type-safe representation for the thread identifier.
> Add functions for comparing thread ids and obtaining the thread id
> for the current thread.
> 
> Signed-off-by: Narcisa Vasile <navasile@microsoft.com>
> ---
>  lib/eal/common/rte_thread.c                   | 105 ++++++++++++++++++
>  lib/eal/include/rte_thread.h                  |  53 +++++++--
>  lib/eal/include/rte_thread_types.h            |  10 ++
>  .../include/rte_windows_thread_types.h        |  10 ++
>  lib/eal/windows/rte_thread.c                  |  17 +++
>  5 files changed, 186 insertions(+), 9 deletions(-)
>  create mode 100644 lib/eal/common/rte_thread.c
>  create mode 100644 lib/eal/include/rte_thread_types.h
>  create mode 100644 lib/eal/windows/include/rte_windows_thread_types.h

It is strange that new files are being filled in the series, but are neither
compiled nor installed until the last patch. Any reason not to replace
lib/eal/unix/rte_thread.c starting from this patch?

A better name for rte_thread_types.h would be rte_posix_thread_types.h
to indicate this file is not really common.

> 
> diff --git a/lib/eal/common/rte_thread.c b/lib/eal/common/rte_thread.c
> new file mode 100644
> index 0000000000..1292f7a8f8
> --- /dev/null
> +++ b/lib/eal/common/rte_thread.c
> @@ -0,0 +1,105 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2021 Mellanox Technologies, Ltd
> + * Copyright(c) 2021 Microsoft Corporation
> + */
> +
> +#include <errno.h>
> +#include <pthread.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +#include <rte_common.h>
> +#include <rte_errno.h>
> +#include <rte_log.h>
> +#include <rte_thread.h>
> +
> +struct eal_tls_key {
> +	pthread_key_t thread_index;
> +};
> +
> +rte_thread_t
> +rte_thread_self(void)
> +{
> +	rte_thread_t thread_id = { 0 };

(Applies to entire series.)
Please do not initialize variables when you intend to overwrite them.
This prevents compiler from reporting code paths where the variable is used
before a proper assignment.

> +
> +	thread_id.opaque_id = pthread_self();
> +
> +	return thread_id;
> +}
> +

[...]
> diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
> index 8be8ed8f36..347df1a6ae 100644
> --- a/lib/eal/include/rte_thread.h
> +++ b/lib/eal/include/rte_thread.h
> @@ -1,6 +1,8 @@
>  /* SPDX-License-Identifier: BSD-3-Clause
>   * Copyright(c) 2021 Mellanox Technologies, Ltd
> + * Copyright(c) 2021 Microsoft Corporation
>   */
> +#include <stdint.h>
>  
>  #include <rte_os.h>
>  #include <rte_compat.h>
> @@ -20,11 +22,50 @@
>  extern "C" {
>  #endif
>  
> +#include <sched.h>
> +#if defined(RTE_USE_WINDOWS_THREAD_TYPES)

Redundant braces are discouraged in DPDK codebase.

[...]
> diff --git a/lib/eal/include/rte_thread_types.h b/lib/eal/include/rte_thread_types.h
> new file mode 100644
> index 0000000000..d67b24a563
> --- /dev/null
> +++ b/lib/eal/include/rte_thread_types.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2021 Microsoft Corporation
> + */
> +
> +#ifndef _RTE_THREAD_TYPES_H_
> +#define _RTE_THREAD_TYPES_H_
> +
> +#include <pthread.h>
> +
> +#endif /* _RTE_THREAD_TYPES_H_ */
> diff --git a/lib/eal/windows/include/rte_windows_thread_types.h b/lib/eal/windows/include/rte_windows_thread_types.h
> new file mode 100644
> index 0000000000..60e6d94553
> --- /dev/null
> +++ b/lib/eal/windows/include/rte_windows_thread_types.h
> @@ -0,0 +1,10 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2021 Microsoft Corporation
> + */
> +
> +#ifndef _RTE_THREAD_TYPES_H_
> +#define _RTE_THREAD_TYPES_H_
> +
> +#include <rte_windows.h>
> +
> +#endif /* _RTE_THREAD_TYPES_H_ */

Thread types headers should have a check that forbids including them
directly, see lib/eal/$arch/rte_atomic_64.h for examples.

