From f3cf8211e32b3dbeaf58abc8b5cd8996cb84ceba Mon Sep 17 00:00:00 2001
From: nddrylliog <ndd@rylliog.cz>
Date: Sat, 14 Aug 2010 23:58:18 +0200
Subject: [PATCH] Pure ooc coroutines implementations on top of ucontext, based
 on libcoroutine. Doesn't work yet for channels, for some reason.

---
 sdk/lang/Memory.ooc  |   2 +
 sdk/lang/Numbers.ooc |   5 +-
 sdk/os/Coro.ooc      | 126 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 131 insertions(+), 2 deletions(-)
 create mode 100644 sdk/os/Coro.ooc

diff --git a/sdk/lang/Memory.ooc b/sdk/lang/Memory.ooc
index d987055e..2fabc67c 100644
--- a/sdk/lang/Memory.ooc
+++ b/sdk/lang/Memory.ooc
@@ -12,6 +12,7 @@ version(!gc) {
     gc_malloc_atomic: extern(malloc) func (size: SizeT) -> Pointer
     gc_realloc: extern(realloc) func (ptr: Pointer, size: SizeT) -> Pointer
     gc_calloc: extern(calloc) func (nmemb: SizeT, size: SizeT) -> Pointer
+    gc_free: extern(free) func (ptr: Pointer)
 }
 
 version(gc) {
@@ -23,6 +24,7 @@ version(gc) {
     gc_calloc: func (nmemb: SizeT, size: SizeT) -> Pointer {
         gc_malloc(nmemb * size)
     }
+    gc_free: extern(GC_FREE) func (ptr: Pointer)
 }
 
 // memory management
diff --git a/sdk/lang/Numbers.ooc b/sdk/lang/Numbers.ooc
index fe9f1618..02bc49ed 100644
--- a/sdk/lang/Numbers.ooc
+++ b/sdk/lang/Numbers.ooc
@@ -1,4 +1,4 @@
-include stdlib, stdint, stdbool, float, ctype, sys/types
+include stdlib, stdint, stdbool, stddef, float, ctype, sys/types
 
 LLong: cover from signed long long {
 
@@ -26,7 +26,7 @@ LLong: cover from signed long long {
         for (i in 0..this) {
             fn(i)
         }
-    } 
+    }
 }
 
 Long:  cover from signed long  extends LLong
@@ -73,6 +73,7 @@ UInt64: cover from uint64_t extends ULLong
 Octet:  cover from uint8_t
 SizeT:  cover from size_t extends ULLong
 SSizeT:  cover from ssize_t extends LLong
+PtrDiff: cover from ptrdiff_t extends SizeT
 
 /**
  * real types
diff --git a/sdk/os/Coro.ooc b/sdk/os/Coro.ooc
new file mode 100644
index 00000000..4a960b48
--- /dev/null
+++ b/sdk/os/Coro.ooc
@@ -0,0 +1,126 @@
+
+Coro: class {
+
+    // this was originally commented '128k needed on PPC due to parser'
+    // I have no idea what that means but 128k sounds reasonable.
+    DEFAULT_STACK_SIZE := static 128 * 1_024
+    MIN_STACK_SIZE := static 8_192
+
+    requestedStackSize: SizeT { get set }
+    allocatedStackSize: SizeT
+    stack: Pointer { get set }
+    env: UContext
+    isMain: Bool
+
+    init: func {
+        requestedStackSize = DEFAULT_STACK_SIZE
+        allocatedStackSize = 0
+    }
+
+    allocStackIfNeeded: func {
+        if (stack != null && allocatedStackSize > requestedStackSize) {
+           gc_free(stack)
+           stack = gc_malloc(requestedStackSize)
+           "Coro_%p re-allocating stack size %i" printfln(this, requestedStackSize)
+        }
+
+        if (stack == null) {
+            stack = gc_malloc(requestedStackSize)
+           "Coro_%p allocating stack size %i" printfln(this, requestedStackSize)
+        }
+    }
+
+    free: func {
+        if(stack) {
+            gc_free(stack)
+        }
+        "Coro_%p free" printfln(this)
+    }
+
+    currentStackPointer: func -> UInt8* {
+        a: UInt8
+        b := a& // to avoid compiler warning about unused variables
+        b
+    }
+
+    bytesLeftOnStack: func -> SizeT {
+        dummy: UChar
+        p1: PtrDiff = dummy&
+        p2: PtrDiff = currentStackPointer()
+
+        start: PtrDiff = stack
+        end: PtrDiff = stack + requestedStackSize
+
+        stackMovesUp := (p2 > p1)
+        if(stackMovesUp) { // like x86
+            end - p1
+        } else { // like OSX on PPC
+            p1 - start
+        }
+    }
+
+    stackSpaceAlmostGone: func -> Bool {
+        bytesLeftOnStack() < MIN_STACK_SIZE
+    }
+
+    initializeMainCoro: func {
+        isMain = true
+    }
+
+    startCoro: func (other: This, callback: Func) {
+        other allocStackIfNeeded()
+        other setup(callback)
+        switchTo(other)
+    }
+
+    setup: func (callback: Func) {
+        getcontext(env&)
+
+        env stack stackPointer = stack + requestedStackSize - 8
+        env stack stackSize    = requestedStackSize
+        env stack flags        = 0
+        env link               = null
+
+        "Setting up Closure %p, callback thunk/context = %p/%p, env& = %p" printfln(this, callback as Closure thunk, callback as Closure context, env&)
+        makecontext(env&, callback as Closure thunk, 1, callback as Closure context)
+    }
+
+    switchTo: func (next: This) {
+        swapcontext(env&, next env&)
+    }
+
+}
+
+/* ------ C interfacing ------- */
+
+include ucontext
+
+StackT: cover from stack_t {
+    stackPointer: extern(ss_sp) Pointer
+    flags: extern(ss_flags) Int
+    stackSize: extern(ss_size) SizeT
+}
+
+UContext: cover from ucontext_t {
+    stack: extern(uc_stack) StackT
+    link: extern(uc_link) Pointer
+}
+
+getcontext: extern func (ucp: UContext*) -> Int
+setcontext: extern func (ucp: UContext*) -> Int
+makecontext: extern func (ucp: UContext*, _func: Pointer, argc: Int, ...)
+swapcontext: extern func (oucp: UContext*, ucp: UContext*) -> Int
+
+
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