| Message ID | 20190501230126.229218-4-brendanhiggins@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kunit: introduce KUnit, the Linux kernel unit testing framework | expand |
On 5/1/19 5:01 PM, Brendan Higgins wrote: > A number of test features need to do pretty complicated string printing > where it may not be possible to rely on a single preallocated string > with parameters. > > So provide a library for constructing the string as you go similar to > C++'s std::string. > > Signed-off-by: Brendan Higgins <brendanhiggins@google.com> > --- > include/kunit/string-stream.h | 51 ++++++++++++ > kunit/Makefile | 3 +- > kunit/string-stream.c | 144 ++++++++++++++++++++++++++++++++++ > 3 files changed, 197 insertions(+), 1 deletion(-) > create mode 100644 include/kunit/string-stream.h > create mode 100644 kunit/string-stream.c > > diff --git a/include/kunit/string-stream.h b/include/kunit/string-stream.h > new file mode 100644 > index 0000000000000..567a4629406da > --- /dev/null > +++ b/include/kunit/string-stream.h > @@ -0,0 +1,51 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * C++ stream style string builder used in KUnit for building messages. > + * > + * Copyright (C) 2019, Google LLC. > + * Author: Brendan Higgins <brendanhiggins@google.com> > + */ > + > +#ifndef _KUNIT_STRING_STREAM_H > +#define _KUNIT_STRING_STREAM_H > + > +#include <linux/types.h> > +#include <linux/spinlock.h> > +#include <linux/kref.h> > +#include <stdarg.h> > + > +struct string_stream_fragment { > + struct list_head node; > + char *fragment; > +}; > + > +struct string_stream { > + size_t length; > + struct list_head fragments; > + > + /* length and fragments are protected by this lock */ > + spinlock_t lock; > + struct kref refcount; > +}; > + > +struct string_stream *new_string_stream(void); > + > +void destroy_string_stream(struct string_stream *stream); > + > +void string_stream_get(struct string_stream *stream); > + > +int string_stream_put(struct string_stream *stream); > + > +int string_stream_add(struct string_stream *this, const char *fmt, ...); > + > +int string_stream_vadd(struct string_stream *this, > + const char *fmt, > + va_list args); > + > +char *string_stream_get_string(struct string_stream *this); > + > +void string_stream_clear(struct string_stream *this); > + > +bool string_stream_is_empty(struct string_stream *this); > + > +#endif /* _KUNIT_STRING_STREAM_H */ > diff --git a/kunit/Makefile b/kunit/Makefile > index 5efdc4dea2c08..275b565a0e81f 100644 > --- a/kunit/Makefile > +++ b/kunit/Makefile > @@ -1 +1,2 @@ > -obj-$(CONFIG_KUNIT) += test.o > +obj-$(CONFIG_KUNIT) += test.o \ > + string-stream.o > diff --git a/kunit/string-stream.c b/kunit/string-stream.c > new file mode 100644 > index 0000000000000..7018194ecf2fa > --- /dev/null > +++ b/kunit/string-stream.c > @@ -0,0 +1,144 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * C++ stream style string builder used in KUnit for building messages. > + * > + * Copyright (C) 2019, Google LLC. > + * Author: Brendan Higgins <brendanhiggins@google.com> > + */ > + > +#include <linux/list.h> > +#include <linux/slab.h> > +#include <kunit/string-stream.h> > + > +int string_stream_vadd(struct string_stream *this, > + const char *fmt, > + va_list args) > +{ > + struct string_stream_fragment *fragment; Since there is field with the same name, please use a different name. Using the same name for the struct which contains a field of the same name get very confusing and will hard to maintain the code. > + int len; > + va_list args_for_counting; > + unsigned long flags; > + > + /* Make a copy because `vsnprintf` could change it */ > + va_copy(args_for_counting, args); > + > + /* Need space for null byte. */ > + len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1; > + > + va_end(args_for_counting); > + > + fragment = kmalloc(sizeof(*fragment), GFP_KERNEL); > + if (!fragment) > + return -ENOMEM; > + > + fragment->fragment = kmalloc(len, GFP_KERNEL); This is confusing. See above comment. > + if (!fragment->fragment) { > + kfree(fragment); > + return -ENOMEM; > + } > + > + len = vsnprintf(fragment->fragment, len, fmt, args); > + spin_lock_irqsave(&this->lock, flags); > + this->length += len; > + list_add_tail(&fragment->node, &this->fragments); > + spin_unlock_irqrestore(&this->lock, flags); > + return 0; > +} > + > +int