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authorArnaldo Carvalho de Melo <acme@redhat.com>2014-09-08 11:24:01 -0300
committerArnaldo Carvalho de Melo <acme@redhat.com>2014-09-25 16:46:55 -0300
commit2171a9256862ec139a042832a9ae737b942ca882 (patch)
tree6664a28341e22f1aa0f6486b54621033047d05a9 /tools/lib
parent82396986032915c1572bfb74b224fcc2e4e8ba7c (diff)
downloadlinux-2171a9256862ec139a042832a9ae737b942ca882.tar.bz2
tools lib fd array: Allow associating an integer cookie with each entry
We will use this in perf's evlist class so that it can, at fdarray__filter() time, to unmap the associated ring buffer. We may need to have further info associated with each fdarray entry, in that case we'll make that int array a 'union fdarray_priv' one and put a pointer there so that users can stash whatever they want there. For now, an int is enough tho. v2: Add clarification to the per array entry priv area, as well as make it a union, which makes usage a bit longer, but if/when we make it use more space by allowing per entry pointers existing users source code will not have to be changed, just rebuilt. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jean Pihet <jean.pihet@linaro.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Link: http://lkml.kernel.org/n/tip-0p00bn83quck3fio3kcs9vca@git.kernel.org
Diffstat (limited to 'tools/lib')
-rw-r--r--tools/lib/api/fd/array.c28
-rw-r--r--tools/lib/api/fd/array.h16
2 files changed, 39 insertions, 5 deletions
diff --git a/tools/lib/api/fd/array.c b/tools/lib/api/fd/array.c
index 4889c7d42961..0e636c4339b8 100644
--- a/tools/lib/api/fd/array.c
+++ b/tools/lib/api/fd/array.c
@@ -13,21 +13,31 @@
void fdarray__init(struct fdarray *fda, int nr_autogrow)
{
fda->entries = NULL;
+ fda->priv = NULL;
fda->nr = fda->nr_alloc = 0;
fda->nr_autogrow = nr_autogrow;
}
int fdarray__grow(struct fdarray *fda, int nr)
{
+ void *priv;
int nr_alloc = fda->nr_alloc + nr;
+ size_t psize = sizeof(fda->priv[0]) * nr_alloc;
size_t size = sizeof(struct pollfd) * nr_alloc;
struct pollfd *entries = realloc(fda->entries, size);
if (entries == NULL)
return -ENOMEM;
+ priv = realloc(fda->priv, psize);
+ if (priv == NULL) {
+ free(entries);
+ return -ENOMEM;
+ }
+
fda->nr_alloc = nr_alloc;
fda->entries = entries;
+ fda->priv = priv;
return 0;
}
@@ -50,6 +60,7 @@ struct fdarray *fdarray__new(int nr_alloc, int nr_autogrow)
void fdarray__exit(struct fdarray *fda)
{
free(fda->entries);
+ free(fda->priv);
fdarray__init(fda, 0);
}
@@ -61,6 +72,8 @@ void fdarray__delete(struct fdarray *fda)
int fdarray__add(struct fdarray *fda, int fd, short revents)
{
+ int pos = fda->nr;
+
if (fda->nr == fda->nr_alloc &&
fdarray__grow(fda, fda->nr_autogrow) < 0)
return -ENOMEM;
@@ -68,10 +81,11 @@ int fdarray__add(struct fdarray *fda, int fd, short revents)
fda->entries[fda->nr].fd = fd;
fda->entries[fda->nr].events = revents;
fda->nr++;
- return 0;
+ return pos;
}
-int fdarray__filter(struct fdarray *fda, short revents)
+int fdarray__filter(struct fdarray *fda, short revents,
+ void (*entry_destructor)(struct fdarray *fda, int fd))
{
int fd, nr = 0;
@@ -79,11 +93,17 @@ int fdarray__filter(struct fdarray *fda, short revents)
return 0;
for (fd = 0; fd < fda->nr; ++fd) {
- if (fda->entries[fd].revents & revents)
+ if (fda->entries[fd].revents & revents) {
+ if (entry_destructor)
+ entry_destructor(fda, fd);
+
continue;
+ }
- if (fd != nr)
+ if (fd != nr) {
fda->entries[nr] = fda->entries[fd];
+ fda->priv[nr] = fda->priv[fd];
+ }
++nr;
}
diff --git a/tools/lib/api/fd/array.h b/tools/lib/api/fd/array.h
index de38361ba69e..45db01818f45 100644
--- a/tools/lib/api/fd/array.h
+++ b/tools/lib/api/fd/array.h
@@ -5,11 +5,24 @@
struct pollfd;
+/**
+ * struct fdarray: Array of file descriptors
+ *
+ * @priv: Per array entry priv area, users should access just its contents,
+ * not set it to anything, as it is kept in synch with @entries, being
+ * realloc'ed, * for instance, in fdarray__{grow,filter}.
+ *
+ * I.e. using 'fda->priv[N].idx = * value' where N < fda->nr is ok,
+ * but doing 'fda->priv = malloc(M)' is not allowed.
+ */
struct fdarray {
int nr;
int nr_alloc;
int nr_autogrow;
struct pollfd *entries;
+ union {
+ int idx;
+ } *priv;
};
void fdarray__init(struct fdarray *fda, int nr_autogrow);
@@ -20,7 +33,8 @@ void fdarray__delete(struct fdarray *fda);
int fdarray__add(struct fdarray *fda, int fd, short revents);
int fdarray__poll(struct fdarray *fda, int timeout);
-int fdarray__filter(struct fdarray *fda, short revents);
+int fdarray__filter(struct fdarray *fda, short revents,
+ void (*entry_destructor)(struct fdarray *fda, int fd));
int fdarray__grow(struct fdarray *fda, int extra);
int fdarray__fprintf(struct fdarray *fda, FILE *fp);