jdk/src/solaris/native/java/lang/UNIXProcess_md.c
changeset 2 90ce3da70b43
child 48 dc5744ca15ea
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/solaris/native/java/lang/UNIXProcess_md.c	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,645 @@
+/*
+ * Copyright 1995-2006 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+#undef  _LARGEFILE64_SOURCE
+#define _LARGEFILE64_SOURCE 1
+
+#include "jni.h"
+#include "jvm.h"
+#include "jvm_md.h"
+#include "jni_util.h"
+#include "io_util.h"
+
+/*
+ * Platform-specific support for java.lang.Process
+ */
+#include <assert.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <ctype.h>
+#include <wait.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <limits.h>
+
+#ifndef STDIN_FILENO
+#define STDIN_FILENO 0
+#endif
+
+#ifndef STDOUT_FILENO
+#define STDOUT_FILENO 1
+#endif
+
+#ifndef STDERR_FILENO
+#define STDERR_FILENO 2
+#endif
+
+#ifndef SA_NOCLDSTOP
+#define SA_NOCLDSTOP 0
+#endif
+
+#ifndef SA_RESTART
+#define SA_RESTART 0
+#endif
+
+#define FAIL_FILENO (STDERR_FILENO + 1)
+
+static void
+setSIGCHLDHandler(JNIEnv *env)
+{
+    /* There is a subtle difference between having the signal handler
+     * for SIGCHLD be SIG_DFL and SIG_IGN.  We cannot obtain process
+     * termination information for child processes if the signal
+     * handler is SIG_IGN.  It must be SIG_DFL.
+     *
+     * We used to set the SIGCHLD handler only on Linux, but it's
+     * safest to set it unconditionally.
+     *
+     * Consider what happens if java's parent process sets the SIGCHLD
+     * handler to SIG_IGN.  Normally signal handlers are inherited by
+     * children, but SIGCHLD is a controversial case.  Solaris appears
+     * to always reset it to SIG_DFL, but this behavior may be
+     * non-standard-compliant, and we shouldn't rely on it.
+     *
+     * References:
+     * http://www.opengroup.org/onlinepubs/7908799/xsh/exec.html
+     * http://www.pasc.org/interps/unofficial/db/p1003.1/pasc-1003.1-132.html
+     */
+    struct sigaction sa;
+    sa.sa_handler = SIG_DFL;
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;
+    if (sigaction(SIGCHLD, &sa, NULL) < 0)
+        JNU_ThrowInternalError(env, "Can't set SIGCHLD handler");
+}
+
+static void*
+xmalloc(JNIEnv *env, size_t size)
+{
+    void *p = malloc(size);
+    if (p == NULL)
+        JNU_ThrowOutOfMemoryError(env, NULL);
+    return p;
+}
+
+#define NEW(type, n) ((type *) xmalloc(env, (n) * sizeof(type)))
+
+/**
+ * If PATH is not defined, the OS provides some default value.
+ * Unfortunately, there's no portable way to get this value.
+ * Fortunately, it's only needed if the child has PATH while we do not.
+ */
+static const char*
+defaultPath(void)
+{
+#ifdef __solaris__
+    /* These really are the Solaris defaults! */
+    return (geteuid() == 0 || getuid() == 0) ?
+        "/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin:/usr/sbin" :
+        "/usr/xpg4/bin:/usr/ccs/bin:/usr/bin:/opt/SUNWspro/bin:";
+#else
+    return ":/bin:/usr/bin";    /* glibc */
+#endif
+}
+
+static const char*
+effectivePath(void)
+{
+    const char *s = getenv("PATH");
+    return (s != NULL) ? s : defaultPath();
+}
+
+static int
+countOccurrences(const char *s, char c)
+{
+    int count;
+    for (count = 0; *s != '\0'; s++)
+        count += (*s == c);
+    return count;
+}
+
+static const char * const *
+splitPath(JNIEnv *env, const char *path)
+{
+    const char *p, *q;
+    char **pathv;
+    int i;
+    int count = countOccurrences(path, ':') + 1;
+
+    pathv = NEW(char*, count+1);
+    pathv[count] = NULL;
+    for (p = path, i = 0; i < count; i++, p = q + 1) {
+        for (q = p; (*q != ':') && (*q != '\0'); q++)
+            ;
+        if (q == p)             /* empty PATH component => "." */
+            pathv[i] = "./";
+        else {
+            int addSlash = ((*(q - 1)) != '/');
+            pathv[i] = NEW(char, q - p + addSlash + 1);
+            memcpy(pathv[i], p, q - p);
+            if (addSlash)
+                pathv[i][q - p] = '/';
+            pathv[i][q - p + addSlash] = '\0';
+        }
+    }
+    return (const char * const *) pathv;
+}
+
+/**
+ * Cached value of JVM's effective PATH.
