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Date:      Thu, 23 Oct 2003 12:28:39 +0300
From:      Alexey Zelkin <phantom@FreeBSD.org.ua>
To:        java@freebsd.org
Subject:   jdk14 fork() problem fix
Message-ID:  <20031023122839.A75570@phantom.cris.net>

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hi,

This is an intermediate version of fix of jdk fork problem (i.e.
Runtime.getRuntime().exec() and friends).

It does affect only people who use libc_r (kse and thr should not
be affected).

Please try this one and report me if it fixes problems for you.

PS: If you are rebuilding already built jdk (i.e. object files are
already compiled) remove 'control/build/bsd-i586/tmp/java/java.lang' directory
before restarting of build.

Index: UNIXProcess_md.c.bsd
===================================================================
RCS file: /home/jdk14-cvs/jdk142-src/j2se/src/solaris/native/java/lang/UNIXProcess_md.c.bsd,v
retrieving revision 1.2
diff -u -r1.2 UNIXProcess_md.c.bsd
--- UNIXProcess_md.c.bsd	15 Oct 2003 15:49:39 -0000	1.2
+++ UNIXProcess_md.c.bsd	23 Oct 2003 10:20:48 -0000
@@ -22,6 +22,12 @@
 #include <errno.h>
 #include <unistd.h>
 
+#if defined(__FreeBSD__)
+#include <dlfcn.h>
+#include <pthread.h>
+#include <pthread_np.h>
+#endif
+
 /* path in the environment */
 static char **PATH = 0;
 /* effective uid */
@@ -228,6 +234,61 @@
     }
 }
 
+#if defined(__FreeBSD__)
+
+extern pid_t   __sys_fork(void);
+
+static pid_t
+jdk_fork_wrapper()
+{
+    pid_t resultPid;
+#if (__FreeBSD_version < 5)
+    static int is_libc_r = -1;
+    void *funcref;
+
+    if (is_libc_r == -1) {
+	is_libc_r = 1;
+
+	/*
+         * BSDNOTE: Check for loaded symbols.
+         *
+         * If "_thr_critical_enter" is found assume we are using 'libthr'.
+         * If _kse_critical_enter is found assume we are using 'libkse'.
+         * Otherwise we are using libc_r.
+         *
+         * If libc_r is loaded, use fork system call drectly to avoid
+         * problems with using protected pages. 
+         *
+         * --phantom
+	 */
+	funcref = dlsym(RTLD_DEFAULT, "_kse_critical_enter");
+	if (funcref != NULL)
+	    is_libc_r = 0;
+	else {
+	    funcref = dlsym(RTLD_DEFAULT, "_thr_critical_enter");
+	    if (funcref != NULL)
+		is_libc_r = 0;
+	}
+    }
+
+    if (is_libc_r == 0) {
+	/* Not a libc_r */
+	resultPid = fork();
+    } else {
+#endif /* __FreeBSD_version < 5 */
+        pthread_suspend_all_np(); 
+        resultPid = __sys_fork();
+        if (resultPid != 0)
+	    /* leave child in single threading mode */
+ 	    pthread_resume_all_np();
+#if (__FreeBSD_version < 5)
+    }
+#endif /* __FreeBSD_version < 5 */
+
+    return resultPid;
+}
+#endif /* __FreeBSD__ */
+
 JNIEXPORT jint JNICALL
 Java_java_lang_UNIXProcess_forkAndExec(JNIEnv *env,
 				       jobject process,
@@ -335,8 +396,12 @@
     if (path != NULL) {
         cwd = (char *)JNU_GetStringPlatformChars(env, path, NULL);
     }
- 
+
+#if defined(__FreeBSD__)
+    resultPid = jdk_fork_wrapper();
+#else
     resultPid = fork();
+#endif
 
     if (resultPid < 0) {
 	char errmsg[128];



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