/*
* UCW Library -- Configuration-Dependent Definitions
*
- * (c) 1997--2007 Martin Mares <mj@ucw.cz>
+ * (c) 1997--2009 Martin Mares <mj@ucw.cz>
* (c) 2006 Robert Spalek <robert@ucw.cz>
*
* This software may be freely distributed and used according to the terms
#include <stddef.h>
#include <stdint.h>
-typedef uint8_t byte; /* exactly 8 bits, unsigned */
-typedef uint8_t u8; /* exactly 8 bits, unsigned */
-typedef int8_t s8; /* exactly 8 bits, signed */
-typedef uint16_t u16; /* exactly 16 bits, unsigned */
-typedef int16_t s16; /* exactly 16 bits, signed */
-typedef uint32_t u32; /* exactly 32 bits, unsigned */
-typedef int32_t s32; /* exactly 32 bits, signed */
-typedef uint64_t u64; /* exactly 64 bits, unsigned */
-typedef int64_t s64; /* exactly 64 bits, signed */
-
-typedef unsigned int uns; /* at least 32 bits */
-typedef u32 ucw_time_t; /* seconds since UNIX epoch */
-typedef s64 timestamp_t; /* milliseconds since UNIX epoch */
-
-#ifdef CONFIG_LARGE_FILES /* File positions */
-typedef s64 ucw_off_t;
+typedef uint8_t byte; /** Exactly 8 bits, unsigned **/
+typedef uint8_t u8; /** Exactly 8 bits, unsigned **/
+typedef int8_t s8; /** Exactly 8 bits, signed **/
+typedef uint16_t u16; /** Exactly 16 bits, unsigned **/
+typedef int16_t s16; /** Exactly 16 bits, signed **/
+typedef uint32_t u32; /** Exactly 32 bits, unsigned **/
+typedef int32_t s32; /** Exactly 32 bits, signed **/
+typedef uint64_t u64; /** Exactly 64 bits, unsigned **/
+typedef int64_t s64; /** Exactly 64 bits, signed **/
+
+typedef unsigned int uns; /** A better pronounceable alias for `unsigned int` **/
+typedef u32 ucw_time_t; /** Seconds since UNIX epoch **/
+typedef s64 timestamp_t; /** Milliseconds since UNIX epoch **/
+
+#ifdef CONFIG_LARGE_FILES
+typedef s64 ucw_off_t; /** File position (either 32- or 64-bit, depending on `CONFIG_LARGE_FILES`). **/
#else
typedef s32 ucw_off_t;
#endif
/*
* The UCW Library -- Miscellaneous Functions
*
- * (c) 1997--2008 Martin Mares <mj@ucw.cz>
+ * (c) 1997--2009 Martin Mares <mj@ucw.cz>
* (c) 2005 Tomas Valla <tom@ucw.cz>
* (c) 2006 Robert Spalek <robert@ucw.cz>
* (c) 2007 Pavel Charvat <pchar@ucw.cz>
#include "ucw/config.h"
#include <stdarg.h>
-/* Macros for handling structurues, offsets and alignment */
+/*** === Macros for handling structures, offsets and alignment ***/
-#define CHECK_PTR_TYPE(x, type) ((x)-(type)(x) + (type)(x))
-#define PTR_TO(s, i) &((s*)0)->i
-#define OFFSETOF(s, i) ((unsigned int) (uintptr_t) PTR_TO(s, i))
-#define SKIP_BACK(s, i, p) ((s *)((char *)p - OFFSETOF(s, i)))
+#define CHECK_PTR_TYPE(x, type) ((x)-(type)(x) + (type)(x)) /** Check that a pointer @x is of type @type. Fail compilation if not. **/
+#define PTR_TO(s, i) &((s*)0)->i /** Return OFFSETOF() in form of a pointer. **/
+#define OFFSETOF(s, i) ((unsigned int) (uintptr_t) PTR_TO(s, i)) /** Offset of item @i from the start of structure @s **/
+#define SKIP_BACK(s, i, p) ((s *)((char *)p - OFFSETOF(s, i))) /** Given a pointer @p to item @i of structure @s, return a pointer to the start of the struct. **/
+
+/**
+ * Align an integer @s to the nearest higher multiple of @a (which should be a power of two)
+ **/
#define ALIGN_TO(s, a) (((s)+a-1)&~(a-1))
+
+/**
+ * Align a pointer @p to the nearest higher multiple of @s.
