Author: Armin Rigo <[email protected]>
Branch: fast-gil
Changeset: r72185:eaa2cbefc0e6
Date: 2014-06-24 12:03 +0200
http://bitbucket.org/pypy/pypy/changeset/eaa2cbefc0e6/
Log: in-progress
diff --git a/rpython/jit/backend/llsupport/assembler.py
b/rpython/jit/backend/llsupport/assembler.py
--- a/rpython/jit/backend/llsupport/assembler.py
+++ b/rpython/jit/backend/llsupport/assembler.py
@@ -307,11 +307,21 @@
@staticmethod
@rgc.no_collect
def _reacquire_gil_asmgcc(css, old_rpy_fastgil):
- # Only called if rpy_fastgil was reset to a different value
- # by another thread or by a callback. See description in
- # transator/c/src/thread_pthread.c.
- if not old_rpy_fastgil:
- # first reacquire the GIL
+ # Before doing an external call, 'rpy_fastgil' is initialized to
+ # be equal to css. This function is called if we find out after
+ # the call that it is no longer equal to css. See description
+ # in transator/c/src/thread_pthread.c.
+
+ if old_rpy_fastgil == 0:
+ # this case occurs if some other thread stole the GIL but
+ # released it again. What occurred here is that we changed
+ # 'rpy_fastgil' from 0 to 1, thus successfully requiring the
+ # GIL.
+ pass
+
+ elif old_rpy_fastgil == 1:
+ # 'rpy_fastgil' was (and still is) locked by someone else.
+ # We need to wait for the regular mutex.
after = rffi.aroundstate.after
if after:
after()
@@ -326,6 +336,7 @@
oth.prev = asmgcroot.gcrootanchor
asmgcroot.gcrootanchor.next = oth
next.prev = oth
+
# similar to trackgcroot.py:pypy_asm_stackwalk, second part:
# detach the 'css' from the chained list
from rpython.memory.gctransform import asmgcroot
@@ -339,14 +350,15 @@
@rgc.no_collect
def _reacquire_gil_shadowstack():
# Simplified version of _reacquire_gil_asmgcc(): in shadowstack mode,
- # rpy_fastgil contains only 0 or 1, and this must only be called when
- # the old value stored in rpy_fastgil was 0.
+ # 'rpy_fastgil' contains only zero or non-zero, and this is only
+ # called when the old value stored in 'rpy_fastgil' was non-zero
+ # (i.e. still locked, must wait with the regular mutex)
after = rffi.aroundstate.after
if after:
after()
_REACQGIL0_FUNC = lltype.Ptr(lltype.FuncType([], lltype.Void))
- _REACQGIL2_FUNC = lltype.Ptr(lltype.FuncType([rffi.CCHARP, rffi.CCHARP],
+ _REACQGIL2_FUNC = lltype.Ptr(lltype.FuncType([rffi.CCHARP, lltype.Signed],
lltype.Void))
def _build_release_gil(self, gcrootmap):
diff --git a/rpython/jit/backend/x86/callbuilder.py
b/rpython/jit/backend/x86/callbuilder.py
--- a/rpython/jit/backend/x86/callbuilder.py
+++ b/rpython/jit/backend/x86/callbuilder.py
@@ -98,9 +98,10 @@
from rpython.jit.backend.x86.assembler import heap
#
if not self.asm._is_asmgcc():
- # the helper takes no argument
+ # shadowstack: change 'rpy_fastgil' to 0 (it should be
+ # non-zero right now).
