2 * The UCW Library -- Miscellaneous Functions
4 * (c) 1997--2009 Martin Mares <mj@ucw.cz>
5 * (c) 2005 Tomas Valla <tom@ucw.cz>
6 * (c) 2006 Robert Spalek <robert@ucw.cz>
7 * (c) 2007 Pavel Charvat <pchar@ucw.cz>
9 * This software may be freely distributed and used according to the terms
10 * of the GNU Lesser General Public License.
16 #include "ucw/config.h"
19 /*** === Macros for handling structures, offsets and alignment ***/
21 #define CHECK_PTR_TYPE(x, type) ((x)-(type)(x) + (type)(x)) /** Check that a pointer @x is of type @type. Fail compilation if not. **/
22 #define PTR_TO(s, i) &((s*)0)->i /** Return OFFSETOF() in form of a pointer. **/
23 #define OFFSETOF(s, i) ((unsigned int) (uintptr_t) PTR_TO(s, i)) /** Offset of item @i from the start of structure @s **/
24 #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. **/
27 * Align an integer @s to the nearest higher multiple of @a (which should be a power of two)
29 #define ALIGN_TO(s, a) (((s)+a-1)&~(a-1))
32 * Align a pointer @p to the nearest higher multiple of @s.
34 #define ALIGN_PTR(p, s) ((uintptr_t)(p) % (s) ? (typeof(p))((uintptr_t)(p) + (s) - (uintptr_t)(p) % (s)) : (p))
36 #define UNALIGNED_PART(ptr, type) (((uintptr_t) (ptr)) % sizeof(type))
38 /*** === Other utility macros ***/
40 #define MIN(a,b) (((a)<(b))?(a):(b)) /** Minimum of two numbers **/
41 #define MAX(a,b) (((a)>(b))?(a):(b)) /** Maximum of two numbers **/
42 #define CLAMP(x,min,max) ({ int _t=x; (_t < min) ? min : (_t > max) ? max : _t; }) /** Clip a number @x to interval [@min,@max] **/
43 #define ABS(x) ((x) < 0 ? -(x) : (x)) /** Absolute value **/
44 #define ARRAY_SIZE(a) (sizeof(a)/sizeof(*(a))) /** The number of elements of an array **/
45 #define STRINGIFY(x) #x /** Convert macro parameter to a string **/
46 #define STRINGIFY_EXPANDED(x) STRINGIFY(x) /** Convert an expanded macro parameter to a string **/
47 #define GLUE(x,y) x##y /** Glue two tokens together **/
48 #define GLUE_(x,y) x##_##y /** Glue two tokens together, separating them by an underscore **/
50 #define COMPARE(x,y) do { if ((x)<(y)) return -1; if ((x)>(y)) return 1; } while(0) /** Numeric comparison function for qsort() **/
51 #define REV_COMPARE(x,y) COMPARE(y,x) /** Reverse numeric comparison **/
52 #define COMPARE_LT(x,y) do { if ((x)<(y)) return 1; if ((x)>(y)) return 0; } while(0)
53 #define COMPARE_GT(x,y) COMPARE_LT(y,x)
55 #define ROL(x, bits) (((x) << (bits)) | ((uns)(x) >> (sizeof(uns)*8 - (bits)))) /** Bitwise rotation of an unsigned int to the left **/
56 #define ROR(x, bits) (((uns)(x) >> (bits)) | ((x) << (sizeof(uns)*8 - (bits)))) /** Bitwise rotation of an unsigned int to the right **/
58 /*** === Shortcuts for GCC Extensions ***/
63 #define NONRET __attribute__((noreturn)) /** Function does not return **/
64 #define UNUSED __attribute__((unused)) /** Variable/parameter is knowingly unused **/
65 #define CONSTRUCTOR __attribute__((constructor)) /** Call function upon start of program **/
66 #define PACKED __attribute__((packed)) /** Structure should be packed **/
67 #define CONST __attribute__((const)) /** Function depends only on arguments **/
68 #define PURE __attribute__((pure)) /** Function depends only on arguments and global vars **/
69 #define FORMAT_CHECK(x,y,z) __attribute__((format(x,y,z))) /** Checking of printf-like format strings **/
70 #define likely(x) __builtin_expect((x),1) /** Use `if (likely(@x))` if @x is almost always true **/
71 #define unlikely(x) __builtin_expect((x),0) /** Use `if (unlikely(@x))` to hint that @x is almost always false **/
73 #if __GNUC__ >= 4 || __GNUC__ == 3 && __GNUC_MINOR__ >= 3
74 #define ALWAYS_INLINE inline __attribute__((always_inline)) /** Forcibly inline **/
75 #define NO_INLINE __attribute__((noinline)) /** Forcibly uninline **/
77 #define ALWAYS_INLINE inline
81 #define LIKE_MALLOC __attribute__((malloc)) /** Function returns a "new" pointer **/
82 #define SENTINEL_CHECK __attribute__((sentinel)) /** The last argument must be NULL **/
85 #define SENTINEL_CHECK
89 #error This program requires the GNU C compiler.
95 * === Basic logging functions (see <<log:,Logging>> and <ucw/log.h> for more)
98 enum log_levels { /** The available log levels to pass to msg() and friends. **/
99 L_DEBUG=0, // 'D' - Debugging
100 L_INFO, // 'I' - Informational
101 L_WARN, // 'W' - Warning
102 L_ERROR, // 'E' - Error, but non-critical
103 L_INFO_R, // 'i' - An alternative set of levels for messages caused by remote events
104 L_WARN_R, // 'w' (e.g., a packet received via network)
106 L_FATAL, // '!' - Fatal error
109 #define L_SIGHANDLER 0x80000000 /** Avoid operations that are unsafe in signal handlers **/
112 * This is the basic printf-like function for logging a message.
