From a67c21f093202f142438689d3f7cfbdf4ea82eea Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Sun, 28 Oct 2007 19:13:50 +0000 Subject: merge 'lennart' branch back into trunk. git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@1971 fefdeb5f-60dc-0310-8127-8f9354f1896f --- src/pulsecore/shm.c | 247 +++++++++++++++++++++++++++++++++++++--------------- 1 file changed, 176 insertions(+), 71 deletions(-) (limited to 'src/pulsecore/shm.c') diff --git a/src/pulsecore/shm.c b/src/pulsecore/shm.c index 444d4010..6882e7f8 100644 --- a/src/pulsecore/shm.c +++ b/src/pulsecore/shm.c @@ -1,32 +1,31 @@ /* $Id$ */ /*** - This file is part of PulseAudio. + This file is part of PulseAudio. - Copyright 2006 Lennart Poettering - Copyright 2006 Pierre Ossman for Cendio AB + Copyright 2006 Lennart Poettering + Copyright 2006 Pierre Ossman for Cendio AB - PulseAudio is free software; you can redistribute it and/or modify - it under the terms of the GNU Lesser General Public License as - published by the Free Software Foundation; either version 2.1 of the - License, or (at your option) any later version. + PulseAudio is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License as + published by the Free Software Foundation; either version 2.1 of the + License, or (at your option) any later version. - PulseAudio is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. + PulseAudio is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. - You should have received a copy of the GNU Lesser General Public - License along with PulseAudio; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 - USA. + You should have received a copy of the GNU Lesser General Public + License along with PulseAudio; if not, write to the Free Software + Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 + USA. ***/ #ifdef HAVE_CONFIG_H #include #endif -#include #include #include #include @@ -34,15 +33,22 @@ #include #include #include +#include +#include +#include #ifdef HAVE_SYS_MMAN_H #include #endif +#include + #include #include #include -#include +#include +#include +#include #include "shm.h" @@ -50,10 +56,31 @@ #define MADV_REMOVE 9 #endif -#define MAX_SHM_SIZE (1024*1024*20) +#define MAX_SHM_SIZE (PA_ALIGN(1024*1024*20)) + +#ifdef __linux__ +/* On Linux we know that the shared memory blocks are files in + * /dev/shm. We can use that information to list all blocks and + * cleanup unused ones */ +#define SHM_PATH "/dev/shm/" +#else +#undef SHM_PATH +#endif + +#define SHM_MARKER ((int) 0xbeefcafe) + +/* We now put this SHM marker at the end of each segment. It's optional to not require a reboot when upgrading, though */ +struct shm_marker { + pa_atomic_t marker; /* 0xbeefcafe */ + pa_atomic_t pid; + void *_reserverd1; + void *_reserverd2; + void *_reserverd3; + void *_reserverd4; +}; static char *segment_name(char *fn, size_t l, unsigned id) { - snprintf(fn, l, "/pulse-shm-%u", id); + pa_snprintf(fn, l, "/pulse-shm-%u", id); return fn; } @@ -61,10 +88,17 @@ int pa_shm_create_rw(pa_shm *m, size_t size, int shared, mode_t mode) { char fn[32]; int fd = -1; - assert(m); - assert(size > 0); - assert(size < MAX_SHM_SIZE); - assert(mode >= 0600); + pa_assert(m); + pa_assert(size > 0); + pa_assert(size < MAX_SHM_SIZE); + pa_assert(mode >= 0600); + + /* Each time we create a new SHM area, let's first drop all stale + * ones */ + pa_shm_cleanup(); + + /* Round up to make it aligned */ + size = PA_ALIGN(size); if (!shared) { m->id = 0; @@ -79,7 +113,7 @@ int pa_shm_create_rw(pa_shm *m, size_t size, int shared, mode_t mode) { { int r; - if ((r = posix_memalign(&m->ptr, sysconf(_SC_PAGESIZE), size)) < 0) { + if ((r = posix_memalign(&m->ptr, PA_PAGE_SIZE, size)) < 0) { pa_log("posix_memalign() failed: %s", pa_cstrerror(r)); goto fail; } @@ -92,6 +126,8 @@ int pa_shm_create_rw(pa_shm *m, size_t size, int shared, mode_t mode) { } else { #ifdef HAVE_SHM_OPEN + struct shm_marker *marker; + pa_random(&m->id, sizeof(m->id)); segment_name(fn, sizeof(fn), m->id); @@ -100,7 +136,9 @@ int pa_shm_create_rw(pa_shm *m, size_t size, int shared, mode_t mode) { goto fail; } - if (ftruncate(fd, m->size = size) < 0) { + m->size = size + PA_ALIGN(sizeof(struct shm_marker)); + + if (ftruncate(fd, m->size) < 0) { pa_log("ftruncate() failed: %s", pa_cstrerror(errno)); goto fail; } @@ -110,10 +148,16 @@ int pa_shm_create_rw(pa_shm *m, size_t size, int shared, mode_t mode) { goto fail; } - close(fd); + /* 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 - PA_ALIGN(sizeof(struct shm_marker))); + pa_atomic_store(&marker->pid, (int) getpid()); + pa_atomic_store(&marker->marker, SHM_MARKER); + + pa_assert_se(close(fd) == 0); m->do_unlink = 1; #else - return -1; + return -1; #endif } @@ -126,7 +170,7 @@ fail: #ifdef HAVE_SHM_OPEN if (fd >= 0) { shm_unlink(fn); - close(fd); + pa_close(fd); } #endif @@ -134,76 +178,70 @@ fail: } void pa_shm_free(pa_shm *m) { - assert(m); - assert(m->ptr); - assert(m->size > 0); + pa_assert(m); + pa_assert(m->ptr); + pa_assert(m->size > 0); #ifdef MAP_FAILED - assert(m->ptr != MAP_FAILED); + pa_assert(m->ptr != MAP_FAILED); #endif - if (!m->shared) { + if (!m->shared) { #ifdef MAP_ANONYMOUS - if (munmap(m->ptr, m->size) < 0) - pa_log("munmap() failed: %s", pa_cstrerror(errno)); + 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 { + } else { #ifdef HAVE_SHM_OPEN - if (munmap(m->ptr, m->size) < 0) - pa_log("munmap() failed: %s", pa_cstrerror(errno)); + if (munmap(m->ptr, m->size) < 0) + pa_log("munmap() failed: %s", pa_cstrerror(errno)); - if (m->do_unlink) { - char fn[32]; + if (m->do_unlink) { + char fn[32]; - segment_name(fn, sizeof(fn), m->id); + segment_name(fn, sizeof(fn), m->id); - if (shm_unlink(fn) < 0) - pa_log(" shm_unlink(%s) failed: %s", fn, pa_cstrerror(errno)); - } + 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 */ - assert(0); + /* We shouldn't be here without shm support */ + pa_assert_not_reached(); #endif - } + } memset(m, 0, sizeof(*m)); } void pa_shm_punch(pa_shm *m, size_t offset, size_t size) { void *ptr; + size_t o, ps; - assert(m); - assert(m->ptr); - assert(m->size > 0); - assert(offset+size <= m->size); + pa_assert(m); + pa_assert(m->ptr); + pa_assert(m->size > 0); + pa_assert(offset+size <= m->size); #ifdef MAP_FAILED - assert(m->ptr != MAP_FAILED); + pa_assert(m->ptr != MAP_FAILED); #endif /* You're welcome to implement this as NOOP on systems that don't * support it */ + /* Align this to multiples of the page size */ ptr = (uint8_t*) m->ptr + offset; - -#ifdef __linux__ -{ - /* On Linux ptr must be page aligned */ - long psz = sysconf(_SC_PAGESIZE); - unsigned o; - - o = ((unsigned long) ptr) - ((((unsigned long) ptr)/psz) * psz); + o = (uint8_t*) ptr - (uint8_t*) PA_PAGE_ALIGN_PTR(ptr); if (o > 0) { - ptr = (uint8_t*) ptr + (psz - o); - size -= psz - o; + ps = PA_PAGE_SIZE; + ptr = (uint8_t*) ptr + (ps - o); + size -= ps - o; } -} -#endif #ifdef MADV_REMOVE if (madvise(ptr, size, MADV_REMOVE) >= 0) @@ -216,7 +254,9 @@ void pa_shm_punch(pa_shm *m, size_t offset, size_t size) { #endif #ifdef MADV_DONTNEED - madvise(ptr, size, MADV_DONTNEED); + pa_assert_se(madvise(ptr, size, MADV_DONTNEED) == 0); +#elif defined(POSIX_MADV_DONTNEED) + pa_assert_se(posix_madvise(ptr, size, POSIX_MADV_DONTNEED) == 0); #endif } @@ -227,12 +267,13 @@ int pa_shm_attach_ro(pa_shm *m, unsigned id) { int fd = -1; struct stat st; - assert(m); + pa_assert(m); segment_name(fn, sizeof(fn), m->id = id); if ((fd = shm_open(fn, O_RDONLY, 0)) < 0) { - pa_log("shm_open() failed: %s", pa_cstrerror(errno)); + if (errno != EACCES) + pa_log("shm_open() failed: %s", pa_cstrerror(errno)); goto fail; } @@ -241,7 +282,7 @@ int pa_shm_attach_ro(pa_shm *m, unsigned id) { goto fail; } - if (st.st_size <= 0 || st.st_size > MAX_SHM_SIZE) { + if (st.st_size <= 0 || st.st_size > MAX_SHM_SIZE+PA_ALIGN(sizeof(struct shm_marker)) || PA_ALIGN(st.st_size) != st.st_size) { pa_log("Invalid shared memory segment size"); goto fail; } @@ -256,13 +297,13 @@ int pa_shm_attach_ro(pa_shm *m, unsigned id) { m->do_unlink = 0; m->shared = 1; - close(fd); + pa_assert_se(pa_close(fd) == 0); return 0; fail: if (fd >= 0) - close(fd); + pa_close(fd); return -1; } @@ -270,7 +311,71 @@ fail: #else /* HAVE_SHM_OPEN */ int pa_shm_attach_ro(pa_shm *m, unsigned id) { - return -1; + return -1; } #endif /* HAVE_SHM_OPEN */ + +int pa_shm_cleanup(void) { + +#ifdef SHM_PATH + DIR *d; + struct dirent *de; + + if (!(d = opendir(SHM_PATH))) { + pa_log_warn("Failed to read "SHM_PATH": %s", pa_cstrerror(errno)); + return -1; + } + + while ((de = readdir(d))) { + pa_shm seg; + unsigned id; + pid_t pid; + char fn[128]; + struct shm_marker *m; + + if (strncmp(de->d_name, "pulse-shm-", 10)) + continue; + + if (pa_atou(de->d_name + 10, &id) < 0) + continue; + + if (pa_shm_attach_ro(&seg, id) < 0) + continue; + + if (seg.size < PA_ALIGN(sizeof(struct shm_marker))) { + pa_shm_free(&seg); + continue; + } + + m = (struct shm_marker*) ((uint8_t*) seg.ptr + seg.size - PA_ALIGN(sizeof(struct shm_marker))); + + if (pa_atomic_load(&m->marker) != SHM_MARKER) { + pa_shm_free(&seg); + continue; + } + + if (!(pid = (pid_t) pa_atomic_load(&m->pid))) { + pa_shm_free(&seg); + continue; + } + + if (kill(pid, 0) == 0 || errno != ESRCH) { + pa_shm_free(&seg); + continue; + } + + pa_shm_free(&seg); + + /* Ok, the owner of this shms segment is dead, so, let's remove the segment */ + segment_name(fn, sizeof(fn), id); + + if (shm_unlink(fn) < 0 && errno != EACCES) + pa_log_warn("Failed to remove SHM segment %s: %s\n", fn, pa_cstrerror(errno)); + } + + closedir(d); +#endif + + return 0; +} -- cgit