66 строки
1,8 КиБ
Go
66 строки
1,8 КиБ
Go
// +build scheduler.tasks,tinygo.riscv
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package task
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import "unsafe"
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var systemStack uintptr
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// calleeSavedRegs is the list of registers that must be saved and restored when
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// switching between tasks. Also see scheduler_riscv.S that relies on the
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// exact layout of this struct.
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type calleeSavedRegs struct {
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s0 uintptr // x8 (fp)
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s1 uintptr // x9
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s2 uintptr // x18
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s3 uintptr // x19
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s4 uintptr // x20
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s5 uintptr // x21
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s6 uintptr // x22
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s7 uintptr // x23
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s8 uintptr // x24
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s9 uintptr // x25
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s10 uintptr // x26
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s11 uintptr // x27
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pc uintptr
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}
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// archInit runs architecture-specific setup for the goroutine startup.
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func (s *state) archInit(r *calleeSavedRegs, fn uintptr, args unsafe.Pointer) {
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// Store the initial sp for the startTask function (implemented in assembly).
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s.sp = uintptr(unsafe.Pointer(r))
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// Initialize the registers.
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// These will be popped off of the stack on the first resume of the goroutine.
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// Start the function at tinygo_startTask (defined in src/internal/task/task_stack_riscv.S).
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// This assembly code calls a function (passed in s0) with a single argument
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// (passed in s1). After the function returns, it calls Pause().
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r.pc = uintptr(unsafe.Pointer(&startTask))
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// Pass the function to call in s0.
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// This function is a compiler-generated wrapper which loads arguments out
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// of a struct pointer. See createGoroutineStartWrapper (defined in
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// compiler/goroutine.go) for more information.
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r.s0 = fn
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// Pass the pointer to the arguments struct in s1.
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r.s1 = uintptr(args)
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}
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func (s *state) resume() {
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swapTask(s.sp, &systemStack)
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}
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func (s *state) pause() {
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newStack := systemStack
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systemStack = 0
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swapTask(newStack, &s.sp)
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}
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// SystemStack returns the system stack pointer when called from a task stack.
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// When called from the system stack, it returns 0.
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func SystemStack() uintptr {
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return systemStack
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}
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