[pulseaudio-discuss] [PATCH v3 05/11] SHM: Refactor private allocations
Ahmed S. Darwish
darwish.07 at gmail.com
Sat Mar 12 23:01:38 UTC 2016
pa_shm_create_rw() is responsible for creating two types of memory:
POSIX shared memory and regular malloc()-ed ones.
A third memory type, memfds, will be added later. Thus to add this
extra shared memory type in a sane manner, refactor private memory
allocations into their own static methods.
Signed-off-by: Ahmed S. Darwish <darwish.07 at gmail.com>
---
src/pulsecore/shm.c | 160 ++++++++++++++++++++++++++++------------------------
1 file changed, 87 insertions(+), 73 deletions(-)
diff --git a/src/pulsecore/shm.c b/src/pulsecore/shm.c
index 758dece..c3306b7 100644
--- a/src/pulsecore/shm.c
+++ b/src/pulsecore/shm.c
@@ -101,10 +101,40 @@ static char *segment_name(char *fn, size_t l, unsigned id) {
}
#endif
+static int privatemem_create(pa_shm *m, size_t size) {
+ pa_assert(m);
+ pa_assert(size > 0);
+
+ m->id = 0;
+ m->size = size;
+ m->do_unlink = false;
+
+#ifdef MAP_ANONYMOUS
+ if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, (off_t) 0)) == MAP_FAILED) {
+ pa_log("mmap() failed: %s", pa_cstrerror(errno));
+ return -1;
+ }
+#elif defined(HAVE_POSIX_MEMALIGN)
+ {
+ int r;
+
+ if ((r = posix_memalign(&m->ptr, PA_PAGE_SIZE, size)) < 0) {
+ pa_log("posix_memalign() failed: %s", pa_cstrerror(r));
+ return r;
+ }
+ }
+#else
+ m->ptr = pa_xmalloc(m->size);
+#endif
+
+ return 0;
+}
+
int pa_shm_create_rw(pa_shm *m, pa_mem_type_t type, size_t size, mode_t mode) {
#ifdef HAVE_SHM_OPEN
char fn[32];
int fd = -1;
+ struct shm_marker *marker;
#endif
pa_assert(m);
@@ -120,72 +150,47 @@ int pa_shm_create_rw(pa_shm *m, pa_mem_type_t type, size_t size, mode_t mode) {
/* Round up to make it page aligned */
size = PA_PAGE_ALIGN(size);
- if (!pa_mem_type_is_shared(type)) {
- m->id = 0;
- m->size = size;
-
-#ifdef MAP_ANONYMOUS
- if ((m->ptr = mmap(NULL, m->size, PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE, -1, (off_t) 0)) == MAP_FAILED) {
- pa_log("mmap() failed: %s", pa_cstrerror(errno));
- goto fail;
- }
-#elif defined(HAVE_POSIX_MEMALIGN)
- {
- int r;
-
- if ((r = posix_memalign(&m->ptr, PA_PAGE_SIZE, size)) < 0) {
- pa_log("posix_memalign() failed: %s", pa_cstrerror(r));
- goto fail;
- }
- }
-#else
- m->ptr = pa_xmalloc(m->size);
-#endif
+ m->type = type;
- m->do_unlink = false;
+ if (type == PA_MEM_TYPE_PRIVATE)
+ return privatemem_create(m, size);
- } else {
#ifdef HAVE_SHM_OPEN
- struct shm_marker *marker;
-
- pa_random(&m->id, sizeof(m->id));
- segment_name(fn, sizeof(fn), m->id);
+ pa_random(&m->id, sizeof(m->id));
+ segment_name(fn, sizeof(fn), m->id);
- if ((fd = shm_open(fn, O_RDWR|O_CREAT|O_EXCL, mode)) < 0) {
- pa_log("shm_open() failed: %s", pa_cstrerror(errno));
- goto fail;
- }
+ if ((fd = shm_open(fn, O_RDWR|O_CREAT|O_EXCL, mode)) < 0) {
+ pa_log("shm_open() failed: %s", pa_cstrerror(errno));
+ goto fail;
+ }
- m->size = size + SHM_MARKER_SIZE;
+ m->size = size + SHM_MARKER_SIZE;
- if (ftruncate(fd, (off_t) m->size) < 0) {
