File size: 6,355 Bytes
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#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <sched.h>
#if CPUINFO_MOCK
#include <cpuinfo-mock.h>
#endif
#include <linux/api.h>
#include <cpuinfo/log.h>
/*
* Size, in chars, of the on-stack buffer used for parsing cpu lists.
* This is also the limit on the length of a single entry
* (<cpu-number> or <cpu-number-start>-<cpu-number-end>)
* in the cpu list.
*/
#define BUFFER_SIZE 256
/* Locale-independent */
inline static bool is_whitespace(char c) {
switch (c) {
case ' ':
case '\t':
case '\n':
case '\r':
return true;
default:
return false;
}
}
inline static const char* parse_number(const char* string, const char* end, uint32_t number_ptr[restrict static 1]) {
uint32_t number = 0;
while (string != end) {
const uint32_t digit = (uint32_t) (*string) - (uint32_t) '0';
if (digit >= 10) {
break;
}
number = number * UINT32_C(10) + digit;
string += 1;
}
*number_ptr = number;
return string;
}
inline static bool parse_entry(const char* entry_start, const char* entry_end, cpuinfo_cpulist_callback callback, void* context) {
/* Skip whitespace at the beginning of an entry */
for (; entry_start != entry_end; entry_start++) {
if (!is_whitespace(*entry_start)) {
break;
}
}
/* Skip whitespace at the end of an entry */
for (; entry_end != entry_start; entry_end--) {
if (!is_whitespace(entry_end[-1])) {
break;
}
}
const size_t entry_length = (size_t) (entry_end - entry_start);
if (entry_length == 0) {
cpuinfo_log_warning("unexpected zero-length cpu list entry ignored");
return false;
}
#if CPUINFO_LOG_DEBUG_PARSERS
cpuinfo_log_debug("parse cpu list entry \"%.*s\" (%zu chars)", (int) entry_length, entry_start, entry_length);
#endif
uint32_t first_cpu, last_cpu;
const char* number_end = parse_number(entry_start, entry_end, &first_cpu);
if (number_end == entry_start) {
/* Failed to parse the number; ignore the entry */
cpuinfo_log_warning("invalid character '%c' in the cpu list entry \"%.*s\": entry is ignored",
entry_start[0], (int) entry_length, entry_start);
return false;
} else if (number_end == entry_end) {
/* Completely parsed the entry */
#if CPUINFO_LOG_DEBUG_PARSERS
cpuinfo_log_debug("cpulist: call callback with list_start = %"PRIu32", list_end = %"PRIu32,
first_cpu, first_cpu + 1);
#endif
return callback(first_cpu, first_cpu + 1, context);
}
/* Parse the second part of the entry */
if (*number_end != '-') {
cpuinfo_log_warning("invalid character '%c' in the cpu list entry \"%.*s\": entry is ignored",
*number_end, (int) entry_length, entry_start);
return false;
}
const char* number_start = number_end + 1;
number_end = parse_number(number_start, entry_end, &last_cpu);
if (number_end == number_start) {
/* Failed to parse the second number; ignore the entry */
cpuinfo_log_warning("invalid character '%c' in the cpu list entry \"%.*s\": entry is ignored",
*number_start, (int) entry_length, entry_start);
return false;
}
if (number_end != entry_end) {
/* Partially parsed the entry; ignore unparsed characters and continue with the parsed part */
cpuinfo_log_warning("ignored invalid characters \"%.*s\" at the end of cpu list entry \"%.*s\"",
(int) (entry_end - number_end), number_start, (int) entry_length, entry_start);
}
if (last_cpu < first_cpu) {
cpuinfo_log_warning("ignored cpu list entry \"%.*s\": invalid range %"PRIu32"-%"PRIu32,
(int) entry_length, entry_start, first_cpu, last_cpu);
return false;
}
/* Parsed both parts of the entry; update CPU set */
#if CPUINFO_LOG_DEBUG_PARSERS
cpuinfo_log_debug("cpulist: call callback with list_start = %"PRIu32", list_end = %"PRIu32,
first_cpu, last_cpu + 1);
#endif
return callback(first_cpu, last_cpu + 1, context);
}
bool cpuinfo_linux_parse_cpulist(const char* filename, cpuinfo_cpulist_callback callback, void* context) {
bool status = true;
int file = -1;
char buffer[BUFFER_SIZE];
#if CPUINFO_LOG_DEBUG_PARSERS
cpuinfo_log_debug("parsing cpu list from file %s", filename);
#endif
#if CPUINFO_MOCK
file = cpuinfo_mock_open(filename, O_RDONLY);
#else
file = open(filename, O_RDONLY);
#endif
if (file == -1) {
cpuinfo_log_info("failed to open %s: %s", filename, strerror(errno));
status = false;
goto cleanup;
}
size_t position = 0;
const char* buffer_end = &buffer[BUFFER_SIZE];
char* data_start = buffer;
ssize_t bytes_read;
do {
#if CPUINFO_MOCK
bytes_read = cpuinfo_mock_read(file, data_start, (size_t) (buffer_end - data_start));
#else
bytes_read = read(file, data_start, (size_t) (buffer_end - data_start));
#endif
if (bytes_read < 0) {
cpuinfo_log_info("failed to read file %s at position %zu: %s", filename, position, strerror(errno));
status = false;
goto cleanup;
}
position += (size_t) bytes_read;
const char* data_end = data_start + (size_t) bytes_read;
const char* entry_start = buffer;
if (bytes_read == 0) {
/* No more data in the file: process the remaining text in the buffer as a single entry */
const char* entry_end = data_end;
const bool entry_status = parse_entry(entry_start, entry_end, callback, context);
status &= entry_status;
} else {
const char* entry_end;
do {
/* Find the end of the entry, as indicated by a comma (',') */
for (entry_end = entry_start; entry_end != data_end; entry_end++) {
if (*entry_end == ',') {
break;
}
}
/*
* If we located separator at the end of the entry, parse it.
* Otherwise, there may be more data at the end; read the file once again.
*/
if (entry_end != data_end) {
const bool entry_status = parse_entry(entry_start, entry_end, callback, context);
status &= entry_status;
entry_start = entry_end + 1;
}
} while (entry_end != data_end);
/* Move remaining partial entry data at the end to the beginning of the buffer */
const size_t entry_length = (size_t) (entry_end - entry_start);
memmove(buffer, entry_start, entry_length);
data_start = &buffer[entry_length];
}
} while (bytes_read != 0);
cleanup:
if (file != -1) {
#if CPUINFO_MOCK
cpuinfo_mock_close(file);
#else
close(file);
#endif
file = -1;
}
return status;
}
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