diff options
author | rizzo <rizzo@f38db490-d61c-443f-a65b-d21fe96a405b> | 2006-12-15 22:08:46 +0000 |
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committer | rizzo <rizzo@f38db490-d61c-443f-a65b-d21fe96a405b> | 2006-12-15 22:08:46 +0000 |
commit | 5343b4f73dd0495d58bb77399d044ff586ef9638 (patch) | |
tree | 2229580e652fea2c03599c4c5bd2a1a3eb38ef00 /include/asterisk/threadstorage.h | |
parent | ec2fcf6ae943b08b1806539ffd758b985b9035a9 (diff) |
move the dynamic string support in a better place i.e. string.h
While doing this, add a bit of documentation, and slightly
extend the functionality as follows:
+ a max_len of -1 means that we take whatever the current size
is, and never try to extend the buffer;
+ add support for alloca()-ted dynamic strings, which is very
useful for all cases where we do an ast_build_string() now.
Next step is to simplify the interface by using shorter names
(e.g. ast_str as a prefix) and removing the _thread variant
of the functions by saving the threadstorage reference into
the struct ast_str. This can be done by overloading the
'type' field.
Finally, I will do my best to remove the convoluted interface
that results from trying to support platforms without va_copy().
git-svn-id: http://svn.digium.com/svn/asterisk/trunk@48509 f38db490-d61c-443f-a65b-d21fe96a405b
Diffstat (limited to 'include/asterisk/threadstorage.h')
-rw-r--r-- | include/asterisk/threadstorage.h | 335 |
1 files changed, 4 insertions, 331 deletions
diff --git a/include/asterisk/threadstorage.h b/include/asterisk/threadstorage.h index d087f81d0..469f46389 100644 --- a/include/asterisk/threadstorage.h +++ b/include/asterisk/threadstorage.h @@ -56,14 +56,10 @@ * \brief data for a thread locally stored variable */ struct ast_threadstorage { - /*! Ensure that the key is only initialized by one thread */ - pthread_once_t once; - /*! The key used to retrieve this thread's data */ - pthread_key_t key; - /*! The function that initializes the key */ - void (*key_init)(void); - /*! Custom initialization function specific to the object */ - int (*custom_init)(void *); + pthread_once_t once; /*!< Ensure that the key is only initialized by one thread */ + pthread_key_t key; /*!< The key used to retrieve this thread's data */ + void (*key_init)(void); /*!< The function that initializes the key */ + int (*custom_init)(void *); /*!< Custom initialization function specific to the object */ }; /*! @@ -161,327 +157,4 @@ void *ast_threadstorage_get(struct ast_threadstorage *ts, size_t init_size), void __ast_threadstorage_cleanup(void *); -/*! - * A dynamic length string. This is just a C string prefixed by a length - * field. len reflects the actual space allocated, while the string is - * NUL-terminated as a regular C string. - * One should never declare a variable with this type, but only a pointer - * to it, and use ast_dynamic_str_create() to initialize it. - */ -struct ast_dynamic_str { - size_t len; /*!< The current maximum length of the string */ - char str[0]; /*!< The string buffer */ -}; - -/*! - * \brief Create a dynamic length string - * - * \arg init_len This is the initial length of the string buffer - * - * \return This function returns a pointer to the dynamic string length. The - * result will be NULL in the case of a memory allocation error. - * - * \note The result of this function is dynamically allocated memory, and must - * be free()'d after it is no longer needed. - */ -AST_INLINE_API( -struct ast_dynamic_str * attribute_malloc ast_dynamic_str_create(size_t init_len), -{ - struct ast_dynamic_str *buf; - - if (!(buf = ast_calloc(1, sizeof(*buf) + init_len))) - return NULL; - - buf->len = init_len; - - return buf; -} -) - -/*! - * \brief Retrieve a thread locally stored dynamic string - * - * \arg ts This is a pointer to the thread storage structure declared by using - * the AST_THREADSTORAGE macro. If declared with - * AST_THREADSTORAGE(my_buf, my_buf_init), then this argument would be - * (&my_buf). - * \arg init_len This is the initial length of the thread's dynamic string. The - * current length may be bigger if previous operations in this thread have - * caused it to increase. - * - * \return This function will return the thread locally stored dynamic string - * associated with the thread storage management variable passed as the - * first argument. - * The result will be NULL in the case of a memory allocation error. - * - * Example usage: - * \code - * AST_THREADSTORAGE(my_str, my_str_init); - * #define MY_STR_INIT_SIZE 128 - * ... - * void my_func(const char *fmt, ...) - * { - * struct ast_dynamic_str *buf; - * - * if (!