Changeset 10419 in vbox for trunk/src/VBox/Runtime/r3/linux

Timestamp:

Jul 9, 2008 1:46:17 PM (17 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

33078

Message:

Linux implementation of the RTMp* bits we current need in ring-3.

File:

• trunk/src/VBox/Runtime/r3/linux/mp-linux.cpp (copied) (copied from trunk/src/VBox/Runtime/r3/win/mp-win.cpp ) (6 diffs)

trunk/src/VBox/Runtime/r3/linux/mp-linux.cpp

@@ -1 +1 @@
 /* $Id$ */
 /** @file
- * IPRT - Multiprocessor, Windows.
+ * IPRT - Multiprocessor, Linux.
  */
 
 /*
- * Copyright (C) 2006-2007 Sun Microsystems, Inc.
+ * Copyright (C) 2006-2008 Sun Microsystems, Inc.
  *
  * This file is part of VirtualBox Open Source Edition (OSE), as
@@ -34 +34 @@
 *******************************************************************************/
 #define LOG_GROUP RTLOGGROUP_SYSTEM
-#include <Windows.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/sysctl.h>
+#include <sys/stat.h>
+#include <sys/fcntl.h>
+#include <errno.h>
+
 #include <iprt/mp.h>
 #include <iprt/cpuset.h>
 #include <iprt/assert.h>
+#include <iprt/string.h>
+
+
+/** @todo move the rtLinuxSysFs* bits into sysfs.cpp and sysfs.h. */
+
+/**
+ * Checks if a sysfs file (or directory, device, symlink, whatever) exists.
+ *
+ * @returns true / false, errno is preserved.
+ * @param   pszFormat   The name format, without "/sys/".
+ * @param   va          The format args.
+ */
+bool rtLinuxSysFsExistsV(const char *pszFormat, va_list va)
+{
+    int iSavedErrno = errno;
+
+    /*
+     * Construct the filename and call stat.
+     */
+    char szFilename[128];
+    static const size_t cchPrefix = sizeof("/sys/") - 1;
+    strcpy(szFilename, "/sys/");
+    size_t cch = RTStrPrintfV(&szFilename[cchPrefix], sizeof(szFilename) - cchPrefix, pszFormat, va);
+    Assert(cch < sizeof(szFilename) - cchPrefix - 1);
+
+    struct stat st;
+    bool fRet = stat(szFilename, &st) == 0;
+
+    errno = iSavedErrno;
+    return fRet;
+}
+
+/**
+ * Checks if a sysfs file (or directory, device, symlink, whatever) exists.
+ *
+ * @returns true / false, errno is preserved.
+ * @param   pszFormat   The name format, without "/sys/".
+ * @param   ...         The format args.
+ */
+bool rtLinuxSysFsExists(const char *pszFormat, ...)
+{
+    va_list va;
+    va_start(va, pszFormat);
+    bool fRet = rtLinuxSysFsExistsV(pszFormat, va);
+    va_end(va);
+    return fRet;
+}
+
+
+/**
+ * Opens a sysfs file.
+ *
+ * @returns The file descriptor. -1 and errno on failure.
+ * @param   pszFormat   The name format, without "/sys/".
+ * @param   va          The format args.
+ */
+int rtLinuxSysFsOpenV(const char *pszFormat, va_list va)
+{
+    /*
+     * Construct the filename and call open.
+     */
+    char szFilename[128];
+    static const size_t cchPrefix = sizeof("/sys/") - 1;
+    strcpy(szFilename, "/sys/");
+    size_t cch = RTStrPrintfV(&szFilename[cchPrefix], sizeof(szFilename) - cchPrefix, pszFormat, va);
+    Assert(cch < sizeof(szFilename) - cchPrefix - 1);
+
+    return open(szFilename, O_RDONLY, 0);
+}
+
+
+/**
+ * Opens a sysfs file.
+ *
