/*
- * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks.
+ * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <config.h>
#include "util.h"
-#include <assert.h>
#include <errno.h>
#include <limits.h>
+#include <pthread.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/stat.h>
#include <unistd.h>
#include "byte-order.h"
#include "coverage.h"
-#include "openvswitch/types.h"
+#include "ovs-thread.h"
#include "vlog.h"
VLOG_DEFINE_THIS_MODULE(util);
COVERAGE_DEFINE(util_xalloc);
+/* argv[0] without directory names. */
const char *program_name;
+
+/* Name for the currently running thread or process, for log messages, process
+ * listings, and debuggers. */
+DEFINE_PER_THREAD_MALLOCED_DATA(char *, subprogram_name);
+
+/* --version option output. */
static char *program_version;
+/* Buffer used by ovs_strerror(). */
+DEFINE_PER_THREAD_DATA(struct { char s[128]; }, strerror_buffer, { "" });
+
+void
+ovs_assert_failure(const char *where, const char *function,
+ const char *condition)
+{
+ /* Prevent an infinite loop (or stack overflow) in case VLOG_ABORT happens
+ * to trigger an assertion failure of its own. */
+ static int reentry = 0;
+
+ switch (reentry++) {
+ case 0:
+ VLOG_ABORT("%s: assertion %s failed in %s()",
+ where, condition, function);
+ NOT_REACHED();
+
+ case 1:
+ fprintf(stderr, "%s: assertion %s failed in %s()",
+ where, condition, function);
+ abort();
+
+ default:
+ abort();
+ }
+}
+
void
out_of_memory(void)
{
va_list args;
va_start(args, format);
- ovs_error_valist(err_no, format, args);
- va_end(args);
+ ovs_abort_valist(err_no, format, args);
+}
+/* Same as ovs_abort() except that the arguments are supplied as a va_list. */
+void
+ovs_abort_valist(int err_no, const char *format, va_list args)
+{
+ ovs_error_valist(err_no, format, args);
abort();
}
void
ovs_error_valist(int err_no, const char *format, va_list args)
{
+ const char *subprogram_name = get_subprogram_name();
int save_errno = errno;
- fprintf(stderr, "%s: ", program_name);
+ if (subprogram_name[0]) {
+ fprintf(stderr, "%s(%s): ", program_name, subprogram_name);
+ } else {
+ fprintf(stderr, "%s: ", program_name);
+ }
+
vfprintf(stderr, format, args);
if (err_no != 0) {
fprintf(stderr, " (%s)", ovs_retval_to_string(err_no));
const char *
ovs_retval_to_string(int retval)
{
- static char unknown[48];
+ return (!retval ? ""
+ : retval == EOF ? "End of file"
+ : ovs_strerror(retval));
+}
+
+const char *
+ovs_strerror(int error)
+{
+ enum { BUFSIZE = sizeof strerror_buffer_get()->s };
+ int save_errno;
+ char *buffer;
+ char *s;
- if (!retval) {
- return "";
- }
- if (retval > 0) {
- return strerror(retval);
- }
- if (retval == EOF) {
- return "End of file";
+ save_errno = errno;
+ buffer = strerror_buffer_get()->s;
+
+#if STRERROR_R_CHAR_P
+ /* GNU style strerror_r() might return an immutable static string, or it
+ * might write and return 'buffer', but in either case we can pass the
+ * returned string directly to the caller. */
+ s = strerror_r(error, buffer, BUFSIZE);
+#else /* strerror_r() returns an int. */
+ s = buffer;
+ if (strerror_r(error, buffer, BUFSIZE)) {
+ /* strerror_r() is only allowed to fail on ERANGE (because the buffer
+ * is too short). We don't check the actual failure reason because
+ * POSIX requires strerror_r() to return the error but old glibc
+ * (before 2.13) returns -1 and sets errno. */
+ snprintf(buffer, BUFSIZE, "Unknown error %d", error);
}
- snprintf(unknown, sizeof unknown, "***unknown return value: %d***", retval);
- return unknown;
+#endif
+
+ errno = save_errno;
+
+ return s;
}
/* Sets global "program_name" and "program_version" variables. Should
* be called at the beginning of main() with "argv[0]" as the argument
* to 'argv0'.
*
+ * 'version' should contain the version of the caller's program. If 'version'
+ * is the same as the VERSION #define, the caller is assumed to be part of Open
+ * vSwitch. Otherwise, it is assumed to be an external program linking against
+ * the Open vSwitch libraries.
+ *
* The 'date' and 'time' arguments should likely be called with
* "__DATE__" and "__TIME__" to use the time the binary was built.
* Alternatively, the "set_program_name" macro may be called to do this
* automatically.
