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lib: Replace qsort() with g_qsort_with_data()

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While glibc provides qsort(), which usually is just a mergesort,
until sorting arrays so huge that temporary array used by
mergesort would not fit into physical memory (which in our case
is never), we are not guaranteed it'll use mergesort. The
advantage of mergesort is clear - it's stable. IOW, if we have an
array of values parsed from XML, qsort() it and produce some
output based on those values, we can then compare the output with
some expected output, line by line.

But with newer glibc this is all history. After [1], qsort() is
no longer mergesort but introsort instead, which is not stable.
This is suboptimal, because in some cases we want to preserve
order of equal items. For instance, in ebiptablesApplyNewRules(),
nwfilter rules are sorted by their priority. But if two rules
have the same priority, we want to keep them in the order they
appear in the XML. Since it's hard/needless work to identify
places where stable or unstable sorting is needed, let's just
play it safe and use stable sorting everywhere.

Fortunately, glib provides g_qsort_with_data() which indeed
implement mergesort and it's a drop in replacement for qsort(),
almost. It accepts fifth argument (pointer to opaque data), that
is passed to comparator function, which then accepts three
arguments.

We have to keep one occurance of qsort() though - in NSS module
which deliberately does not link with glib.

1: https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=03bf8357e8291857a435afcc3048e0b697b6cc04
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Martin Kletzander <mkletzan@redhat.com>
This commit is contained in:
Michal Privoznik
2023-11-22 14:58:49 +01:00
parent 97457cdf65
commit cfcbba4c2b
30 changed files with 196 additions and 111 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
tools/virsh-checkpoint.c
View File

@@ -526,7 +526,8 @@ virshCheckpointListFree(struct virshCheckpointList *checkpointlist)
static int
virshChkSorter(const void *a,
const void *b)
const void *b,
void *opaque G_GNUC_UNUSED)
{
const struct virshChk *sa = a;
const struct virshChk *sb = b;
@@ -594,9 +595,10 @@ virshCheckpointListCollect(vshControl *ctl,
}
if (!(orig_flags & VIR_DOMAIN_CHECKPOINT_LIST_TOPOLOGICAL) &&
checkpointlist->chks)
qsort(checkpointlist->chks, checkpointlist->nchks,
sizeof(*checkpointlist->chks), virshChkSorter);
checkpointlist->chks) {
g_qsort_with_data(checkpointlist->chks, checkpointlist->nchks,
sizeof(*checkpointlist->chks), virshChkSorter, NULL);
}
ret = g_steal_pointer(&checkpointlist);

11
tools/virsh-domain-monitor.c
View File

@@ -1483,7 +1483,9 @@ static const vshCmdInfo info_list[] = {
/* compare domains, pack NULLed ones at the end */
static int
virshDomainSorter(const void *a, const void *b)
virshDomainSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virDomainPtr *da = (virDomainPtr *) a;
virDomainPtr *db = (virDomainPtr *) b;
@@ -1741,9 +1743,10 @@ virshDomainListCollect(vshControl *ctl, unsigned int flags)
finished:
/* sort the list */
if (list->domains && list->ndomains)
qsort(list->domains, list->ndomains, sizeof(*list->domains),
virshDomainSorter);
if (list->domains && list->ndomains) {
g_qsort_with_data(list->domains, list->ndomains,
sizeof(*list->domains), virshDomainSorter, NULL);
}
/* truncate the list if filter simulation deleted entries */
if (deleted)

7
tools/virsh-host.c
View File

@@ -300,7 +300,9 @@ static const vshCmdOptDef opts_freepages[] = {
};
static int
vshPageSizeSorter(const void *a, const void *b)
vshPageSizeSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
unsigned int pa = *(unsigned int *)a;
unsigned int pb = *(unsigned int *)b;
@@ -377,7 +379,8 @@ cmdFreepages(vshControl *ctl, const vshCmd *cmd)
* @pagesize array will contain duplicates. We should
* remove them otherwise not very nice output will be
* produced. */
qsort(pagesize, nodes_cnt, sizeof(*pagesize), vshPageSizeSorter);
g_qsort_with_data(pagesize, nodes_cnt,
sizeof(*pagesize), vshPageSizeSorter, NULL);
for (i = 0; i < nodes_cnt - 1;) {
if (pagesize[i] == pagesize[i + 1]) {

11
tools/virsh-interface.c
View File

@@ -141,7 +141,9 @@ cmdInterfaceEdit(vshControl *ctl, const vshCmd *cmd)
}
static int
virshInterfaceSorter(const void *a, const void *b)
virshInterfaceSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virInterfacePtr *ia = (virInterfacePtr *) a;
virInterfacePtr *ib = (virInterfacePtr *) b;
@@ -281,9 +283,10 @@ virshInterfaceListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->ifaces && list->nifaces)
qsort(list->ifaces, list->nifaces,
sizeof(*list->ifaces), virshInterfaceSorter);
if (list->ifaces && list->nifaces) {
g_qsort_with_data(list->ifaces, list->nifaces,
sizeof(*list->ifaces), virshInterfaceSorter, NULL);
}
/* truncate the list if filter simulation deleted entries */
if (deleted)

