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+/*-
+ * BSD LICENSE
+ *
+ * Copyright(c) 2010-2012 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * 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.
+ *
+ * version: DPDK.L.1.2.3-3
+ */
+
+#ifndef _RTE_TIMER_H_
+#define _RTE_TIMER_H_
+
+/**
+ * @file
+ RTE Timer
+ *
+ * This library provides a timer service to RTE Data Plane execution
+ * units that allows the execution of callback functions asynchronously.
+ *
+ * - Timers can be periodic or single (one-shot).
+ * - The timers can be loaded from one core and executed on another. This has
+ * to be specified in the call to rte_timer_reset().
+ * - High precision is possible. NOTE: this depends on the call frequency to
+ * rte_timer_manage() that check the timer expiration for the local core.
+ * - If not used in an application, for improved performance, it can be
+ * disabled at compilation time by not calling the rte_timer_manage()
+ * to improve performance.
+ *
+ * The timer library uses the rte_get_hpet_cycles() function that
+ * uses the HPET, when available, to provide a reliable time reference. [HPET
+ * routines are provided by EAL, which falls back to using the chip TSC (time-
+ * stamp counter) as fallback when HPET is not available]
+ *
+ * This library provides an interface to add, delete and restart a
+ * timer. The API is based on the BSD callout(9) API with a few
+ * differences.
+ *
+ * See the RTE architecture documentation for more information about the
+ * design of this library.
+ */
+
+#include <stdint.h>
+#include <stddef.h>
+#include <sys/queue.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define RTE_TIMER_STOP 0 /**< State: timer is stopped. */
+#define RTE_TIMER_PENDING 1 /**< State: timer is scheduled. */
+#define RTE_TIMER_RUNNING 2 /**< State: timer function is running. */
+#define RTE_TIMER_CONFIG 3 /**< State: timer is being configured. */
+
+#define RTE_TIMER_NO_OWNER -1 /**< Timer has no owner. */
+
+/**
+ * Timer type: Periodic or single (one-shot).
+ */
+enum rte_timer_type {
+ SINGLE,
+ PERIODICAL
+};
+
+/**
+ * Timer status: A union of the state (stopped, pending, running,
+ * config) and an owner (the id of the lcore that owns the timer).
+ */
+union rte_timer_status {
+ struct {
+ uint16_t state; /**< Stop, pending, running, config. */
+ int16_t owner; /**< The lcore that owns the timer. */
+ };
+ uint32_t u32; /**< To atomic-set status + owner. */
+};
+
+#ifdef RTE_LIBRTE_TIMER_DEBUG
+/**
+ * A structure that stores the timer statistics (per-lcore).
+ */
+struct rte_timer_debug_stats {
+ uint64_t reset; /**< Number of success calls to rte_timer_reset(). */
+ uint64_t stop; /**< Number of success calls to rte_timer_stop(). */
+ uint64_t manage; /**< Number of calls to rte_timer_manage(). */
+ uint64_t pending; /**< Number of pending/running timers. */
+};
+#endif
+
+struct rte_timer;
+
+/**
+ * Callback function type for timer expiry.
+ */
+typedef void (rte_timer_cb_t)(struct rte_timer *, void *);
+
+/**
+ * A structure describing a timer in RTE.
+ */
+struct rte_timer
+{
+ LIST_ENTRY(rte_timer) next; /**< Next and prev in list. */
+ volatile union rte_timer_status status; /**< Status of timer. */
+ uint64_t period; /**< Period of timer (0 if not periodic). */
+ uint64_t expire; /**< Time when timer expire. */
+ rte_timer_cb_t *f; /**< Callback function. */
+ void *arg; /**< Argument to callback function. */
+};
+
+
+#ifdef __cplusplus
+/**
+ * A C++ static initializer for a timer structure.
+ */
+#define RTE_TIMER_INITIALIZER { \
+ {0, 0}, \
+ {{RTE_TIMER_STOP, RTE_TIMER_NO_OWNER}}, \
+ 0, \
+ 0, \
+ NULL, \
+ NULL, \
+ }
+#else
+/**
+ * A static initializer for a timer structure.
+ */
+#define RTE_TIMER_INITIALIZER { \
+ .status = {{ \
+ .state = RTE_TIMER_STOP, \
+ .owner = RTE_TIMER_NO_OWNER, \
+ }}, \
+ }
+#endif
+
+/**
+ * Initialize the timer library.
+ *
+ * Initializes internal variables (list, locks and so on) for the RTE
+ * timer library.
+ */
+void rte_timer_subsystem_init(void);
+
+/**
+ * Initialize a timer handle.
+ *
+ * The rte_timer_init() function initializes the timer handle *tim*
+ * for use. No operations can be performed on a timer before it is
+ * initialized.
+ *
+ * @param tim
+ * The timer to initialize.
+ */
+void rte_timer_init(struct rte_timer *tim);
+
+/**
+ * Reset and start the timer associated with the timer handle.
