Avoid thundering herd problem
[qemu-kvm/fedora.git] / osdep.c
blob824120f7d662dbfea019e6528ee7e607e6cb4aef
1 /*
2 * QEMU low level functions
4 * Copyright (c) 2003 Fabrice Bellard
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include <stdarg.h>
27 #include <string.h>
28 #include <errno.h>
29 #include <unistd.h>
30 #include <fcntl.h>
31 #ifdef HOST_SOLARIS
32 #include <sys/types.h>
33 #include <sys/statvfs.h>
34 #endif
36 #include "qemu-common.h"
37 #include "sysemu.h"
39 #ifdef _WIN32
40 #define WIN32_LEAN_AND_MEAN
41 #include <windows.h>
42 #elif defined(_BSD)
43 #include <stdlib.h>
44 #else
45 #include <malloc.h>
46 #endif
48 #include "qemu_socket.h"
50 #if defined(_WIN32)
51 void *qemu_memalign(size_t alignment, size_t size)
53 return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
56 void *qemu_vmalloc(size_t size)
58 /* FIXME: this is not exactly optimal solution since VirtualAlloc
59 has 64Kb granularity, but at least it guarantees us that the
60 memory is page aligned. */
61 return VirtualAlloc(NULL, size, MEM_COMMIT, PAGE_READWRITE);
64 void qemu_vfree(void *ptr)
66 VirtualFree(ptr, 0, MEM_RELEASE);
69 #else
71 #if defined(USE_KQEMU)
73 #ifdef __OpenBSD__
74 #include <sys/param.h>
75 #include <sys/types.h>
76 #include <sys/mount.h>
77 #else
78 #ifndef __FreeBSD__
79 #include <sys/vfs.h>
80 #endif
81 #endif
83 #include <sys/mman.h>
84 #include <fcntl.h>
86 static void *kqemu_vmalloc(size_t size)
88 static int phys_ram_fd = -1;
89 static int phys_ram_size = 0;
90 void *ptr;
92 /* no need (?) for a dummy file on OpenBSD/FreeBSD */
93 #if defined(__OpenBSD__) || defined(__FreeBSD__)
94 int map_anon = MAP_ANON;
95 #else
96 int map_anon = 0;
97 const char *tmpdir;
98 char phys_ram_file[1024];
99 #ifdef HOST_SOLARIS
100 struct statvfs stfs;
101 #else
102 struct statfs stfs;
103 #endif
105 if (phys_ram_fd < 0) {
106 tmpdir = getenv("QEMU_TMPDIR");
107 if (!tmpdir)
108 #ifdef HOST_SOLARIS
109 tmpdir = "/tmp";
110 if (statvfs(tmpdir, &stfs) == 0) {
111 #else
112 tmpdir = "/dev/shm";
113 if (statfs(tmpdir, &stfs) == 0) {
114 #endif
115 int64_t free_space;
116 int ram_mb;
118 free_space = (int64_t)stfs.f_bavail * stfs.f_bsize;
119 if ((ram_size + 8192 * 1024) >= free_space) {
120 ram_mb = (ram_size / (1024 * 1024));
121 fprintf(stderr,
122 "You do not have enough space in '%s' for the %d MB of QEMU virtual RAM.\n",
123 tmpdir, ram_mb);
124 if (strcmp(tmpdir, "/dev/shm") == 0) {
125 fprintf(stderr, "To have more space available provided you have enough RAM and swap, do as root:\n"
126 "mount -o remount,size=%dm /dev/shm\n",
127 ram_mb + 16);
128 } else {
129 fprintf(stderr,
130 "Use the '-m' option of QEMU to diminish the amount of virtual RAM or use the\n"
131 "QEMU_TMPDIR environment variable to set another directory where the QEMU\n"
132 "temporary RAM file will be opened.\n");
134 fprintf(stderr, "Or disable the accelerator module with -no-kqemu\n");
135 exit(1);
138 snprintf(phys_ram_file, sizeof(phys_ram_file), "%s/qemuXXXXXX",
139 tmpdir);
140 phys_ram_fd = mkstemp(phys_ram_file);
141 if (phys_ram_fd < 0) {
142 fprintf(stderr,
143 "warning: could not create temporary file in '%s'.\n"
144 "Use QEMU_TMPDIR to select a directory in a tmpfs filesystem.\n"
145 "Using '/tmp' as fallback.\n",
146 tmpdir);
147 snprintf(phys_ram_file, sizeof(phys_ram_file), "%s/qemuXXXXXX",
148 "/tmp");
149 phys_ram_fd = mkstemp(phys_ram_file);
150 if (phys_ram_fd < 0) {
