Mu - subx/056write.subx

From 6e181e7fd998a0d542cb531c929c905a243ea2f6 Mon Sep 17 00:00:00 2001 From: Kartik Agaram Date: Tue, 5 Feb 2019 23:30:12 -0800 Subject: 4953 --- html/subx/056write.subx.html | 268 ------------------------------------------- 1 file changed, 268 deletions(-) delete mode 100644 html/subx/056write.subx.html (limited to 'html/subx/056write.subx.html') diff --git a/html/subx/056write.subx.html b/html/subx/056write.subx.html deleted file mode 100644 index f9f81766..00000000 --- a/html/subx/056write.subx.html +++ /dev/null @@ -1,268 +0,0 @@ - - - - -Mu - subx/056write.subx - - - - - - - - - - -https://github.com/akkartik/mu/blob/master/subx/056write.subx -
-  1 # write: like _write, but also support in-memory streams in addition to file
-  2 # descriptors.
-  3 #
-  4 # Our first dependency-injected and testable primitive. We can pass it either
-  5 # a file descriptor or an address to a stream. If a file descriptor is passed
-  6 # in, we _write to it using the right syscall. If a 'fake file descriptor' or
-  7 # stream is passed in, we append to the stream. This lets us redirect output
-  8 # in tests and check it later.
-  9 #
- 10 # We assume our data segment will never begin at an address shorter than
- 11 # 0x08000000, so any smaller arguments are assumed to be real file descriptors.
- 12 #
- 13 # A stream looks like this:
- 14 #   read: int  # index at which to read next
- 15 #   write: int  # index at which writes go
- 16 #   data: (array byte)  # prefixed by length as usual
- 17 
- 18 == code
- 19 #   instruction                     effective address                                                   register    displacement    immediate
- 20 # . op          subop               mod             rm32          base        index         scale       r32
- 21 # . 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
- 22 
- 23 # main:
- 24     e8/call  run-tests/disp32  # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'.
- 25     # syscall(exit, Num-test-failures)
- 26     8b/copy                         0/mod/indirect  5/rm32/.disp32            .             .           3/r32/EBX   Num-test-failures/disp32          # copy *Num-test-failures to EBX
- 27     b8/copy-to-EAX  1/imm32/exit
- 28     cd/syscall  0x80/imm8
- 29 
- 30 # TODO: come up with a way to signal when a write to disk fails
- 31 write:  # f : fd or (address stream), s : (address array byte) -> <void>
- 32     # . prolog
- 33     55/push-EBP
- 34     89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
- 35     # if (f < 0x08000000) _write(f, s), return  # f can't be a user-mode address, so treat it as a kernel file descriptor
- 36     81          7/subop/compare     1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         0x08000000/imm32  # compare *(EBP+8)
- 37     7d/jump-if-greater-or-equal  $write:fake/disp8
- 38     # . . push args
- 39     ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
- 40     ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           8/disp8         .                 # push *(EBP+8)
- 41     # . . call
- 42     e8/call  _write/disp32
- 43     # . . discard args
- 44     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
- 45     eb/jump  $write:end/disp8
- 46 $write:fake:
- 47     # otherwise, treat 'f' as a stream to append to
- 48     # . save registers
- 49     50/push-EAX
- 50     51/push-ECX
- 51     52/push-EDX
- 52     53/push-EBX
- 53     # ECX = f
- 54     8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         1/r32/ECX   8/disp8         .                 # copy *(EBP+8) to ECX
- 55     # EDX = f->write
- 56     8b/copy                         0/mod/indirect  1/rm32/ECX    .           .             .           2/r32/EDX   .               .                 # copy *ECX to EDX
- 57     # EBX = f->length
- 58     8b/copy                         1/mod/*+disp8   1/rm32/ECX    .           .             .           3/r32/EBX   8/disp8         .                 # copy *(ECX+8) to EBX
- 59     # EAX = _append-3(&f->data[f->write], &f->data[f->length], s)
- 60     # . . push s
- 61     ff          6/subop/push        1/mod/*+disp8   5/rm32/EBP    .           .             .           .           0xc/disp8       .                 # push *(EBP+12)
- 62     # . . push &f->data[f->length]
- 63     8d/copy-address                 1/mod/*+disp8   4/rm32/sib    1/base/ECX  3/index/EBX   .           3/r32/EBX   0xc/disp8       .                 # copy ECX+EBX+12 to EBX
- 64     53/push-EBX
- 65     # . . push &f->data[f->write]
- 66     8d/copy-address                 1/mod/*+disp8   4/rm32/sib    1/base/ECX  2/index/EDX   .           3/r32/EBX   0xc/disp8       .                 # copy ECX+EDX+12 to EBX
- 67     53/push-EBX
- 68     # . . call
- 69     e8/call  _append-3/disp32
- 70     # . . discard args
- 71     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
- 72     # f->write += EAX
- 73     01/add                          0/mod/indirect  1/rm32/ECX    .           .             .           0/r32/EAX   .               .                 # add EAX to *ECX
- 74     # . restore registers
- 75     5b/pop-to-EBX
- 76     5a/pop-to-EDX
- 77     59/pop-to-ECX
- 78     58/pop-to-EAX
- 79 $write:end:
- 80     # . epilog
- 81     89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
- 82     5d/pop-to-EBP
- 83     c3/return
- 84 
- 85 clear-stream:  # f : (address stream) -> <void>
- 86     # . prolog
