ivampiresp/Spdk
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

include/io_channel.h: add comments for public APIs

Browse Source 
Change-Id: I85dfac522eb77e5d53fb2fc9c5bb8a75463f1480
Signed-off-by: Yanbo Zhou <yanbo.zhou@intel.com>
Reviewed-on: https://review.gerrithub.io/392919
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
This commit is contained in:
Yanbo Zhou 2017-12-25 16:33:25 +08:00 committed by Jim Harris
parent 63d09e11cb
commit 4dbff01ba3
1 changed files with 141 additions and 67 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

208
include/spdk/io_channel.h
View File

@ -94,16 +94,19 @@ struct spdk_io_channel {
};
/**
* \brief Initializes the calling thread for I/O channel allocation.
* Initializes the calling thread for I/O channel allocation.
*
* @param fn A function that may be called from any thread and is
* passed a function pointer (spdk_thread_fn) that must be
* called on the same thread that spdk_allocate_thread
* was called from.
* @param thread_ctx Context that will be passed to fn.
* @param name Human-readable name for the thread; can be retrieved with spdk_thread_get_name().
* The string is copied, so the pointed-to data only needs to be valid during the
* spdk_allocate_thread() call. May be NULL to specify no name.
* \param msg_fn A function that may be called from any thread and is passed a function
* pointer (spdk_thread_fn) that must be called on the same thread that spdk_allocate_thread
* was called from.
* \param start_poller_fn Function to be called to start a poller for the thread.
* \param stop_poller_fn Function to be called to stop a poller for the thread.
* \param thread_ctx Context that will be passed to fn, start_poller_fn and spdk_stop_poller.
* \param name Human-readable name for the thread; can be retrieved with spdk_thread_get_name().
* The string is copied, so the pointed-to data only needs to be valid during the
* spdk_allocate_thread() call. May be NULL to specify no name.
*
* \return a pointer to the allocated thread on success or NULL on failure..
*/
struct spdk_thread *spdk_allocate_thread(spdk_thread_pass_msg msg_fn,
spdk_start_poller start_poller_fn,
@ -112,114 +115,146 @@ struct spdk_thread *spdk_allocate_thread(spdk_thread_pass_msg msg_fn,
const char *name);
/**
* \brief Releases any resources related to the calling thread for I/O channel allocation.
* Release any resources related to the calling thread for I/O channel allocation.
*
* All I/O channel references related to the calling thread must be released using
* spdk_put_io_channel() prior to calling this function.
* spdk_put_io_channel() prior to calling this function.
*/
void spdk_free_thread(void);
/**
* \brief Get a handle to the current thread. This handle may be passed
* to other threads and used as the target of spdk_thread_send_msg().
* Get a handle to the current thread.
*
* This handle may be passed to other threads and used as the target of
* spdk_thread_send_msg().
*
* \sa spdk_io_channel_get_thread()
*
* \return a pointer to the current thread on success or NULL on failure.
*/
struct spdk_thread *spdk_get_thread(void);
/**
* \brief Get a thread's name.
* Get a thread's name.
*
* \param thread Thread to query.
*
* \return the name of the thread.
*/
const char *spdk_thread_get_name(const struct spdk_thread *thread);
/**
* \brief Send a message to the given thread. The message
* may be sent asynchronously - i.e. spdk_thread_send_msg
* may return prior to `fn` being called.
* Send a message to the given thread.
*
* @param thread The target thread.
* @param fn This function will be called on the given thread.
* @param ctx This context will be passed to fn when called.
* The message may be sent asynchronously - i.e. spdk_thread_send_msg may return
* prior to `fn` being called.
*
* \param thread The target thread.
* \param fn This function will be called on the given thread.
* \param ctx This context will be passed to fn when called.
*/
void spdk_thread_send_msg(const struct spdk_thread *thread, spdk_thread_fn fn, void *ctx);
/**
* \brief Send a message to each thread, serially. The message
* is sent asynchronously - i.e. spdk_for_each_thread
* will return prior to `fn` being called on each thread.
* Send a message to each thread, serially.
*
* @param fn This is the function that will be called on each thread.
* @param ctx This context will be passed to fn when called.
