Commit ff87d29c authored by Ben Walker's avatar Ben Walker Committed by Jim Harris
Browse files

io_channel: Add mechanism to call a function on each channel 



For a given I/O device, call a user function on the correct
thread for each channel.

Change-Id: I568a443184ac834c80c5e36b80aa9b6f8bb0ac99
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-on: https://review.gerrithub.io/362256


Tested-by: default avatarSPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent a30ffb98

include/spdk/io_channel.h

+17 −0
Original line number Diff line number Diff line
@@ -52,6 +52,10 @@ typedef void (*spdk_thread_pass_msg)(spdk_thread_fn fn, void *ctx, 
typedef int (*spdk_io_channel_create_cb)(void *io_device, void *ctx_buf);

typedef void (*spdk_io_channel_destroy_cb)(void *io_device, void *ctx_buf);



typedef void (*spdk_channel_msg)(void *io_device, struct spdk_io_channel *ch,

				 void *ctx);

typedef void (*spdk_channel_for_each_cpl)(void *io_device, void *ctx);



/**

 * \brief Initializes the calling thread for I/O channel allocation.

 *
@@ -136,4 +140,17 @@ void spdk_put_io_channel(struct spdk_io_channel *ch); 
 */

void *spdk_io_channel_get_ctx(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.

 *

 * Once 'fn' has been called on each channel, 'cpl' will be called

 * on the thread that spdk_for_each_channel was initially called from.

 */

void spdk_for_each_channel(void *io_device, spdk_channel_msg fn, void *ctx,

			   spdk_channel_for_each_cpl cpl);



#endif /* SPDK_IO_CHANNEL_H_ */

lib/util/io_channel.c

+86 −0
Original line number Diff line number Diff line
@@ -295,3 +295,89 @@ spdk_io_channel_get_ctx(struct spdk_io_channel *ch) 
{

	return (uint8_t *)ch + sizeof(*ch);

}



struct call_channel {

	void *io_device;

	spdk_channel_msg fn;

	void *ctx;



	struct spdk_thread *cur_thread;

	struct spdk_io_channel *cur_ch;



	struct spdk_thread *orig_thread;

	spdk_channel_for_each_cpl cpl;

};



static void

_call_channel(void *ctx)

{

	struct call_channel *ch_ctx = ctx;

	struct spdk_thread *thread;

	struct spdk_io_channel *ch;



	thread = ch_ctx->cur_thread;

	ch = ch_ctx->cur_ch;



	ch_ctx->fn(ch_ctx->io_device, ch, ch_ctx->ctx);



	pthread_mutex_lock(&g_devlist_mutex);

	thread = TAILQ_NEXT(thread, tailq);

	while (thread) {

		TAILQ_FOREACH(ch, &thread->io_channels, tailq) {

			if (ch->io_device == ch_ctx->io_device) {

				ch_ctx->cur_thread = thread;

				ch_ctx->cur_ch = ch;

				pthread_mutex_unlock(&g_devlist_mutex);

				spdk_thread_send_msg(thread, _call_channel, ch_ctx);

				return;

			}

		}

		thread = TAILQ_NEXT(thread, tailq);

	}



	pthread_mutex_unlock(&g_devlist_mutex);



	ch_ctx->cpl(ch_ctx->io_device, ch_ctx->ctx);

	free(ch_ctx);

}



void

spdk_for_each_channel(void *io_device, spdk_channel_msg fn, void *ctx,

		      spdk_channel_for_each_cpl cpl)

{

	struct spdk_thread *thread;

	struct spdk_io_channel *ch;

	struct call_channel *ch_ctx;



	ch_ctx = calloc(1, sizeof(*ch_ctx));

	if (!ch_ctx) {

		SPDK_ERRLOG("Unable to allocate context\n");

		return;

	}



	ch_ctx->io_device = io_device;

	ch_ctx->fn = fn;

	ch_ctx->ctx = ctx;

	ch_ctx->cpl = cpl;



	pthread_mutex_lock(&g_devlist_mutex);

	ch_ctx->orig_thread = _get_thread();



	TAILQ_FOREACH(thread, &g_threads, tailq) {

		TAILQ_FOREACH(ch, &thread->io_channels, tailq) {

			if (ch->io_device == io_device) {

				ch_ctx->cur_thread = thread;

				ch_ctx->cur_ch = ch;

				pthread_mutex_unlock(&g_devlist_mutex);

				spdk_thread_send_msg(thread, _call_channel, ch_ctx);

				return;

			}

		}

	}



	free(ch_ctx);



	pthread_mutex_unlock(&g_devlist_mutex);



	cpl(io_device, ctx);

}