Summary
Read out available samples.
Declaration
#include <zircon/syscalls.h>
zx_status_t zx_sampler_read(zx_handle_t sampler,
void* data,
size_t data_size,
size_t* actual);
Description
Read data written during the most recent sampling session. The provided
buffer must be large enough to read all available data. This size can be
queried by calling with data set to nullptr. The required minimum size
will be written to actual.
On a successful read, returns ZX_OK and sets actual to the number of
bytes actually read.
Additionally, on a ZX_ERR return code, a partial read may have still
occurred, and the number of bytes written to data will be returned in
actual.
Errors
ZX_ERR_NOT_SUPPORTED kernel.enable-debugging-syscalls is not set to true
on the kernel command line or the experimental_thread_sampler_enabled
build param is not set to true.
ZX_ERR_PERMISION_DENIED sampler is not a sampler returned by zx_sampler_create.
ZX_ERR_BAD_STATE the sampler is currently active