musl/src/thread, branch v0.9.3 musl - an implementation of the standard library for Linux-based systems retry on cas failures in sem_trywait 2012-07-24T04:51:36+00:00 Rich Felker dalias@aerifal.cx 2012-07-24T04:51:36+00:00 07e62953c768f9f09485388c22ffaed98d11d676 this seems counter-intuitive since sem_trywait is supposed to just try once, not wait for the semaphore. however, the retry loop is not a wait. instead, it's to handle the case where the value changes due to a simultaneous post or wait from another thread while the semaphore value remains positive. in such a case, it's absolutely wrong for sem_trywait to fail with EAGAIN because the semaphore is not busy. 
this seems counter-intuitive since sem_trywait is supposed to just try
once, not wait for the semaphore. however, the retry loop is not a
wait. instead, it's to handle the case where the value changes due to
a simultaneous post or wait from another thread while the semaphore
value remains positive. in such a case, it's absolutely wrong for
sem_trywait to fail with EAGAIN because the semaphore is not busy.
avoid blx instruction which does not exist on armv4t or armv4 2012-07-15T00:15:02+00:00 Rich Felker dalias@aerifal.cx 2012-07-15T00:15:02+00:00 7be3b5a073e77f1147acfa728725f9f81d20ceb0 






fix several locks that weren't updated right for new futex-based __lock
2012-07-12T15:23:43+00:00

Rich Felker
dalias@aerifal.cx

2012-07-12T15:23:43+00:00

bbbe87e35cfeef593e23010e35528e722027567f

these could have caused memory corruption due to invalid accesses to
the next field. all should be fixed now; I found the errors with fgrep
-r '__lock(&', which is bogus since the argument should be an array.





these could have caused memory corruption due to invalid accesses to
the next field. all should be fixed now; I found the errors with fgrep
-r '__lock(&', which is bogus since the argument should be an array.







fix pthread_kill unlocking
2012-07-12T15:14:12+00:00

Rich Felker
dalias@aerifal.cx

2012-07-12T15:14:12+00:00

c89f130f39b413d1fb1733166ca63d694685c529

it had not been updated for the futex-based locks





it had not been updated for the futex-based locks







fix potential race condition in detached threads
2012-07-12T03:36:46+00:00

Rich Felker
dalias@aerifal.cx

2012-07-12T03:36:46+00:00

92f8396b0c8e4f146563b87f46137484cfb36e31

after the thread unmaps its own stack/thread structure, the kernel,
performing child tid clear and futex wake, could clobber a new mapping
made at the same location as the just-removed thread's tid field.
disable kernel clearing of child tid to prevent this.





after the thread unmaps its own stack/thread structure, the kernel,
performing child tid clear and futex wake, could clobber a new mapping
made at the same location as the just-removed thread's tid field.
disable kernel clearing of child tid to prevent this.







mips clone: don't free stack space used to copy arg
2012-07-12T03:01:09+00:00

Rich Felker
dalias@aerifal.cx

2012-07-12T03:01:09+00:00

a03f69d4456d3ac5120cc07a22af8ecb631444bb

the mips abi reserves stack space equal to the size of the in-register
args for the callee to save the args, if desired. this would cause the
beginning of the thread structure to be clobbered...





the mips abi reserves stack space equal to the size of the in-register
args for the callee to save the args, if desired. this would cause the
beginning of the thread structure to be clobbered...







fix mips clone() on real linux kernel
2012-07-12T02:59:43+00:00

Rich Felker
dalias@aerifal.cx

2012-07-12T02:59:43+00:00

b58f738bcb5877c83aef49129b40827a1d5ae4c7

the old code worked in qemu app-level emulation, but not on real
kernels where the clone syscall does not copy the register values to
the new thread. save arguments on the new thread stack instead.





the old code worked in qemu app-level emulation, but not on real
kernels where the clone syscall does not copy the register values to
the new thread. save arguments on the new thread stack instead.







fix clone() on mips (args were in wrong order)
2012-07-12T00:44:38+00:00

Rich Felker
dalias@aerifal.cx

2012-07-12T00:44:38+00:00

715b6403ce25110d594c7814e9cff860486a6f85

with this change, threads on mips seem to be working





with this change, threads on mips seem to be working







first attempt at making threads work on mips
2012-07-11T15:35:27+00:00

Rich Felker
dalias@aerifal.cx

2012-07-11T15:35:27+00:00

5c94367a9b0f1c1dd0deadb0f320242b59f844bb












generic c version of __set_thread_area for archs where it works
2012-07-11T15:34:46+00:00

Rich Felker
dalias@aerifal.cx

2012-07-11T15:34:46+00:00

d0bfbd9dca27e3053534bbf70b36e229d0c0cf21

on other archs, like x86[_64], asm version is required





on other archs, like x86[_64], asm version is required