+ * @returns The file descriptor. -1 and errno on failure.
+ * @param   pszFormat   The name format, without "/sys/".
+ * @param   ...         The format args.
+ */
+int rtLinuxSysFsOpen(const char *pszFormat, ...)
+{
+    va_list va;
+    va_start(va, pszFormat);
+    int fd = rtLinuxSysFsOpenV(pszFormat, va);
+    va_end(va);
+    return fd;
+}
+
+
+/**
+ * Closes a file opened with rtLinuxSysFsOpen or rtLinuxSysFsOpenV.
+ *
+ * @param   fd
+ */
+void rtLinuxSysFsClose(int fd)
+{
+    int iSavedErrno = errno;
+    close(fd);
+    errno = iSavedErrno;
+}
+
+
+/**
+ * Closes a file opened with rtLinuxSysFsOpen or rtLinuxSysFsOpenV.
+ *
+ * @returns The number of bytes read. -1 and errno on failure.
+ * @param   fd          The file descriptor returned by rtLinuxSysFsOpen or rtLinuxSysFsOpenV.
+ * @param   pszBuf      Where to store the string.
+ * @param   cchBuf      The size of the buffer. Must be at least 2 bytes.
+ */
+ssize_t rtLinuxSysFsReadStr(int fd, char *pszBuf, size_t cchBuf)
+{
+    Assert(cchBuf > 1);
+    ssize_t cchRead = read(fd, pszBuf, cchBuf - 1);
+    pszBuf[cchRead >= 0 ? cchRead : 0] = '\0';
+    return cchRead;
+}
+
+
+/**
+ * Reads a sysfs file.
+ *
+ * @returns 64-bit signed value on success, -1 and errno on failure.
+ * @param   uBase       The number base, 0 for autodetect.
+ * @param   pszFormat   The filename format, without "/sys/".
+ * @param   va          Format args.
+ */
+int64_t rtLinuxSysFsReadIntFileV(unsigned uBase, const char *pszFormat, va_list va)
+{
+    int fd = rtLinuxSysFsOpenV(pszFormat, va);
+    if (fd == -1)
+        return -1;
+
+    int64_t i64Ret = -1;
+    char szNum[128];
+    ssize_t cchNum = rtLinuxSysFsReadStr(fd, szNum, sizeof(szNum));
+    if (cchNum > 0)
+    {
+        int rc = RTStrToInt64Ex(szNum, NULL, uBase, &i64Ret);
+        if (RT_FAILURE(rc))
+        {
+            i64Ret = -1;
+            errno = -ETXTBSY; /* just something that won't happen at read / open. */
+        }
+    }
+    else if (cchNum == 0)
+        errno = -ETXTBSY; /* just something that won't happen at read / open. */
+
+    rtLinuxSysFsClose(fd);
+    return i64Ret;
+}
+
+
+/**
+ * Reads a sysfs file.
+ *
+ * @returns 64-bit signed value on success, -1 and errno on failure.
+ * @param   uBase       The number base, 0 for autodetect.
+ * @param   pszFormat   The filename format, without "/sys/".
+ * @param   ...         Format args.
+ */
+static int64_t rtLinuxSysFsReadIntFile(unsigned uBase, const char *pszFormat, ...)
+{
+    va_list va;
+    va_start(va, pszFormat);
+    int64_t i64Ret = rtLinuxSysFsReadIntFileV(uBase, pszFormat, va);
+    va_end(va);
+    return i64Ret;
+}
+
+
+/**
+ * Internal worker that determins the max possible CPU count.
+ *
+ * @returns Max cpus.
+ */
+DECLINLINE(RTCPUID) rtMpLinuxMaxCpus(void)
+{
+    int cMax = sysconf(_SC_NPROCESSORS_CONF);
+    Assert(cMax >= 1);
+    return cMax;
+}
 
 
@@ -44 +231 @@
 RTDECL(int) RTMpCpuIdToSetIndex(RTCPUID idCpu)
 {
-    return idCpu < MAXIMUM_PROCESSORS ? idCpu : -1;
+    return idCpu < rtMpLinuxMaxCpus() ? idCpu : -1;
 }
 