29
tools/virsh-network.c
View File

@@ -791,7 +791,9 @@ cmdNetworkInfo(vshControl *ctl, const vshCmd *cmd)
}
static int
virshNetworkSorter(const void *a, const void *b)
virshNetworkSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virNetworkPtr *na = (virNetworkPtr *) a;
virNetworkPtr *nb = (virNetworkPtr *) b;
@@ -982,9 +984,10 @@ virshNetworkListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->nets && list->nnets)
qsort(list->nets, list->nnets,
sizeof(*list->nets), virshNetworkSorter);
if (list->nets && list->nnets) {
g_qsort_with_data(list->nets, list->nnets,
sizeof(*list->nets), virshNetworkSorter, NULL);
}
/* truncate the list if filter simulation deleted entries */
if (deleted)
@@ -1801,7 +1804,9 @@ static const vshCmdOptDef opts_network_dhcp_leases[] = {
};
static int
virshNetworkDHCPLeaseSorter(const void *a, const void *b)
virshNetworkDHCPLeaseSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virNetworkDHCPLeasePtr *lease1 = (virNetworkDHCPLeasePtr *) a;
virNetworkDHCPLeasePtr *lease2 = (virNetworkDHCPLeasePtr *) b;
@@ -1840,7 +1845,8 @@ cmdNetworkDHCPLeases(vshControl *ctl, const vshCmd *cmd)
}
/* Sort the list according to MAC Address/IAID */
qsort(leases, nleases, sizeof(*leases), virshNetworkDHCPLeaseSorter);
g_qsort_with_data(leases, nleases,
sizeof(*leases), virshNetworkDHCPLeaseSorter, NULL);
table = vshTableNew(_("Expiry Time"), _("MAC address"), _("Protocol"),
_("IP address"), _("Hostname"), _("Client ID or DUID"),
@@ -2068,7 +2074,9 @@ cmdNetworkPortDelete(vshControl *ctl, const vshCmd *cmd)
static int
virshNetworkPortSorter(const void *a, const void *b)
virshNetworkPortSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virNetworkPortPtr *na = (virNetworkPortPtr *) a;
virNetworkPortPtr *nb = (virNetworkPortPtr *) b;
@@ -2129,9 +2137,10 @@ virshNetworkPortListCollect(vshControl *ctl,
list->nports = ret;
/* sort the list */
if (list->ports && list->nports)
qsort(list->ports, list->nports,
sizeof(*list->ports), virshNetworkPortSorter);
if (list->ports && list->nports) {
g_qsort_with_data(list->ports, list->nports,
sizeof(*list->ports), virshNetworkPortSorter, NULL);
}
success = true;

11
tools/virsh-nodedev.c
View File

@@ -183,7 +183,9 @@ virshNodeListLookup(int devid, bool parent, void *opaque)
}
static int
virshNodeDeviceSorter(const void *a, const void *b)
virshNodeDeviceSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virNodeDevicePtr *na = (virNodeDevicePtr *) a;
virNodeDevicePtr *nb = (virNodeDevicePtr *) b;
@@ -334,9 +336,10 @@ virshNodeDeviceListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->devices && list->ndevices)
qsort(list->devices, list->ndevices,
sizeof(*list->devices), virshNodeDeviceSorter);
if (list->devices && list->ndevices) {
g_qsort_with_data(list->devices, list->ndevices,
sizeof(*list->devices), virshNodeDeviceSorter, NULL);
}
/* truncate the list if filter simulation deleted entries */
if (deleted)

22
tools/virsh-nwfilter.c
View File

@@ -220,7 +220,9 @@ cmdNWFilterDumpXML(vshControl *ctl, const vshCmd *cmd)
}
static int
virshNWFilterSorter(const void *a, const void *b)
virshNWFilterSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virNWFilterPtr *fa = (virNWFilterPtr *) a;
virNWFilterPtr *fb = (virNWFilterPtr *) b;
@@ -323,9 +325,10 @@ virshNWFilterListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->filters && list->nfilters)
qsort(list->filters, list->nfilters,
sizeof(*list->filters), virshNWFilterSorter);
if (list->filters && list->nfilters) {
g_qsort_with_data(list->filters, list->nfilters,
sizeof(*list->filters), virshNWFilterSorter, NULL);
}
/* truncate the list for not found filter objects */
if (deleted)
@@ -644,7 +647,9 @@ cmdNWFilterBindingDumpXML(vshControl *ctl, const vshCmd *cmd)
static int
virshNWFilterBindingSorter(const void *a, const void *b)
virshNWFilterBindingSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virNWFilterBindingPtr *fa = (virNWFilterBindingPtr *) a;
virNWFilterBindingPtr *fb = (virNWFilterBindingPtr *) b;
@@ -702,9 +707,10 @@ virshNWFilterBindingListCollect(vshControl *ctl,
list->nbindings = ret;
/* sort the list */
if (list->bindings && list->nbindings > 1)
qsort(list->bindings, list->nbindings,
sizeof(*list->bindings), virshNWFilterBindingSorter);
if (list->bindings && list->nbindings > 1) {
g_qsort_with_data(list->bindings, list->nbindings,
sizeof(*list->bindings), virshNWFilterBindingSorter, NULL);
}
success = true;

