template <typename NotifyFn>class CpuContextExchange
Defined at line 59 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
CpuContextExchange is a place for a CPU to synchronously receive the context
of another CPU. CpuContextExchange is thread-safe and intended for
concurrent use.
Example usage:
// Sends an IPI to |target|.
void SendIpi(cput_num_t target);
CpuContextExchange exchange(SendIpi);
...
// On CPU-1 with interrupts disabled...
CpuContextExchange context;
zx_status_t status = exchange.RequestContext(2, ZX_MSEC(10), context);
if (status == ZX_OK) {
Print(
&context
);
}
...
// On CPU-2 with interrupts disabled...
void NmiHandler(iframe_t* frame) {
exchange.HandleRequest(frame->rbp, *frame);
}
The template parameter |NotifyFn| is functor that accepts one cpu_num_t
argument. It will be called by |RequestContext| with interrupts disabled and
be passed |target_cpu|. When called it should *somehow* notify |target_cpu|
that another CPU has requested its context. The |target_cpu| should then
call |HandleRequest|.
Public Methods
void CpuContextExchange<NotifyFn> (NotifyFn notify_fn)Defined at line 61 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
void CpuContextExchange<NotifyFn> (const CpuContextExchange<NotifyFn> & )No copy. No move.
Defined at line 83 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
CpuContextExchange<NotifyFn> & operator= (const CpuContextExchange<NotifyFn> & )Defined at line 84 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
void CpuContextExchange<NotifyFn> (CpuContextExchange<NotifyFn> && )Defined at line 85 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
CpuContextExchange<NotifyFn> & operator= (CpuContextExchange<NotifyFn> && )Defined at line 86 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
zx_status_t RequestContext (cpu_num_t target_cpu, zx_duration_mono_t timeout, CpuContext & context)Synchronously request |target_cpu| to fill in |context|. Spins until
|target_cpu| handles the request or |timeout| has elapsed.
All requests for a given exchange instance are serialized so if the target
does not respond, the exchange will remain "tied up" indefinitely. When
this happens, subsequent requests will spin for |timeout| before failing
with ZX_ERR_TIMED_OUT.
Must be called with interrupts disabled.
Defined at line 104 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h
void HandleRequest (vaddr_t fp, const iframe_t & frame)Synchronously reply to a request. This method is a no-op if there is no
active request for this CPU's context.
Safe for use in interrupt context.
Must be called with interrupts disabled.
Defined at line 158 of file ../../zircon/kernel/lib/backtrace/include/lib/backtrace/cpu_context_exchange.h