class SharedMemory
Defined at line 43 of file ../../src/sys/fuzzing/common/shared-memory.h
This class can be used to share VMOs mapped into multiple processes.
For example, to share a fixed length data, one process may create an object using:
SharedMemory sender;
sender.Mirror(data, size);
To share variable-length data, |Mirror| can be replaced with |Reserve|, e.g.:
SharedMemory sender;
sender.Reserve(capacity);
In either case, the process can created a shared VMO from the object:
zx::vmo vmo;
sender.Share(
&vmo
);
It can then send it to another process via FIDL, which can link it:
SharedMemory receiver;
receiver.Link(std::move(vmo));
At this point, the sender can |Update| the fixed length data, or |Write| to the variable length
data. In the latter case, the receiver needs to |Read| before accessing the data with |data| and
|size|. Reading and writing this size is not guaranteed to be atomic, so callers should use some
other method to coordinate when the size changes, e.g. with an |AsyncEventPair|.
Public Methods
SharedMemory & operator= (SharedMemory && other)Defined at line 26 of file ../../src/sys/fuzzing/common/shared-memory.cc
void ~SharedMemory ()Public methods
Defined at line 24 of file ../../src/sys/fuzzing/common/shared-memory.cc
zx_status_t Reserve (size_t capacity)Resets this object, then creates a VMO of at least |capacity| bytes, maps it. The size of the
shared memory is recorded in the buffer itself, making it compatible with |Resize| and |Write|.
Defined at line 37 of file ../../src/sys/fuzzing/common/shared-memory.cc
zx_status_t Mirror (void * data, size_t size)Resets and configures the object so subsequent calls to |Update| copy the region of memory
described by |data| and |size|. This region of memory MUST remain valid until this object is
destroyed or reset. The primary use of this method is to share compiler-provided
instrumentation across processes.
Defined at line 44 of file ../../src/sys/fuzzing/common/shared-memory.cc
void SharedMemory ()Defined at line 45 of file ../../src/sys/fuzzing/common/shared-memory.h
void SharedMemory (SharedMemory && other)Defined at line 46 of file ../../src/sys/fuzzing/common/shared-memory.h
uint8_t * data ()Defined at line 50 of file ../../src/sys/fuzzing/common/shared-memory.h
size_t size ()Defined at line 51 of file ../../src/sys/fuzzing/common/shared-memory.h
size_t capacity ()Defined at line 52 of file ../../src/sys/fuzzing/common/shared-memory.h
zx_status_t Share (zx::vmo * out)Returns a buffer containing a duplicate of the VMO backing this memory region via |out|,
suitable for sending to another process. The size is written to the ZX_PROP_VMO_CONTENT_SIZE
property of the VMO, as in |fuchsia.debugdata.Publisher|.
Defined at line 60 of file ../../src/sys/fuzzing/common/shared-memory.cc
zx_status_t Link (zx::vmo vmo)Resets this object, then takes ownership of the |vmo| and maps it. The VMO must have been
|Share|d from an object that was |Reserve|d or |Mirror|ed.
Defined at line 68 of file ../../src/sys/fuzzing/common/shared-memory.cc
zx_status_t Read ()Refreshes the valid region of the mapped memory. Callers should use this method before calling
|size()|.
Defined at line 80 of file ../../src/sys/fuzzing/common/shared-memory.cc
zx_status_t Write (const void * data, size_t size)Replaces the contents of the VMO with the given |data|.
Defined at line 92 of file ../../src/sys/fuzzing/common/shared-memory.cc
void Update ()Copies data from the mirrored memory region into this object. Must only be called on an object
that was |Mirror|ed.
Defined at line 108 of file ../../src/sys/fuzzing/common/shared-memory.cc
void Clear ()Zeros the |Mirror|ed memory, if any.
Defined at line 113 of file ../../src/sys/fuzzing/common/shared-memory.cc