(buf = ast_dynamic_str_thread_get(&my_str, MY_STR_INIT_SIZE))) - * return; - * ... - * } - * \endcode - */ -AST_INLINE_API( -struct ast_dynamic_str *ast_dynamic_str_thread_get(struct ast_threadstorage *ts, - size_t init_len), -{ - struct ast_dynamic_str *buf; - - if (!(buf = ast_threadstorage_get(ts, sizeof(*buf) + init_len))) - return NULL; - - if (!buf->len) - buf->len = init_len; - - return buf; -} -) - -/*! - * \brief Error codes from ast_dynamic_str_thread_build_va() - */ -enum { - /*! An error has occured and the contents of the dynamic string - * are undefined */ - AST_DYNSTR_BUILD_FAILED = -1, - /*! The buffer size for the dynamic string had to be increased, and - * ast_dynamic_str_thread_build_va() needs to be called again after - * a va_end() and va_start(). - */ - AST_DYNSTR_BUILD_RETRY = -2 -}; - -/*! - * \brief Set a thread locally stored dynamic string from a va_list - * - * \arg buf This is the address of a pointer to an ast_dynamic_str which should - * have been retrieved using ast_dynamic_str_thread_get. It will need to - * be updated in the case that the buffer has to be reallocated to - * accommodate a longer string than what it currently has space for. - * \arg max_len This is the maximum length to allow the string buffer to grow - * to. If this is set to 0, then there is no maximum length. - * \arg ts This is a pointer to the thread storage structure declared by using - * the AST_THREADSTORAGE macro. If declared with - * AST_THREADSTORAGE(my_buf, my_buf_init), then this argument would be - * (&my_buf). - * \arg fmt This is the format string (printf style) - * \arg ap This is the va_list - * - * \return The return value of this function is the same as that of the printf - * family of functions. - * - * Example usage: - * \code - * AST_THREADSTORAGE(my_str, my_str_init); - * #define MY_STR_INIT_SIZE 128 - * ... - * void my_func(const char *fmt, ...) - * { - * struct ast_dynamic_str *buf; - * va_list ap; - * - * if (!(buf = ast_dynamic_str_thread_get(&my_str, MY_STR_INIT_SIZE))) - * return; - * ... - * va_start(fmt, ap); - * ast_dynamic_str_thread_set_va(&buf, 0, &my_str, fmt, ap); - * va_end(ap); - * - * printf("This is the string we just built: %s\n", buf->str); - * ... - * } - * \endcode - */ -#define ast_dynamic_str_thread_set_va(buf, max_len, ts, fmt, ap) \ - ({ \ - int __res; \ - while ((__res = ast_dynamic_str_thread_build_va(buf, max_len, \ - ts, 0, fmt, ap)) == AST_DYNSTR_BUILD_RETRY) { \ - va_end(ap); \ - va_start(ap, fmt); \ - } \ - (__res); \ - }) - -/*! - * \brief Append to a thread local dynamic string using a va_list - * - * The arguments, return values, and usage of this are the same as those for - * ast_dynamic_str_thread_set_va(). However, instead of setting a new value - * for the string, this will append to the current value. - */ -#define ast_dynamic_str_thread_append_va(buf, max_len, ts, fmt, ap) \ - ({ \ - int __res; \ - while ((__res = ast_dynamic_str_thread_build_va(buf, max_len, \ - ts, 1, fmt, ap)) == AST_DYNSTR_BUILD_RETRY) { \ - va_end(ap); \ - va_start(ap, fmt); \ - } \ - (__res); \ - }) - -/*! - * \brief Core functionality of ast_dynamic_str_thread_(set|append)_va - * - * The arguments to this function are the same as those described for - * ast_dynamic_str_thread_set_va except for an addition argument, append. - * If append is non-zero, this will append to the current string instead of - * writing over it. - * - * In the case that this function is called and the buffer was not large enough - * to hold the result, the partial write will be truncated, and the result - * AST_DYNSTR_BUILD_RETRY will be returned to indicate that the buffer size - * was increased, and the function should be called a second time. - * - * A return of AST_DYNSTR_BUILD_FAILED indicates a memory allocation error. - * - * A return value greater than or equal to zero indicates the number of - * characters that have