Commit 443590c2 authored by Ladi Prosek's avatar Ladi Prosek Committed by Amit Shah
Browse files

rng: switch request queue to QSIMPLEQ 



QSIMPLEQ supports appending to tail in O(1) and is intrusive so
it doesn't require extra memory allocations for the bookkeeping
data.

Suggested-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarLadi Prosek <lprosek@redhat.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Reviewed-by: default avatarAmit Shah <amit.shah@redhat.com>
Message-Id: <1457010971-24771-1-git-send-email-lprosek@redhat.com>
Signed-off-by: default avatarAmit Shah <amit.shah@redhat.com>
parent 97556fe8

backends/rng-egd.c

+4 −5
Original line number Diff line number Diff line
@@ -49,11 +49,10 @@ static void rng_egd_request_entropy(RngBackend *b, RngRequest *req) 
static int rng_egd_chr_can_read(void *opaque)

{

    RngEgd *s = RNG_EGD(opaque);

    GSList *i;

    RngRequest *req;

    int size = 0;



    for (i = s->parent.requests; i; i = i->next) {

        RngRequest *req = i->data;

    QSIMPLEQ_FOREACH(req, &s->parent.requests, next) {

        size += req->size - req->offset;

    }
@@ -65,8 +64,8 @@ static void rng_egd_chr_read(void *opaque, const uint8_t *buf, int size) 
    RngEgd *s = RNG_EGD(opaque);

    size_t buf_offset = 0;



    while (size > 0 && s->parent.requests) {

        RngRequest *req = s->parent.requests->data;

    while (size > 0 && !QSIMPLEQ_EMPTY(&s->parent.requests)) {

        RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);

        int len = MIN(size, req->size - req->offset);



        memcpy(req->data + req->offset, buf + buf_offset, len);

backends/rng-random.c

+3 −3
Original line number Diff line number Diff line
@@ -35,8 +35,8 @@ static void entropy_available(void *opaque) 
{

    RndRandom *s = RNG_RANDOM(opaque);



    while (s->parent.requests != NULL) {

        RngRequest *req = s->parent.requests->data;

    while (!QSIMPLEQ_EMPTY(&s->parent.requests)) {

        RngRequest *req = QSIMPLEQ_FIRST(&s->parent.requests);

        ssize_t len;



        len = read(s->fd, req->data, req->size);
@@ -58,7 +58,7 @@ static void rng_random_request_entropy(RngBackend *b, RngRequest *req) 
{

    RndRandom *s = RNG_RANDOM(b);



    if (s->parent.requests == NULL) {

    if (QSIMPLEQ_EMPTY(&s->parent.requests)) {

        /* If there are no pending requests yet, we need to

         * install our fd handler. */

        qemu_set_fd_handler(s->fd, entropy_available, NULL, s);

backends/rng.c

+10 −7
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ void rng_backend_request_entropy(RngBackend *s, size_t size, 


        k->request_entropy(s, req);



        s->requests = g_slist_append(s->requests, req);

        QSIMPLEQ_INSERT_TAIL(&s->requests, req, next);

    }

}
@@ -83,24 +83,27 @@ static void rng_backend_free_request(RngRequest *req) 


static void rng_backend_free_requests(RngBackend *s)

{

    GSList *i;

    RngRequest *req, *next;



    for (i = s->requests; i; i = i->next) {

        rng_backend_free_request(i->data);

    QSIMPLEQ_FOREACH_SAFE(req, &s->requests, next, next) {

        rng_backend_free_request(req);

    }



    g_slist_free(s->requests);

    s->requests = NULL;

    QSIMPLEQ_INIT(&s->requests);

}



void rng_backend_finalize_request(RngBackend *s, RngRequest *req)

{

    s->requests = g_slist_remove(s->requests, req);

    QSIMPLEQ_REMOVE(&s->requests, req, RngRequest, next);

    rng_backend_free_request(req);

}



static void rng_backend_init(Object *obj)

{

    RngBackend *s = RNG_BACKEND(obj);



    QSIMPLEQ_INIT(&s->requests);



    object_property_add_bool(obj, "opened",

                             rng_backend_prop_get_opened,

                             rng_backend_prop_set_opened,

include/sysemu/rng.h

+2 −1
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ struct RngRequest 
    void *opaque;

    size_t offset;

    size_t size;

    QSIMPLEQ_ENTRY(RngRequest) next;

};



struct RngBackendClass
@@ -56,7 +57,7 @@ struct RngBackend 


    /*< protected >*/

    bool opened;

    GSList *requests;

    QSIMPLEQ_HEAD(requests, RngRequest) requests;

};