+ * (We don't support putenv("PATH=...") in native code)
+ */
+static const char *parentPath;
+
+/**
+ * Split, canonicalized version of parentPath
+ */
+static const char * const *parentPathv;
+
+static jfieldID field_exitcode;
+
+JNIEXPORT void JNICALL
+Java_java_lang_UNIXProcess_initIDs(JNIEnv *env, jclass clazz)
+{
+    field_exitcode = (*env)->GetFieldID(env, clazz, "exitcode", "I");
+
+    parentPath  = effectivePath();
+    parentPathv = splitPath(env, parentPath);
+
+    setSIGCHLDHandler(env);
+}
+
+
+#ifndef WIFEXITED
+#define WIFEXITED(status) (((status)&0xFF) == 0)
+#endif
+
+#ifndef WEXITSTATUS
+#define WEXITSTATUS(status) (((status)>>8)&0xFF)
+#endif
+
+#ifndef WIFSIGNALED
+#define WIFSIGNALED(status) (((status)&0xFF) > 0 && ((status)&0xFF00) == 0)
+#endif
+
+#ifndef WTERMSIG
+#define WTERMSIG(status) ((status)&0x7F)
+#endif
+
+/* Block until a child process exits and return its exit code.
+   Note, can only be called once for any given pid. */
+JNIEXPORT jint JNICALL
+Java_java_lang_UNIXProcess_waitForProcessExit(JNIEnv* env,
+                                              jobject junk,
+                                              jint pid)
+{
+    /* We used to use waitid() on Solaris, waitpid() on Linux, but
+     * waitpid() is more standard, so use it on all POSIX platforms. */
+    int status;
+    /* Wait for the child process to exit.  This returns immediately if
+       the child has already exited. */
+    while (waitpid(pid, &status, 0) < 0) {
+        switch (errno) {
+        case ECHILD: return 0;
+        case EINTR: break;
+        default: return -1;
+        }
+    }
+
+    if (WIFEXITED(status)) {
+        /*
+         * The child exited normally; get its exit code.
+         */
+        return WEXITSTATUS(status);
+    } else if (WIFSIGNALED(status)) {
+        /* The child exited because of a signal.
+         * The best value to return is 0x80 + signal number,
+         * because that is what all Unix shells do, and because
+         * it allows callers to distinguish between process exit and
+         * process death by signal.
+         * Unfortunately, the historical behavior on Solaris is to return
+         * the signal number, and we preserve this for compatibility. */
+#ifdef __solaris__
+        return WTERMSIG(status);
+#else
+        return 0x80 + WTERMSIG(status);
+#endif
+    } else {
+        /*
+         * Unknown exit code; pass it through.
