X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.h;h=325723f740787a79d9f84987a8424df15429e9b0;hb=816c50a5589bcf756f67119e657ae348e4858357;hp=d26df2855c43510310922a23ad449ccbfd5eba8d;hpb=584bfdc4e1093e43e4eb328a418b012745935a29;p=sbcl.git

diff --git a/src/runtime/interrupt.h b/src/runtime/interrupt.h
index d26df28..325723f 100644
--- a/src/runtime/interrupt.h
+++ b/src/runtime/interrupt.h
@@ -26,9 +26,30 @@
 /* FIXME: do not rely on NSIG being a multiple of 8 */
 #define REAL_SIGSET_SIZE_BYTES ((NSIG/8))
 
+/* Set all deferrable signals into *s. */
+extern void sigaddset_deferrable(sigset_t *s);
+/* Set all blockable signals into *s. */
+extern void sigaddset_blockable(sigset_t *s);
+/* Set all gc signals into *s. */
+extern void sigaddset_gc(sigset_t *s);
+
+extern sigset_t deferrable_sigset;
+extern sigset_t blockable_sigset;
+extern sigset_t gc_sigset;
+
+extern void block_deferrable_signals(void);
+extern void block_blockable_signals(void);
+extern void unblock_deferrable_signals(void);
+extern void unblock_gc_signals(void);
+extern void unblock_signals_in_context_and_maybe_warn(os_context_t *context);
+
+extern boolean deferrables_blocked_in_sigset_p(sigset_t *sigset);
+extern void check_deferrables_blocked_or_lose(void);
 extern void check_blockables_blocked_or_lose(void);
 extern void check_gc_signals_unblocked_or_lose(void);
-extern void unblock_gc_signals(void);
+extern void check_gc_signals_unblocked_in_sigset_or_lose(sigset_t *sigset);
+
+extern void maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset);
 
 static inline void
 sigcopyset(sigset_t *new, sigset_t *old)
@@ -38,12 +59,30 @@ sigcopyset(sigset_t *new, sigset_t *old)
 
 /* maximum signal nesting depth
  *
- * Note: In CMU CL, this was 4096, but there was no explanation given,
- * and it's hard to see why we'd need that many nested interrupts, so
- * I've scaled it back (to 256) to see what happens. -- WHN 20000730
-
- * Nothing happened, so let's creep it back a bit further -- dan 20030411 */
-#define MAX_INTERRUPTS 32
+ * FIXME: In CMUCL this was 4096, and it was first scaled down to 256
+ * and then 32, until finally Stumpwm broke: it is possible to receive
+ * interrupts in sufficiently quick succession that handler nesting
+ * can become preposterous. Scaling this back up to 1024 is a bandaid:
+ * for a real fix we should consider the following things:
+ *
+ *   We should almost certainly always use
+ *   arrange_return_to_lisp_function, though it needs to be thought
+ *   about arguments, and it needs to be able to pass a frobbable
+ *   context to the callee...
+ *
+ *   There are cases when nesting handlers is exactly what we want:
+ *   eg. SIGINT.
+ *
+ *   There are cases when we probably want to drop duplicate signals
+ *   on the floor if they arrive before the previous one has been handled.
+ *   Eg. SIGPROF.
+ *
+ *   There are cases when we probably want to handle duplicate signals
+ *   after the previous handler has returned, not before. Eg. SIGALARM.
+ *
+ * -- NS 2007-01-29
+ */
+#define MAX_INTERRUPTS 1024
 
 union interrupt_handler {
     lispobj lisp;
@@ -59,9 +98,14 @@ struct interrupt_data {
     int pending_signal;
     siginfo_t pending_info;
     sigset_t pending_mask;
+    /* Was pending mask saved for gc request? True if GC_PENDING or
+     * SIG_STOP_FOR_GC happened in a pseudo atomic with no GC_INHIBIT
+     * NIL. Both deferrable interrupt handlers and gc are careful not
+     * to clobber each other's pending_mask. */
+    boolean gc_blocked_deferrables;
 };
 
-
+extern boolean interrupt_handler_pending_p(void);
 extern void interrupt_init(void);
 extern void fake_foreign_function_call(os_context_t* context);
 extern void undo_fake_foreign_function_call(os_context_t* context);
@@ -91,13 +135,6 @@ extern unsigned long install_handler(int signal,
 
 extern union interrupt_handler interrupt_handlers[NSIG];
 
-/* Set all deferrable signals into *s. */
-extern void sigaddset_deferrable(sigset_t *s);
-/* Set all blockable signals into *s. */
-extern void sigaddset_blockable(sigset_t *s);
-
-extern void block_blockable_signals(void);
-
 /* The void* casting here avoids having to mess with the various types
  * of function argument lists possible for signal handlers:
  * SA_SIGACTION handlers have one signature, and the default old-style
@@ -108,7 +145,8 @@ extern void block_blockable_signals(void);
 extern void handle_trap(os_context_t *context, int trap);
 
 #ifndef LISP_FEATURE_WIN32
-extern void lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr);
+extern void lisp_memory_fault_error(os_context_t *context,
+                                    os_vm_address_t addr);
 #endif
 
 #endif