#define HAS_FLS_U32
#endif
+#if defined(__x86_64)
+static inline
+unsigned int fls_u64(uint64_t x)
+{
+ long r;
+
+ asm("bsrq %1,%0\n\t"
+ "jnz 1f\n\t"
+ "movq $-1,%0\n\t"
+ "1:\n\t"
+ : "=r" (r) : "rm" (x));
+ return r + 1;
+}
+#define HAS_FLS_U64
+#endif
+
+#ifndef HAS_FLS_U64
+static __attribute__((unused))
+unsigned int fls_u64(uint64_t x)
+{
+ unsigned int r = 64;
+
+ if (!x)
+ return 0;
+
+ if (!(x & 0xFFFFFFFF00000000ULL)) {
+ x <<= 32;
+ r -= 32;
+ }
+ if (!(x & 0xFFFF000000000000ULL)) {
+ x <<= 16;
+ r -= 16;
+ }
+ if (!(x & 0xFF00000000000000ULL)) {
+ x <<= 8;
+ r -= 8;
+ }
+ if (!(x & 0xF000000000000000ULL)) {
+ x <<= 4;
+ r -= 4;
+ }
+ if (!(x & 0xC000000000000000ULL)) {
+ x <<= 2;
+ r -= 2;
+ }
+ if (!(x & 0x8000000000000000ULL)) {
+ x <<= 1;
+ r -= 1;
+ }
+ return r;
+}
+#endif
+
#ifndef HAS_FLS_U32
static __attribute__((unused)) unsigned int fls_u32(uint32_t x)
{
return fls_u32(x - 1);
}
+/*
+ * Return the minimum order for which x <= (1UL << order).
+ * Return -1 if x is 0.
+ */
+LTTNG_HIDDEN
+int utils_get_count_order_u64(uint64_t x)
+{
+ if (!x) {
+ return -1;
+ }
+
+ return fls_u64(x - 1);
+}
+
/**
* Obtain the value of LTTNG_HOME environment variable, if exists.
* Otherwise returns the value of HOME.
int utils_truncate_stream_file(int fd, off_t length)
{
int ret;
+ off_t lseek_ret;
ret = ftruncate(fd, length);
if (ret < 0) {
PERROR("ftruncate");
goto end;
}
- ret = lseek(fd, length, SEEK_SET);
- if (ret < 0) {
+ lseek_ret = lseek(fd, length, SEEK_SET);
+ if (lseek_ret < 0) {
PERROR("lseek");
+ ret = -1;
goto end;
}
end:
section_string, page_name, NULL);
return ret;
}
+
+LTTNG_HIDDEN
+int utils_change_working_dir(const char *path)
+{
+ int ret;
+
+ assert(path);
+
+ ret = chdir(path);
+ if (ret) {
+ PERROR("Failed to change working directory: %s", path);
+ goto end;
+ }
+
+ /* Check for write access */
+ if (access(path, W_OK)) {
+ if (errno == EACCES) {
+ /*
+ * Do not treat this as an error since the permission
+ * might change in the lifetime of the process
+ */
+ DBG("Working directory is not writable: %s", path);
+ } else {
+ PERROR("access");
+ }
+ }
+
+end:
+ return ret;
+}