Changeset 6011658

Timestamp:

Dec 3, 2020, 3:15:55 PM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

fe9468e2

Parents:

62e456f

Message:

Fixed abort to no longer deadlock when calling itself recursively.
abort now disable interrupts indefinitely.

Location:

libcfa/src

Files:

• concurrency/kernel.cfa (modified) (1 diff)
• interpose.cfa (modified) (1 diff)

libcfa/src/concurrency/kernel.cfa

@@ -619 +619 @@
         lock( kernel_abort_lock __cfaabi_dbg_ctx2 );
 
+        // disable interrupts, it no longer makes sense to try to interrupt this processor
+        disable_interrupts();
+
         // first task to abort ?
         if ( kernel_abort_called ) {                    // not first task to abort ?

libcfa/src/interpose.cfa

@@ -220 +220 @@
 }
 
+static volatile int __abort_stage = 0;
+
 // Cannot forward va_list.
 void __abort( bool signalAbort, const char fmt[], va_list args ) {
-        void * kernel_data = kernel_abort();                            // must be done here to lock down kernel
-        int len;
-
-        signal( SIGABRT, SIG_DFL );                                                     // prevent final "real" abort from recursing to handler
-
-        len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
-        __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
-
-        assert( fmt );
-        len = vsnprintf( abort_text, abort_text_size, fmt, args );
-        __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
-
-        if ( fmt[strlen( fmt ) - 1] != '\n' ) {                         // add optional newline if missing at the end of the format text
-                __cfaabi_bits_write( STDERR_FILENO, "\n", 1 );
-        } // if
-        kernel_abort_msg( kernel_data, abort_text, abort_text_size );
-
-        __cfaabi_backtrace( signalAbort ? 4 : 2 );
-
-        __cabi_libc.abort();                                                            // print stack trace in handler
+        int stage = __atomic_add_fetch( &__abort_stage, 1, __ATOMIC_SEQ_CST );
+
+        // First stage: stop the cforall kernel and print
+        if(stage == 1) {
+                // increment stage
+                stage = __atomic_add_fetch( &__abort_stage, 1, __ATOMIC_SEQ_CST );
+
+                // must be done here to lock down kernel
+                void * kernel_data = kernel_abort();
+                int len;
+
+                signal( SIGABRT, SIG_DFL );                                                     // prevent final "real" abort from recursing to handler
+
+                len = snprintf( abort_text, abort_text_size, "Cforall Runtime error (UNIX pid:%ld) ", (long int)getpid() ); // use UNIX pid (versus getPid)
+                __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
+
+                assert( fmt );
+                len = vsnprintf( abort_text, abort_text_size, fmt, args );
+                __cfaabi_bits_write( STDERR_FILENO, abort_text, len );
+
+                // add optional newline if missing at the end of the format text
+                if ( fmt[strlen( fmt ) - 1] != '\n' ) {
+                        __cfaabi_bits_write( STDERR_FILENO, "\n", 1 );
+                } // if
+                kernel_abort_msg( kernel_data, abort_text, abort_text_size );
+        }
+
+        // Second stage: print the backtrace
+        if(stage == 2) {
+                // increment stage
+                stage = __atomic_add_fetch( &__abort_stage, 1, __ATOMIC_SEQ_CST );
+
+                // print stack trace in handler
+                __cfaabi_backtrace( signalAbort ? 4 : 2 );
+        }
+
+        do {
+                // Finally call abort
+                __cabi_libc.abort();
+
+                // Loop so that we never return
+        } while(true);
 }