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Diffstat (limited to 'libipt/src/pt_event_queue.c')
| -rw-r--r-- | libipt/src/pt_event_queue.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/libipt/src/pt_event_queue.c b/libipt/src/pt_event_queue.c new file mode 100644 index 000000000000..e0d449016a97 --- /dev/null +++ b/libipt/src/pt_event_queue.c @@ -0,0 +1,203 @@ +/* + * Copyright (c) 2013-2019, Intel Corporation + * + * 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 "pt_event_queue.h" + +#include <string.h> + + +static inline uint8_t pt_evq_inc(uint8_t idx) +{ + idx += 1; + idx %= evq_max; + + return idx; +} + +static struct pt_event *pt_event_init(struct pt_event *event) +{ + if (event) + memset(event, 0, sizeof(*event)); + + return event; +} + +void pt_evq_init(struct pt_event_queue *evq) +{ + if (!evq) + return; + + memset(evq, 0, sizeof(*evq)); +} + +struct pt_event *pt_evq_standalone(struct pt_event_queue *evq) +{ + if (!evq) + return NULL; + + return pt_event_init(&evq->standalone); +} + +struct pt_event *pt_evq_enqueue(struct pt_event_queue *evq, + enum pt_event_binding evb) +{ + uint8_t begin, end, gap, idx; + + if (!evq) + return NULL; + + if (evb_max <= evb) + return NULL; + + begin = evq->begin[evb]; + idx = evq->end[evb]; + + if (evq_max <= begin) + return NULL; + + if (evq_max <= idx) + return NULL; + + end = pt_evq_inc(idx); + gap = pt_evq_inc(end); + + /* Leave a gap so we don't overwrite the last dequeued event. */ + if (begin == gap) + return NULL; + + evq->end[evb] = end; + + return pt_event_init(&evq->queue[evb][idx]); +} + +struct pt_event *pt_evq_dequeue(struct pt_event_queue *evq, + enum pt_event_binding evb) +{ + uint8_t begin, end; + + if (!evq) + return NULL; + + if (evb_max <= evb) + return NULL; + + begin = evq->begin[evb]; + end = evq->end[evb]; + + if (evq_max <= begin) + return NULL; + + if (evq_max <= end) + return NULL; + + if (begin == end) + return NULL; + + evq->begin[evb] = pt_evq_inc(begin); + + return &evq->queue[evb][begin]; +} + +int pt_evq_clear(struct pt_event_queue *evq, enum pt_event_binding evb) +{ + if (!evq) + return -pte_internal; + + if (evb_max <= evb) + return -pte_internal; + + evq->begin[evb] = 0; + evq->end[evb] = 0; + + return 0; +} + +int pt_evq_empty(const struct pt_event_queue *evq, enum pt_event_binding evb) +{ + uint8_t begin, end; + + if (!evq) + return -pte_internal; + + if (evb_max <= evb) + return -pte_internal; + + begin = evq->begin[evb]; + end = evq->end[evb]; + + if (evq_max <= begin) + return -pte_internal; + + if (evq_max <= end) + return -pte_internal; + + return begin == end; +} + +int pt_evq_pending(const struct pt_event_queue *evq, enum pt_event_binding evb) +{ + int errcode; + + errcode = pt_evq_empty(evq, evb); + if (errcode < 0) + return errcode; + + return !errcode; +} + +struct pt_event *pt_evq_find(struct pt_event_queue *evq, + enum pt_event_binding evb, + enum pt_event_type evt) +{ + uint8_t begin, end; + + if (!evq) + return NULL; + + if (evb_max <= evb) + return NULL; + + begin = evq->begin[evb]; + end = evq->end[evb]; + + if (evq_max <= begin) + return NULL; + + if (evq_max <= end) + return NULL; + + for (; begin != end; begin = pt_evq_inc(begin)) { + struct pt_event *ev; + + ev = &evq->queue[evb][begin]; + if (ev->type == evt) + return ev; + } + + return NULL; +} |