文件系统完结

C13-Linux系统编程/fs/jmp.c

@@ -0,0 +1,99 @@
+#include <setjmp.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+static jmp_buf save;
+
+static void d(void)
+{
+    printf("%s():Begin.\n", __FUNCTION__);
+
+    printf("%s():Jump now.\n", __FUNCTION__);
+    longjmp(save, 6);
+    // longjmp(save, 0);   // !!! 如果返回0，实际会返回1，避免与另一种情况冲突
+
+    printf("%s():End.\n", __FUNCTION__);
+}
+
+static void c(void)
+{
+    printf("%s():Begin.\n", __FUNCTION__);
+    printf("%s():Call d().\n", __FUNCTION__);
+
+    d();
+
+    printf("%s():d() returned.\n", __FUNCTION__);
+    printf("%s():End.\n", __FUNCTION__);
+}
+
+static void b(void)
+{
+    printf("%s():Begin.\n", __FUNCTION__);
+    printf("%s():Call c().\n", __FUNCTION__);
+
+    c();
+
+    printf("%s():c() returned.\n", __FUNCTION__);
+    printf("%s():End.\n", __FUNCTION__);
+}
+
+static void a(void)
+{
+    int ret;
+
+    printf("%s():Begin.\n", __FUNCTION__);
+
+    ret = setjmp(save);
+    if (0 == ret)
+    {
+        printf("%s():Call b().\n", __FUNCTION__);
+        b();
+        printf("%s():b() returned.\n", __FUNCTION__);
+    }
+    else
+    {
+        printf("%s():Jumped back here with code %d.\n", __FUNCTION__, ret);
+    }
+
+    printf("%s():End.\n", __FUNCTION__);
+}
+
+
+/**
+ * @brief   jmp
+ * @details
+ *           d跳回a
+ *
+ * @param    argc
+ * @param    argv
+ * @return  int
+ */
+int main(int argc, char **argv)
+{
+    printf("%s():Begin.\n", __FUNCTION__);
+    printf("%s():Call a().\n", __FUNCTION__);
+
+    a();
+
+    printf("%s():a() returned.\n", __FUNCTION__);
+    printf("%s():End.\n", __FUNCTION__);
+
+    exit(0);
+}
+
+
+// ! out
+// main():Begin.
+// main():Call a().
+// a():Begin.
+// a():Call b().
+// b():Begin.
+// b():Call c().
+// c():Begin.
+// c():Call d().
+// d():Begin.
+// d():Jump now.
+// a():Jumped back here with code 6.
+// a():End.
+// main():a() returned.
+// main():End.