For the threads scheduler, it makes sense to have NumCPU available.
For all other schedulers, the number of available CPUs is practically
limited to one by the scheduler (even though the system might have more
CPUs).
This is not a scheduler in the runtime, instead every goroutine is
mapped to a single OS thread - meaning 1:1 scheduling.
While this may not perform well (or at all) for large numbers of
threads, it greatly simplifies many things in the runtime. For example,
blocking syscalls can be called directly instead of having to use epoll
or similar. Also, we don't need to do anything special to call C code -
the default stack is all we need.
Somewhat surprisingly, this results in smaller code than the old code
with the cooperative (tasks) scheduler. Probably because the new RWMutex
is also simpler.
Using a global lock may be slow, but it is certainly simple and safe.
If this global lock becomes a bottleneck, we can of course look into
making the GC truly support multithreading.
The mutex implementation needs a different implementation once support
for threading lands. This implementation just moves code to the
internal/task package to centralize these algorithms.
The latest golang.org/x/net websocket package v0.33.0 needs
Dialer.DailContext in crypto/tls. This PR adds it.
Apps using golang.org/x/net are encouraged to use v0.33.0 to address:
CVE-2024-45338: Non-linear parsing of case-insensitive content in golang.org/x/net/html
CVE-2023-45288: net/http, x/net/http2: close connections when receiving too many headers
Tested with examples/net/websocket/dial.
If `ld.lld` is a version-specific binary (e.g., `ld.lld-18`), then its
error messages include the version. The parsing previously incorrectly
assumed it would be unversioned.
Show which files cause a binary size increase. This makes it easier to
see where the size is going: for example, this makes it easy to see how
much the GC contributes to code size compared to other runtime parts.
This is not a big change over the existing size report with -size=full,
but it is a bit more readable.
More information will be added in subsequent commits.
* initial implementation for Tillitis TKey device
* add UART implementation for TKey
* add Pin interface implementation for TKey touch sensor
* add RNG interface implementation for TKey
* add helpful machine package functions to return identifiers such as name and version for TKey
* use built-in timer for sleep timing on TKey
* modify UART implementation for TKey to implement Serialer interface
* implement BLAKE2s ROM function call for TKey device
* handle abort by triggering TKey device fault using illegal instruction to halt CPU
* simplify TKey implementation by inheriting from existing riscv32 target
* return error for trying to configure invalid baudrates on UART
* add tkey to builder test
* be very specific for features passed to LLVM for specific config in use for TKey
* handle feedback items from TKey device code review
Signed-off-by: deadprogram <ron@hybridgroup.com>
This actually simplifies the code and avoids a heap allocation in the
call to Wait. Instead, it uses the Data field of the task to store
information on whether a task was signalled early.
See the code comments for details. But in short, this implements a futex
for the cooperative scheduler (that is single threaded and
non-reentrant). Similar implementations can be made for basically every
other operating system, and even WebAssembly with the threading
(actually: atomics) proposal.
Using this basic futex implementation means we can use the same
implementation for synchronisation primitives on cooperative and
multicore systems.
For more information on futex across operating systems:
https://outerproduct.net/futex-dictionary.html
This adds some non-atomic types that have the same interface as the ones
in sync/atomic.
We currently don't need these to be atomic (because the scheduler is
entirely cooperative), but once we add support for a scheduler with
multiple threads and/or preemptive scheduling we can trivially add some
type aliases under a different build tag in the future when real
atomicity is needed for threading.
I don't think this is used anywhere right now, and it would need to be
updated to work with multithreading. So instead of fixing it, I think we
can remove it.
My original intention was to have something like this that could be used
in the machine package, but since this is in the runtime package (and
the runtime package imports the machine package on baremetal) it can't
actually be used that way.
I checked the TinyGo repo and the drivers repo, and `runtime.Cond` isn't
used anywhere except in that one test.
Ayke van Laethem
milkpirate
vaaski
Scott Feldman
Roman Grudzinski
Volodymyr Pobochii
Yurii Soldak
deadprogram
Elliott Sales de Andrade
sago35
soypat
Thomas Legris