qemu/oslib-posix.c
Paolo Bonzini cbcfa0418f link the main loop and its dependencies into the tools
Using the main loop code from QEMU enables tools to operate fully
asynchronously.  Advantages include better Windows portability (for some
definition of portability) over glib's.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2011-12-22 11:53:58 +01:00

254 lines
6.3 KiB
C

/*
* os-posix-lib.c
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2010 Red Hat, Inc.
*
* QEMU library functions on POSIX which are shared between QEMU and
* the QEMU tools.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/* The following block of code temporarily renames the daemon() function so the
compiler does not see the warning associated with it in stdlib.h on OSX */
#ifdef __APPLE__
#define daemon qemu_fake_daemon_function
#include <stdlib.h>
#undef daemon
extern int daemon(int, int);
#endif
#if defined(__linux__) && defined(__x86_64__)
/* Use 2 MiB alignment so transparent hugepages can be used by KVM.
Valgrind does not support alignments larger than 1 MiB,
therefore we need special code which handles running on Valgrind. */
# define QEMU_VMALLOC_ALIGN (512 * 4096)
# define CONFIG_VALGRIND
#else
# define QEMU_VMALLOC_ALIGN getpagesize()
#endif
#include "config-host.h"
#include "sysemu.h"
#include "trace.h"
#include "qemu_socket.h"
#if defined(CONFIG_VALGRIND)
static int running_on_valgrind = -1;
#else
# define running_on_valgrind 0
#endif
#ifdef CONFIG_LINUX
#include <sys/syscall.h>
#endif
#ifdef CONFIG_EVENTFD
#include <sys/eventfd.h>
#endif
int qemu_get_thread_id(void)
{
#if defined(__linux__)
return syscall(SYS_gettid);
#else
return getpid();
#endif
}
int qemu_daemon(int nochdir, int noclose)
{
return daemon(nochdir, noclose);
}
void *qemu_oom_check(void *ptr)
{
if (ptr == NULL) {
fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
abort();
}
return ptr;
}
void *qemu_memalign(size_t alignment, size_t size)
{
void *ptr;
#if defined(_POSIX_C_SOURCE) && !defined(__sun__)
int ret;
ret = posix_memalign(&ptr, alignment, size);
if (ret != 0) {
fprintf(stderr, "Failed to allocate %zu B: %s\n",
size, strerror(ret));
abort();
}
#elif defined(CONFIG_BSD)
ptr = qemu_oom_check(valloc(size));
#else
ptr = qemu_oom_check(memalign(alignment, size));
#endif
trace_qemu_memalign(alignment, size, ptr);
return ptr;
}
/* alloc shared memory pages */
void *qemu_vmalloc(size_t size)
{
void *ptr;
size_t align = QEMU_VMALLOC_ALIGN;
#if defined(CONFIG_VALGRIND)
if (running_on_valgrind < 0) {
/* First call, test whether we are running on Valgrind.
This is a substitute for RUNNING_ON_VALGRIND from valgrind.h. */
const char *ld = getenv("LD_PRELOAD");
running_on_valgrind = (ld != NULL && strstr(ld, "vgpreload"));
}
#endif
if (size < align || running_on_valgrind) {
align = getpagesize();
}
ptr = qemu_memalign(align, size);
trace_qemu_vmalloc(size, ptr);
return ptr;
}
void qemu_vfree(void *ptr)
{
trace_qemu_vfree(ptr);
free(ptr);
}
void socket_set_block(int fd)
{
int f;
f = fcntl(fd, F_GETFL);
fcntl(fd, F_SETFL, f & ~O_NONBLOCK);
}
void socket_set_nonblock(int fd)
{
int f;
f = fcntl(fd, F_GETFL);
fcntl(fd, F_SETFL, f | O_NONBLOCK);
}
void qemu_set_cloexec(int fd)
{
int f;
f = fcntl(fd, F_GETFD);
fcntl(fd, F_SETFD, f | FD_CLOEXEC);
}
/*
* Creates a pipe with FD_CLOEXEC set on both file descriptors
*/
int qemu_pipe(int pipefd[2])
{
int ret;
#ifdef CONFIG_PIPE2
ret = pipe2(pipefd, O_CLOEXEC);
if (ret != -1 || errno != ENOSYS) {
return ret;
}
#endif
ret = pipe(pipefd);
if (ret == 0) {
qemu_set_cloexec(pipefd[0]);
qemu_set_cloexec(pipefd[1]);
}
return ret;
}
/*
* Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
*/
int qemu_eventfd(int fds[2])
{
#ifdef CONFIG_EVENTFD
int ret;
ret = eventfd(0, 0);
if (ret >= 0) {
fds[0] = ret;
fds[1] = dup(ret);
if (fds[1] == -1) {
close(ret);
return -1;
}
qemu_set_cloexec(ret);
qemu_set_cloexec(fds[1]);
return 0;
}
if (errno != ENOSYS) {
return -1;
}
#endif
return qemu_pipe(fds);
}
int qemu_utimens(const char *path, const struct timespec *times)
{
struct timeval tv[2], tv_now;
struct stat st;
int i;
#ifdef CONFIG_UTIMENSAT
int ret;
ret = utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW);
if (ret != -1 || errno != ENOSYS) {
return ret;
}
#endif
/* Fallback: use utimes() instead of utimensat() */
/* happy if special cases */
if (times[0].tv_nsec == UTIME_OMIT && times[1].tv_nsec == UTIME_OMIT) {
return 0;
}
if (times[0].tv_nsec == UTIME_NOW && times[1].tv_nsec == UTIME_NOW) {
return utimes(path, NULL);
}
/* prepare for hard cases */
if (times[0].tv_nsec == UTIME_NOW || times[1].tv_nsec == UTIME_NOW) {
gettimeofday(&tv_now, NULL);
}
if (times[0].tv_nsec == UTIME_OMIT || times[1].tv_nsec == UTIME_OMIT) {
stat(path, &st);
}
for (i = 0; i < 2; i++) {
if (times[i].tv_nsec == UTIME_NOW) {
tv[i].tv_sec = tv_now.tv_sec;
tv[i].tv_usec = tv_now.tv_usec;
} else if (times[i].tv_nsec == UTIME_OMIT) {
tv[i].tv_sec = (i == 0) ? st.st_atime : st.st_mtime;
tv[i].tv_usec = 0;
} else {
tv[i].tv_sec = times[i].tv_sec;
tv[i].tv_usec = times[i].tv_nsec / 1000;
}
}
return utimes(path, &tv[0]);
}