qemu/osdep.c
Juan Quintela 1298cb6804 documentation: qemu_write_full don't work with non-blocking fd's
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-03-09 11:23:00 -06:00

383 lines
8 KiB
C

/*
* QEMU low level functions
*
* Copyright (c) 2003 Fabrice Bellard
*
* 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.
*/
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
/* Needed early for CONFIG_BSD etc. */
#include "config-host.h"
#ifdef CONFIG_SOLARIS
#include <sys/types.h>
#include <sys/statvfs.h>
#endif
#ifdef CONFIG_EVENTFD
#include <sys/eventfd.h>
#endif
#ifdef _WIN32
#include <windows.h>
#elif defined(CONFIG_BSD)
#include <stdlib.h>
#else
#include <malloc.h>
#endif
#include "qemu-common.h"
#include "sysemu.h"
#include "qemu_socket.h"
#if !defined(_POSIX_C_SOURCE) || defined(_WIN32) || defined(__sun__)
static void *oom_check(void *ptr)
{
if (ptr == NULL) {
#if defined(_WIN32)
fprintf(stderr, "Failed to allocate memory: %lu\n", GetLastError());
#else
fprintf(stderr, "Failed to allocate memory: %s\n", strerror(errno));
#endif
abort();
}
return ptr;
}
#endif
#if defined(_WIN32)
void *qemu_memalign(size_t alignment, size_t size)
{
if (!size) {
abort();
}
return oom_check(VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE));
}
void *qemu_vmalloc(size_t size)
{
/* FIXME: this is not exactly optimal solution since VirtualAlloc
has 64Kb granularity, but at least it guarantees us that the
memory is page aligned. */
if (!size) {
abort();
}
return oom_check(VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE));
}
void qemu_vfree(void *ptr)
{
VirtualFree(ptr, 0, MEM_RELEASE);
}
#else
void *qemu_memalign(size_t alignment, size_t size)
{
#if defined(_POSIX_C_SOURCE) && !defined(__sun__)
int ret;
void *ptr;
ret = posix_memalign(&ptr, alignment, size);
if (ret != 0) {
fprintf(stderr, "Failed to allocate %zu B: %s\n",
size, strerror(ret));
abort();
}
return ptr;
#elif defined(CONFIG_BSD)
return oom_check(valloc(size));
#else
return oom_check(memalign(alignment, size));
#endif
}
/* alloc shared memory pages */
void *qemu_vmalloc(size_t size)
{
return qemu_memalign(getpagesize(), size);
}
void qemu_vfree(void *ptr)
{
free(ptr);
}
#endif
int qemu_create_pidfile(const char *filename)
{
char buffer[128];
int len;
#ifndef _WIN32
int fd;
fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
if (fd == -1)
return -1;
if (lockf(fd, F_TLOCK, 0) == -1)
return -1;
len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
if (write(fd, buffer, len) != len)
return -1;
#else
HANDLE file;
OVERLAPPED overlap;
BOOL ret;
memset(&overlap, 0, sizeof(overlap));
file = CreateFile(filename, GENERIC_WRITE, FILE_SHARE_READ, NULL,
OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (file == INVALID_HANDLE_VALUE)
return -1;
len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
ret = WriteFileEx(file, (LPCVOID)buffer, (DWORD)len,
&overlap, NULL);
if (ret == 0)
return -1;
#endif
return 0;
}
#ifdef _WIN32
/* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */
#define _W32_FT_OFFSET (116444736000000000ULL)
int qemu_gettimeofday(qemu_timeval *tp)
{
union {
unsigned long long ns100; /*time since 1 Jan 1601 in 100ns units */
FILETIME ft;
} _now;
if(tp)
{
GetSystemTimeAsFileTime (&_now.ft);
tp->tv_usec=(long)((_now.ns100 / 10ULL) % 1000000ULL );
tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000ULL);
}
/* Always return 0 as per Open Group Base Specifications Issue 6.
Do not set errno on error. */
return 0;
}
#endif /* _WIN32 */
#ifdef _WIN32
void socket_set_nonblock(int fd)
{
unsigned long opt = 1;
ioctlsocket(fd, FIONBIO, &opt);
}
int inet_aton(const char *cp, struct in_addr *ia)
{
uint32_t addr = inet_addr(cp);
if (addr == 0xffffffff)
return 0;
ia->s_addr = addr;
return 1;
}
void qemu_set_cloexec(int fd)
{
}
#else
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);
}
#endif
/*
* Opens a file with FD_CLOEXEC set
*/
int qemu_open(const char *name, int flags, ...)
{
int ret;
int mode = 0;
if (flags & O_CREAT) {
va_list ap;
va_start(ap, flags);
mode = va_arg(ap, int);
va_end(ap);
}
#ifdef O_CLOEXEC
ret = open(name, flags | O_CLOEXEC, mode);
#else
ret = open(name, flags, mode);
if (ret >= 0) {
qemu_set_cloexec(ret);
}
#endif
return ret;
}
/*
* A variant of write(2) which handles partial write.
*
* Return the number of bytes transferred.
* Set errno if fewer than `count' bytes are written.
*
* This function don't work with non-blocking fd's.
* Any of the possibilities with non-bloking fd's is bad:
* - return a short write (then name is wrong)
* - busy wait adding (errno == EAGAIN) to the loop
*/
ssize_t qemu_write_full(int fd, const void *buf, size_t count)
{
ssize_t ret = 0;
ssize_t total = 0;
while (count) {
ret = write(fd, buf, count);
if (ret < 0) {
if (errno == EINTR)
continue;
break;
}
count -= ret;
buf += ret;
total += ret;
}
return total;
}
#ifndef _WIN32
/*
* 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;
qemu_set_cloexec(ret);
if ((fds[1] = dup(ret)) == -1) {
close(ret);
return -1;
}
qemu_set_cloexec(fds[1]);
return 0;
}
if (errno != ENOSYS) {
return -1;
}
#endif
return qemu_pipe(fds);
}
/*
* 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;
}
#endif
/*
* Opens a socket with FD_CLOEXEC set
*/
int qemu_socket(int domain, int type, int protocol)
{
int ret;
#ifdef SOCK_CLOEXEC
ret = socket(domain, type | SOCK_CLOEXEC, protocol);
if (ret != -1 || errno != EINVAL) {
return ret;
}
#endif
ret = socket(domain, type, protocol);
if (ret >= 0) {
qemu_set_cloexec(ret);
}
return ret;
}
/*
* Accept a connection and set FD_CLOEXEC
*/
int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
int ret;
#ifdef CONFIG_ACCEPT4
ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
if (ret != -1 || errno != ENOSYS) {
return ret;
}
#endif
ret = accept(s, addr, addrlen);
if (ret >= 0) {
qemu_set_cloexec(ret);
}
return ret;
}