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      1 /**
      2  * \file include/global.h
      3  * \brief Application interface library for the ALSA driver
      4  * \author Jaroslav Kysela <perex (at) perex.cz>
      5  * \author Abramo Bagnara <abramo (at) alsa-project.org>
      6  * \author Takashi Iwai <tiwai (at) suse.de>
      7  * \date 1998-2001
      8  *
      9  * Application interface library for the ALSA driver
     10  */
     11 /*
     12  *   This library is free software; you can redistribute it and/or modify
     13  *   it under the terms of the GNU Lesser General Public License as
     14  *   published by the Free Software Foundation; either version 2.1 of
     15  *   the License, or (at your option) any later version.
     16  *
     17  *   This program is distributed in the hope that it will be useful,
     18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
     19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     20  *   GNU Lesser General Public License for more details.
     21  *
     22  *   You should have received a copy of the GNU Lesser General Public
     23  *   License along with this library; if not, write to the Free Software
     24  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
     25  *
     26  */
     27 
     28 #ifndef __ALSA_GLOBAL_H_
     29 #define __ALSA_GLOBAL_H_
     30 
     31 /* for timeval and timespec */
     32 #include <time.h>
     33 
     34 #ifdef __cplusplus
     35 extern "C" {
     36 #endif
     37 
     38 /**
     39  *  \defgroup Global Global defines and functions
     40  *  Global defines and functions.
     41  *  \par
     42  *  The ALSA library implementation uses these macros and functions.
     43  *  Most applications probably do not need them.
     44  *  \{
     45  */
     46 
     47 const char *snd_asoundlib_version(void);
     48 
     49 #ifndef ATTRIBUTE_UNUSED
     50 /** do not print warning (gcc) when function parameter is not used */
     51 #define ATTRIBUTE_UNUSED __attribute__ ((__unused__))
     52 #endif
     53 
     54 #ifdef PIC /* dynamic build */
     55 
     56 /** \hideinitializer \brief Helper macro for #SND_DLSYM_BUILD_VERSION. */
     57 #define __SND_DLSYM_VERSION(name, version) _ ## name ## version
     58 /**
     59  * \hideinitializer
     60  * \brief Appends the build version to the name of a versioned dynamic symbol.
     61  */
     62 #define SND_DLSYM_BUILD_VERSION(name, version) char __SND_DLSYM_VERSION(name, version);
     63 
     64 #else /* static build */
     65 
     66 struct snd_dlsym_link {
     67 	struct snd_dlsym_link *next;
     68 	const char *dlsym_name;
     69 	const void *dlsym_ptr;
     70 };
     71 
     72 extern struct snd_dlsym_link *snd_dlsym_start;
     73 
     74 /** \hideinitializer \brief Helper macro for #SND_DLSYM_BUILD_VERSION. */
     75 #define __SND_DLSYM_VERSION(prefix, name, version) _ ## prefix ## name ## version
     76 /**
     77  * \hideinitializer
     78  * \brief Appends the build version to the name of a versioned dynamic symbol.
     79  */
     80 #define SND_DLSYM_BUILD_VERSION(name, version) \
     81   static struct snd_dlsym_link __SND_DLSYM_VERSION(snd_dlsym_, name, version); \
     82   void __SND_DLSYM_VERSION(snd_dlsym_constructor_, name, version) (void) __attribute__ ((constructor)); \
     83   void __SND_DLSYM_VERSION(snd_dlsym_constructor_, name, version) (void) { \
     84     __SND_DLSYM_VERSION(snd_dlsym_, name, version).next = snd_dlsym_start; \
     85     __SND_DLSYM_VERSION(snd_dlsym_, name, version).dlsym_name = # name; \
     86     __SND_DLSYM_VERSION(snd_dlsym_, name, version).dlsym_ptr = (void *)&name; \
     87     snd_dlsym_start = &__SND_DLSYM_VERSION(snd_dlsym_, name, version); \
     88   }
     89 
     90 #endif
     91 
     92 #ifndef __STRING
     93 /** \brief Return 'x' argument as string */
     94 #define __STRING(x)     #x
     95 #endif
     96 
     97 /** \brief Returns the version of a dynamic symbol as a string. */
     98 #define SND_DLSYM_VERSION(version) __STRING(version)
     99 
    100 void *snd_dlopen(const char *file, int mode);
    101 void *snd_dlsym(void *handle, const char *name, const char *version);
    102 int snd_dlclose(void *handle);
    103 
    104 
    105 /** \brief alloca helper macro. */
    106 #define __snd_alloca(ptr,type) do { *ptr = (type##_t *) alloca(type##_sizeof()); memset(*ptr, 0, type##_sizeof()); } while (0)
    107 
    108 /**
    109  * \brief Internal structure for an async notification client handler.
    110  *
    111  * The ALSA library uses a pointer to this structure as a handle to an async
    112  * notification object. Applications don't access its contents directly.
    113  */
    114 typedef struct _snd_async_handler snd_async_handler_t;
    115 
    116 /**
    117  * \brief Async notification callback.
    118  *
    119  * See the #snd_async_add_handler function for details.
    120  */
    121 typedef void (*snd_async_callback_t)(snd_async_handler_t *handler);
    122 
    123 int snd_async_add_handler(snd_async_handler_t **handler, int fd,
    124 			  snd_async_callback_t callback, void *private_data);
    125 int snd_async_del_handler(snd_async_handler_t *handler);
    126 int snd_async_handler_get_fd(snd_async_handler_t *handler);
    127 int snd_async_handler_get_signo(snd_async_handler_t *handler);
    128 void *snd_async_handler_get_callback_private(snd_async_handler_t *handler);
    129 
    130 struct snd_shm_area *snd_shm_area_create(int shmid, void *ptr);
    131 struct snd_shm_area *snd_shm_area_share(struct snd_shm_area *area);
    132 int snd_shm_area_destroy(struct snd_shm_area *area);
    133 
    134 int snd_user_file(const char *file, char **result);
    135 
    136 #if !defined(_POSIX_C_SOURCE) && !defined(_POSIX_SOURCE)
    137 struct timeval {
    138 	time_t		tv_sec;		/* seconds */
    139 	long		tv_usec;	/* microseconds */
    140 };
    141 
    142 struct timespec {
    143 	time_t		tv_sec;		/* seconds */
    144 	long		tv_nsec;	/* nanoseconds */
    145 };
    146 #endif
    147 
    148 /** Timestamp */
    149 typedef struct timeval snd_timestamp_t;
    150 /** Hi-res timestamp */
    151 typedef struct timespec snd_htimestamp_t;
    152 
    153 /** \} */
    154 
    155 #ifdef __cplusplus
    156 }
    157 #endif
    158 
    159 #endif /* __ALSA_GLOBAL_H */
    160