Changeset 9c16c36 in mainline for uspace/lib/c/generic/async/client.c

Timestamp:

2018-06-07T17:00:32Z (6 years ago)

Author:

Jiří Zárevúcky <jiri.zarevucky@…>

Children:

95faa4d

Parents:

8404342

git-author:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-05-25 17:07:26)

git-committer:

Jiří Zárevúcky <jiri.zarevucky@…> (2018-06-07 17:00:32)

Message:

initial implementation of a new async call api

File:

• uspace/lib/c/generic/async/client.c (modified) (1 diff)

uspace/lib/c/generic/async/client.c

@@ -1346 +1346 @@
 }
 
+void async_call_begin(async_call_t *call, async_sess_t *sess, sysarg_t imethod,
+    sysarg_t arg1, sysarg_t arg2, sysarg_t arg3, sysarg_t arg4)
+{
+        memset(call, 0, sizeof(*call));
+
+        call->exch = async_exchange_begin(sess);
+        if (!call->exch) {
+                call->rc = ENOMEM;
+                return;
+        }
+
+        async_call_method(call, &call->initial, imethod,
+            arg1, arg2, arg3, arg4);
+}
+
+static suseconds_t time_until(const struct timeval *t)
+{
+        struct timeval tv;
+        getuptime(&tv);
+        if (tv_gteq(&tv, t))
+                return 1;
+
+        return tv_sub_diff(t, &tv);
+}
+
+static errno_t async_call_finish_internal(async_call_t *call, const struct timeval *expires)
+{
+        errno_t rc;
+
+        /* Wait for all the fragments. */
+        while (!list_empty(&call->fragments)) {
+                link_t *tmp = list_first(&call->fragments);
+                async_call_data_t *frag =
+                    list_get_instance(tmp, async_call_data_t, link);
+
+                if (expires) {
+                        errno_t trc = async_wait_timeout(frag->msgid, &rc,
+                            time_until(expires));
+                        if (trc != EOK)
+                                return trc;
+                } else {
+                        async_wait_for(frag->msgid, &rc);
+                }
+
+                list_remove(tmp);
+
+                if (rc != EOK)
+                        return rc;
+
+                if (frag->finalizer) {
+                        rc = frag->finalizer(frag);
+                        if (rc != EOK)
+                                return rc;
+                }
+        }
+
+        return EOK;
+}
+
+errno_t async_call_finish_timeout(async_call_t *call, const struct timeval *expires)
+{
+        assert(call);
+
+        if (call->rc)
+                return call->rc;
+
+        if (call->exch) {
+                async_exchange_end(call->exch);
+                call->exch = NULL;
+        }
+
+        errno_t rc = async_call_finish_internal(call, expires);
+        if (rc == ETIMEOUT)
+                return rc;
+
+        /* If one fails, abort the call. */
+        if (rc != EOK)
+                async_call_abort(call);
+
+        assert(list_empty(&call->fragments));
+        call->rc = rc;
+        return rc;
+}
+
+// Ends the call, and waits for all in-flight fragments to finish.
+errno_t async_call_finish(async_call_t *call)
+{
+        return async_call_finish_timeout(call, NULL);
+}
+
+// Aborts the call. After this function returns, auxiliary structures
+// and buffers are safe to deallocate.
+extern void async_call_abort(async_call_t *call)
+{
+        // FIXME: Proper abort needs kernel support. A system call should
+        //        clean up bookkeeping structures in the kernel and notify
+        //        the server of the abort as well.
+
+        //        Currently, we just wait, which is less than ideal,
+        //        but at the same time, nothing in HelenOS currently
+        //        benefits from timeouts.
+
+        assert(call);
+
+        if (call->exch) {
+                async_exchange_end(call->exch);
+                call->exch = NULL;
+        }
+
+        /* Wait for all the fragments. */
+        while (!list_empty(&call->fragments)) {
+                // TODO: abort instead of waiting
+                (void) async_call_finish_internal(call, NULL);
+        }
+
+        assert(list_empty(&call->fragments));
+}
+
+// Waits for all in-flight fragments to finish, but doesn't end the call.
