diff options
| -rw-r--r-- | docs/man/nng_aio_set_iov.3.adoc | 29 | ||||
| -rw-r--r-- | src/core/aio.c | 102 | ||||
| -rw-r--r-- | src/core/aio.h | 5 |
3 files changed, 42 insertions, 94 deletions
diff --git a/docs/man/nng_aio_set_iov.3.adoc b/docs/man/nng_aio_set_iov.3.adoc index 8d720c1d..3c774bd1 100644 --- a/docs/man/nng_aio_set_iov.3.adoc +++ b/docs/man/nng_aio_set_iov.3.adoc @@ -1,6 +1,6 @@ = nng_aio_set_iov(3) // -// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech> +// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech> // Copyright 2018 Capitar IT Group BV <info@capitar.com> // // This document is supplied under the terms of the MIT License, a @@ -15,7 +15,7 @@ nng_aio_set_iov - set scatter/gather vector == SYNOPSIS -[source, c] +[source,c] ---- #include <nng/nng.h> @@ -24,13 +24,12 @@ int nng_aio_set_iov(nng_aio *aio, unsigned int niov, nng_iov *iov); == DESCRIPTION -The `nng_aio_set_iov()` function sets a ((scatter/gather)) vector _iov_ on the -handle _aio_. +The `nng_aio_set_iov()` function sets a ((scatter/gather)) vector _iov_ on the handle _aio_. The _iov_ is a pointer to an array of _niov_ xref:nng_iov.5.adoc[`nng_iov`] structures, which have the following definition: -[source, c] +[source,c] ---- typedef struct nng_iov { void * iov_buf; @@ -38,21 +37,14 @@ structures, which have the following definition: }; ---- -The _iov_ is copied into storage in the _aio_ itself, so that callers -may use stack allocated `nng_iov` structures. The values pointed to -by the `iov_buf` members are *not* copied by this function though. +The _iov_ is copied into storage in the _aio_ itself, so that callers may use stack allocated `nng_iov` structures. +The values pointed to by the `iov_buf` members are *not* copied by this function though. -Up to four `nng_iov` members may be supplied without causing any -allocations, and thus this operation is guaranteed to succeed for -values of _niov_ less than four. +A maximum of eight (8) `nng_iov` members may be supplied. -More than four (4) `nng_iov` members may be supplied, but this may require -heap allocations, and so the operation may fail with `NNG_ENOMEM`. -Additionally, not every operation can support longer vectors; the -actual limit is determined by the system, but is generally at least -sixteen (16). -Furthermore, values for _niov_ larger than sixty-four (64) will -generally result in `NNG_EINVAL`. +NOTE: Earlier versions of the library could accept longer scatter-gather lists. +However, no known consumers have ever needed a scatter-gather list longer than 4 vectors. +As a result, the implementation limit was reduced, and heap allocations which could fail were removed. == RETURN VALUES @@ -61,7 +53,6 @@ This function returns 0 on success, and non-zero otherwise. == ERRORS [horizontal] -`NNG_ENOMEM`:: Insufficient free memory to perform operation. `NNG_EINVAL`:: Value of specified _niov_ is too large. == SEE ALSO diff --git a/src/core/aio.c b/src/core/aio.c index 28f61e50..738dd48b 100644 --- a/src/core/aio.c +++ b/src/core/aio.c @@ -1,5 +1,5 @@ // -// Copyright 2019 Staysail Systems, Inc. <info@staysail.tech> +// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech> // Copyright 2018 Capitar IT Group BV <info@capitar.com> // // This software is supplied under the terms of the MIT License, a @@ -45,7 +45,7 @@ static nni_aio *nni_aio_expire_aio; // "prepare" the task for an aio when a caller marks an aio as starting // (with nni_aio_begin), and that marks the task as bus. Then, all we have // to do is