Changeset e0a4686 in mainline for uspace/lib/c/generic/setjmp.c

Timestamp:

2018-03-08T18:25:31Z (6 years ago)

Author:

Jiří Zárevúcky <zarevucky.jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

53ad43c, 615e83d

Parents:

fd57cf17

git-author:

Jiří Zárevúcky <zarevucky.jiri@…> (2018-03-06 22:03:11)

git-committer:

Jiří Zárevúcky <zarevucky.jiri@…> (2018-03-08 18:25:31)

Message:

Introduce context_swap() and use it to simplify fibril implementation.

This wraps the use of context_save()/context_restore(), to provide a more
natural (and easier to understand) control flow. The patch also hides the
details of the underlying context, requiring the use of context_get_pc()
to acquire program counter. This might allow context_swap() to only store
one pointer in the context, storing the remaining information in its stack
frame. However, that is not done in this patch.

File:

• uspace/lib/c/generic/setjmp.c (modified) (2 diffs)

uspace/lib/c/generic/setjmp.c

@@ -37 +37 @@
 
 #include <setjmp.h>
-#include <libarch/fibril.h>
-#include <fibril.h>
+#include <context.h>
+
+// TODO: setjmp/longjmp are basically a stronger version of
+// context_save/context_restore. It would be preferable to turn
+// those two into setjmp/longjmp (all it would need is preserving the
+// return value).
 
 /**
@@ -52 +56 @@
         env[0].return_value = (val == 0) ? 1 : val;
         context_restore(&env[0].context);
-        __builtin_unreachable();
 }