- 87     55/push-EBP
- 88     89/copy                         3/mod/direct    5/rm32/EBP    .           .             .           4/r32/ESP   .               .                 # copy ESP to EBP
- 89     # . save registers
- 90     50/push-EAX
- 91     51/push-ECX
- 92     # EAX = f
- 93     8b/copy                         1/mod/*+disp8   5/rm32/EBP    .           .                         0/r32/EAX   8/disp8         .                 # copy *(EBP+8) to EAX
- 94     # ECX = f->length
- 95     8b/copy                         1/mod/*+disp8   0/rm32/EAX    .           .             .           1/r32/ECX   8/disp8         .                 # copy *(EAX+8) to ECX
- 96     # ECX = &f->data[f->length]
- 97     8d/copy-address                 1/mod/*+disp8   4/rm32/sib    0/base/EAX  1/index/ECX   .           1/r32/ECX   0xc/disp8       .                 # copy EAX+ECX+12 to ECX
- 98     # f->write = 0
- 99     c7          0/subop/copy        0/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm32           # copy to *EAX
-100     # f->read = 0
-101     c7          0/subop/copy        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           4/disp8         0/imm32           # copy to *(EAX+4)
-102     # EAX = f->data
-103     81          0/subop/add         3/mod/direct    0/rm32/EAX    .           .             .           .           .               0xc/imm32         # add to EAX
-104     # while (true)
-105 $clear-stream:loop:
-106     # if EAX >= ECX break
-107     39/compare                      3/mod/direct    0/rm32/EAX    .           .             .           1/r32/ECX   .               .                 # compare EAX with ECX
-108     7d/jump-if-greater-or-equal  $clear-stream:end/disp8
-109     # *EAX = 0
-110     c6          0/subop/copy        0/mod/direct    0/rm32/EAX    .           .             .           .           .               0/imm8            # copy byte to *EAX
-111     # ++EAX
-112     40/increment-EAX
-113     eb/jump  $clear-stream:loop/disp8
-114 $clear-stream:end:
-115     # . restore registers
-116     59/pop-to-ECX
-117     58/pop-to-EAX
-118     # . epilog
-119     89/copy                         3/mod/direct    4/rm32/ESP    .           .             .           5/r32/EBP   .               .                 # copy EBP to ESP
-120     5d/pop-to-EBP
-121     c3/return
-122 
-123 test-write-single:
-124     # clear-stream(_test-stream)
-125     # . . push args
-126     68/push  _test-stream/imm32
-127     # . . call
-128     e8/call  clear-stream/disp32
-129     # . . discard args
-130     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-131     # write(_test-stream, "Ab")
-132     # . . push args
-133     68/push  "Ab"/imm32
-134     68/push  _test-stream/imm32
-135     # . . call
-136     e8/call  write/disp32
-137     # . . discard args
-138     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-139     # check-ints-equal(*_test-stream->data, 41/A 62/b 00 00, msg)
-140     # . . push args
-141     68/push  "F - test-write-single"/imm32
-142     68/push  0x006241/imm32/Ab
-143     # . . push *_test-stream->data
-144     b8/copy-to-EAX  _test-stream/imm32
-145     ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           0xc/disp8       .                 # push *(EAX+12)
-146     # . . call
-147     e8/call  check-ints-equal/disp32
-148     # . . discard args
-149     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-150     # end
-151     c3/return
-152 
-153 test-write-appends:
-154     # clear-stream(_test-stream)
-155     # . . push args
-156     68/push  _test-stream/imm32
-157     # . . call
-158     e8/call  clear-stream/disp32
-159     # . . discard args
-160     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               4/imm32           # add to ESP
-161     # write(_test-stream, "C")
-162     # . . push args
-163     68/push  "C"/imm32
-164     68/push  _test-stream/imm32
-165     # . . call
-166     e8/call  write/disp32
-167     # . . discard args
-168     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-169     # write(_test-stream, "D")
-170     # . . push args
-171     68/push  "D"/imm32
-172     68/push  _test-stream/imm32
-173     # . . call
-174     e8/call  write/disp32
-175     # . . discard args
-176     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               8/imm32           # add to ESP
-177     # check-ints-equal(*_test-stream->data, 43/C 44/D 00 00, msg)
-178     # . . push args
-179     68/push  "F - test-write-appends"/imm32
-180     68/push  0x00004443/imm32/C-D
-181     # . . push *_test-stream->data
-182     b8/copy-to-EAX  _test-stream/imm32
-183     ff          6/subop/push        1/mod/*+disp8   0/rm32/EAX    .           .             .           .           0xc/disp8       .                 # push *(EAX+12)
-184     # . . call
-185     e8/call  check-ints-equal/disp32
-186     # . . discard args
-187     81          0/subop/add         3/mod/direct    4/rm32/ESP    .           .             .           .           .               0xc/imm32         # add to ESP
-188     # end
-189     c3/return
-190 
-191 == data
-192 
-193 _test-stream:
-194     # current write index
-195     00 00 00 00
-196     # current read index
-197     00 00 00 00
-198     # length (= 8)
-199     08 00 00 00
-200     # data
-201     00 00 00 00 00 00 00 00  # 8 bytes
-202 
-203 # . . vim:nowrap:textwidth=0
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