+         */
+        return status;
+    }
+}
+
+static int
+closeDescriptors(void)
+{
+    DIR *dp;
+    struct dirent64 *dirp;
+    int from_fd = FAIL_FILENO + 1;
+
+    /* We're trying to close all file descriptors, but opendir() might
+     * itself be implemented using a file descriptor, and we certainly
+     * don't want to close that while it's in use.  We assume that if
+     * opendir() is implemented using a file descriptor, then it uses
+     * the lowest numbered file descriptor, just like open().  So we
+     * close a couple explicitly.  */
+
+    close(from_fd);             /* for possible use by opendir() */
+    close(from_fd + 1);         /* another one for good luck */
+
+    if ((dp = opendir("/proc/self/fd")) == NULL)
+        return 0;
+
+    /* We use readdir64 instead of readdir to work around Solaris bug
+     * 6395699: /proc/self/fd fails to report file descriptors >= 1024 on Solaris 9
+     */
+    while ((dirp = readdir64(dp)) != NULL) {
+        int fd;
+        if (isdigit(dirp->d_name[0]) &&
+            (fd = strtol(dirp->d_name, NULL, 10)) >= from_fd + 2)
+            close(fd);
+    }
+
+    closedir(dp);
+
+    return 1;
+}
+
+static void
+moveDescriptor(int fd_from, int fd_to)
+{
+    if (fd_from != fd_to) {
+        dup2(fd_from, fd_to);
+        close(fd_from);
+    }
+}
+
+static const char *
+getBytes(JNIEnv *env, jbyteArray arr)
+{
+    return arr == NULL ? NULL :
+        (const char*) (*env)->GetByteArrayElements(env, arr, NULL);
+}
+
+static void
+releaseBytes(JNIEnv *env, jbyteArray arr, const char* parr)
+{
+    if (parr != NULL)
+        (*env)->ReleaseByteArrayElements(env, arr, (jbyte*) parr, JNI_ABORT);
+}
+
+static void
+initVectorFromBlock(const char**vector, const char* block, int count)
+{
+    int i;
+    const char *p;
+    for (i = 0, p = block; i < count; i++) {
+        /* Invariant: p always points to the start of a C string. */
+        vector[i] = p;
+        while (*(p++));
+    }
+    vector[count] = NULL;
+}
+
+static void
+throwIOException(JNIEnv *env, int errnum, const char *defaultDetail)
+{
+    static const char * const format = "error=%d, %s";
+    const char *detail = defaultDetail;
+    char *errmsg;
+    jstring s;
+
+    if (errnum != 0) {
+        const char *s = strerror(errnum);
+        if (strcmp(s, "Unknown error") != 0)
+            detail = s;
+    }
+    /* ASCII Decimal representation uses 2.4 times as many bits as binary. */
+    errmsg = NEW(char, strlen(format) + strlen(detail) + 3 * sizeof(errnum));
+    sprintf(errmsg, format, errnum, detail);
+    s = JNU_NewStringPlatform(env, errmsg);
+    if (s != NULL) {
+        jobject x = JNU_NewObjectByName(env, "java/io/IOException",
+                                        "(Ljava/lang/String;)V", s);
+        if (x != NULL)
+            (*env)->Throw(env, x);
+    }
+    free(errmsg);
+}
+
+#ifdef DEBUG_PROCESS
+/* Debugging process code is difficult; where to write debug output? */
+static void
+debugPrint(char *format, ...)
+{
+    FILE *tty = fopen("/dev/tty", "w");
+    va_list ap;
+    va_start(ap, format);
+    vfprintf(tty, format, ap);
+    va_end(ap);
+    fclose(tty);
+}
+#endif /* DEBUG_PROCESS */
+
+/* Version of execvpe when child's PATH differs from parent's */
+static int
+execvp_usingParentPath(const char *file, const char *const argv[])
+{
+    char expanded_file[PATH_MAX];
+    int filelen = strlen(file);
+    int sticky_errno = 0;
+    const char * const * dirs;
+    /* Search parent's PATH */
+    for (dirs = parentPathv; *dirs; dirs++) {
+        const char * dir = *dirs;
+        int dirlen = strlen(dir);
+        if (filelen + dirlen + 1 >= PATH_MAX) {
+            /* Resist the urge to remove this limit;
+             * calling malloc after fork is unsafe. */
+            errno = ENAMETOOLONG;
+            continue;
+        }
+        strcpy(expanded_file, dir);
+        strcpy(expanded_file + dirlen, file);
+        execvp(expanded_file, (char **) argv);
+        /* There are 3 responses to various classes of errno:
+         * return immediately, continue (especially for ENOENT),
+         * or continue with "sticky" errno.
+         *
+         * From exec(3):
+         *
+         * If permission is denied for a file (the attempted
+         * execve returned EACCES), these functions will continue
+         * searching the rest of the search path.  If no other
+         * file is found, however, they will return with the
+         * global variable errno set to EACCES.