*/
void
-set_program_name__(const char *argv0, const char *date, const char *time)
+set_program_name__(const char *argv0, const char *version, const char *date,
+ const char *time)
{
const char *slash = strrchr(argv0, '/');
+
+ assert_single_threaded();
+
program_name = slash ? slash + 1 : argv0;
free(program_version);
- program_version = xasprintf("%s (Open vSwitch) "VERSION BUILDNR"\n"
- "Compiled %s %s\n",
- program_name, date, time);
+
+ if (!strcmp(version, VERSION)) {
+ program_version = xasprintf("%s (Open vSwitch) "VERSION"\n"
+ "Compiled %s %s\n",
+ program_name, date, time);
+ } else {
+ program_version = xasprintf("%s %s\n"
+ "Open vSwitch Library "VERSION"\n"
+ "Compiled %s %s\n",
+ program_name, version, date, time);
+ }
+}
+
+/* Returns the name of the currently running thread or process. */
+const char *
+get_subprogram_name(void)
+{
+ const char *name = subprogram_name_get();
+ return name ? name : "";
+}
+
+/* Sets 'name' as the name of the currently running thread or process. (This
+ * appears in log messages and may also be visible in system process listings
+ * and debuggers.) */
+void
+set_subprogram_name(const char *name)
+{
+ free(subprogram_name_set(xstrdup(name)));
+#if HAVE_GLIBC_PTHREAD_SETNAME_NP
+ pthread_setname_np(pthread_self(), name);
+#elif HAVE_NETBSD_PTHREAD_SETNAME_NP
+ pthread_setname_np(pthread_self(), "%s", name);
+#elif HAVE_PTHREAD_SET_NAME_NP
+ pthread_set_name_np(pthread_self(), name);
+#endif
}
/* Returns a pointer to a string describing the program version. The
int error = errno;
free(buf);
if (error != ERANGE) {
- VLOG_WARN("getcwd failed (%s)", strerror(error));
+ VLOG_WARN("getcwd failed (%s)", ovs_strerror(error));
return NULL;
}
size *= 2;
}
}
+/* Like readlink(), but returns the link name as a null-terminated string in
+ * allocated memory that the caller must eventually free (with free()).
+ * Returns NULL on error, in which case errno is set appropriately. */
+char *
+xreadlink(const char *filename)
+{
+ size_t size;
+
+ for (size = 64; ; size *= 2) {
+ char *buf = xmalloc(size);
+ ssize_t retval = readlink(filename, buf, size);
+ int error = errno;
+
+ if (retval >= 0 && retval < size) {
+ buf[retval] = '\0';
+ return buf;
+ }
+
+ free(buf);
+ if (retval < 0) {
+ errno = error;
+ return NULL;
+ }
+ }
+}
+
+/* Returns a version of 'filename' with symlinks in the final component
+ * dereferenced. This differs from realpath() in that:
+ *
+ * - 'filename' need not exist.
+ *
+ * - If 'filename' does exist as a symlink, its referent need not exist.
+ *
+ * - Only symlinks in the final component of 'filename' are dereferenced.
+ *
+ * The caller must eventually free the returned string (with free()). */
+char *
+follow_symlinks(const char *filename)
+{
+ struct stat s;
+ char *fn;
+ int i;
+
+ fn = xstrdup(filename);
+ for (i = 0; i < 10; i++) {
+ char *linkname;
+ char *next_fn;
+
+ if (lstat(fn, &s) != 0 || !S_ISLNK(s.st_mode)) {
+ return fn;
+ }
+
+ linkname = xreadlink(fn);
+ if (!linkname) {
+ VLOG_WARN("%s: readlink failed (%s)",
+ filename, ovs_strerror(errno));
+ return fn;
+ }
+
+ if (linkname[0] == '/') {
+ /* Target of symlink is absolute so use it raw. */
+ next_fn = linkname;
+ } else {
+ /* Target of symlink is relative so add to 'fn''s directory. */
+ char *dir = dir_name(fn);
+
+ if (!strcmp(dir, ".")) {
+ next_fn = linkname;
+ } else {
+ char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
+ next_fn = xasprintf("%s%s%s", dir, separator, linkname);
+ free(linkname);
+ }
+
+ free(dir);
+ }
+
+ free(fn);
+ fn = next_fn;
+ }
+
+ VLOG_WARN("%s: too many levels of symlinks", filename);
+ free(fn);
+ return xstrdup(filename);
+}
/* Pass a value to this function if it is marked with
* __attribute__((warn_unused_result)) and you genuinely want to ignore
int
log_2_floor(uint32_t n)
{
- assert(n);
+ ovs_assert(n);
#if !defined(UINT_MAX) || !defined(UINT32_MAX)
#error "Someone screwed up the #includes."
int
log_2_ceil(uint32_t n)
{
- return log_2_floor(n) + !IS_POW2(n);
+ return log_2_floor(n) + !is_pow2(n);
}
-/* Returns the number of trailing 0-bits in 'n', or 32 if 'n' is 0. */
-int
-ctz(uint32_t n)
-{
- if (!n) {
- return 32;
- } else {
+/* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
#if !defined(UINT_MAX) || !defined(UINT32_MAX)
#error "Someone screwed up the #includes."
