1.0.0.31: pthread-futex: another pthread back-end of mutex

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

diff --git a/src/runtime/linux-os.c b/src/runtime/linux-os.c
index 8b6972c..4c6ef83 100644 (file)
--- a/src/runtime/linux-os.c
+++ b/src/runtime/linux-os.c
@@ -62,7 +62,7 @@ int personality (unsigned long);
 
 size_t os_vm_page_size;
 
-#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_SB_LUTEX)
+#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_SB_LUTEX) && !defined(LISP_FEATURE_SB_PTHREAD_FUTEX)
 #include <sys/syscall.h>
 #include <unistd.h>
 #include <errno.h>
@@ -84,7 +84,18 @@ static inline int sys_futex (void *futex, int op, int val, struct timespec *rel)
 int
 futex_wait(int *lock_word, int oldval)
 {
-    int t= sys_futex(lock_word,FUTEX_WAIT,oldval, 0);
+    int t;
+  again:
+    t = sys_futex(lock_word,FUTEX_WAIT,oldval, 0);
+
+    /* Interrupted FUTEX_WAIT calls may return early.
+     *
+     * If someone manages to wake the futex while we're spinning
+     * around it, we will just return with -1 and errno EWOULDBLOCK,
+     * because the value has changed, so that's ok. */
+    if (t != 0 && errno == EINTR)
+        goto again;
+
     return t;
 }
 
@@ -134,7 +145,7 @@ 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)
+#if defined(LISP_FEATURE_SB_THREAD) && !defined(LISP_FEATURE_SB_LUTEX) && !defined(LISP_FEATURE_SB_PTHREAD_FUTEX)
     int *futex=0;
 #endif
     struct utsname name;
@@ -160,7 +171,7 @@ os_init(char *argv[], char *envp[])
 #endif
     }
 #ifdef LISP_FEATURE_SB_THREAD
-#if !defined(LISP_FEATURE_SB_LUTEX)
+#if !defined(LISP_FEATURE_SB_LUTEX) && !defined(LISP_FEATURE_SB_PTHREAD_FUTEX)
     futex_wait(futex,-1);
     if(errno==ENOSYS) {
        lose("This version of SBCL is compiled with threading support, but your kernel\n"
@@ -377,7 +388,7 @@ sigsegv_handler(int signal, siginfo_t *info, void* void_context)
 #endif
         if (!handle_guard_page_triggered(context, addr))
 #ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
-            arrange_return_to_lisp_function(context, SymbolFunction(MEMORY_FAULT_ERROR));
+            lisp_memory_fault_error(context, addr);
 #else
             interrupt_handle_now(signal, info, context);
 #endif