+         */
+        switch (errno) {
+        case EACCES:
+            sticky_errno = errno;
+            /* FALLTHRU */
+        case ENOENT:
+        case ENOTDIR:
+#ifdef ELOOP
+        case ELOOP:
+#endif
+#ifdef ESTALE
+        case ESTALE:
+#endif
+#ifdef ENODEV
+        case ENODEV:
+#endif
+#ifdef ETIMEDOUT
+        case ETIMEDOUT:
+#endif
+            break; /* Try other directories in PATH */
+        default:
+            return -1;
+        }
+    }
+    if (sticky_errno != 0)
+        errno = sticky_errno;
+    return -1;
+}
+
+/* execvpe should have been included in the Unix standards. */
+static int
+execvpe(const char *file, const char *const argv[], const char *const envp[])
+{
+    /* This is one of the rare times it's more portable to declare an
+     * external symbol explicitly, rather than via a system header.
+     * The declaration is standardized as part of UNIX98, but there is
+     * no standard (not even de-facto) header file where the
+     * declaration is to be found.  See:
+     * http://www.opengroup.org/onlinepubs/009695399/functions/environ.html
+     * http://www.opengroup.org/onlinepubs/009695399/functions/xsh_chap02_02.html
+     *
+     * "All identifiers in this volume of IEEE Std 1003.1-2001, except
+     * environ, are defined in at least one of the headers" (!)
+     */
+    extern char **environ;
+
+    if (envp != NULL)
+        environ = (char **) envp;
+
+    if (/* Parent and child environment the same?  Use child PATH. */
+        (envp == NULL)
+
+        /* http://www.opengroup.org/onlinepubs/009695399/functions/exec.html
+         * "If the file argument contains a slash character, it is used as
+         * the pathname for this file.  Otherwise, the path prefix for this
+         * file is obtained by a search of the directories passed in the
+         * PATH environment variable" */
+        || (strchr(file, '/') != NULL)
+
+        /* Parent and child PATH the same?  Use child PATH. */
+        || (strcmp(parentPath, effectivePath()) == 0)
+
+        /* We want ENOENT, not EACCES, for zero-length program names. */
+        || (*file == '\0'))
+
+        return execvp(file, (char **) argv);
+    else
+        return execvp_usingParentPath(file, argv);
+}
+
+static void
+closeSafely(int fd)
+{
+    if (fd != -1)
+        close(fd);
+}
+
+#ifndef __solaris__
+#undef fork1
+#define fork1() fork()
+#endif
+
+JNIEXPORT jint JNICALL
+Java_java_lang_UNIXProcess_forkAndExec(JNIEnv *env,
+                                       jobject process,
+                                       jbyteArray prog,
+                                       jbyteArray argBlock, jint argc,
+                                       jbyteArray envBlock, jint envc,
+                                       jbyteArray dir,
+                                       jboolean redirectErrorStream,
+                                       jobject stdin_fd,
+                                       jobject stdout_fd,
+                                       jobject stderr_fd)
+{
+    int errnum;
+    int resultPid = -1;
+    int in[2], out[2], err[2], fail[2];
+    const char **argv = NULL;
+    const char **envv = NULL;
+    const char *pprog     = getBytes(env, prog);
+    const char *pargBlock = getBytes(env, argBlock);
+    const char *penvBlock = getBytes(env, envBlock);
+    const char *pdir      = getBytes(env, dir);
+
+    in[0] = in[1] = out[0] = out[1] = err[0] = err[1] = fail[0] = fail[1] = -1;
+
+    assert(prog != NULL && argBlock != NULL);
+    if (pprog     == NULL) goto Catch;
+    if (pargBlock == NULL) goto Catch;
+    if (envBlock  != NULL && penvBlock == NULL) goto Catch;
+    if (dir       != NULL && pdir      == NULL) goto Catch;
+
+    /* Convert pprog + pargBlock into a char ** argv */
+    if ((argv = NEW(const char *, argc + 2)) == NULL)
+        goto Catch;
+    argv[0] = pprog;
+    initVectorFromBlock(argv+1, pargBlock, argc);
+
+    if (envBlock != NULL) {
+        /* Convert penvBlock into a char ** envv */
+        if ((envv = NEW(const char *, envc + 1)) == NULL)
+            goto Catch;
+        initVectorFromBlock(envv, penvBlock, envc);
+    }
+
+    if ((pipe(in)   < 0) ||
+        (pipe(out)  < 0) ||
+        (pipe(err)  < 0) ||
+        (pipe(fail) < 0)) {
+        throwIOException(env, errno, "Bad file descriptor");
+        goto Catch;
+    }
+
+    resultPid = fork1();
+    if (resultPid < 0) {
+        throwIOException(env, errno, "Fork failed");
+        goto Catch;
+    }
+
+    if (resultPid == 0) {
+        /* Child process */
+
+        /* Close the parent sides of the pipe.