string_stream_add(struct string_stream *this, const char *fmt, ...) > +{ > + va_list args; > + int result; > + > + va_start(args, fmt); > + result = string_stream_vadd(this, fmt, args); > + va_end(args); > + return result; > +} > + > +void string_stream_clear(struct string_stream *this) > +{ > + struct string_stream_fragment *fragment, *fragment_safe; > + unsigned long flags; > + > + spin_lock_irqsave(&this->lock, flags); > + list_for_each_entry_safe(fragment, > + fragment_safe, > + &this->fragments, > + node) { > + list_del(&fragment->node); > + kfree(fragment->fragment); > + kfree(fragment); This is what git me down the road of checking the structure name to begin with. :) > + } > + this->length = 0; > + spin_unlock_irqrestore(&this->lock, flags); > +} > + > +char *string_stream_get_string(struct string_stream *this) > +{ > + struct string_stream_fragment *fragment; > + size_t buf_len = this->length + 1; /* +1 for null byte. */ > + char *buf; > + unsigned long flags; > + > + buf = kzalloc(buf_len, GFP_KERNEL); > + if (!buf) > + return NULL; > + > + spin_lock_irqsave(&this->lock, flags); > + list_for_each_entry(fragment, &this->fragments, node) > + strlcat(buf, fragment->fragment, buf_len); > + spin_unlock_irqrestore(&this->lock, flags); > + > + return buf; > +} > + > +bool string_stream_is_empty(struct string_stream *this) > +{ > + bool is_empty; > + unsigned long flags; > + > + spin_lock_irqsave(&this->lock, flags); > + is_empty = list_empty(&this->fragments); > + spin_unlock_irqrestore(&this->lock, flags); > + > + return is_empty; > +} > + > +void destroy_string_stream(struct string_stream *stream) > +{ > + string_stream_clear(stream); > + kfree(stream); > +} > + > +static void string_stream_destroy(struct kref *kref) > +{ > + struct string_stream *stream = container_of(kref, > + struct string_stream, > + refcount); > + destroy_string_stream(stream); > +} > + > +struct string_stream *new_string_stream(void) > +{ > + struct string_stream *stream = kzalloc(sizeof(*stream), GFP_KERNEL); > + > + if (!stream) > + return NULL; > + > + INIT_LIST_HEAD(&stream->fragments); > + spin_lock_init(&stream->lock); > + kref_init(&stream->refcount); > + return stream; > +} > + > +void string_stream_get(struct string_stream *stream) > +{ > + kref_get(&stream->refcount); > +} > + > +int string_stream_put(struct string_stream *stream) > +{ > + return kref_put(&stream->refcount, &string_stream_destroy); > +} > + > thanks, -- Shuah
On Thu, May 2, 2019 at 6:26 PM shuah <shuah@kernel.org> wrote: > > On 5/1/19 5:01 PM, Brendan Higgins wrote: < snip > > > diff --git a/kunit/Makefile b/kunit/Makefile > > index 5efdc4dea2c08..275b565a0e81f 100644 > > --- a/kunit/Makefile > > +++ b/kunit/Makefile > > @@ -1 +1,2 @@ > > -obj-$(CONFIG_KUNIT) += test.o > > +obj-$(CONFIG_KUNIT) += test.o \ > > + string-stream.o > > diff --git a/kunit/string-stream.c b/kunit/string-stream.c > > new file mode 100644 > > index 0000000000000..7018194ecf2fa > > --- /dev/null > > +++ b/kunit/string-stream.c > > @@ -0,0 +1,144 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * C++ stream style string builder used in KUnit for building messages. > > + * > > + * Copyright (C) 2019, Google LLC. > > + * Author: Brendan Higgins <brendanhiggins@google.com> > > + */ > > + > > +#include <linux/list.h> > > +#include <linux/slab.h> > > +#include <kunit/string-stream.h> > > + > > +int string_stream_vadd(struct string_stream *this, > > + const char *fmt, > > + va_list args) > > +{ > > + struct string_stream_fragment *fragment; > > Since there is field with the same name, please use a different > name. Using the same name for the struct which contains a field > of the same name get very confusing and will hard to maintain > the code. > > > + int len; > > + va_list args_for_counting; > > + unsigned long flags; > > + > > + /* Make a copy because `vsnprintf` could change it */ > > + va_copy(args_for_counting, args); > > + > > + /* Need space for null byte. */ > > + len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1; > > + > > + va_end(args_for_counting); > > + > > + fragment = kmalloc(sizeof(*fragment), GFP_KERNEL); > > + if (!fragment) > > + return -ENOMEM; > > + > > + fragment->fragment = kmalloc(len, GFP_KERNEL); > > This is confusing. See above comment. Good point. Will fix in the next revision. < snip > Thanks!
