Changeset 5b11c25 for libcfa/src/concurrency/CtxSwitch-x86_64.S

Timestamp:

Apr 30, 2019, 2:53:41 PM (5 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

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

Children:

8278abf

Parents:

673cd63

Message:

Added new suspen_then function which runs a callback in the middle of susending

File:

• libcfa/src/concurrency/CtxSwitch-x86_64.S (modified) (2 diffs)

libcfa/src/concurrency/CtxSwitch-x86_64.S

@@ -40 +40 @@
 #define FP_OFFSET       ( 1 * PTR_BYTE )
 
+//-----------------------------------------------------------------------------
+// Regular context switch routine which enables switching from one context to anouther
         .text
         .align 2
@@ -77 +79 @@
         .size  CtxSwitch, .-CtxSwitch
 
-.text
+//-----------------------------------------------------------------------------
+// Part of a 2 part context switch routine, use with CtxRet, stores the current context and then makes a function call
+        .text
         .align 2
-.globl  CtxInvokeStub
+        .globl CtxStore
+        .type  CtxStore, @function
+CtxStore:
+
+        // Save volatile registers on the stack.
+
+        pushq %r15
+        pushq %r14
+        pushq %r13
+        pushq %r12
+        pushq %rbx
+
+        // Save old context in the "from" area.
+
+        movq %rsp,SP_OFFSET(%rdi)
+        movq %rbp,FP_OFFSET(%rdi)
+
+        // Don't load a new context, directly jump to the desired function
+
+        jmp *%rsi
+        .size  CtxStore, .-CtxStore
+
+//-----------------------------------------------------------------------------
+// Part of a 2 part context switch routine, use with CtxStore, context switches to the desired target without saving the current context
+        .text
+        .align 2
+        .globl CtxRet
+        .type  CtxRet, @function
+CtxRet:
+        // Load new context from the "to" area.
+
+        movq SP_OFFSET(%rdi),%rsp
+        movq FP_OFFSET(%rdi),%rbp
+
+        // Load volatile registers from the stack.
+
+        popq %rbx
+        popq %r12
+        popq %r13
+        popq %r14
+        popq %r15
+
+        // Return to thread.
+
+        ret
+        .size  CtxRet, .-CtxRet
+
+
+//-----------------------------------------------------------------------------
+// Stub used to create new stacks which are ready to be context switched to
+        .text
+        .align 2
+        .globl CtxInvokeStub
+        .type    CtxInvokeStub, @function
 CtxInvokeStub:
         movq %rbx, %rdi
         jmp *%r12
+        .size  CtxInvokeStub, .-CtxInvokeStub
 
 // Local Variables: //