+           Give the child sides of the pipes the right fileno's.
+           Closing pipe fds here is redundant, since closeDescriptors()
+           would do it anyways, but a little paranoia is a good thing. */
+        /* Note: it is possible for in[0] == 0 */
+        close(in[1]);
+        moveDescriptor(in[0], STDIN_FILENO);
+        close(out[0]);
+        moveDescriptor(out[1], STDOUT_FILENO);
+        close(err[0]);
+        if (redirectErrorStream) {
+            close(err[1]);
+            dup2(STDOUT_FILENO, STDERR_FILENO);
+        } else {
+            moveDescriptor(err[1], STDERR_FILENO);
+        }
+        close(fail[0]);
+        moveDescriptor(fail[1], FAIL_FILENO);
+
+        /* close everything */
+        if (closeDescriptors() == 0) { /* failed,  close the old way */
+            int max_fd = (int)sysconf(_SC_OPEN_MAX);
+            int i;
+            for (i = FAIL_FILENO + 1; i < max_fd; i++)
+                close(i);
+        }
+
+        /* change to the new working directory */
+        if (pdir != NULL && chdir(pdir) < 0)
+            goto WhyCantJohnnyExec;
+
+        if (fcntl(FAIL_FILENO, F_SETFD, FD_CLOEXEC) == -1)
+            goto WhyCantJohnnyExec;
+
+        execvpe(argv[0], argv, envv);
+
+    WhyCantJohnnyExec:
+        /* We used to go to an awful lot of trouble to predict whether the
+         * child would fail, but there is no reliable way to predict the
+         * success of an operation without *trying* it, and there's no way
+         * to try a chdir or exec in the parent.  Instead, all we need is a
+         * way to communicate any failure back to the parent.  Easy; we just
+         * send the errno back to the parent over a pipe in case of failure.
+         * The tricky thing is, how do we communicate the *success* of exec?
+         * We use FD_CLOEXEC together with the fact that a read() on a pipe
+         * yields EOF when the write ends (we have two of them!) are closed.
+         */
+        errnum = errno;
+        write(FAIL_FILENO, &errnum, sizeof(errnum));
+        close(FAIL_FILENO);
+        _exit(-1);
+    }
+
+    /* parent process */
+
+    close(fail[1]); fail[1] = -1; /* See: WhyCantJohnnyExec */
+    if (read(fail[0], &errnum, sizeof(errnum)) != 0) {
+        waitpid(resultPid, NULL, 0);
+        throwIOException(env, errnum, "Exec failed");
+        goto Catch;
+    }
+
+    (*env)->SetIntField(env, stdin_fd,  IO_fd_fdID, in [1]);
+    (*env)->SetIntField(env, stdout_fd, IO_fd_fdID, out[0]);
+    (*env)->SetIntField(env, stderr_fd, IO_fd_fdID, err[0]);
+
+ Finally:
+    /* Always clean up the child's side of the pipes */
+    closeSafely(in [0]);
+    closeSafely(out[1]);
+    closeSafely(err[1]);
+
+    /* Always clean up fail descriptors */
+    closeSafely(fail[0]);
+    closeSafely(fail[1]);
+
+    free(argv);
+    free(envv);
+
+    releaseBytes(env, prog,     pprog);
+    releaseBytes(env, argBlock, pargBlock);
+    releaseBytes(env, envBlock, penvBlock);
+    releaseBytes(env, dir,      pdir);
+
+    return resultPid;
+
+ Catch:
+    /* Clean up the parent's side of the pipes in case of failure only */
+    closeSafely(in [1]);
+    closeSafely(out[0]);
+    closeSafely(err[0]);
+    goto Finally;
+}
+
+JNIEXPORT void JNICALL
+Java_java_lang_UNIXProcess_destroyProcess(JNIEnv *env, jobject junk, jint pid)
+{
+    kill(pid, SIGTERM);
+}