151 fprintf(stderr, "Could not create temporary memory file '%s'\n",
152 phys_ram_file);
153 exit(1);
156 unlink(phys_ram_file);
158 size = (size + 4095) & ~4095;
159 ftruncate(phys_ram_fd, phys_ram_size + size);
160 #endif /* !(__OpenBSD__ || __FreeBSD__) */
161 ptr = mmap(NULL,
162 size,
163 PROT_WRITE | PROT_READ, map_anon | MAP_SHARED,
164 phys_ram_fd, phys_ram_size);
165 if (ptr == MAP_FAILED) {
166 fprintf(stderr, "Could not map physical memory\n");
167 exit(1);
169 phys_ram_size += size;
170 return ptr;
173 static void kqemu_vfree(void *ptr)
175 /* may be useful some day, but currently we do not need to free */
178 #endif
180 void *qemu_memalign(size_t alignment, size_t size)
182 #if defined(_POSIX_C_SOURCE)
183 int ret;
184 void *ptr;
185 ret = posix_memalign(&ptr, alignment, size);
186 if (ret != 0)
187 return NULL;
188 return ptr;
189 #elif defined(_BSD)
190 return valloc(size);
191 #else
192 return memalign(alignment, size);
193 #endif
196 /* alloc shared memory pages */
197 void *qemu_vmalloc(size_t size)
199 #if defined(USE_KQEMU)
200 if (kqemu_allowed)
201 return kqemu_vmalloc(size);
202 #endif
203 return qemu_memalign(getpagesize(), size);
206 void qemu_vfree(void *ptr)
208 #if defined(USE_KQEMU)
209 if (kqemu_allowed)
210 kqemu_vfree(ptr);
211 #endif
212 free(ptr);
215 #endif
217 int qemu_create_pidfile(const char *filename)
219 char buffer[128];
220 int len;
221 #ifndef _WIN32
222 int fd;
224 fd = open(filename, O_RDWR | O_CREAT, 0600);
225 if (fd == -1)
226 return -1;
228 if (lockf(fd, F_TLOCK, 0) == -1)
229 return -1;
231 len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
232 if (write(fd, buffer, len) != len)
233 return -1;
234 #else
235 HANDLE file;
236 DWORD flags;
237 OVERLAPPED overlap;
238 BOOL ret;
240 /* Open for writing with no sharing. */
241 file = CreateFile(filename, GENERIC_WRITE, 0, NULL,
242 OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
244 if (file == INVALID_HANDLE_VALUE)
245 return -1;
247 flags = LOCKFILE_EXCLUSIVE_LOCK | LOCKFILE_FAIL_IMMEDIATELY;
248 overlap.hEvent = 0;
249 /* Lock 1 byte. */
250 ret = LockFileEx(file, flags, 0, 0, 1, &overlap);
251 if (ret == 0)
252 return -1;
254 /* Write PID to file. */
255 len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
256 ret = WriteFileEx(file, (LPCVOID)buffer, (DWORD)len,
257 &overlap, NULL);
258 if (ret == 0)
259 return -1;
260 #endif
261 return 0;
264 #ifdef _WIN32
266 /* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */
267 #define _W32_FT_OFFSET (116444736000000000ULL)
269 int qemu_gettimeofday(qemu_timeval *tp)
271 union {
272 unsigned long long ns100; /*time since 1 Jan 1601 in 100ns units */
273 FILETIME ft;
274 } _now;
276 if(tp)
278 GetSystemTimeAsFileTime (&_now.ft);
279 tp->tv_usec=(long)((_now.ns100 / 10ULL) % 1000000ULL );
280 tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000ULL);
282 /* Always return 0 as per Open Group Base Specifications Issue 6.
283 Do not set errno on error. */
284 return 0;
286 #endif /* _WIN32 */
289 #ifdef _WIN32
290 void socket_set_nonblock(int fd)
292 unsigned long opt = 1;
293 ioctlsocket(fd, FIONBIO, &opt);
296 int inet_aton(const char *cp, struct in_addr *ia)
298 uint32_t addr = inet_addr(cp);
299 if (addr == 0xffffffff)
300 return 0;
301 ia->s_addr = addr;
302 return 1;
304 #else
305 void socket_set_nonblock(int fd)
307 int f;
308 f = fcntl(fd, F_GETFL);
309 fcntl(fd, F_SETFL, f | O_NONBLOCK);
311 #endif