11
tools/virsh-pool.c
View File

@@ -814,7 +814,9 @@ cmdPoolDumpXML(vshControl *ctl, const vshCmd *cmd)
}
static int
virshStoragePoolSorter(const void *a, const void *b)
virshStoragePoolSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virStoragePoolPtr *pa = (virStoragePoolPtr *) a;
virStoragePoolPtr *pb = (virStoragePoolPtr *) b;
@@ -1005,9 +1007,10 @@ virshStoragePoolListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->pools && list->npools)
qsort(list->pools, list->npools,
sizeof(*list->pools), virshStoragePoolSorter);
if (list->pools && list->npools) {
g_qsort_with_data(list->pools, list->npools,
sizeof(*list->pools), virshStoragePoolSorter, NULL);
}
/* truncate the list if filter simulation deleted entries */
if (deleted)

11
tools/virsh-secret.c
View File

@@ -399,7 +399,9 @@ cmdSecretUndefine(vshControl *ctl, const vshCmd *cmd)
}
static int
virshSecretSorter(const void *a, const void *b)
virshSecretSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virSecretPtr *sa = (virSecretPtr *) a;
virSecretPtr *sb = (virSecretPtr *) b;
@@ -509,9 +511,10 @@ virshSecretListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->secrets && list->nsecrets)
qsort(list->secrets, list->nsecrets,
sizeof(*list->secrets), virshSecretSorter);
if (list->secrets && list->nsecrets) {
g_qsort_with_data(list->secrets, list->nsecrets,
sizeof(*list->secrets), virshSecretSorter, NULL);
}
/* truncate the list for not found secret objects */
if (deleted)

10
tools/virsh-snapshot.c
View File

@@ -982,7 +982,9 @@ virshSnapshotListFree(struct virshSnapshotList *snaplist)
}
static int
virshSnapSorter(const void *a, const void *b)
virshSnapSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
const struct virshSnap *sa = a;
const struct virshSnap *sb = b;
@@ -1232,7 +1234,7 @@ virshSnapshotListCollect(vshControl *ctl, virDomainPtr dom,
* still in list. We mark known descendants by clearing
* snaps[i].parents. Sorry, this is O(n^3) - hope your
* hierarchy isn't huge. XXX Is it worth making O(n^2 log n)
* by using qsort and bsearch? */
* by using g_qsort_with_data and bsearch? */
if (start_index < 0) {
vshError(ctl, _("snapshot %1$s disappeared from list"), fromname);
goto cleanup;
@@ -1312,8 +1314,8 @@ virshSnapshotListCollect(vshControl *ctl, virDomainPtr dom,
}
if (!(orig_flags & VIR_DOMAIN_SNAPSHOT_LIST_TOPOLOGICAL) &&
snaplist->snaps && snaplist->nsnaps) {
qsort(snaplist->snaps, snaplist->nsnaps, sizeof(*snaplist->snaps),
virshSnapSorter);
g_qsort_with_data(snaplist->snaps, snaplist->nsnaps,
sizeof(*snaplist->snaps), virshSnapSorter, NULL);
}
snaplist->nsnaps -= deleted;

10
tools/virsh-volume.c
View File

@@ -1200,7 +1200,9 @@ cmdVolDumpXML(vshControl *ctl, const vshCmd *cmd)
}
static int
virshStorageVolSorter(const void *a, const void *b)
virshStorageVolSorter(const void *a,
const void *b,
void *opaque G_GNUC_UNUSED)
{
virStorageVolPtr *va = (virStorageVolPtr *) a;
virStorageVolPtr *vb = (virStorageVolPtr *) b;
@@ -1299,8 +1301,10 @@ virshStorageVolListCollect(vshControl *ctl,
finished:
/* sort the list */
if (list->vols && list->nvols)
qsort(list->vols, list->nvols, sizeof(*list->vols), virshStorageVolSorter);
if (list->vols && list->nvols) {
g_qsort_with_data(list->vols, list->nvols,
sizeof(*list->vols), virshStorageVolSorter, NULL);
}
if (deleted)
VIR_SHRINK_N(list->vols, list->nvols, deleted);