+ **/
#define ALIGN_PTR(p, s) ((uintptr_t)(p) % (s) ? (typeof(p))((uintptr_t)(p) + (s) - (uintptr_t)(p) % (s)) : (p))
+
#define UNALIGNED_PART(ptr, type) (((uintptr_t) (ptr)) % sizeof(type))
-/* Some other macros */
+/*** === Other utility macros ***/
-#define MIN(a,b) (((a)<(b))?(a):(b))
-#define MAX(a,b) (((a)>(b))?(a):(b))
-#define CLAMP(x,min,max) ({ int _t=x; (_t < min) ? min : (_t > max) ? max : _t; })
-#define ABS(x) ((x) < 0 ? -(x) : (x))
-#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a)))
-#define STRINGIFY(x) #x
-#define STRINGIFY_EXPANDED(x) STRINGIFY(x)
-#define GLUE(x,y) x##y
-#define GLUE_(x,y) x##_##y
+#define MIN(a,b) (((a)<(b))?(a):(b)) /** Minimum of two numbers **/
+#define MAX(a,b) (((a)>(b))?(a):(b)) /** Maximum of two numbers **/
+#define CLAMP(x,min,max) ({ int _t=x; (_t < min) ? min : (_t > max) ? max : _t; }) /** Clip a number @x to interval [@min,@max] **/
+#define ABS(x) ((x) < 0 ? -(x) : (x)) /** Absolute value **/
+#define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a))) /** The number of elements of an array **/
+#define STRINGIFY(x) #x /** Convert macro parameter to a string **/
+#define STRINGIFY_EXPANDED(x) STRINGIFY(x) /** Convert an expanded macro parameter to a string **/
+#define GLUE(x,y) x##y /** Glue two tokens together **/
+#define GLUE_(x,y) x##_##y /** Glue two tokens together, separating them by an underscore **/
-#define COMPARE(x,y) do { if ((x)<(y)) return -1; if ((x)>(y)) return 1; } while(0)
-#define REV_COMPARE(x,y) COMPARE(y,x)
+#define COMPARE(x,y) do { if ((x)<(y)) return -1; if ((x)>(y)) return 1; } while(0) /** Numeric comparison function for qsort() **/
+#define REV_COMPARE(x,y) COMPARE(y,x) /** Reverse numeric comparison **/
#define COMPARE_LT(x,y) do { if ((x)<(y)) return 1; if ((x)>(y)) return 0; } while(0)
#define COMPARE_GT(x,y) COMPARE_LT(y,x)
-#define ROL(x, bits) (((x) << (bits)) | ((uns)(x) >> (sizeof(uns)*8 - (bits)))) /* Bitwise rotation of an uns to the left */
-#define ROR(x, bits) (((uns)(x) >> (bits)) | ((x) << (sizeof(uns)*8 - (bits))))
+#define ROL(x, bits) (((x) << (bits)) | ((uns)(x) >> (sizeof(uns)*8 - (bits)))) /** Bitwise rotation of an unsigned int to the left **/
+#define ROR(x, bits) (((uns)(x) >> (bits)) | ((x) << (sizeof(uns)*8 - (bits)))) /** Bitwise rotation of an unsigned int to the right **/
-/* GCC Extensions */
+/*** === Shortcuts for GCC Extensions ***/
#ifdef __GNUC__
#undef inline
-#define NONRET __attribute__((noreturn))
-#define UNUSED __attribute__((unused))
-#define CONSTRUCTOR __attribute__((constructor))
-#define PACKED __attribute__((packed))
-#define CONST __attribute__((const))
-#define PURE __attribute__((pure))
-#define FORMAT_CHECK(x,y,z) __attribute__((format(x,y,z)))
-#define likely(x) __builtin_expect((x),1)
-#define unlikely(x) __builtin_expect((x),0)
+#define NONRET __attribute__((noreturn)) /** Function does not return **/
+#define UNUSED __attribute__((unused)) /** Variable/parameter is knowingly unused **/
+#define CONSTRUCTOR __attribute__((constructor)) /** Call function upon start of program **/
+#define PACKED __attribute__((packed)) /** Structure should be packed **/
+#define CONST __attribute__((const)) /** Function depends only on arguments **/