* @param cpl This will be called on the originating thread after `fn` has been
* called on each thread.
* The message is sent asynchronously - i.e. spdk_for_each_thread will return
* prior to `fn` being called on each thread.
*
* \param fn This is the function that will be called on each thread.
* \param ctx This context will be passed to fn when called.
* \param cpl This will be called on the originating thread after `fn` has been
* called on each thread.
*/
void spdk_for_each_thread(spdk_thread_fn fn, void *ctx, spdk_thread_fn cpl);
/**
* \brief Register a poller on the current thread. The poller can be
* unregistered by calling spdk_poller_unregister().
* Register a poller on the current thread.
*
* @param fn This function will be called every `period_microseconds`
* @param arg Passed to fn
* @param period_microseconds How often to call `fn`. If 0, call `fn` as often as possible.
* The poller can be unregistered by calling spdk_poller_unregister().
*
* \param fn This function will be called every `period_microseconds`.
* \param arg Argument passed to fn.
* \param period_microseconds How often to call `fn`. If 0, call `fn` as often
* as possible.
*
* \return a pointer to the poller registered on the current thread on success
* or NULL on failure.
*/
struct spdk_poller *spdk_poller_register(spdk_thread_fn fn,
void *arg,
uint64_t period_microseconds);
/**
* \brief Unregister a poller on the current thread.
* Unregister a poller on the current thread.
*
* @param ppoller The poller to unregister.
* \param ppoller The poller to unregister.
*/
void spdk_poller_unregister(struct spdk_poller **ppoller);
/**
* \brief Register the opaque io_device context as an I/O device.
* Register the opaque io_device context as an I/O device.
*
* After an I/O device is registered, it can return I/O channels using the
* spdk_get_io_channel() function. create_cb is the callback function invoked
* to allocate any resources required for a new I/O channel. destroy_cb is the
* callback function invoked to release the resources for an I/O channel. ctx_size
* is the size of the context buffer allocated to store references to allocated I/O
* channel resources.
* spdk_get_io_channel() function.
*
* \param io_device The pointer to io_device context.
* \param create_cb Callback function invoked to allocate any resources required
* for a new I/O channel.
* \param destroy_cb Callback function invoked to release the resources for an
* I/O channel.
* \param ctx_size The size of the context buffer allocated to store references
* to allocated I/O channel resources.
*/
void spdk_io_device_register(void *io_device, spdk_io_channel_create_cb create_cb,
spdk_io_channel_destroy_cb destroy_cb, uint32_t ctx_size);
/**
* \brief Unregister the opaque io_device context as an I/O device.
* Unregister the opaque io_device context as an I/O device.
*
* The actual unregistration might be deferred until all active I/O channels are destroyed.
* unregister_cb is an optional callback function invoked to release any references to
* this I/O device.
* The actual unregistration might be deferred until all active I/O channels are
* destroyed.
*
* \param io_device The pointer to io_device context.
* \param unregister_cb An optional callback function invoked to release any
* references to this I/O device.
*/
void spdk_io_device_unregister(void *io_device, spdk_io_device_unregister_cb unregister_cb);
/**
* \brief Gets an I/O channel for the specified io_device to be used by the calling thread.
* Get an I/O channel for the specified io_device to be used by the calling thread.
*
* The io_device context pointer specified must have previously been registered using
* spdk_io_device_register(). If an existing I/O channel does not exist yet for the given
* io_device on the calling thread, it will allocate an I/O channel and invoke the create_cb
* function pointer specified in spdk_io_device_register(). If an I/O channel already
* exists for the given io_device on the calling thread, its reference is returned rather
* than creating a new I/O channel.
* The io_device context pointer specified must have previously been registered
* using spdk_io_device_register(). If an existing I/O channel does not exist
* yet for the given io_device on the calling thread, it will allocate an I/O
* channel and invoke the create_cb function pointer specified in spdk_io_device_register().
* If an I/O channel already exists for the given io_device on the calling thread,
* its reference is returned rather than creating a new I/O channel.
*
* \param io_device The pointer to io_device context.
*
* \return a pointer to the I/O channel for this device on success or NULL on failure.
*/
struct spdk_io_channel *spdk_get_io_channel(void *io_device);
/**
* \brief Releases a reference to an I/O channel. This happens asynchronously.