been written, not including the terminating '\0'. - * In the append case, this only includes the number of characters appended. - * - * \note This function should never need to be called directly. It should - * through calling one of the other functions or macros defined in this - * file. - */ -int ast_dynamic_str_thread_build_va(struct ast_dynamic_str **buf, size_t max_len, - struct ast_threadstorage *ts, int append, const char *fmt, va_list ap); - -/*! - * \brief Set a thread locally stored dynamic string using variable arguments - * - * \arg buf This is the address of a pointer to an ast_dynamic_str which should - * have been retrieved using ast_dynamic_str_thread_get. It will need to - * be updated in the case that the buffer has to be reallocated to - * accomodate a longer string than what it currently has space for. - * \arg max_len This is the maximum length to allow the string buffer to grow - * to. If this is set to 0, then there is no maximum length. - * \arg ts This is a pointer to the thread storage structure declared by using - * the AST_THREADSTORAGE macro. If declared with - * AST_THREADSTORAGE(my_buf, my_buf_init), then this argument would be - * (&my_buf). - * \arg fmt This is the format string (printf style) - * - * \return The return value of this function is the same as that of the printf - * family of functions. - * - * Example usage: - * \code - * AST_THREADSTORAGE(my_str, my_str_init); - * #define MY_STR_INIT_SIZE 128 - * ... - * void my_func(int arg1, int arg2) - * { - * struct ast_dynamic_str *buf; - * va_list ap; - * - * if (!(buf = ast_dynamic_str_thread_get(&my_str, MY_STR_INIT_SIZE))) - * return; - * ... - * ast_dynamic_str_thread_set(&buf, 0, &my_str, "arg1: %d arg2: %d\n", - * arg1, arg2); - * - * printf("This is the string we just built: %s\n", buf->str); - * ... - * } - * \endcode - */ -AST_INLINE_API( -int __attribute__ ((format (printf, 4, 5))) ast_dynamic_str_thread_set( - struct ast_dynamic_str **buf, size_t max_len, - struct ast_threadstorage *ts, const char *fmt, ...), -{ - int res; - va_list ap; - - va_start(ap, fmt); - res = ast_dynamic_str_thread_set_va(buf, max_len, ts, fmt, ap); - va_end(ap); - - return res; -} -) - -/*! - * \brief Append to a thread local dynamic string - * - * The arguments, return values, and usage of this function are the same as - * ast_dynamic_str_thread_set(). However, instead of setting a new value for - * the string, this function appends to the current value. - */ -AST_INLINE_API( -int __attribute__ ((format (printf, 4, 5))) ast_dynamic_str_thread_append( - struct ast_dynamic_str **buf, size_t max_len, - struct ast_threadstorage *ts, const char *fmt, ...), -{ - int res; - va_list ap; - - va_start(ap, fmt); - res = ast_dynamic_str_thread_append_va(buf, max_len, ts, fmt, ap); - va_end(ap); - - return res; -} -) - -/*! - * \brief Set a dynamic string - * - * \arg buf This is the address of a pointer to an ast_dynamic_str. It will - * need to be updated in the case that the buffer has to be reallocated to - * accommodate a longer string than what it currently has space for. - * \arg max_len This is the maximum length to allow the string buffer to grow - * to. If this is set to 0, then there is no maximum length. - * - * \return The return value of this function is the same as that of the printf - * family of functions. - */ -AST_INLINE_API( -int __attribute__ ((format (printf, 3, 4))) ast_dynamic_str_set( - struct ast_dynamic_str **buf, size_t max_len, - const char *fmt, ...), -{ - int res; - va_list ap; - - va_start(ap, fmt); - res = ast_dynamic_str_thread_set_va(buf, max_len, NULL, fmt, ap); - va_end(ap); - - return res; -} -) - -/*! - * \brief Append to a dynamic string - * - * The arguments, return values, and usage of this function are the same as - * ast_dynamic_str_set(). However, this function appends to the string instead - * of setting a new value. - */ -AST_INLINE_API( -int __attribute__ ((format (printf, 3, 4))) ast_dynamic_str_append( - struct ast_dynamic_str **buf, size_t max_len, - const char *fmt, ...), -{ - int res; - va_list ap; - - va_start(ap, fmt); - res = ast_dynamic_str_thread_append_va(buf, max_len, NULL, fmt, ap); - va_end(ap); - - return res; -} -) - #endif /* ASTERISK_THREADSTORAGE_H */ |