tags 589896 + patch thanks On Mon, 23 Aug 2010 at 08:24:44 -0700, Dan Chen wrote: > [Apologies for top-posting due to broken MUA] > > Please see > http://git.alsa-project.org/?p=alsa-lib.git;a=commitdiff_plain;h=91c9c8f1b85e69b4bdc94a777d2767c4906c3f47
Thanks, I've backported this patch and prepared an NMU.
I attach the backported patch; nmudiff to follow.
S
From 5c158e58fe9516cafca8dd25d7c8cd7e33a3d73c Mon Sep 17 00:00:00 2001 From: Jaroslav Kysela <pe...@perex.cz> Date: Thu, 7 Oct 2010 23:13:29 +0100 Subject: [PATCH] general: recoded snd_dlobj_ functions - changed logic to get/put blocks - added mutex locking of the symbol list - added reference counting (do not free used dl handles) Backported: by Simon McVittie <s...@debian.org>, conflicts: src/pcm/pcm.c Origin: backport, http://git.alsa-project.org/?p=alsa-lib.git;a=commitdiff;h=91c9c8f1b85e69b4bdc94a777d2767c4906c3f47 Bug: https://bugtrack.alsa-project.org/alsa-bug/view.php?id=4426 Bug-Debian: http://bugs.debian.org/589896 --- include/local.h | 12 ++-- src/control/control.c | 40 +++---------- src/control/control_local.h | 2 +- src/dlmisc.c | 132 +++++++++++++++++++++++++++++++++--------- src/pcm/pcm.c | 38 +++---------- src/pcm/pcm_local.h | 2 +- src/pcm/pcm_rate.c | 46 +++++++-------- 7 files changed, 151 insertions(+), 121 deletions(-) diff --git a/include/local.h b/include/local.h index fa3f0b7..4dc6562 100644 --- a/include/local.h +++ b/include/local.h @@ -254,10 +254,10 @@ static inline int snd_open_device(const char *filename, int fmode) } /* make local functions really local */ -#define snd_dlobj_cache_lookup \ - snd1_dlobj_cache_lookup -#define snd_dlobj_cache_add \ - snd1_dlobj_cache_add +#define snd_dlobj_cache_get \ + snd1_dlobj_cache_get +#define snd_dlobj_cache_put \ + snd1_dlobj_cache_put #define snd_dlobj_cache_cleanup \ snd1_dlobj_cache_cleanup #define snd_config_set_hop \ @@ -268,8 +268,8 @@ static inline int snd_open_device(const char *filename, int fmode) snd1_config_search_alias_hooks /* dlobj cache */ -void *snd_dlobj_cache_lookup(const char *name); -int snd_dlobj_cache_add(const char *name, void *dlobj, void *open_func); +void *snd_dlobj_cache_get(const char *lib, const char *name, const char *version, int verbose); +int snd_dlobj_cache_put(void *open_func); void snd_dlobj_cache_cleanup(void); /* for recursive checks */ diff --git a/src/control/control.c b/src/control/control.c index b63a28c..19e9389 100644 --- a/src/control/control.c +++ b/src/control/control.c @@ -94,8 +94,7 @@ int snd_ctl_close(snd_ctl_t *ctl) } err = ctl->ops->close(ctl); free(ctl->name); - if (ctl->dl_handle) - snd_dlclose(ctl->dl_handle); + snd_dlobj_cache_put(ctl->open_func); free(ctl); return err; } @@ -768,7 +767,6 @@ static int snd_ctl_open_conf(snd_ctl_t **ctlp, const char *name, #ifndef PIC extern void *snd_control_open_symbols(void); #endif - void *h = NULL; if (snd_config_get_type(ctl_conf) != SND_CONFIG_TYPE_COMPOUND) { if (name) SNDERR("Invalid type for CTL %s definition", name); @@ -854,40 +852,22 @@ static int snd_ctl_open_conf(snd_ctl_t **ctlp, const char *name, #ifndef PIC snd_control_open_symbols(); #endif - open_func = snd_dlobj_cache_lookup(open_name); + open_func = snd_dlobj_cache_get(lib, open_name, + SND_DLSYM_VERSION(SND_CONTROL_DLSYM_VERSION), 1); if (open_func) { - err = 0; - goto _err; - } - h = snd_dlopen(lib, RTLD_NOW); - if (h) - open_func = snd_dlsym(h, open_name, SND_DLSYM_VERSION(SND_CONTROL_DLSYM_VERSION)); - err = 0; - if (!h) { - SNDERR("Cannot open shared library %s", lib); - err = -ENOENT; - } else if (!open_func) { - SNDERR("symbol %s is not defined inside %s", open_name, lib); - snd_dlclose(h); - err = -ENXIO; - } - _err: - if (type_conf) - snd_config_delete(type_conf); - if (err >= 0) { err = open_func(ctlp, name, ctl_root, ctl_conf, mode); if (err >= 0) { - if (h /*&& (mode & SND_CTL_KEEP_ALIVE)*/) { - snd_dlobj_cache_add(open_name, h, open_func); - h = NULL; - } - (*ctlp)->dl_handle = h; + (*ctlp)->open_func = open_func; err = 0; } else { - if (h) - snd_dlclose(h); + snd_dlobj_cache_put(open_func); } + } else { + err = -ENXIO; } + _err: + if (type_conf) + snd_config_delete(type_conf); free(buf); free(buf1); return err; diff --git a/src/control/control_local.h b/src/control/control_local.h index fd9f941..49150d8 100644 --- a/src/control/control_local.h +++ b/src/control/control_local.h @@ -56,7 +56,7 @@ typedef struct _snd_ctl_ops { struct _snd_ctl { - void *dl_handle; + void *open_func; char *name; snd_ctl_type_t type; const snd_ctl_ops_t *ops; diff --git a/src/dlmisc.c b/src/dlmisc.c index a0d62d3..ecbbe8d 100644 --- a/src/dlmisc.c +++ b/src/dlmisc.c @@ -29,6 +29,9 @@ #include "list.h" #include "local.h" +#ifdef HAVE_LIBPTHREAD +#include <pthread.h> +#endif #ifndef DOC_HIDDEN #ifndef PIC @@ -169,69 +172,140 @@ void *snd_dlsym(void *handle, const char *name, const char *version) /* * dlobj cache - * - * FIXME: add reference counter and proper locking */ #ifndef DOC_HIDDEN struct dlobj_cache { + const char *lib; const char *name; - void *obj; + void *dlobj; void *func; + unsigned int refcnt; struct list_head list; }; -static LIST_HEAD(pcm_dlobj_list); +#ifdef HAVE_LIBPTHREAD +static pthread_mutex_t snd_dlobj_mutex = PTHREAD_MUTEX_INITIALIZER; -void *snd_dlobj_cache_lookup(const char *name) +static inline void snd_dlobj_lock(void) { - struct list_head *p; - struct dlobj_cache *c; + pthread_mutex_lock(&snd_dlobj_mutex); +} - list_for_each(p, &pcm_dlobj_list) { - c = list_entry(p, struct dlobj_cache, list); - if (strcmp(c->name, name) == 0) - return c->func; - } - return NULL; +static inline void snd_dlobj_unlock(void) +{ + pthread_mutex_unlock(&snd_dlobj_mutex); } +#else +static inline void snd_dlobj_lock(void) {} +static inline void snd_dlobj_unlock(void) {} +#endif + +static LIST_HEAD(pcm_dlobj_list); -int snd_dlobj_cache_add(const char *name, void *dlobj, void *open_func) +void *snd_dlobj_cache_get(const char *lib, const char *name, + const char *version, int verbose) { struct list_head *p; struct dlobj_cache *c; + void *func, *dlobj = NULL; + int dlobj_close = 0; + snd_dlobj_lock(); list_for_each(p, &pcm_dlobj_list) { c = list_entry(p, struct dlobj_cache, list); - if (strcmp(c->name, name) == 0) - return 0; /* already exists */ + if (c->lib && lib && strcmp(c->lib, lib) != 0) + continue; + if (!c->lib && lib) + continue; + if (!lib && c->lib) + continue; + dlobj = c->dlobj; + if (strcmp(c->name, name) == 0) { + c->refcnt++; + func = c->func; + snd_dlobj_unlock(); + return func; + } + } + if (dlobj == NULL) { + dlobj = snd_dlopen(lib, RTLD_NOW); + if (dlobj == NULL) { + if (verbose) + SNDERR("Cannot open shared library %s", + lib ? lib : "[builtin]"); + snd_dlobj_unlock(); + return NULL; + } + dlobj_close = 1; + } + func = snd_dlsym(dlobj, name, version); + if (func == NULL) { + if (verbose) + SNDERR("symbol %s is not defined inside %s", + name, lib ? lib : "[builtin]"); + goto __err; } c = malloc(sizeof(*c)); if (! c) - return -ENOMEM; + goto __err; + c->refcnt = 1; + c->lib = lib ? strdup(lib) : NULL; c->name = strdup(name); - if (! c->name) { + if ((lib && ! c->lib) || ! c->name) { + free((void *)c->name); + free((void *)c->lib); free(c); - return -ENOMEM; + __err: + if (dlobj_close) + snd_dlclose(dlobj); + snd_dlobj_unlock(); + return NULL; } - c->obj = dlobj; - c->func = open_func; + c->dlobj = dlobj; + c->func = func; list_add_tail(&c->list, &pcm_dlobj_list); - return 0; + snd_dlobj_unlock(); + return func; } -void snd_dlobj_cache_cleanup(void) +int snd_dlobj_cache_put(void *func) { struct list_head *p; struct dlobj_cache *c; + unsigned int refcnt; - while (! list_empty(&pcm_dlobj_list)) { - p = pcm_dlobj_list.next; + snd_dlobj_lock(); + list_for_each(p, &pcm_dlobj_list) { c = list_entry(p, struct dlobj_cache, list); - list_del(p); - snd_dlclose(c->obj); - free((void *)c->name); /* shut up gcc warning */ - free(c); + if (c->func == func) { + refcnt = c->refcnt; + if (c->refcnt > 0) + c->refcnt--; + snd_dlobj_unlock(); + return refcnt == 1 ? 0 : -EINVAL; + } + } + snd_dlobj_unlock(); + return -ENOENT; +} + +void snd_dlobj_cache_cleanup(void) +{ + struct list_head *p, *npos; + struct dlobj_cache *c; + + snd_dlobj_lock(); + list_for_each_safe(p, npos, &pcm_dlobj_list) { + c = list_entry(p, struct dlobj_cache, list); + if (c->refcnt == 0) { + list_del(p); + snd_dlclose(c->dlobj); + free((void *)c->name); /* shut up gcc warning */ + free((void *)c->lib); /* shut up gcc warning */ + free(c); + } } + snd_dlobj_unlock(); } #endif diff --git a/src/pcm/pcm.c b/src/pcm/pcm.c index f910189..f525994 100644 --- a/src/pcm/pcm.c +++ b/src/pcm/pcm.c @@ -2068,7 +2068,6 @@ static int snd_pcm_open_conf(snd_pcm_t **pcmp, const char *name, #ifndef PIC extern void *snd_pcm_open_symbols(void); #endif - void *h = NULL; if (snd_config_get_type(pcm_conf) != SND_CONFIG_TYPE_COMPOUND) { char *val; id = NULL; @@ -2157,40 +2156,20 @@ static int snd_pcm_open_conf(snd_pcm_t **pcmp, const char *name, #ifndef PIC snd_pcm_open_symbols(); /* this call is for static linking only */ #endif - open_func = snd_dlobj_cache_lookup(open_name); + open_func = snd_dlobj_cache_get(lib, open_name, + SND_DLSYM_VERSION(SND_PCM_DLSYM_VERSION), 1); if (open_func) { - err = 0; - goto _err; - } - h = snd_dlopen(lib, RTLD_NOW); - if (h) - open_func = snd_dlsym(h, open_name, SND_DLSYM_VERSION(SND_PCM_DLSYM_VERSION)); - err = 0; - if (!h) { - SNDERR("Cannot open shared library %s", - lib ? lib : "[builtin]"); - err = -ENOENT; - } else if (!open_func) { - SNDERR("symbol %s is not defined inside %s", open_name, - lib ? lib : "[builtin]"); - snd_dlclose(h); - err = -ENXIO; - } - _err: - if (err >= 0) { err = open_func(pcmp, name, pcm_root, pcm_conf, stream, mode); if (err >= 0) { - if (h /*&& (mode & SND_PCM_KEEP_ALIVE)*/) { - snd_dlobj_cache_add(open_name, h, open_func); - h = NULL; - } - (*pcmp)->dl_handle = h; + (*pcmp)->open_func = open_func; err = 0; } else { - if (h) - snd_dlclose(h); + snd_dlobj_cache_put(open_func); } + } else { + err = -ENXIO; } + _err: if (type_conf) snd_config_delete(type_conf); free(buf); @@ -2286,8 +2265,7 @@ int snd_pcm_free(snd_pcm_t *pcm) free(pcm->name); free(pcm->hw.link_dst); free(pcm->appl.link_dst); - if (pcm->dl_handle) - snd_dlclose(pcm->dl_handle); + snd_dlobj_cache_put(pcm->open_func); free(pcm); return 0; } diff --git a/src/pcm/pcm_local.h b/src/pcm/pcm_local.h index 