* Release a reference to an I/O channel. This happens asynchronously.
*
* Actual release will happen on the same thread that called spdk_get_io_channel() for the
* specified I/O channel. If this releases the last reference to the I/O channel, The
* destroy_cb function specified in spdk_io_device_register() will be invoked to release
* any associated resources.
* Actual release will happen on the same thread that called spdk_get_io_channel()
* for the specified I/O channel. If this releases the last reference to the
* I/O channel, The destroy_cb function specified in spdk_io_device_register()
* will be invoked to release any associated resources.
*
* \param ch I/O channel to release a reference.
*/
void spdk_put_io_channel(struct spdk_io_channel *ch);
/**
* \brief Returns the context buffer associated with an I/O channel.
* Get the context buffer associated with an I/O channel.
*
* \param ch I/O channel.
*
* \return a pointer to the context buffer.
*/
static inline void *
spdk_io_channel_get_ctx(struct spdk_io_channel *ch)
@ -228,36 +263,75 @@ spdk_io_channel_get_ctx(struct spdk_io_channel *ch)
}
/**
* \brief Returns an I/O channel from a context buffer. This is
* the inverse of spdk_io_channel_get_ctx().
* Get I/O channel from the context buffer. This is the inverse of
* spdk_io_channel_get_ctx().
*
* \param ctx The pointer to the context buffer.
*
* \return a pointer to the I/O channel associated with the context buffer.
*/
struct spdk_io_channel *spdk_io_channel_from_ctx(void *ctx);
/**
* \brief Returns the spdk_thread associated with an I/O channel.
* Get the thread associated with an I/O channel.
*
* \param ch I/O channel.
*
* \return a pointer to the thread associated with the I/O channel
*/
struct spdk_thread *spdk_io_channel_get_thread(struct spdk_io_channel *ch);
/**
* \brief Call 'fn' on each channel associated with io_device. This happens
* asynchronously, so fn may be called after spdk_for_each_channel returns.
* 'fn' will be called on the correct thread for each channel. 'fn' will be
* called for each channel serially, such that two calls to 'fn' will not
* overlap in time. After 'fn' has been called, call
* Call 'fn' on each channel associated with io_device.
*
* This happens asynchronously, so fn may be called after spdk_for_each_channel
* returns. 'fn' will be called for each channel serially, such that two calls
* to 'fn' will not overlap in time. After 'fn' has been called, call
* spdk_for_each_channel_continue() to continue iterating.
*
* Once 'fn' has been called on each channel, 'cpl' will be called
* on the thread that spdk_for_each_channel was initially called from.
* \param io_device 'fn' will be called on each channel associated with this io_device.
* \param fn Called on the appropriate thread for each channel associated with io_device.
* \param ctx Context buffer registered to spdk_io_channel_iter that can be obatined
* form the function spdk_io_channel_iter_get_ctx().
* \param cpl Called on the thread that spdk_for_each_channel was initially called
* from when 'fn' has been called on each channel.
*/
void spdk_for_each_channel(void *io_device, spdk_channel_msg fn, void *ctx,
spdk_channel_for_each_cpl cpl);
/**
* Get io_device from the I/O channel iterator.
*
* \param i I/O channel iterator.
*
* \return a pointer to the io_device.
*/
void *spdk_io_channel_iter_get_io_device(struct spdk_io_channel_iter *i);
/**
* Get I/O channel from the I/O channel iterator.
*
* \param i I/O channel iterator.
*
* \return a pointer to the I/O channel.
*/
struct spdk_io_channel *spdk_io_channel_iter_get_channel(struct spdk_io_channel_iter *i);
/**
* Get context buffer from the I/O channel iterator.
*
* \param i I/O channel iterator.
*
* \return a pointer to the context buffer.
*/
void *spdk_io_channel_iter_get_ctx(struct spdk_io_channel_iter *i);
/**
* Helper function to iterate all channels for spdk_for_each_channel().
*
* \param i I/O channel iterator.
* \param status Status for the I/O channel iterator.
*/
void spdk_for_each_channel_continue(struct spdk_io_channel_iter *i, int status);
#ifdef __cplusplus