Nastrel pthread_mq
authorTomas Mudrunka <tomas@mudrunka.cz>
Wed, 23 Jun 2021 09:41:32 +0000 (11:41 +0200)
committerTomas Mudrunka <tomas@mudrunka.cz>
Wed, 23 Jun 2021 09:41:32 +0000 (11:41 +0200)
c/pthread_extra/pthread_msgqueue.c [new file with mode: 0644]

diff --git a/c/pthread_extra/pthread_msgqueue.c b/c/pthread_extra/pthread_msgqueue.c
new file mode 100644 (file)
index 0000000..0d4e07e
--- /dev/null
@@ -0,0 +1,93 @@
+/*
+ * CFLAGS=-lpthread make pthread_msgqueue
+ */
+
+#include <pthread.h>
+#include <time.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+typedef struct pthread_mq_t {
+       static pthread_mutex_t lock;
+       static pthread_cond_t cond_readable;
+       static pthread_cond_t cond_writable;
+       void * data;
+       size_t msg_size;
+       size_t msg_count;
+       size_t msg_count_max;
+       size_t head_idx;
+       char * name;
+} pthread_mq_t;
+
+bool pthread_mq_readable(pthread_mq_t *mq) { return (mq->count > 0); }
+bool pthread_mq_writable(pthread_mq_t *mq) { return (mq->count < mq->count_max); }
+
+bool pthread_mq_init(pthread_mq_t *mq, size_t msg_size, size_t msg_count_max) {
+       mq->lock = PTHREAD_MUTEX_INITIALIZER;
+       mq->cond_readable = PTHREAD_COND_INITIALIZER;
+       mq->cond_writable = PTHREAD_COND_INITIALIZER;
+       mq->data = malloc(msg_size*msg_count_max);
+       mq->msg_size = msg_size;
+       mq->msg_count_max = msg_count_max;
+       mq->msg_count = 0;
+       mq->head_idx = 0;
+       mq->name = NULL;
+
+       if(((msg_size*msg_count_max) > 0) && mq->data == NULL) return false;
+       return true;
+}
+
+void pthread_mq_free(pthread_mq_t *mq) {
+       free(mq->data);
+}
+
+
+void pthread_mq_cond(pthread_mq_t *mq) {
+       if(pthread_mq_readable(mq)) pthread_cond_broadcast(&mq->cond_readable);
+       if(pthread_mq_writable(mq)) pthread_cond_broadcast(&mq->cond_writable);
+}
+
+bool pthread_mq_send_generic(pthread_mq_t *mq, void * data, bool to_front, bool block, const struct timespec *restrict abs_timeout) {
+       pthread_mutex_timedlock(&mq->lock, abs_timeout);
+
+       while(!pthread_mq_writable(mq)) {
+               pthread_mutex_unlock(&mq->lock);
+               return false;
+       }
+
+       size_t idx = ( ( mq->count_max + mq->head_idx + (to_front?-1:mq->count) ) % mq->count_max );
+       void *ptr = mq->data + (idx * mq->msg_size);
+       mq->msg_count++;
+       memcpy(ptr, data, mq->msg_size);
+
+       pthread_mq_cond(mq);
+       pthread_mutex_unlock(&mq->lock);
+       return true;
+}
+
+/*
+              mq_timedreceive(3)   mq_timedreceive(2)
+
+              mq_timedsend(3)      mq_timedsend(2)
+
+void vQueueDelete( QueueHandle_t xQueue );
+BaseType_t xQueueReset( QueueHandle_t xQueue );
+
+ BaseType_t xQueueSend(
+                            QueueHandle_t xQueue,
+                            const void * pvItemToQueue,
+                            TickType_t xTicksToWait
+                         );
+ BaseType_t xQueueReceive(
+                               QueueHandle_t xQueue,
+                               void *pvBuffer,
+                               TickType_t xTicksToWait
+                            );
+
+*/
+
+int main() {
+
+}
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