Note that rte_*_thread_types.h should be `indirect_headers`, not `headers`
in `meson.build` so that they're not checked by `buildtools/chkincs` when is
gets enabled for Windows. This is especially
true for lib/eal/common/rte_thread.h that cannot work without pthread.

However, in later patches these headers only contain mutex bits,
see the comment to pathc 07/10 about them. Maybe we don't need these files
after all.
  
Narcisa Ana Maria Vasile June 18, 2021, 9:30 p.m. UTC | #2
On Wed, Jun 09, 2021 at 02:03:48AM +0300, Dmitry Kozlyuk wrote:
> 2021-06-04 16:44 (UTC-0700), Narcisa Ana Maria Vasile:
> > From: Narcisa Vasile <navasile@microsoft.com>
> > 
> > Use a portable, type-safe representation for the thread identifier.
> > Add functions for comparing thread ids and obtaining the thread id
> > for the current thread.
> > 
> > Signed-off-by: Narcisa Vasile <navasile@microsoft.com>
> > ---
> >  lib/eal/common/rte_thread.c                   | 105 ++++++++++++++++++
> >  lib/eal/include/rte_thread.h                  |  53 +++++++--
> >  lib/eal/include/rte_thread_types.h            |  10 ++
> >  .../include/rte_windows_thread_types.h        |  10 ++
> >  lib/eal/windows/rte_thread.c                  |  17 +++
> >  5 files changed, 186 insertions(+), 9 deletions(-)
> >  create mode 100644 lib/eal/common/rte_thread.c
> >  create mode 100644 lib/eal/include/rte_thread_types.h
> >  create mode 100644 lib/eal/windows/include/rte_windows_thread_types.h
> 
> It is strange that new files are being filled in the series, but are neither
> compiled nor installed until the last patch. Any reason not to replace
> lib/eal/unix/rte_thread.c starting from this patch?
> 
Replaced unix/rte_thread.c starting from here.

> A better name for rte_thread_types.h would be rte_posix_thread_types.h
> to indicate this file is not really common.
> 
> > 
> > +rte_thread_t
> > +rte_thread_self(void)
> > +{
> > +	rte_thread_t thread_id = { 0 };
> 
> (Applies to entire series.)
> Please do not initialize variables when you intend to overwrite them.
> This prevents compiler from reporting code paths where the variable is used
> before a proper assignment.

Thanks for the explanation, Dmitry!
> 
> 
> [...]
> > diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
> > index 8be8ed8f36..347df1a6ae 100644
> directly, see lib/eal/$arch/rte_atomic_64.h for examples.
> 
> Note that rte_*_thread_types.h should be `indirect_headers`, not `headers`
> in `meson.build` so that they're not checked by `buildtools/chkincs` when is
> gets enabled for Windows. This is especially
> true for lib/eal/common/rte_thread.h that cannot work without pthread.
> 
> However, in later patches these headers only contain mutex bits,
> see the comment to pathc 07/10 about them. Maybe we don't need these files
> after all.

Agreed, I was able to remove them after reimplementing the mutex functions.
  