113 * The @flags contain the log level and possibly other flag bits (like `L_SIGHANDLER`).
115 void msg(uns flags, const char *fmt, ...) FORMAT_CHECK(printf,2,3);
116 void vmsg(uns flags, const char *fmt, va_list args); /** A vararg version of msg(). **/
117 void die(const char *, ...) NONRET FORMAT_CHECK(printf,1,2); /** Log a fatal error message and exit the program. **/
119 extern char *log_title; /** An optional log message title. Set to program name by log_init(). **/
120 extern int log_pid; /** An optional PID printed in each log message. Set to 0 if it shouldn't be logged. **/
121 extern void (*log_die_hook)(void); /** An optional function called just before die() exists. **/
123 void log_init(const char *argv0); /** Set @log_title to the program name extracted from @argv[0]. **/
124 void log_fork(void); /** Call after fork() to update @log_pid. **/
125 void log_file(const char *name); /** Establish logging to the named file. Also redirect stderr there. **/
127 void assert_failed(const char *assertion, const char *file, int line) NONRET;
128 void assert_failed_noinfo(void) NONRET;
132 * Check an assertion. If the condition @x is false, stop the program with a fatal error.
133 * Assertion checks are compiled only when `DEBUG_ASSERTS` is defined.
135 #define ASSERT(x) ({ if (unlikely(!(x))) assert_failed(#x, __FILE__, __LINE__); 1; })
137 #define ASSERT(x) ({ if (__builtin_constant_p(x) && !(x)) assert_failed_noinfo(); 1; })
140 #define COMPILE_ASSERT(name,x) typedef char _COMPILE_ASSERT_##name[!!(x)-1]
143 #define DBG(x,y...) msg(L_DEBUG, x,##y) /** If `LOCAL_DEBUG` is defined before including <ucw/lib.h>, log a debug message. Otherwise do nothing. **/
145 #define DBG(x,y...) do { } while(0)
148 /*** === Memory allocation ***/
151 * Unfortunately, several libraries we might want to link to define
152 * their own xmalloc and we don't want to interfere with them, hence
155 #define xmalloc ucw_xmalloc
156 #define xrealloc ucw_xrealloc
157 #define xfree ucw_xfree
159 void *xmalloc(uns) LIKE_MALLOC; /** Allocate memory and die() if there is none. **/
160 void *xrealloc(void *, uns); /** Reallocate memory and die() if there is none. **/
161 void xfree(void *); /** Free memory allocated by xmalloc() or xrealloc(). **/
163 void *xmalloc_zero(uns) LIKE_MALLOC; /** Allocate memory and fill it by zeroes. **/
164 char *xstrdup(const char *) LIKE_MALLOC; /** Make a xmalloc()'ed copy of a string. **/
166 /*** === Trivial timers (timer.c) ***/
168 timestamp_t get_timestamp(void); /** Get current time as a millisecond timestamp. **/
170 void init_timer(timestamp_t *timer); /** Initialize a timer. **/
171 uns get_timer(timestamp_t *timer); /** Get the number of milliseconds since last init/get of a timer. **/
172 uns switch_timer(timestamp_t *oldt, timestamp_t *newt); /** Stop ticking of one timer and resume another. **/
174 /*** === Random numbers (random.c) ***/
176 uns random_u32(void); /** Return a pseudorandom 32-bit number. **/
177 uns random_max(uns max); /** Return a pseudorandom 32-bit number in range [0,@max). **/
178 u64 random_u64(void); /** Return a pseudorandom 64-bit number. **/
179 u64 random_max_u64(u64 max); /** Return a pseudorandom 64-bit number in range [0,@max). **/
183 void *mmap_file(const char *name, unsigned *len, int writeable);
184 void munmap_file(void *start, unsigned len);
188 void setproctitle_init(int argc, char **argv);
189 void setproctitle(const char *msg, ...) FORMAT_CHECK(printf,1,2);
190 char *getproctitle(void);
194 void randomkey(byte *buf, uns size);
198 #define EXIT_STATUS_MSG_SIZE 32
199 int format_exit_status(char *msg, int stat);
203 int run_command(const char *cmd, ...);
204 void NONRET exec_command(const char *cmd, ...);
205 void echo_command(char *buf, int size, const char *cmd, ...);
206 int run_command_v(const char *cmd, va_list args);
207 void NONRET exec_command_v(const char *cmd, va_list args);
208 void echo_command_v(char *buf, int size, const char *cmd, va_list args);
212 int careful_read(int fd, void *buf, int len);
213 int careful_write(int fd, const void *buf, int len);
217 void sync_dir(const char *name);
221 typedef int (*ucw_sighandler_t)(int); // gets signum, returns nonzero if abort() should be called
223 void handle_signal(int signum);
224 void unhandle_signal(int signum);
225 ucw_sighandler_t set_signal_handler(int signum, ucw_sighandler_t newh);
229 void *page_alloc(u64 len) LIKE_MALLOC; // allocates a multiple of CPU_PAGE_SIZE bytes with mmap
230 void *page_alloc_zero(u64 len) LIKE_MALLOC;
231 void page_free(void *start, u64 len);
232 void *page_realloc(void *start, u64 old_len, u64 new_len);
234 void *big_alloc(u64 len) LIKE_MALLOC; // allocate a large memory block in the most efficient way available
235 void *big_alloc_zero(u64 len) LIKE_MALLOC;
236 void big_free(void *start, u64 len);