wait for the task to complete (the busy flag to be cleared) -// when we want to know if the aio's operation itself is complete. +// when we want to know if the operation itself is complete. // // In order to guard against aio reuse during teardown, we set the a_stop // flag. Any attempt to initialize for a new operation after that point @@ -68,18 +68,14 @@ struct nng_aio { nni_time a_expire; // Absolute timeout nni_duration a_timeout; // Relative timeout - // These fields are private to the aio framework. - bool a_stop; // shutting down (no new operations) - bool a_sleep; // sleeping with no action - int a_sleeprv; // result when sleep wakes + bool a_stop; // shutting down (no new operations) + bool a_sleep; // sleeping with no action + bool a_expire_ok; // expire from sleep is ok nni_task *a_task; // Read/write operations. - nni_iov *a_iov; + nni_iov a_iov[8]; unsigned a_niov; - nni_iov a_iovinl[4]; // inline IOVs - when the IOV list is short - nni_iov *a_iovalloc; // dynamically allocated IOVs - unsigned a_niovalloc; // number of allocated IOVs // Message operations. nni_msg *a_msg; @@ -97,7 +93,6 @@ struct nng_aio { // Provider-use fields. nni_aio_cancelfn a_cancel_fn; void * a_cancel_arg; - void * a_prov_data; nni_list_node a_prov_node; void * a_prov_extra[4]; // Extra data used by provider @@ -126,11 +121,9 @@ nni_aio_init(nni_aio **aiop, nni_cb cb, void *arg) NNI_FREE_STRUCT(aio); return (rv); } - aio->a_expire = NNI_TIME_NEVER; - aio->a_timeout = NNG_DURATION_INFINITE; - aio->a_iov = aio->a_iovinl; - aio->a_niovalloc = 0; - *aiop = aio; + aio->a_expire = NNI_TIME_NEVER; + aio->a_timeout = NNG_DURATION_INFINITE; + *aiop = aio; return (0); } @@ -173,11 +166,6 @@ nni_aio_fini(nni_aio *aio) nni_task_fini(aio->a_task); - // At this point the AIO is done. - if (aio->a_niovalloc > 0) { - NNI_FREE_STRUCTS(aio->a_iovalloc, aio->a_niovalloc); - } - NNI_FREE_STRUCT(aio); } } @@ -185,39 +173,27 @@ nni_aio_fini(nni_aio *aio) int nni_aio_set_iov(nni_aio *aio, unsigned niov, const nni_iov *iov) { + + if (niov > NNI_NUM_ELEMENTS((aio->a_iov))) { + return (NNG_EINVAL); + } + // Sometimes we are resubmitting our own io vector, with - // just a smaller niov. - if (aio->a_iov != iov) { - if ((niov > NNI_NUM_ELEMENTS(aio->a_iovinl)) && - (niov > aio->a_niovalloc)) { - nni_iov *newiov = NNI_ALLOC_STRUCTS(newiov, niov); - if (newiov == NULL) { - return (NNG_ENOMEM); - } - if (aio->a_niovalloc > 0) { - NNI_FREE_STRUCTS( - aio->a_iovalloc, aio->a_niovalloc); - } - aio->a_iov = newiov; - aio->a_iovalloc = newiov; - aio->a_niovalloc = niov; - } - if (niov <= NNI_NUM_ELEMENTS(aio->a_iovinl)) { - aio->a_iov = aio->a_iovinl; - } else { - aio->a_iov = aio->a_iovalloc; + // just a smaller count. We copy them only if we are not. + if (iov != &aio->a_iov[0]) { + for (unsigned i = 0; i < niov; i++) { + aio->a_iov[i] = iov[i]; } - memcpy(aio->a_iov, iov, niov * sizeof(nni_iov)); } aio->a_niov = niov; return (0); } -// nni_aio_stop cancels any oustanding operation, and waits for the +// nni_aio_stop cancels any outstanding operation, and waits for the // callback to complete, if still running. It also marks the AIO as // stopped, preventing further calls to nni_aio_begin from succeeding. // To correctly tear down an AIO, call stop, and make sure any other -// calles are not also stopped, before calling nni_aio_fini to release +// callers are not also stopped, before calling nni_aio_fini to release // actual memory. void nni_aio_stop(nni_aio *aio) @@ -363,6 +339,7 @@ nni_aio_begin(nni_aio *aio) aio->a_cancel_arg = NULL; aio->a_expire = NNI_TIME_NEVER; aio->a_sleep = false; + aio->a_expire_ok = false; nni_mtx_unlock(&nni_aio_lk); nni_task_dispatch(aio->a_task); @@ -504,13 +481,6 @@ nni_aio_list_append(nni_list *list, nni_aio *aio) } void -nni_aio_list_prepend(nni_list *list, nni_aio *aio) -{ - nni_aio_list_remove(aio); - nni_list_prepend(list, aio); -} - -void nni_aio_list_remove(nni_aio *aio) { nni_list_node_remove(&aio->a_prov_node); @@ -546,11 +516,11 @@ nni_aio_expire_add(nni_aio *aio) } static void -nni_aio_expire_loop(void *notused) +nni_aio_expire_loop(void *unused) { nni_list *aios = &nni_aio_expire_aios; - NNI_ARG_UNUSED(notused); + NNI_ARG_UNUSED(unused); for (;;) { nni_aio_cancelfn fn; @@ -584,7 +554,7 @@ nni_aio_expire_loop(void *notused) // This aio's time has come. Expire it, canceling any // outstanding I/O. nni_list_remove(aios, aio); - rv = aio->a_sleep ? aio->a_sleeprv : NNG_ETIMEDOUT; + rv = aio->a_expire_ok ? 0 : NNG_ETIMEDOUT; if ((fn = aio->a_cancel_fn) != NULL) { void *arg = aio->a_cancel_arg; @@ -610,18 +580,6 @@ nni_aio_expire_loop(void *notused) } void * -nni_aio_get_prov_data(nni_aio *aio) -{ - return (aio->a_prov_data); -} - -void -nni_aio_set_prov_data(nni_aio *aio, void *data) -{ - aio->a_prov_data = data; -} - -void * nni_aio_get_prov_extra(nni_aio *aio, unsigned index) { return (aio->a_prov_extra[index]); @@ -678,8 +636,10 @@ nni_aio_iov_advance(nni_aio *aio, size_t n) } resid -= aio->a_iov[0].iov_len; n -= aio->a_iov[0].iov_len; - aio->a_iov = &aio->a_iov[1]; aio->a_niov--; + for (unsigned i = 0; i < aio->a_niov; i++) { + aio->a_iov[i] = aio->a_iov[i + 1]; + } } return (resid); // we might not have used all of n for this iov } @@ -709,8 +669,8 @@ nni_sleep_aio(nng_duration ms, nng_aio *aio) if (nni_aio_begin(aio) != 0) { return; } - aio->a_sleeprv = 0; - aio->a_sleep = true; + aio->a_expire_ok = true; + aio->a_sleep = true; switch (aio->a_timeout) { case NNG_DURATION_DEFAULT: case NNG_DURATION_INFINITE: @@ -720,8 +680,8 @@ nni_sleep_aio(nng_duration ms, nng_aio *aio) // If the timeout on the aio is shorter than our sleep time, // then let it still wake up early, but with NNG_ETIMEDOUT. if (ms > aio->a_timeout) { - aio->a_sleeprv = NNG_ETIMEDOUT; - ms = aio->a_timeout; + aio->a_expire_ok = false; + ms = aio->a_timeout; } } aio->a_expire = nni_clock() + ms; diff --git a/src/core/aio.h b/src/core/aio.h index 304f184c..83c068b5 100644 --- a/src/core/aio.h +++ b/src/core/aio.h @@ -1,5 +1,5 @@ // -// Copyright 2019 Staysail Systems, Inc. <info@staysail.tech> +// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech> // Copyright 2018 Capitar IT Group BV <info@capitar.com> // // This software is supplied under the terms of the MIT License, a @@ -102,7 +102,6 @@ extern void nni_aio_wait(nni_aio *); // and append will perform any necessary remove first. extern void nni_aio_list_init(nni_list *); extern void nni_aio_list_append(nni_list *, nni_aio *); -extern void nni_aio_list_prepend(nni_list *, nni_aio *); extern void nni_aio_list_remove(nni_aio *); extern int nni_aio_list_active(nni_aio *); @@ -129,8 +128,6 @@ extern void nni_aio_abort(nni_aio *, int rv); // nng_aio_finish family of functions.) extern int nni_aio_begin(nni_aio *); -extern void *nni_aio_get_prov_data(nni_aio *); -extern void nni_aio_set_prov_data(nni_aio *, void *); extern void *nni_aio_get_prov_extra(nni_aio *, unsigned); extern void nni_aio_set_prov_extra(nni_aio *, unsigned, void *); // nni_aio_advance_iov moves up the iov, reflecting that some I/O as |