Patch

diff --git a/lib/eal/common/rte_thread.c b/lib/eal/common/rte_thread.c
new file mode 100644
index 0000000000..1292f7a8f8
--- /dev/null
+++ b/lib/eal/common/rte_thread.c
@@ -0,0 +1,105 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2021 Mellanox Technologies, Ltd
+ * Copyright(c) 2021 Microsoft Corporation
+ */
+
+#include <errno.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <rte_common.h>
+#include <rte_errno.h>
+#include <rte_log.h>
+#include <rte_thread.h>
+
+struct eal_tls_key {
+	pthread_key_t thread_index;
+};
+
+rte_thread_t
+rte_thread_self(void)
+{
+	rte_thread_t thread_id = { 0 };
+
+	thread_id.opaque_id = pthread_self();
+
+	return thread_id;
+}
+
+int
+rte_thread_equal(rte_thread_t t1, rte_thread_t t2)
+{
+	return pthread_equal(t1.opaque_id, t2.opaque_id);
+}
+
+int
+rte_thread_key_create(rte_thread_key *key, void (*destructor)(void *))
+{
+	int err;
+	rte_thread_key k;
+
+	k = malloc(sizeof(*k));
+	if (k == NULL) {
+		RTE_LOG(DEBUG, EAL, "Cannot allocate TLS key.\n");
+		return EINVAL;
+	}
+	err = pthread_key_create(&(k->thread_index), destructor);
+	if (err != 0) {
+		RTE_LOG(DEBUG, EAL, "pthread_key_create failed: %s\n",
+			 strerror(err));
+		free(k);
+		return err;
+	}
+	*key = k;
+	return 0;
+}
+
+int
+rte_thread_key_delete(rte_thread_key key)
+{
+	int err;
+
+	if (key == NULL) {
+		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		return EINVAL;
+	}
+	err = pthread_key_delete(key->thread_index);
+	if (err != 0) {
+		RTE_LOG(DEBUG, EAL, "pthread_key_delete failed: %s\n",
+			 strerror(err));
+		free(key);
+		return err;
+	}
+	free(key);
+	return 0;
+}
+
+int
+rte_thread_value_set(rte_thread_key key, const void *value)
+{
+	int err;
+
+	if (key == NULL) {
+		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		return EINVAL;
+	}
+	err = pthread_setspecific(key->thread_index, value);
+	if (err != 0) {
+		RTE_LOG(DEBUG, EAL, "pthread_setspecific failed: %s\n",
+			strerror(err));
+		return err;
+	}
+	return 0;
+}
+
+void *
+rte_thread_value_get(rte_thread_key key)
+{
+	if (key == NULL) {
+		RTE_LOG(DEBUG, EAL, "Invalid TLS key.\n");
+		rte_errno = EINVAL;
+		return NULL;
+	}
+	return pthread_getspecific(key->thread_index);
+}
diff --git a/lib/eal/include/rte_thread.h b/lib/eal/include/rte_thread.h
index 8be8ed8f36..347df1a6ae 100644
--- a/lib/eal/include/rte_thread.h
+++ b/lib/eal/include/rte_thread.h
@@ -1,6 +1,8 @@ 
 /* SPDX-License-Identifier: BSD-3-Clause
  * Copyright(c) 2021 Mellanox Technologies, Ltd
+ * Copyright(c) 2021 Microsoft Corporation
  */
+#include <stdint.h>
 
 #include <rte_os.h>
 #include <rte_compat.h>
@@ -20,11 +22,50 @@ 
 extern "C" {
 #endif
 
+#include <sched.h>
+#if defined(RTE_USE_WINDOWS_THREAD_TYPES)
+#include <rte_windows_thread_types.h>
+#else
+#include <rte_thread_types.h>
+#endif
+
+/**
+ * Thread id descriptor.
+ */
+typedef struct rte_thread_tag {
+	uintptr_t opaque_id; /**< thread identifier */
+} rte_thread_t;
+
 /**
  * TLS key type, an opaque pointer.
  */
 typedef struct eal_tls_key *rte_thread_key;
 
+/**
+ * Get the id of the calling thread.
+ *
+ * @return
+ *   Return the thread id of the calling thread.
+ */
+__rte_experimental
+rte_thread_t rte_thread_self(void);
+
+/**
+ * Check if 2 thread ids are equal.
+ *
+ * @param t1
+ *   First thread id.
+ *
+ * @param t2
+ *   Second thread id.
+ *
+ * @return
+ *   If the ids are equal, return nonzero.
+ *   Otherwise, return 0.
+ */
+__rte_experimental
+int rte_thread_equal(rte_thread_t t1, rte_thread_t t2);
+
 #ifdef RTE_HAS_CPUSET
 
