*------------------------------------------------------------------
* svm_queue.h - shared-memory queues
*
- * Copyright (c) 2009 Cisco and/or its affiliates.
+ * Copyright (c) 2009-2019 Cisco and/or its affiliates.
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
int maxsize;
int elsize;
int consumer_pid;
- int signal_when_queue_non_empty;
+ int producer_evtfd;
+ int consumer_evtfd;
char data[0];
} svm_queue_t;
typedef enum
{
- /**
- * blocking call
- */
- SVM_Q_WAIT = 0,
-
- /**
- * non-blocking call
- */
- SVM_Q_NOWAIT,
-
- /**
- * blocking call, return on signal or time-out
- */
- SVM_Q_TIMEDWAIT,
+ SVM_Q_WAIT = 0, /**< blocking call - best used in combination with
+ condvars, for eventfds we don't yield the cpu */
+ SVM_Q_NOWAIT, /**< non-blocking call - works with both condvar and
+ eventfd signaling */
+ SVM_Q_TIMEDWAIT, /**< blocking call, returns on signal or time-out -
+ best used in combination with condvars, with
+ eventfds we don't yield the cpu */
} svm_q_conditional_wait_t;
-svm_queue_t *svm_queue_init (int nels,
- int elsize,
- int consumer_pid,
- int signal_when_queue_non_empty);
+/**
+ * Allocate and initialize svm queue
+ *
+ * @param nels number of elements on the queue
+ * @param elsize element size, presumably 4 and cacheline-size will
+ * be popular choices.
+ * @param pid consumer pid
+ * @return a newly initialized svm queue
+ *
+ * The idea is to call this function in the queue consumer,
+ * and e-mail the queue pointer to the producer(s).
+ *
+ * The vpp process / main thread allocates one of these
+ * at startup; its main input queue. The vpp main input queue
+ * has a pointer to it in the shared memory segment header.
+ *
+ * You probably want to be on an svm data heap before calling this
+ * function.
+ */
+svm_queue_t *svm_queue_alloc_and_init (int nels, int elsize,
+ int consumer_pid);
+svm_queue_t *svm_queue_init (void *base, int nels, int elsize);
void svm_queue_free (svm_queue_t * q);
int svm_queue_add (svm_queue_t * q, u8 * elem, int nowait);
int svm_queue_add2 (svm_queue_t * q, u8 * elem, u8 * elem2, int nowait);
u32 time);
int svm_queue_sub2 (svm_queue_t * q, u8 * elem);
void svm_queue_lock (svm_queue_t * q);
+void svm_queue_send_signal (svm_queue_t * q, u8 is_prod);
void svm_queue_unlock (svm_queue_t * q);
int svm_queue_is_full (svm_queue_t * q);
int svm_queue_add_nolock (svm_queue_t * q, u8 * elem);
int svm_queue_sub_raw (svm_queue_t * q, u8 * elem);
-int svm_queue_add_raw (svm_queue_t * q, u8 * elem);
+
+/**
+ * Wait for queue event
+ *
+ * Must be called with mutex held.
+ */
+void svm_queue_wait (svm_queue_t * q);
+
+/**
+ * Timed wait for queue event
+ *
+ * Must be called with mutex held.
+ *
+ * @param q svm queue
+ * @param timeout time in seconds
+ * @return 0 on success, ETIMEDOUT on timeout or an error
+ */
+int svm_queue_timedwait (svm_queue_t * q, double timeout);
+
+/**
+ * Add element to queue with mutex held
+ * @param q queue
+ * @param elem pointer element data to add
+ */
+void svm_queue_add_raw (svm_queue_t * q, u8 * elem);
+
+/**
+ * Set producer's event fd
+ *
+ * When the producer must generate an event it writes 1 to the provided fd.
+ * Once this is set, condvars are not used anymore for signaling.
+ */
+void svm_queue_set_producer_event_fd (svm_queue_t * q, int fd);
+
+/**
+ * Set consumer's event fd
+ *
+ * When the consumer must generate an event it writes 1 to the provided fd.
+ * Although in practice the two fds point to the same underlying file
+ * description, because the producer and consumer are different processes
+ * the descriptors will be different. It's the caller's responsibility to
+ * ensure the file descriptors are properly exchanged between the two peers.
+ */
+void svm_queue_set_consumer_event_fd (svm_queue_t * q, int fd);
/*
* DEPRECATED please use svm_queue_t instead