#elif __GNUC__ >= 4 && UINT_MAX == UINT32_MAX
- return __builtin_ctz(n);
+/* Defined inline in util.h. */
#else
- unsigned int k;
- int count = 31;
+static int
+raw_ctz(uint32_t n)
+{
+ unsigned int k;
+ int count = 31;
#define CTZ_STEP(X) \
- k = n << (X); \
- if (k) { \
- count -= X; \
- n = k; \
- }
- CTZ_STEP(16);
- CTZ_STEP(8);
- CTZ_STEP(4);
- CTZ_STEP(2);
- CTZ_STEP(1);
+ k = n << (X); \
+ if (k) { \
+ count -= X; \
+ n = k; \
+ }
+ CTZ_STEP(16);
+ CTZ_STEP(8);
+ CTZ_STEP(4);
+ CTZ_STEP(2);
+ CTZ_STEP(1);
#undef CTZ_STEP
- return count;
+ return count;
+}
#endif
- }
+
+/* Returns the number of 1-bits in 'x', between 0 and 32 inclusive. */
+unsigned int
+popcount(uint32_t x)
+{
+ /* In my testing, this implementation is over twice as fast as any other
+ * portable implementation that I tried, including GCC 4.4
+ * __builtin_popcount(), although nonportable asm("popcnt") was over 50%
+ * faster. */
+#define INIT1(X) \
+ ((((X) & (1 << 0)) != 0) + \
+ (((X) & (1 << 1)) != 0) + \
+ (((X) & (1 << 2)) != 0) + \
+ (((X) & (1 << 3)) != 0) + \
+ (((X) & (1 << 4)) != 0) + \
+ (((X) & (1 << 5)) != 0) + \
+ (((X) & (1 << 6)) != 0) + \
+ (((X) & (1 << 7)) != 0))
+#define INIT2(X) INIT1(X), INIT1((X) + 1)
+#define INIT4(X) INIT2(X), INIT2((X) + 2)
+#define INIT8(X) INIT4(X), INIT4((X) + 4)
+#define INIT16(X) INIT8(X), INIT8((X) + 8)
+#define INIT32(X) INIT16(X), INIT16((X) + 16)
+#define INIT64(X) INIT32(X), INIT32((X) + 32)
+
+ static const uint8_t popcount8[256] = {
+ INIT64(0), INIT64(64), INIT64(128), INIT64(192)
+ };
+
+ return (popcount8[x & 0xff] +
+ popcount8[(x >> 8) & 0xff] +
+ popcount8[(x >> 16) & 0xff] +
+ popcount8[x >> 24]);
}
/* Returns true if the 'n' bytes starting at 'p' are zeros. */
}
}
+/* Sets to 1 all of the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'.
+ * 'dst' is 'dst_len' bytes long.
+ *
+ * If you consider all of 'dst' to be a single unsigned integer in network byte
+ * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
+ * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
+ * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
+ * 2], and so on.
+ *
+ * Required invariant:
+ * dst_ofs + n_bits <= dst_len * 8
+ */
+void
+bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
+ unsigned int n_bits)
+{
+ uint8_t *dst = dst_;
+
+ if (!n_bits) {
+ return;
+ }
+
+ dst += dst_len - (dst_ofs / 8 + 1);
+ dst_ofs %= 8;
+
+ if (dst_ofs) {
+ unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
+
+ *dst |= ((1 << chunk) - 1) << dst_ofs;
+
+ n_bits -= chunk;
+ if (!n_bits) {
+ return;
+ }
+
+ dst--;
+ }
+
+ while (n_bits >= 8) {
+ *dst-- = 0xff;
+ n_bits -= 8;
+ }
+
+ if (n_bits) {
+ *dst |= (1 << n_bits) - 1;
+ }
+}
+
+/* Scans the 'n_bits' bits starting from bit 'dst_ofs' in 'dst' for 1-bits.
+ * Returns false if any 1-bits are found, otherwise true. 'dst' is 'dst_len'
+ * bytes long.
+ *
+ * If you consider all of 'dst' to be a single unsigned integer in network byte
+ * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
+ * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
+ * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
+ * 2], and so on.
+ *
+ * Required invariant:
+ * dst_ofs + n_bits <= dst_len * 8
+ */
+bool
+bitwise_is_all_zeros(const void *p_, unsigned int len, unsigned int ofs,
+ unsigned int n_bits)
+{
+ const uint8_t *p = p_;
+
+ if (!n_bits) {
+ return true;
+ }
+
+ p += len - (ofs / 8 + 1);
+ ofs %= 8;
+
+ if (ofs) {
+ unsigned int chunk = MIN(n_bits, 8 - ofs);
+
+ if (*p & (((1 << chunk) - 1) << ofs)) {
+ return false;
+ }
+
+ n_bits -= chunk;
+ if (!n_bits) {
+ return true;
+ }
+
+ p--;
+ }
+
+ while (n_bits >= 8) {
+ if (*p) {
+ return false;
+ }
+ n_bits -= 8;
+ p--;
+ }
+
+ if (n_bits && *p & ((1 << n_bits) - 1)) {
+ return false;
+ }
+
+ return true;
+}
+
/* Copies the 'n_bits' low-order bits of 'value' into the 'n_bits' bits
* starting at bit 'dst_ofs' in 'dst', which is 'dst_len' bytes long.
*
git://git.onelab.eu / sliver-openvswitch.git / blobdiff