self.change_extra_stack_depth = False
- css_value = imm(1)
+ css_value = imm(0)
else:
from rpython.memory.gctransform import asmgcroot
# build a 'css' structure on the stack: 2 words for the linkage,
@@ -134,14 +135,14 @@
from rpython.jit.backend.x86.assembler import heap
from rpython.jit.backend.x86 import rx86
#
- # check if we need to call the reopenstack() function
+ # check if we need to call the reacqgil() function or not
# (to acquiring the GIL, remove the asmgcc head from
# the chained list, etc.)
mc = self.mc
restore_edx = False
if not self.asm._is_asmgcc():
css = 0
- css_value = imm(1)
+ css_value = imm(0)
old_value = ecx
else:
from rpython.memory.gctransform import asmgcroot
@@ -158,7 +159,7 @@
old_value = esi
mc.LEA_rs(css_value.value, css)
#
- mc.XOR_rr(old_value.value, old_value.value)
+ mc.MOV(old_value, imm(1))
if rx86.fits_in_32bits(fastgil):
mc.XCHG_rj(old_value.value, fastgil)
else:
@@ -168,15 +169,15 @@
mc.J_il8(rx86.Conditions['E'], 0)
je_location = mc.get_relative_pos()
#
- # Yes, we need to call the reopenstack() function
- self.save_result_value_reacq(restore_edx)
+ # Yes, we need to call the reacqgil() function
+ self.save_result_value_reacq()
if self.asm._is_asmgcc():
if IS_X86_32:
mc.MOV_sr(4, old_value.value)
mc.MOV_sr(0, css_value.value)
# on X86_64, they are already in the right registers
mc.CALL(imm(self.asm.reacqgil_addr))
- self.restore_result_value_reacq(restore_edx)
+ self.restore_result_value_reacq()
#
# patch the JE above
offset = mc.get_relative_pos() - je_location
@@ -198,11 +199,11 @@
#else:
# for shadowstack, done for us by _reload_frame_if_necessary()
- def save_result_value_reacq(self, restore_edx):
+ def save_result_value_reacq(self):
"""Overridden in CallBuilder32 and CallBuilder64"""
raise NotImplementedError
- def restore_result_value_reacq(self, restore_edx):
+ def restore_result_value_reacq(self):
"""Overridden in CallBuilder32 and CallBuilder64"""
raise NotImplementedError
@@ -273,7 +274,7 @@
else:
CallBuilderX86.load_result(self)
- def save_result_value_reacq(self, restore_edx):
+ def save_result_value_reacq(self):
# Temporarily save the result value into [ESP+8]. We use "+8"
# in order to leave the two initial words free, in case it's needed.
# Also note that in this 32-bit case, a long long return value is
@@ -285,8 +286,7 @@
# a float or a long long return
if self.restype == 'L':
self.mc.MOV_sr(8, eax.value) # long long
- if not restore_edx:
- self.mc.MOV_sr(12, edx.value)
+ #self.mc.MOV_sr(12, edx.value) -- already done by the caller
else:
self.mc.FSTPL_s(8) # float return
else:
@@ -297,7 +297,7 @@
assert self.ressize <= WORD
self.mc.MOV_sr(8, eax.value)
- def restore_result_value_reacq(self, restore_edx):
+ def restore_result_value_reacq(self):
# Opposite of save_result_value_reacq()
if self.ressize == 0: # void return
return
@@ -305,8 +305,7 @@
# a float or a long long return
if self.restype == 'L':
self.mc.MOV_rs(eax.value, 8) # long long
- if not restore_edx:
- self.mc.MOV_rs(edx.value, 12)
+ #self.mc.MOV_rs(edx.value, 12) -- will be done by the caller
else:
self.mc.FLDL_s(8) # float return
else:
@@ -430,7 +429,7 @@
else:
CallBuilderX86.load_result(self)
- def save_result_value_reacq(self, restore_edx):
+ def save_result_value_reacq(self):
# Temporarily save the result value into [ESP].
if self.ressize == 0: # void return
return
@@ -448,7 +447,7 @@
assert self.restype == INT
self.mc.MOV_sr(0, eax.value)
- def restore_result_value_reacq(self, restore_edx):
+ def restore_result_value_reacq(self):
# Opposite of save_result_value_reacq()
if self.ressize == 0: # void return
return
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