+#define PURE __attribute__((pure)) /** Function depends only on arguments and global vars **/
+#define FORMAT_CHECK(x,y,z) __attribute__((format(x,y,z))) /** Checking of printf-like format strings **/
+#define likely(x) __builtin_expect((x),1) /** Use `if (likely(@x))` if @x is almost always true **/
+#define unlikely(x) __builtin_expect((x),0) /** Use `if (unlikely(@x))` to hint that @x is almost always false **/
#if __GNUC__ >= 4 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3
-#define ALWAYS_INLINE inline __attribute__((always_inline))
-#define NO_INLINE __attribute__((noinline))
+#define ALWAYS_INLINE inline __attribute__((always_inline)) /** Forcibly inline **/
+#define NO_INLINE __attribute__((noinline)) /** Forcibly uninline **/
#else
#define ALWAYS_INLINE inline
#endif
#if __GNUC__ >= 4
-#define LIKE_MALLOC __attribute__((malloc))
-#define SENTINEL_CHECK __attribute__((sentinel))
+#define LIKE_MALLOC __attribute__((malloc)) /** Function returns a "new" pointer **/
+#define SENTINEL_CHECK __attribute__((sentinel)) /** The last argument must be NULL **/
#else
#define LIKE_MALLOC
#define SENTINEL_CHECK
#define DBG(x,y...) do { } while(0)
#endif
-/* Memory allocation */
-
-#define xmalloc ucw_xmalloc
-#define xrealloc ucw_xrealloc
-#define xfree ucw_xfree
+/*** === Memory allocation ***/
/*
* Unfortunately, several libraries we might want to link to define
* their own xmalloc and we don't want to interfere with them, hence
* the renaming.
*/
-void *xmalloc(uns) LIKE_MALLOC;
-void *xrealloc(void *, uns);
-void xfree(void *);
+#define xmalloc ucw_xmalloc
+#define xrealloc ucw_xrealloc
+#define xfree ucw_xfree
+
+void *xmalloc(uns) LIKE_MALLOC; /** Allocate memory and die() if there is none. **/
+void *xrealloc(void *, uns); /** Reallocate memory and die() if there is none. **/
+void xfree(void *); /** Free memory allocated by xmalloc() or xrealloc(). **/
-void *xmalloc_zero(uns) LIKE_MALLOC;
-char *xstrdup(const char *) LIKE_MALLOC;
+void *xmalloc_zero(uns) LIKE_MALLOC; /** Allocate memory and fill it by zeroes. **/
+char *xstrdup(const char *) LIKE_MALLOC; /** Make a xmalloc()'ed copy of a string. **/
-/* timer.c */
+/*** === Trivial timers (timer.c) ***/
-timestamp_t get_timestamp(void);
+timestamp_t get_timestamp(void); /** Get current time as a millisecond timestamp. **/
-void init_timer(timestamp_t *timer);
-uns get_timer(timestamp_t *timer);
-uns switch_timer(timestamp_t *oldt, timestamp_t *newt);
+void init_timer(timestamp_t *timer); /** Initialize a timer. **/
+uns get_timer(timestamp_t *timer); /** Get the number of milliseconds since last init/get of a timer. **/
+uns switch_timer(timestamp_t *oldt, timestamp_t *newt); /** Stop ticking of one timer and resume another. **/
-/* random.c */
+/*** === Random numbers (random.c) ***/
-uns random_u32(void);
-uns random_max(uns max);
-u64 random_u64(void);
-u64 random_max_u64(u64 max);
+uns random_u32(void); /** Return a pseudorandom 32-bit number. **/
+uns random_max(uns max); /** Return a pseudorandom 32-bit number in range [0,@max). **/
+u64 random_u64(void); /** Return a pseudorandom 64-bit number. **/
+u64 random_max_u64(u64 max); /** Return a pseudorandom 64-bit number in range [0,@max). **/
/* mmap.c */
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