9aa81e1..16fbf1f 100644 --- a/src/pcm/pcm_local.h +++ b/src/pcm/pcm_local.h @@ -174,7 +174,7 @@ typedef struct { } snd_pcm_fast_ops_t; struct _snd_pcm { - void *dl_handle; + void *open_func; char *name; snd_pcm_type_t type; snd_pcm_stream_t stream; diff --git a/src/pcm/pcm_rate.c b/src/pcm/pcm_rate.c index ecf0022..70e30e5 100644 --- a/src/pcm/pcm_rate.c +++ b/src/pcm/pcm_rate.c @@ -61,6 +61,7 @@ struct _snd_pcm_rate { snd_pcm_channel_area_t *pareas; /* areas for splitted period (rate pcm) */ snd_pcm_channel_area_t *sareas; /* areas for splitted period (slave pcm) */ snd_pcm_rate_info_t info; + void *open_func; void *obj; snd_pcm_rate_ops_t ops; unsigned int get_idx; @@ -1204,6 +1205,8 @@ static int snd_pcm_rate_close(snd_pcm_t *pcm) if (rate->ops.close) rate->ops.close(rate->obj); + if (rate->open_func) + snd_dlobj_cache_put(rate->open_func); return snd_pcm_generic_close(pcm); } @@ -1272,33 +1275,23 @@ static const char *const default_rate_plugins[] = { "speexrate", "linear", NULL }; -static int rate_open_func(snd_pcm_rate_t *rate, const char *type) +static int rate_open_func(snd_pcm_rate_t *rate, const char *type, int verbose) { - char open_name[64]; + char open_name[64], lib_name[128], *lib = NULL; snd_pcm_rate_open_func_t open_func; int err; snprintf(open_name, sizeof(open_name), "_snd_pcm_rate_%s_open", type); - open_func = snd_dlobj_cache_lookup(open_name); - if (!open_func) { - void *h; - char lib_name[128], *lib = NULL; - if (!is_builtin_plugin(type)) { - snprintf(lib_name, sizeof(lib_name), + if (!is_builtin_plugin(type)) { + snprintf(lib_name, sizeof(lib_name), "%s/libasound_module_rate_%s.so", ALSA_PLUGIN_DIR, type); - lib = lib_name; - } - h = snd_dlopen(lib, RTLD_NOW); - if (!h) - return -ENOENT; - open_func = snd_dlsym(h, open_name, NULL); - if (!open_func) { - snd_dlclose(h); - return -ENOENT; - } - snd_dlobj_cache_add(open_name, h, open_func); + lib = lib_name; } + open_func = snd_dlobj_cache_get(lib, open_name, NULL, verbose); + if (!open_func) + return -ENOENT; + rate->open_func = open_func; rate->rate_min = SND_PCM_PLUGIN_RATE_MIN; rate->rate_max = SND_PCM_PLUGIN_RATE_MAX; rate->plugin_version = SND_PCM_RATE_PLUGIN_VERSION; @@ -1315,8 +1308,13 @@ static int rate_open_func(snd_pcm_rate_t *rate, const char *type) /* try to open with the old protocol version */ rate->plugin_version = SND_PCM_RATE_PLUGIN_VERSION_OLD; - return open_func(SND_PCM_RATE_PLUGIN_VERSION_OLD, - &rate->obj, &rate->ops); + err = open_func(SND_PCM_RATE_PLUGIN_VERSION_OLD, + &rate->obj, &rate->ops); + if (err) { + snd_dlobj_cache_put(open_func); + rate->open_func = NULL; + } + return err; } #endif @@ -1373,21 +1371,21 @@ int snd_pcm_rate_open(snd_pcm_t **pcmp, const char *name, if (!converter) { const char *const *types; for (types = default_rate_plugins; *types; types++) { - err = rate_open_func(rate, *types); + err = rate_open_func(rate, *types, 0); if (!err) { type = *types; break; } } } else if (!snd_config_get_string(converter, &type)) - err = rate_open_func(rate, type); + err = rate_open_func(rate, type, 1); else if (snd_config_get_type(converter) == SND_CONFIG_TYPE_COMPOUND) { snd_config_iterator_t i, next; snd_config_for_each(i, next, converter) { snd_config_t *n = snd_config_iterator_entry(i); if (snd_config_get_string(n, &type) < 0) break; - err = rate_open_func(rate, type); + err = rate_open_func(rate, type, 0); if (!err) break; } -- 1.7.1
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