+ *
+ * The rte_timer_reset() function resets and starts the timer
+ * associated with the timer handle *tim*. When the timer expires after
+ * *ticks* HPET cycles, the function specified by *fct* will be called
+ * with the argument *arg* on core *tim_lcore*.
+ *
+ * If the timer associated with the timer handle is already running
+ * (in the RUNNING state), the function will fail. The user has to check
+ * the return value of the function to see if there is a chance that the
+ * timer is in the RUNNING state.
+ *
+ * If the timer is being configured on another core (the CONFIG state),
+ * it will also fail.
+ *
+ * If the timer is pending or stopped, it will be rescheduled with the
+ * new parameters.
+ *
+ * @param tim
+ * The timer handle.
+ * @param ticks
+ * The number of cycles (see rte_get_hpet_hz()) before the callback
+ * function is called.
+ * @param type
+ * The type can be either:
+ * - PERIODICAL: The timer is automatically reloaded after execution
+ * (returns to the PENDING state)
+ * - SINGLE: The timer is one-shot, that is, the timer goes to a
+ * STOPPED state after execution.
+ * @param tim_lcore
+ * The ID of the lcore where the timer callback function has to be
+ * executed. If tim_lcore is LCORE_ID_ANY, the timer library will
+ * launch it on a different core for each call (round-robin).
+ * @param fct
+ * The callback function of the timer.
+ * @param arg
+ * The user argument of the callback function.
+ * @return
+ * - 0: Success; the timer is scheduled.
+ * - (-1): Timer is in the RUNNING or CONFIG state.
+ */
+int rte_timer_reset(struct rte_timer *tim, uint64_t ticks,
+ enum rte_timer_type type, unsigned tim_lcore,
+ rte_timer_cb_t fct, void *arg);
+
+
+/**
+ * Loop until rte_timer_reset() succeeds.
+ *
+ * Reset and start the timer associated with the timer handle. Always
+ * succeed. See rte_timer_reset() for details.
+ *
+ * @param tim
+ * The timer handle.
+ * @param ticks
+ * The number of cycles (see rte_get_hpet_hz()) before the callback
+ * function is called.
+ * @param type
+ * The type can be either:
+ * - PERIODICAL: The timer is automatically reloaded after execution
+ * (returns to the PENDING state)
+ * - SINGLE: The timer is one-shot, that is, the timer goes to a
+ * STOPPED state after execution.
+ * @param tim_lcore
+ * The ID of the lcore where the timer callback function has to be
+ * executed. If tim_lcore is LCORE_ID_ANY, the timer library will
+ * launch it on a different core for each call (round-robin).
+ * @param fct
+ * The callback function of the timer.
+ * @param arg
+ * The user argument of the callback function.
+ */
+void
+rte_timer_reset_sync(struct rte_timer *tim, uint64_t ticks,
+ enum rte_timer_type type, unsigned tim_lcore,
+ rte_timer_cb_t fct, void *arg);
+
+/**
+ * Stop a timer.
+ *
+ * The rte_timer_stop() function stops the timer associated with the
+ * timer handle *tim*. It may fail if the timer is currently running or
+ * being configured.
+ *
+ * If the timer is pending or stopped (for instance, already expired),
+ * the function will succeed. The timer handle tim must have been
+ * initialized using rte_timer_init(), otherwise, undefined behavior
+ * will occur.
+ *
+ * This function can be called safely from a timer callback. If it
+ * succeeds, the timer is not referenced anymore by the timer library
+ * and the timer structure can be freed (even in the callback
+ * function).
+ *
+ * @param tim
+ * The timer handle.
+ * @return
+ * - 0: Success; the timer is stopped.
+ * - (-1): The timer is in the RUNNING or CONFIG state.
+ */
+int rte_timer_stop(struct rte_timer *tim);
+
+
+/**
+ * Loop until rte_timer_stop() succeeds.
+ *
+ * After a call to this function, the timer identified by *tim* is
+ * stopped. See rte_timer_stop() for details.
+ *
+ * @param tim
+ * The timer handle.
+ */
+void rte_timer_stop_sync(struct rte_timer *tim);
+
+/**
+ * Test if a timer is pending.
+ *
+ * The rte_timer_pending() function tests the PENDING status
+ * of the timer handle *tim*. A PENDING timer is one that has been
+ * scheduled and whose function has not yet been called.
+ *
+ * @param tim
+ * The timer handle.
+ * @return
+ * - 0: The timer is not pending.
+ * - 1: The timer is pending.
+ */
+int rte_timer_pending(struct rte_timer *tim);
+
+/**
+ * Manage the timer list and execute callback functions.
+ *
+ * This function must be called periodically from all cores
+ * main_loop(). It browses the list of pending timers and runs all
+ * timers that are expired.
+ *
+ * The precision of the timer depends on the call frequency of this
+ * function. However, the more often the function is called, the more
+ * CPU resources it will use.
+ */
+void rte_timer_manage(void);
+
+/**
+ * Dump statistics about timers.
+ */
+void rte_timer_dump_stats(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_TIMER_H_ */