- pa_log("ftruncate() failed: %s", pa_cstrerror(errno));
- goto fail;
- }
+ if (ftruncate(fd, (off_t) m->size) < 0) {
+ pa_log("ftruncate() failed: %s", pa_cstrerror(errno));
+ goto fail;
+ }
#ifndef MAP_NORESERVE
#define MAP_NORESERVE 0
#endif
- if ((m->ptr = mmap(NULL, PA_PAGE_ALIGN(m->size), PROT_READ|PROT_WRITE, MAP_SHARED|MAP_NORESERVE, fd, (off_t) 0)) == MAP_FAILED) {
- pa_log("mmap() failed: %s", pa_cstrerror(errno));
- goto fail;
- }
+ if ((m->ptr = mmap(NULL, PA_PAGE_ALIGN(m->size), PROT_READ|PROT_WRITE, MAP_SHARED|MAP_NORESERVE, fd, (off_t) 0)) == MAP_FAILED) {
+ pa_log("mmap() failed: %s", pa_cstrerror(errno));
+ goto fail;
+ }
- /* We store our PID at the end of the shm block, so that we
- * can check for dead shm segments later */
- marker = (struct shm_marker*) ((uint8_t*) m->ptr + m->size - SHM_MARKER_SIZE);
- pa_atomic_store(&marker->pid, (int) getpid());
- pa_atomic_store(&marker->marker, SHM_MARKER);
+ /* We store our PID at the end of the shm block, so that we
+ * can check for dead shm segments later */
+ marker = (struct shm_marker*) ((uint8_t*) m->ptr + m->size - SHM_MARKER_SIZE);
+ pa_atomic_store(&marker->pid, (int) getpid());
+ pa_atomic_store(&marker->marker, SHM_MARKER);
- pa_assert_se(pa_close(fd) == 0);
- m->do_unlink = true;
+ pa_assert_se(pa_close(fd) == 0);
+ m->do_unlink = true;
#else
- goto fail;
+ goto fail;
#endif
- }
-
- m->type = type;
return 0;
@@ -201,6 +206,21 @@ fail:
return -1;
}
+static void privatemem_free(pa_shm *m) {
+ pa_assert(m);
+ pa_assert(m->ptr);
+ pa_assert(m->size > 0);
+
+#ifdef MAP_ANONYMOUS
+ if (munmap(m->ptr, m->size) < 0)
+ pa_log("munmap() failed: %s", pa_cstrerror(errno));
+#elif defined(HAVE_POSIX_MEMALIGN)
+ free(m->ptr);
+#else
+ pa_xfree(m->ptr);
+#endif
+}
+
void pa_shm_free(pa_shm *m) {
pa_assert(m);
pa_assert(m->ptr);
@@ -210,34 +230,28 @@ void pa_shm_free(pa_shm *m) {
pa_assert(m->ptr != MAP_FAILED);
#endif
- if (!pa_mem_type_is_shared(m->type)) {
-#ifdef MAP_ANONYMOUS
- if (munmap(m->ptr, m->size) < 0)
- pa_log("munmap() failed: %s", pa_cstrerror(errno));
-#elif defined(HAVE_POSIX_MEMALIGN)
- free(m->ptr);
-#else
- pa_xfree(m->ptr);
-#endif
- } else {
-#ifdef HAVE_SHM_OPEN
- if (munmap(m->ptr, PA_PAGE_ALIGN(m->size)) < 0)
- pa_log("munmap() failed: %s", pa_cstrerror(errno));
+ if (m->type == PA_MEM_TYPE_PRIVATE) {
+ privatemem_free(m);
+ goto finish;
+ }
- if (m->do_unlink) {
- char fn[32];
+#ifdef HAVE_SHM_OPEN
+ if (munmap(m->ptr, PA_PAGE_ALIGN(m->size)) < 0)
+ pa_log("munmap() failed: %s", pa_cstrerror(errno));
- segment_name(fn, sizeof(fn), m->id);
+ if (m->do_unlink) {
+ char fn[32];
- if (shm_unlink(fn) < 0)
- pa_log(" shm_unlink(%s) failed: %s", fn, pa_cstrerror(errno));
- }
+ segment_name(fn, sizeof(fn), m->id);
+ if (shm_unlink(fn) < 0)
+ pa_log(" shm_unlink(%s) failed: %s", fn, pa_cstrerror(errno));
+ }
#else
- /* We shouldn't be here without shm support */
- pa_assert_not_reached();
+ /* We shouldn't be here without shm support */
+ pa_assert_not_reached();
#endif
- }
+finish:
pa_zero(*m);
}
--
2.7.2
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