scheduled commit

Author: bitRAKE

algo/freelist.inc

@@ -6,8 +6,6 @@
 ;
 ; requirements:
 ;	g_sysinf SYSTEM_INFO ; populated global structure
-;
-; TODO: reuse handler code for initialization
 
 virtual DATA.64
 FreeList__block_bytes	dq 64		; 64, freelist item size
@@ -25,7 +23,7 @@ namespace FreeList
 
 REGISTER equ r15 ; default global get/set register (or state explicitly)
 
-; these two function are why freelist
+; this is why freelists are used - these two macros
 macro get reg0*, reg1:FreeList.REGISTER
 	mov reg0, reg1
 	mov reg1, [reg1]
@@ -35,6 +33,40 @@ macro put reg0*, reg1:FreeList.REGISTER
 	mov reg1, reg0
 end macro
 
+; The default is to configure through global variables, and let the OS
+; select a base address.
+macro initialize total_bytes:[FreeList__total_bytes],\
+		start_address:0
+	local fail
+	; setup exception handler as first in hierarchy
+	AddVectoredExceptionHandler 1, & FreeList.Handler
+	mov [FreeList__hVector], rax
+	xchg rcx, rax
+	jrcxz fail
+
+; set region start/size here
+	mov rdx, total_bytes
+	mov [FreeList__end_address], rdx
+	VirtualAlloc start_address, rdx, MEM_RESERVE, PAGE_NOACCESS
+	xchg rcx, rax
+	jrcxz fail
+	mov [FreeList__base_address], rcx
+	add [FreeList__end_address], rcx
+	call FreeList.Handler.extend
+	mov FreeList.REGISTER, [FreeList__base_address]
+	xchg ecx, eax
+fail:
+	purge FreeList.initialize
+end macro ; RCX zero on error
+
+macro destroy
+	RemoveVectoredExceptionHandler [FreeList__hVector]
+	VirtualFree [FreeList__base_address], 0, MEM_RELEASE
+	purge FreeList.destroy
+end macro
+
+
+; Chaining is only used by the Handler.
 ; NOTE: `base` is advanced to address after `bytes`
 macro chain base*, reg0*, reg1*, bytes:[g_sysinf.dwAllocationGranularity]
 	local more
@@ -47,7 +79,6 @@ more:	mov reg0, base
 	jnz more
 end macro
 
-
 ; TODO: test if just handling EXCEPTION_ACCESS_VIOLATION is the same?
 ; NOTE: Cannot be used during a system service.
 ;
@@ -78,7 +109,7 @@ Handler:
 ; system removes the `PAGE_GUARD` status, commit next granule, set next guard page
 	; invalidate guard address, no guard page set
 	and [FreeList__guard_address], 0
-
+.extend:
 	virtual at rbp - .frame
 			rq 4
 		.frame := $ - $$
@@ -92,7 +123,7 @@ Handler:
 	; create free blocks
 	chain rcx, rdx, rax, [g_sysinf.dwAllocationGranularity]
 
-	; no guard page possible for large allocation unit
+	; no guard page possible for last allocation unit
 	cmp rcx, [FreeList__end_address]
 	jz .execute
 	VirtualAlloc rcx, dword [g_sysinf.dwPageSize],\
@@ -101,7 +132,6 @@ Handler:
 	jrcxz .commit_fail
 	mov [FreeList__guard_address], rcx
 .execute:
-	; moved guard page, okay to continue
 	assert (EXCEPTION_CONTINUE_EXECUTION and 0xFFFF_FFFF) = 0xFFFF_FFFF
 	or eax, EXCEPTION_CONTINUE_EXECUTION
 	leave
@@ -111,42 +141,4 @@ Handler:
 	leave
 	jmp .search
 
-
-; The default is to configure through global variables, and let the OS
-; select a base address.
-macro initialize total_bytes:[FreeList__total_bytes],\
-		start_bytes:dword [g_sysinf.dwAllocationGranularity],\
-		start_address:0
-	local fail0,fail
-	; setup exception handler as first in hierarchy
-	AddVectoredExceptionHandler 1, & FreeList.Handler
-	mov [FreeList__hVector], rax
-	xchg rcx, rax
-	jrcxz fail0
-
-; set region start/size here
-	mov rdx, total_bytes
-	mov [FreeList__end_address], rdx
-	VirtualAlloc start_address, rdx, MEM_RESERVE, PAGE_NOACCESS
-	xchg rcx, rax
-fail0:
-	jrcxz fail
-	VirtualAlloc rcx, start_bytes, MEM_COMMIT, PAGE_READWRITE
-	xchg rcx, rax
-	jrcxz fail
-	; update start/end addresses
-	mov [FreeList__base_address], rcx
-	add [FreeList__end_address], rcx
-
-	; create free blocks
-	FreeList.chain rcx, rdx, rax, [g_sysinf.dwAllocationGranularity]
-
-	VirtualAlloc rcx, dword [g_sysinf.dwPageSize],\
-		MEM_COMMIT, PAGE_READWRITE or PAGE_GUARD
-	xchg rcx, rax
-	mov [FreeList__guard_address], rcx
-	mov FreeList.REGISTER, [FreeList__base_address]
-fail:
-end macro ; RCX zero on error
-
 end namespace ; FreeList