From 2171a9256862ec139a042832a9ae737b942ca882 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 8 Sep 2014 11:24:01 -0300 Subject: 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 Cc: Borislav Petkov Cc: Corey Ashford Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jean Pihet Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Signed-off-by: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/n/tip-0p00bn83quck3fio3kcs9vca@git.kernel.org --- tools/lib/api/fd/array.c | 28 ++++++++++++++++++++++++---- tools/lib/api/fd/array.h | 16 +++++++++++++++- 2 files changed, 39 insertions(+), 5 deletions(-) (limited to 'tools/lib') 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); -- cgit v1.2.3