Changeset 58fe85a for libcfa/src/concurrency/CtxSwitch-i386.S

Timestamp:

Jan 7, 2021, 3:27:00 PM (5 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

2b4daf2, 64aeca0

Parents:

3c64c668 (diff), eef8dfb (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

Message:

Merge branch 'master' into park_unpark

File:

• libcfa/src/concurrency/CtxSwitch-i386.S (modified) (3 diffs)

libcfa/src/concurrency/CtxSwitch-i386.S

@@ -10 +10 @@
 // Created On       : Tue Dec 6 12:27:26 2016
 // Last Modified By : Peter A. Buhr
-// Last Modified On : Fri Jul 21 22:29:25 2017
-// Update Count     : 1
-//
-// This  library is free  software; you  can redistribute  it and/or  modify it
-// under the terms of the GNU Lesser General Public License as published by the
-// Free Software  Foundation; either  version 2.1 of  the License, or  (at your
-// option) any later version.
-//
-// This library is distributed in the  hope that it will be useful, but WITHOUT
-// ANY  WARRANTY;  without even  the  implied  warranty  of MERCHANTABILITY  or
-// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
-// for more details.
-//
-// You should  have received a  copy of the  GNU Lesser General  Public License
-// along  with this library.
+// Last Modified On : Sun Sep  6 18:23:37 2020
+// Update Count     : 5
 //
 
-// This context switch routine depends on the fact that the stack of a new
-// thread has been set up to look like the thread has saved its context in
-// the normal manner.
-//
-// void CtxSwitch( machine_context *from, machine_context *to );
+// The context switch routine requires the initial the stack of a thread to
+// look like the thread has saved its context in the normal manner.
 
-// Offsets in the context structure. This needs to be synchronized with the
-// high level code a little better.
+// Offsets must synchronized with the __stack_context_t in invoke.h.
 
 #define PTR_BYTE        4
 #define SP_OFFSET       ( 0 * PTR_BYTE )
 #define FP_OFFSET       ( 1 * PTR_BYTE )
-#define PC_OFFSET       ( 2 * PTR_BYTE )
 
+// Context switch between coroutines/tasks.
+//   void __cfactx_switch( struct __stack_context_t * from, struct __stack_context_t * to ) ;
+// Arguments "from" in register 4(%esp), "to" in register 20(%esp)
+
+        .file "CtxSwitch-i386.S"
         .text
         .align 2
-        .globl __cfactx_switch
-        .type  __cfactx_switch, @function
+        .global __cfactx_switch
+        .type __cfactx_switch, @function
 __cfactx_switch:
 
         // Copy the "from" context argument from the stack to register eax
-        // Return address is at 0(%esp), with parameters following
+        // Return address is at 0(%esp), with parameters following.
 
         movl 4(%esp),%eax
@@ -63 +50 @@
         movl %ebp,FP_OFFSET(%eax)
 
-        // Copy the "to" context argument from the stack to register eax
-        // Having pushed three words (= 12 bytes) on the stack, the
-        // argument is now at 8 + 12 = 20(%esp)
+        // Copy the "to" context argument from the stack to register eax. Having
+        // pushed 3 words (= 12 bytes) on the stack, the argument is now at
+        // 8 + 12 = 20(%esp).
 
         movl 20(%esp),%eax
@@ -83 +70 @@
 
         ret
-        .size  __cfactx_switch, .-__cfactx_switch
+        .size __cfactx_switch, .-__cfactx_switch
 
 // Local Variables: //