 /**
@@ -63,9 +104,7 @@  void rte_thread_get_affinity(rte_cpuset_t *cpusetp);
  *
  * @return
  *   On success, zero.
- *   On failure, a negative number and an error number is set in rte_errno.
- *   rte_errno can be: ENOMEM  - Memory allocation error.
- *                     ENOEXEC - Specific OS error.
+ *   On failure, return a positive errno-style error number.
  */
 
 __rte_experimental
@@ -80,9 +119,7 @@  int rte_thread_key_create(rte_thread_key *key,
  *
  * @return
  *   On success, zero.
- *   On failure, a negative number and an error number is set in rte_errno.
- *   rte_errno can be: EINVAL  - Invalid parameter passed.
- *                     ENOEXEC - Specific OS error.
+ *   On failure, return a positive errno-style error number.
  */
 __rte_experimental
 int rte_thread_key_delete(rte_thread_key key);
@@ -97,9 +134,7 @@  int rte_thread_key_delete(rte_thread_key key);
  *
  * @return
  *   On success, zero.
- *   On failure, a negative number and an error number is set in rte_errno.
- *   rte_errno can be: EINVAL  - Invalid parameter passed.
- *                     ENOEXEC - Specific OS error.
+ *   On failure, return a positive errno-style error number.
  */
 __rte_experimental
 int rte_thread_value_set(rte_thread_key key, const void *value);
diff --git a/lib/eal/include/rte_thread_types.h b/lib/eal/include/rte_thread_types.h
new file mode 100644
index 0000000000..d67b24a563
--- /dev/null
+++ b/lib/eal/include/rte_thread_types.h
@@ -0,0 +1,10 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2021 Microsoft Corporation
+ */
+
+#ifndef _RTE_THREAD_TYPES_H_
+#define _RTE_THREAD_TYPES_H_
+
+#include <pthread.h>
+
+#endif /* _RTE_THREAD_TYPES_H_ */
diff --git a/lib/eal/windows/include/rte_windows_thread_types.h b/lib/eal/windows/include/rte_windows_thread_types.h
new file mode 100644
index 0000000000..60e6d94553
--- /dev/null
+++ b/lib/eal/windows/include/rte_windows_thread_types.h
@@ -0,0 +1,10 @@ 
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2021 Microsoft Corporation
+ */
+
+#ifndef _RTE_THREAD_TYPES_H_
+#define _RTE_THREAD_TYPES_H_
+
+#include <rte_windows.h>
+
+#endif /* _RTE_THREAD_TYPES_H_ */
diff --git a/lib/eal/windows/rte_thread.c b/lib/eal/windows/rte_thread.c
index 667287c387..3f3ebba21f 100644
--- a/lib/eal/windows/rte_thread.c
+++ b/lib/eal/windows/rte_thread.c
@@ -1,5 +1,6 @@ 
 /* SPDX-License-Identifier: BSD-3-Clause
  * Copyright 2021 Mellanox Technologies, Ltd
+ * Copyright(c) 2021 Microsoft Corporation
  */
 
 #include <rte_common.h>
@@ -11,6 +12,22 @@  struct eal_tls_key {
 	DWORD thread_index;
 };
 
+rte_thread_t
+rte_thread_self(void)
+{
+	rte_thread_t thread_id = { 0 };
+
+	thread_id.opaque_id = GetCurrentThreadId();
+
+	return thread_id;
+}
+
+int
+rte_thread_equal(rte_thread_t t1, rte_thread_t t2)
+{
+	return t1.opaque_id == t2.opaque_id;
+}
+
 int
 rte_thread_key_create(rte_thread_key *key,
 		__rte_unused void (*destructor)(void *))