diff --git a/include/kunit/string-stream.h b/include/kunit/string-stream.h new file mode 100644 index 0000000000000..567a4629406da --- /dev/null +++ b/include/kunit/string-stream.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * C++ stream style string builder used in KUnit for building messages. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins <brendanhiggins@google.com> + */ + +#ifndef _KUNIT_STRING_STREAM_H +#define _KUNIT_STRING_STREAM_H + +#include <linux/types.h> +#include <linux/spinlock.h> +#include <linux/kref.h> +#include <stdarg.h> + +struct string_stream_fragment { + struct list_head node; + char *fragment; +}; + +struct string_stream { + size_t length; + struct list_head fragments; + + /* length and fragments are protected by this lock */ + spinlock_t lock; + struct kref refcount; +}; + +struct string_stream *new_string_stream(void); + +void destroy_string_stream(struct string_stream *stream); + +void string_stream_get(struct string_stream *stream); + +int string_stream_put(struct string_stream *stream); + +int string_stream_add(struct string_stream *this, const char *fmt, ...); + +int string_stream_vadd(struct string_stream *this, + const char *fmt, + va_list args); + +char *string_stream_get_string(struct string_stream *this); + +void string_stream_clear(struct string_stream *this); + +bool string_stream_is_empty(struct string_stream *this); + +#endif /* _KUNIT_STRING_STREAM_H */ diff --git a/kunit/Makefile b/kunit/Makefile index 5efdc4dea2c08..275b565a0e81f 100644 --- a/kunit/Makefile +++ b/kunit/Makefile @@ -1 +1,2 @@ -obj-$(CONFIG_KUNIT) += test.o +obj-$(CONFIG_KUNIT) += test.o \ + string-stream.o diff --git a/kunit/string-stream.c b/kunit/string-stream.c new file mode 100644 index 0000000000000..7018194ecf2fa --- /dev/null +++ b/kunit/string-stream.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * C++ stream style string builder used in KUnit for building messages. + * + * Copyright (C) 2019, Google LLC. + * Author: Brendan Higgins <brendanhiggins@google.com> + */ + +#include <linux/list.h> +#include <linux/slab.h> +#include <kunit/string-stream.h> + +int string_stream_vadd(struct string_stream *this, + const char *fmt, + va_list args) +{ + struct string_stream_fragment *fragment; + int len; + va_list args_for_counting; + unsigned long flags; + + /* Make a copy because `vsnprintf` could change it */ + va_copy(args_for_counting, args); + + /* Need space for null byte. */ + len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1; + + va_end(args_for_counting); + + fragment = kmalloc(sizeof(*fragment), GFP_KERNEL); + if (!fragment) + return -ENOMEM; + + fragment->fragment = kmalloc(len, GFP_KERNEL); + if (!fragment->fragment) { + kfree(fragment); + return -ENOMEM; + } + + len = vsnprintf(fragment->fragment, len, fmt, args); + spin_lock_irqsave(&this->lock, flags); + this->length += len; + list_add_tail(&fragment->node, &this->fragments); + spin_unlock_irqrestore(&this->lock, flags); + return 0; +} + +int string_stream_add(struct string_stream *this, const char *fmt, ...) +{ + va_list args; + int result; + + va_start(args, fmt); + result = string_stream_vadd(this, fmt, args); + va_end(args); + return result; +} + +void string_stream_clear(struct string_stream *this) +{ + struct string_stream_fragment *fragment, *fragment_safe; + unsigned long flags; + + spin_lock_irqsave(&this->lock, flags); + list_for_each_entry_safe(fragment, + fragment_safe, + &this->fragments, + node) { + list_del(&fragment->node); + kfree(fragment->fragment); + kfree(fragment); + } + this->length = 0; + spin_unlock_irqrestore(&this->lock, flags); +} + +char *string_stream_get_string(struct string_stream *this) +{ + struct string_stream_fragment *fragment; + size_t buf_len = this->length + 1; /* +1 for null byte. */ + char *buf; + unsigned long flags; + + buf = kzalloc(buf_len, GFP_KERNEL); + if (!buf) + return NULL; + + spin_lock_irqsave(&this->lock, flags); + list_for_each_entry(fragment, &this->fragments, node) + strlcat(buf, fragment->fragment, buf_len); + spin_unlock_irqrestore(&this->lock, flags); + + return buf; +} + +bool string_stream_is_empty(struct string_stream *this) +{ + bool is_empty; + unsigned long flags; + + spin_lock_irqsave(&this->lock, flags); + is_empty = list_empty(&this->fragments); + spin_unlock_irqrestore(&this->lock, flags); + + return is_empty; +} + +void destroy_string_stream(struct string_stream *stream) +{ + string_stream_clear(stream); + kfree(stream); +} + +static void string_stream_destroy(struct kref *kref) +{ + struct string_stream *stream = container_of(kref, + struct string_stream, + refcount); + destroy_string_stream(stream); +} + +struct string_stream *new_string_stream(void) +{ + struct string_stream *stream = kzalloc(sizeof(*stream), GFP_KERNEL); + + if (!stream) + return NULL; + + INIT_LIST_HEAD(&stream->fragments); + spin_lock_init(&stream->lock); + kref_init(&stream->refcount); + return stream; +} + +void string_stream_get(struct string_stream *stream) +{ + kref_get(&stream->refcount); +} + +int string_stream_put(struct string_stream *stream) +{ + return kref_put(&stream->refcount, &string_stream_destroy); +} +
A number of test features need to do pretty complicated string printing where it may not be possible to rely on a single preallocated string with parameters. So provide a library for constructing the string as you go similar to C++'s std::string. Signed-off-by: Brendan Higgins <brendanhiggins@google.com> --- include/kunit/string-stream.h | 51 ++++++++++++ kunit/Makefile | 3 +- kunit/string-stream.c | 144 ++++++++++++++++++++++++++++++++++ 3 files changed, 197 insertions(+), 1 deletion(-) create mode 100644 include/kunit/string-stream.h create mode 100644 kunit/string-stream.c