1.0.26.8: QSHOW changes, bug reporting guidelines

[sbcl.git] / src / runtime / linux-os.c

diff --git a/src/runtime/linux-os.c b/src/runtime/linux-os.c
index 8bd86f1..2e58266 100644 (file)
--- a/src/runtime/linux-os.c
+++ b/src/runtime/linux-os.c
@@ -72,39 +72,75 @@ size_t os_vm_page_size;
 /* values taken from the kernel's linux/futex.h.  This header file
    doesn't exist in userspace, which is our excuse for not grovelling
    them automatically */
-#define FUTEX_WAIT (0)
-#define FUTEX_WAKE (1)
+#define FUTEX_WAIT 0
+#define FUTEX_WAKE 1
+/* This is also copied from linux/futex.h so that a binary compiled on
+ * a not so recent Linux system can still take advantage of private
+ * futexes when available.*/
+#define FUTEX_WAIT_PRIVATE (0+128)
+#define FUTEX_WAKE_PRIVATE (1+128)
 #define FUTEX_FD (2)
 #define FUTEX_REQUEUE (3)
 
+/* Not static so that Lisp may query it. */
+boolean futex_private_supported_p;
+
+static inline int
+futex_wait_op()
+{
+    return (futex_private_supported_p ? FUTEX_WAIT_PRIVATE : FUTEX_WAIT);
+}
+
+static inline int
+futex_wake_op()
+{
+    return (futex_private_supported_p ? FUTEX_WAKE_PRIVATE : FUTEX_WAKE);
+}
+
 #define sys_futex sbcl_sys_futex
 static inline int sys_futex (void *futex, int op, int val, struct timespec *rel)
 {
     return syscall (SYS_futex, futex, op, val, rel);
 }
 
+static void
+futex_init()
+{
+    int x = 0;
+    sys_futex(&x, FUTEX_WAIT, 1, 0);
+    if (errno == ENOSYS)
+        lose("This version of SBCL is compiled with threading support, but your kernel\n"
+             "is too old to support this. Please use a more recent kernel or\n"
+             "a version of SBCL without threading support.\n");
+    sys_futex(&x, FUTEX_WAIT_PRIVATE, 1, 0);
+    if (errno == EWOULDBLOCK) {
+        futex_private_supported_p = 1;
+    } else {
+        futex_private_supported_p = 0;
+        SHOW("No futex private suppport\n");
+    }
+}
+
 int
 futex_wait(int *lock_word, int oldval, long sec, unsigned long usec)
 {
   struct timespec timeout;
   int t;
 
- again:
   if (sec<0) {
-    t = sys_futex(lock_word,FUTEX_WAIT,oldval, 0);
+      t = sys_futex(lock_word, futex_wait_op(), oldval, 0);
   }
   else {
-    timeout.tv_sec = sec;
-    timeout.tv_nsec = usec * 1000;
-    t = sys_futex(lock_word,FUTEX_WAIT,oldval, &timeout);
+      timeout.tv_sec = sec;
+      timeout.tv_nsec = usec * 1000;
+      t = sys_futex(lock_word, futex_wait_op(), oldval, &timeout);
   }
   if (t==0)
       return 0;
   else if (errno==ETIMEDOUT)
       return 1;
   else if (errno==EINTR)
-      /* spurious wakeup from interrupt */
-      goto again;
+      return 2;
   else
       /* EWOULDBLOCK and others, need to check the lock */
       return -1;
@@ -113,7 +149,7 @@ futex_wait(int *lock_word, int oldval, long sec, unsigned long usec)
 int
 futex_wake(int *lock_word, int n)
 {
-    return sys_futex(lock_word,FUTEX_WAKE,n,0);
+    return sys_futex(lock_word, futex_wake_op(),n,0);
 }
 #endif
 
@@ -156,9 +192,6 @@ os_init(char *argv[], char *envp[])
 {
     /* Conduct various version checks: do we have enough mmap(), is
      * this a sparc running 2.2, can we do threads? */
-#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_SB_LUTEX) && !defined(LISP_FEATURE_SB_PTHREAD_FUTEX)
-    int *futex=0;
-#endif
     struct utsname name;
     int major_version;
     int minor_version;
@@ -183,12 +216,7 @@ os_init(char *argv[], char *envp[])
     }
 #ifdef LISP_FEATURE_SB_THREAD
 #if !defined(LISP_FEATURE_SB_LUTEX) && !defined(LISP_FEATURE_SB_PTHREAD_FUTEX)
-    futex_wait(futex,-1,-1,0);
-    if(errno==ENOSYS) {
-       lose("This version of SBCL is compiled with threading support, but your kernel\n"
-            "is too old to support this. Please use a more recent kernel or\n"
-            "a version of SBCL without threading support.\n");
-    }
+    futex_init();
 #endif
     if(! isnptl()) {
        lose("This version of SBCL only works correctly with the NPTL threading\n"
@@ -378,9 +406,8 @@ is_valid_lisp_addr(os_vm_address_t addr)
  * page fault on this OS.
  */
 static void
-sigsegv_handler(int signal, siginfo_t *info, void* void_context)
+sigsegv_handler(int signal, siginfo_t *info, os_context_t *context)
 {
-    os_context_t *context = arch_os_get_context(&void_context);
     os_vm_address_t addr = arch_get_bad_addr(signal, info, context);
 
 #ifdef LISP_FEATURE_ALPHA
@@ -405,11 +432,7 @@ sigsegv_handler(int signal, siginfo_t *info, void* void_context)
     if (!cheneygc_handle_wp_violation(context, addr))
 #endif
         if (!handle_guard_page_triggered(context, addr))
-#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
             lisp_memory_fault_error(context, addr);
-#else
-            interrupt_handle_now(signal, info, context);
-#endif
 }
 
 void
@@ -418,12 +441,8 @@ os_install_interrupt_handlers(void)
     undoably_install_low_level_interrupt_handler(SIG_MEMORY_FAULT,
                                                  sigsegv_handler);
 #ifdef LISP_FEATURE_SB_THREAD
-    undoably_install_low_level_interrupt_handler(SIG_INTERRUPT_THREAD,
-                                                 interrupt_thread_handler);
     undoably_install_low_level_interrupt_handler(SIG_STOP_FOR_GC,
                                                  sig_stop_for_gc_handler);
-    undoably_install_low_level_interrupt_handler(SIG_RESUME_FROM_GC,
-                                                 sig_resume_from_gc_handler);
 #endif
 }