refs qorelanguage/qore#4793 fixed signal handling, fixed random deadl…

…ocks in JIT in the JVM on macOS aarch64
qorelanguage · Sep 16, 2023 · 17fd387 · 17fd387
1 parent a475307
commit 17fd387
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Showing 4 changed files with 32 additions and 33 deletions.
diff --git a/CMakeLists.txt b/CMakeLists.txt
@@ -17,7 +17,7 @@ if (POLICY CMP0042)
     cmake_policy(SET CMP0042 NEW)
 endif()
 
-find_package(Qore 1.14 REQUIRED)
+find_package(Qore 1.19 REQUIRED)
 find_package(JNI REQUIRED)
 find_package(Java REQUIRED)
 if (${Java_VERSION_MAJOR} LESS 11)

diff --git a/docs/mainpage.dox.tmpl b/docs/mainpage.dox.tmpl
@@ -215,6 +215,26 @@ class QoreIteratorTest extends AbstractIterator {
 QORE_JNI_MIN_HEAP_SIZE=20m QORE_JNI_MAX_HEAP_SIZE=20m qore -l jni script.q
     @endverbatim
 
+    @subsection jni_signals Signals Used By the JVM
+
+    The JVM requires signals to run properly, and, while %Qore initializes the JVM with reduced signals (using the
+    <tt>-Xrs</tt> argument to the JVM), certain signals are critical to the operation of the JVM and cannot be used by
+    %Qore programs.
+
+    The signals in the following table are reserved by the JVM.
+
+    <b>Signals Reserved by the JVM</b>
+    |!Signal|!Description
+    |\c SIGTRAP|Trap exception
+    |\c SIGSEGV|Segmentation violation
+    |\c SIGBUS|Bus error
+    |\c SIGCHLD|Child process terminated
+    |\c SIGILL|Illegal instruction
+    |\c SIGFPE|Floating-point exception
+
+    If any %Qore code has a signal handler assigned to any of the above signals (for the signals that can be
+    assigned), the \c jni module cannot be initialized and will fail to load.
+
     @section jni_use_java_in_qore Using Java APIs in Qore
 
     @subsection jniimport Importing Java APIs into Qore
@@ -830,6 +850,9 @@ set_save_object_callback(callback);
     @section jnireleasenotes jni Module Release Notes
 
     @subsection jni_2_3_2 jni Module Version 2.3.2
+    - fixed a bugs handling the signal mask that could cause hard-to-debug problems such as deadlocks in JIT in the
+      JVM on macOS aarch64
+      (<a href="https://github.com/qorelanguage/qore/issues/4793">issue 4793</a>)
     - fixed signatures for Java methods with varargs params
       (<a href="https://github.com/qorelanguage/qore/issues/4787">issue 4787</a>)
 

diff --git a/qore-jni-module.spec b/qore-jni-module.spec
@@ -17,9 +17,9 @@ BuildRequires:  gcc-c++
 BuildRequires:  devtoolset-7-gcc-c++
 %endif
 BuildRequires:  cmake >= 3.5
-BuildRequires:  qore-devel >= 1.14
-BuildRequires:  qore-stdlib >= 1.14
-BuildRequires:  qore >= 1.14
+BuildRequires:  qore-devel >= 1.19
+BuildRequires:  qore-stdlib >= 1.19
+BuildRequires:  qore >= 1.19
 BuildRequires:  java-17-openjdk-devel
 BuildRequires:  unzip
 BuildRequires:  doxygen

diff --git a/src/jni-module.cpp b/src/jni-module.cpp
@@ -58,7 +58,7 @@ using namespace jni;
 
 sig_vec_t sig_vec = {
 #ifndef Q_WINDOWS
-    SIGTRAP, SIGUSR1, SIGSEGV, SIGBUS, SIGCHLD
+    SIGTRAP, SIGSEGV, SIGBUS, SIGCHLD, SIGILL, SIGFPE
 #endif
 };
 
@@ -167,7 +167,10 @@ static QoreStringNode* jni_module_init() {
 
     qore_set_module_option("jni", "jni-version", JNI_VERSION_10);
 
-    QoreStringNode* err = nullptr;
+    QoreStringNode* err = qore_reassign_signals(sig_vec, QORE_JNI_MODULE_NAME, true);
+    if (err) {
+        return err;
+    }
 
     ValueHolder jvm_ptr(qore_get_module_option("jni", "jvm-ptr"), nullptr);
     if (jvm_ptr->getType() == NT_INT) {
@@ -211,33 +214,6 @@ static QoreStringNode* jni_module_init() {
 
     printd(5, "jni_module_init() initialized JVM\n");
 
-#ifndef Q_WINDOWS
-    {
-        sig_vec_t new_sig_vec;
-        for (int sig : sig_vec) {
-            QoreStringNode* err = qore_reassign_signal(sig, QORE_JNI_MODULE_NAME);
-            if (err) {
-                printd(5, "%s\n", err->c_str());
-                // ignore errors; already assigned to another module
-                err->deref();
-            }
-            new_sig_vec.push_back(sig);
-        }
-        if (!new_sig_vec.empty()) {
-            sigset_t mask;
-            // setup signal mask
-            sigemptyset(&mask);
-            for (auto& sig : new_sig_vec) {
-                //printd(5, "jni_module_init() unblocking signal %d\n", sig);
-                sigaddset(&mask, sig);
-            }
-            // unblock threads
-            pthread_sigmask(SIG_UNBLOCK, &mask, 0);
-        }
-    }
-
-#endif
-
     if (!bootstrap) {
         return jni_module_init_finalize();
     }