@@ -50 +237 @@
 RTDECL(RTCPUID) RTMpCpuIdFromSetIndex(int iCpu)
 {
-    return (unsigned)iCpu < MAXIMUM_PROCESSORS ? iCpu : NIL_RTCPUID;
+    return (unsigned)iCpu < rtMpLinuxMaxCpus() ? iCpu : NIL_RTCPUID;
 }
 
@@ -56 +243 @@
 RTDECL(RTCPUID) RTMpGetMaxCpuId(void)
 {
-    return MAXIMUM_PROCESSORS - 1;
+    return rtMpLinuxMaxCpus() - 1;
 }
 
@@ -62 +249 @@
 RTDECL(bool) RTMpIsCpuOnline(RTCPUID idCpu)
 {
+    /** @todo check if there is a simpler interface than this... */
+    int i = rtLinuxSysFsReadIntFile(0, "devices/system/cpu/cpu%d/online", (int)idCpu);
+    if (    i == -1
+        &&  rtLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu))
+    {
+        Assert(!rtLinuxSysFsExists("devices/system/cpu/cpu%d/online", (int)idCpu));
+        i = 1;
+    }
+
+    Assert(i == 0 || i == -1 || i == 1);
+    return i != 0 && i != -1;
+}
+
+
+RTDECL(bool) RTMpIsCpuPossible(RTCPUID idCpu)
+{
+    /** @todo check this up with hotplugging! */
+    return rtLinuxSysFsExists("devices/system/cpu/cpu%d", (int)idCpu);
+}
+
+
+RTDECL(PRTCPUSET) RTMpGetSet(PRTCPUSET pSet)
+{
+    RTCpuSetEmpty(pSet);
+    RTCPUID cMax = rtMpLinuxMaxCpus();
+    for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
+        if (RTMpIsCpuPossible(idCpu))
+            RTCpuSetAdd(pSet, idCpu);
+    return pSet;
+}
+
+
+RTDECL(RTCPUID) RTMpGetCount(void)
+{
     RTCPUSET Set;
-    return RTCpuSetIsMember(RTMpGetOnlineSet(&Set), idCpu);
-}
-
-
-RTDECL(bool) RTMpIsCpuPossible(RTCPUID idCpu)
-{
-    RTCPUSET Set;
-    return RTCpuSetIsMember(RTMpGetSet(&Set), idCpu);
-}
-
-
-RTDECL(PRTCPUSET) RTMpGetSet(PRTCPUSET pSet)
-{
-    RTCPUID idCpu = RTMpGetCount();
+    RTMpGetSet(&Set);
+    return RTCpuSetCount(&Set);
+}
+
+
+RTDECL(PRTCPUSET) RTMpGetOnlineSet(PRTCPUSET pSet)
+{
     RTCpuSetEmpty(pSet);
-    while (idCpu-- > 0)
-        RTCpuSetAdd(pSet, idCpu);
+    RTCPUID cMax = rtMpLinuxMaxCpus();
+    for (RTCPUID idCpu = 0; idCpu < cMax; idCpu++)
+        if (RTMpIsCpuOnline(idCpu))
+            RTCpuSetAdd(pSet, idCpu);
     return pSet;
-}
-
-
-RTDECL(RTCPUID) RTMpGetCount(void)
-{
-    SYSTEM_INFO SysInfo;
-    GetSystemInfo(&SysInfo);
-    Assert((RTCPUID)SysInfo.dwNumberOfProcessors == SysInfo.dwNumberOfProcessors);
-    return SysInfo.dwNumberOfProcessors;
-}
-
-
-RTDECL(PRTCPUSET) RTMpGetOnlineSet(PRTCPUSET pSet)
-{
-    SYSTEM_INFO SysInfo;
-    GetSystemInfo(&SysInfo);
-    return RTCpuSetFromU64(pSet, SysInfo.dwActiveProcessorMask);
 }