+errno_t async_call_wait(async_call_t *call)
+{
+        return async_call_wait_timeout(call, NULL);
+}
+
+errno_t async_call_wait_timeout(async_call_t *call, const struct timeval *expires)
+{
+        assert(call);
+
+        if (call->rc)
+                return call->rc;
+
+        /* Wait for all the fragments except the initial one. */
+        assert(list_first(&call->fragments) == &call->initial.link);
+        list_remove(&call->initial.link);
+
+        errno_t rc = async_call_finish_internal(call, expires);
+        list_prepend(&call->initial.link, &call->fragments);
+
+        if (rc == ETIMEOUT)
+                return rc;
+
+        /* If one fails, abort the call. */
+        if (rc != EOK)
+                async_call_abort(call);
+
+        call->rc = rc;
+        return rc;
+}
+
+void async_call_method_with_finalizer(async_call_t *call,
+    async_call_data_t *data, sysarg_t imethod, sysarg_t arg1, sysarg_t arg2,
+    sysarg_t arg3, sysarg_t arg4, async_call_finalizer_t finalizer)
+{
+        assert(call);
+        assert(data);
+        data->finalizer = finalizer;
+
+        if (!call->exch)
+                call->rc = ENOENT;
+
+        if (call->rc)
+                return;
+
+        data->msgid = async_send_fast(call->exch, imethod,
+            arg1, arg2, arg3, arg4, &data->answer);
+        if (!data->msgid) {
+                async_call_abort(call);
+                call->rc = ENOMEM;
+        }
+
+        list_append(&data->link, &call->fragments);
+}
+
+void async_call_method(async_call_t *call, async_call_data_t *data,
+    sysarg_t imethod, sysarg_t arg1, sysarg_t arg2, sysarg_t arg3, sysarg_t arg4)
+{
+        assert(call);
+        assert(data);
+        memset(data, 0, sizeof(*data));
+
+        async_call_method_with_finalizer(call, data, imethod,
+            arg1, arg2, arg3, arg4, NULL);
+}
+
+static errno_t call_read_write_finalizer(async_call_data_t *data)
+{
+        size_t *sz = data->arg1;
+        if (sz)
+                *sz = IPC_GET_ARG2(data->answer);
+        return EOK;
+}
+
+void async_call_read(async_call_t *call, async_call_data_t *data,
+    void *dst, size_t size, size_t *nread)
+{
+        assert(call);
+        assert(data);
+        memset(data, 0, sizeof(*data));
+
+        data->arg1 = nread;
+
+        async_call_method_with_finalizer(call, data,
+            IPC_M_DATA_READ, (sysarg_t) dst, (sysarg_t) size, 0, 0,
+            call_read_write_finalizer);
+}
+
+/**
+ * After the call is successfully finished,
+ * `IPC_GET_ARG2(&data->answer)` holds the actual number of bytes written.
+ */
+void async_call_write(async_call_t *call, async_call_data_t *data,
+    const void *src, size_t size, size_t *nwritten)
+{
+        assert(call);
+        assert(data);
+        memset(data, 0, sizeof(*data));
+
+        data->arg1 = nwritten;
+
+        async_call_method_with_finalizer(call, data,
+            IPC_M_DATA_WRITE, (sysarg_t) src, (sysarg_t) size, 0, 0,
+            call_read_write_finalizer);
+}
+
+static errno_t call_share_in_finalizer(async_call_data_t *data)
+{
+        unsigned int *flags = data->arg1;
+        void **dst = data->arg2;
+
+        if (flags)
+                *flags = IPC_GET_ARG2(data->answer);
+
+        if (dst)
+                *dst = (void *) IPC_GET_ARG4(data->answer);
+
+        return EOK;
+}
+
+void async_call_share_in(async_call_t *call, async_call_data_t *data,
+    size_t size, sysarg_t arg, unsigned int *flags, void **dst)
+{
+        assert(call);
+        assert(data);
+        memset(data, 0, sizeof(*data));
+
+        data->arg1 = flags;
+        data->arg2 = dst;
+
+        async_call_method_with_finalizer(call, data,
+            IPC_M_SHARE_IN, (sysarg_t) size, (sysarg_t) arg, 0, 0,
+            call_share_in_finalizer);
+}
+
+void async_call_share_out(async_call_t *call, async_call_data_t *data,
+    void *src, unsigned int flags)
+{
+        async_call_method(call, data,
+            IPC_M_SHARE_OUT, (sysarg_t) src, 0, (sysarg_t) flags, 0);
+}
+
+// TODO: connect me to, connect to me, vfs handle, etc.
+
 /** @}
  */