Daniel Samson
88ad432758
Generalize capability passing from endpoints to memory objects. The per-task
handle table now holds kind-tagged entries (scheduler.HandleObject{kind, ptr});
closeHandles and shareCapability dispatch by kind, so a shared-memory object
rides an ipc_call send_cap exactly like an endpoint and is refcount-freed only
when its last capability drops.
- shm_create(len) -> vaddr, handle: contiguous, zeroed, cacheable frames wrapped
in a refcounted ShmObject, mapped into the caller's shm arena (PML4[230]).
- shm_map(cap) -> vaddr: map the same physical pages into a receiver that got the
capability. mapUserSharedInto maps WB-cacheable + device_grant, so a sharer's
teardown never frees the shared frames — the object owns them.
- runtime.shm: create(len) -> Region{ptr, handle, len}, map(handle) -> ptr.
Gate: qemu_test.py shm — shm-client creates a region, writes a pattern, passes
its capability to shm-server, which maps it and reads the same bytes back
(shm: shared 4096 bytes ok). ipc/ipc-call/ipc-cap/supervision/dma/usermem/
display-service and host tests all still pass — the handle change broke no IPC.
52 lines
1.6 KiB
Zig
52 lines
1.6 KiB
Zig
//! system/services/shm-client — the creating half of the shm test (docs/display-v2.md V2).
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//! It `shm_create`s a shared region, writes a known pattern into it, and hands the region's
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//! capability to `shm-server` as an `ipc_call` send_cap. The server maps that capability and
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//! confirms the pattern is visible — proving cross-process shared memory over the extended
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//! capability-passing path.
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const runtime = @import("runtime");
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const system = runtime.system;
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const shm = runtime.shm;
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const ipc = runtime.ipc;
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const pattern_len = 4096;
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/// The pattern the server checks — must match shm-server.zig.
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fn expected(i: usize) u8 {
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return @truncate(i *% 7 +% 3);
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}
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fn lookupServer() ?ipc.Handle {
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var attempts: usize = 0;
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while (attempts < 100) : (attempts += 1) {
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if (ipc.lookup(.shm_test)) |h| return h;
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system.sleep(50);
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}
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return null;
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}
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pub fn main() void {
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const region = shm.create(pattern_len) orelse {
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_ = system.write("shm: create failed\n");
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return;
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};
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var i: usize = 0;
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while (i < pattern_len) : (i += 1) region.ptr[i] = expected(i);
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const server = lookupServer() orelse {
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_ = system.write("shm: no server\n");
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return;
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};
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// A non-empty message (so it reaches on_message, not the ping path), carrying the shm
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// region's capability. The reply is empty; we just need the round trip.
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var reply: [64]u8 = undefined;
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_ = ipc.callCap(server, "shm", &reply, region.handle) catch {
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_ = system.write("shm: call failed\n");
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};
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}
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pub const panic = runtime.panic;
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comptime {
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_ = &runtime.start._start;
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}
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