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| author | Kartik Agaram <vc@akkartik.com> | 2020-07-05 12:13:28 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2020-07-05 12:13:28 -0700 |
| commit | c09c91e185aad8e01b570c2569e13c1e429d2f99 (patch) | |
| tree | 52a5ae1494ad5b7b2319411815dc45510e761c24 /115write-byte.subx | |
| parent | f2c5b05374186f9422cfdaf1ada096e39ac91a8b (diff) | |
| download | mu-c09c91e185aad8e01b570c2569e13c1e429d2f99.tar.gz | |
6612 - reorganize layers
Diffstat (limited to '115write-byte.subx')
| -rw-r--r-- | 115write-byte.subx | 403 |
1 files changed, 403 insertions, 0 deletions
diff --git a/115write-byte.subx b/115write-byte.subx new file mode 100644 index 00000000..889439f6 --- /dev/null +++ b/115write-byte.subx @@ -0,0 +1,403 @@ +# write-byte-buffered: add a single byte to a buffered-file. +# flush: write out any buffered writes to disk. +# +# TODO: Come up with a way to signal failure to write to disk. This is hard +# since the failure may impact previous calls that were buffered. + +== data + +# The buffered file for standard output. +Stdout: # buffered-file + # file descriptor or (addr stream byte) + 1/imm32 # standard output +$Stdout->buffer: + # inlined fields for a stream + # current write index + 0/imm32 + # current read index + 0/imm32 + # size + 8/imm32 + # data + 00 00 00 00 00 00 00 00 # 8 bytes + +# TODO: 8 bytes is too small. We'll need to grow the buffer for efficiency. But +# I don't want to type in 1024 bytes here. + +== code +# instruction effective address register displacement immediate +# . op subop mod rm32 base index scale r32 +# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes + +# Write lower byte of 'n' to 'f'. +write-byte-buffered: # f: (addr buffered-file), n: int + # . prologue + 55/push-ebp + 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp + # . save registers + 51/push-ecx + 57/push-edi + # edi = f + 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 7/r32/edi 8/disp8 . # copy *(ebp+8) to edi + # ecx = f->write + 8b/copy 1/mod/*+disp8 7/rm32/edi . . . 1/r32/ecx 4/disp8 . # copy *(edi+4) to ecx + # if (f->write >= f->size) flush and clear f's stream + 3b/compare 1/mod/*+disp8 7/rm32/edi . . . 1/r32/ecx 0xc/disp8 . # compare ecx with *(edi+12) + 7c/jump-if-< $write-byte-buffered:to-stream/disp8 + # . flush(f) + # . . push args + 57/push-edi + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # . clear-stream(stream = f+4) + # . . push args + 8d/copy-address 1/mod/*+disp8 7/rm32/edi . . . 0/r32/eax 4/disp8 . # copy edi+4 to eax + 50/push-eax + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # . f->write must now be 0; update its cache at ecx + 31/xor 3/mod/direct 1/rm32/ecx . . . 1/r32/ecx . . # clear ecx +$write-byte-buffered:to-stream: + # write to stream + # f->data[f->write] = LSB(n) + 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax + 8a/copy-byte 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/AL 0xc/disp8 . # copy byte at *(ebp+12) to AL + 88/copy-byte 1/mod/*+disp8 4/rm32/sib 7/base/edi 1/index/ecx . 0/r32/AL 0x10/disp8 . # copy AL to *(edi+ecx+16) + # ++f->write + ff 0/subop/increment 1/mod/*+disp8 7/rm32/edi . . . . 4/disp8 . # increment *(edi+4) +$write-byte-buffered:end: + # . restore registers + 5f/pop-to-edi + 59/pop-to-ecx + # . epilogue + 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp + 5d/pop-to-ebp + c3/return + +flush: # f: (addr buffered-file) + # . prologue + 55/push-ebp + 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp + # . save registers + 50/push-eax + 51/push-ecx + # eax = f + 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 8/disp8 . # copy *(ebp+8) to eax + # write-stream(f->fd, data = f+4) + # . . push args + 8d/copy-address 1/mod/*+disp8 0/rm32/eax . . . 1/r32/ecx 4/disp8 . # copy eax+4 to ecx + 51/push-ecx + ff 6/subop/push 0/mod/indirect 0/rm32/eax . . . . . . # push *eax + # . . call + e8/call write-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp +$flush:end: + # . restore registers + 59/pop-to-ecx + 58/pop-to-eax + # . epilogue + 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp + 5d/pop-to-ebp + c3/return + +test-write-byte-buffered-single: + # - check that write-byte-buffered writes to first byte of 'file' + # setup + # . clear-stream(_test-stream) + # . . push args + 68/push _test-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # . clear-stream($_test-buffered-file->buffer) + # . . push args + 68/push $_test-buffered-file->buffer/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # write-byte-buffered(_test-buffered-file, 'A') + # . . push args + 68/push 0x41/imm32 + 68/push _test-buffered-file/imm32 + # . . call + e8/call write-byte-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # flush(_test-buffered-file) + # . . push args + 68/push _test-buffered-file/imm32 + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # check-stream-equal(_test-stream, "A", msg) + # . . push args + 68/push "F - test-write-byte-buffered-single"/imm32 + 68/push "A"/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call check-stream-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp + # . end + c3/return + +test-write-byte-buffered-multiple-flushes: + # - check that write-byte-buffered correctly flushes buffered data + # setup + # . clear-stream(_test-stream) + # . . push args + 68/push _test-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # . clear-stream($_test-buffered-file->buffer) + # . . push args + 68/push $_test-buffered-file->buffer/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # fill up the buffer for _test-buffered-file + # . write($_test-buffered-file->buffer, "abcdef") + # . . push args + 68/push "abcdef"/imm32 + 68/push $_test-buffered-file->buffer/imm32 + # . . call + e8/call write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # write-byte-buffered(_test-buffered-file, 'g') + # . . push args + 68/push 0x67/imm32 + 68/push _test-buffered-file/imm32 + # . . call + e8/call write-byte-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # flush(_test-buffered-file) + # . . push args + 68/push _test-buffered-file/imm32 + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # check-stream-equal(_test-stream, "abcdefg", msg) + # . . push args + 68/push "F - test-write-byte-buffered-multiple-flushes"/imm32 + 68/push "abcdefg"/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call check-stream-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp + # . end + c3/return + +# - variant without buffering + +# Write lower byte of 'n' to 'f'. +append-byte: # f: (addr stream byte), n: int + # . prologue + 55/push-ebp + 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp + # . save registers + 51/push-ecx + 57/push-edi + # edi = f + 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 7/r32/edi 8/disp8 . # copy *(ebp+8) to edi + # ecx = f->write + 8b/copy 0/mod/indirect 7/rm32/edi . . . 1/r32/ecx . . # copy *edi to ecx + # if (f->write >= f->size) abort + 3b/compare 1/mod/*+disp8 7/rm32/edi . . . 1/r32/ecx 8/disp8 . # compare ecx with *(edi+8) + 7d/jump-if->= $append-byte:abort/disp8 +$append-byte:to-stream: + # write to stream + # f->data[f->write] = LSB(n) + 31/xor 3/mod/direct 0/rm32/eax . . . 0/r32/eax . . # clear eax + 8a/copy-byte 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/AL 0xc/disp8 . # copy byte at *(ebp+12) to AL + 88/copy-byte 1/mod/*+disp8 4/rm32/sib 7/base/edi 1/index/ecx . 0/r32/AL 0xc/disp8 . # copy AL to *(edi+ecx+12) + # ++f->write + ff 0/subop/increment 0/mod/indirect 7/rm32/edi . . . . . . # increment *edi +$append-byte:end: + # . restore registers + 5f/pop-to-edi + 59/pop-to-ecx + # . epilogue + 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp + 5d/pop-to-ebp + c3/return + +$append-byte:abort: + # . _write(2/stderr, error) + # . . push args + 68/push "append-byte: out of space\n"/imm32 + 68/push 2/imm32/stderr + # . . call + e8/call _write/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # . syscall(exit, 1) + bb/copy-to-ebx 1/imm32 + e8/call syscall_exit/disp32 + # never gets here + +test-append-byte-single: + # - check that append-byte writes to first byte of 'file' + # setup + # . clear-stream(_test-stream) + # . . push args + 68/push _test-stream/imm32 + # . . call + e8/call clear-stream/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp + # append-byte(_test-stream, 'A') + # . . push args + 68/push 0x41/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call append-byte/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp + # check-stream-equal(_test-stream, "A", msg) + # . . push args + 68/push "F - test-append-byte-single"/imm32 + 68/push "A"/imm32 + 68/push _test-stream/imm32 + # . . call + e8/call check-stream-equal/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp + # . end + c3/return + +== data + +_test-output-stream: # (stream byte) + # current write index + 0/imm32 + # current read index + 0/imm32 + # size + 0x400/imm32 # 1024 bytes + # data (64 lines x 16 bytes/line) + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + +# a test buffered file for _test-output-stream +_test-output-buffered-file: # buffered-file + # file descriptor or (addr stream byte) + _test-output-stream/imm32 +$_test-output-buffered-file->buffer: + # current write index + 0/imm32 + # current read index + 0/imm32 + # size + 6/imm32 + # data + 00 00 00 00 00 00 # 6 bytes + +_test-error-stream: # (stream byte) + # current write index + 0/imm32 + # current read index + 0/imm32 + # line + 0x80/imm32 # 128 bytes + # data (8 lines x 16 bytes/line) + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 + +# a test buffered file for _test-error-stream +_test-error-buffered-file: # buffered-file + # file descriptor or (addr stream byte) + _test-error-stream/imm32 +$_test-error-buffered-file->buffer: + # current write index + 0/imm32 + # current read index + 0/imm32 + # size + 6/imm32 + # data + 00 00 00 00 00 00 # 6 bytes + +# . . vim:nowrap:textwidth=0 |