diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/rt/rust_task.cpp | 141 | ||||
| -rw-r--r-- | src/rt/rust_task.h | 8 |
2 files changed, 122 insertions, 27 deletions
diff --git a/src/rt/rust_task.cpp b/src/rt/rust_task.cpp index 8d7157ed..bed4e57b 100644 --- a/src/rt/rust_task.cpp +++ b/src/rt/rust_task.cpp @@ -142,6 +142,18 @@ rust_task::start(uintptr_t exit_task_glue, uintptr_t args, size_t callsz) { + if (spawnee_abi == ABI_X86_RUSTBOOT_CDECL) + start_rustboot(exit_task_glue, spawnee_fn, args, callsz); + else + start_rustc(exit_task_glue, spawnee_fn, args, callsz); +} + +void +rust_task::start_rustboot(uintptr_t exit_task_glue, + uintptr_t spawnee_fn, + uintptr_t args, + size_t callsz) +{ LOGPTR(dom, "exit-task glue", exit_task_glue); LOGPTR(dom, "from spawnee", spawnee_fn); @@ -176,30 +188,25 @@ rust_task::start(uintptr_t exit_task_glue, uintptr_t exit_task_frame_base = 0; - if (spawnee_abi == ABI_X86_RUSTBOOT_CDECL) { - for (size_t j = 0; j < n_callee_saves; ++j) { - - // We want 'frame_base' to point to the old fp in this (exit-task) - // frame, because we're going to inject this frame-pointer into - // the callee-save frame pointer value in the *next* (spawnee) - // frame. A cheap trick, but this means the spawnee frame will - // restore the proper frame pointer of the glue frame as it runs - // its epilogue. - if (j == callee_save_fp) - exit_task_frame_base = (uintptr_t)spp; + for (size_t j = 0; j < n_callee_saves; ++j) { - *spp-- = 0; - } + // We want 'frame_base' to point to the old fp in this (exit-task) + // frame, because we're going to inject this frame-pointer into + // the callee-save frame pointer value in the *next* (spawnee) + // frame. A cheap trick, but this means the spawnee frame will + // restore the proper frame pointer of the glue frame as it runs + // its epilogue. + if (j == callee_save_fp) + exit_task_frame_base = (uintptr_t)spp; - *spp-- = (uintptr_t) dom->root_crate; // crate ptr - *spp-- = (uintptr_t) 0; // frame_glue_fns + *spp-- = 0; } + *spp-- = (uintptr_t) dom->root_crate; // crate ptr + *spp-- = (uintptr_t) 0; // frame_glue_fns + I(dom, args); - if (spawnee_abi == ABI_X86_RUSTBOOT_CDECL) - make_aligned_room_for_bytes(spp, callsz - sizeof(uintptr_t)); - else - make_aligned_room_for_bytes(spp, callsz - 3 * sizeof(uintptr_t)); + make_aligned_room_for_bytes(spp, callsz - sizeof(uintptr_t)); // Copy args from spawner to spawnee. uintptr_t *src = (uintptr_t *)args; @@ -222,16 +229,96 @@ rust_task::start(uintptr_t exit_task_glue, // activating: *spp-- = (uintptr_t) 0x0; // closure-or-obj - if (spawnee_abi == ABI_X86_RUSTBOOT_CDECL) { - // in CDECL mode we write the task + outptr to the spawnee stack. - *spp-- = (uintptr_t) this; // task - *spp-- = (uintptr_t) 0; // output addr - } else { - // in FASTCALL mode we don't, the outptr will be in ecx and the task - // in edx, and the activate_glue will make sure to set that up. - I(dom, spawnee_abi == ABI_X86_RUSTC_FASTCALL); + // in CDECL mode we write the task + outptr to the spawnee stack. + *spp-- = (uintptr_t) this; // task + *spp-- = (uintptr_t) 0; // output addr + + I(dom, spp+1 == align_down(spp+1)); + *spp-- = (uintptr_t) exit_task_glue; // retpc + + // The context the activate_glue needs to switch stack. + *spp-- = (uintptr_t) spawnee_fn; // instruction to start at + for (size_t j = 0; j < n_callee_saves; ++j) { + // callee-saves to carry in when we activate + if (j == callee_save_fp) + *spp-- = exit_task_frame_base; + else + *spp-- = (uintptr_t)NULL; } + // Back up one, we overshot where sp should be. + rust_sp = (uintptr_t) (spp+1); + + transition(&dom->newborn_tasks, &dom->running_tasks); +} + +void +rust_task::start_rustc(uintptr_t exit_task_glue, + uintptr_t spawnee_fn, + uintptr_t args, + size_t callsz) +{ + LOGPTR(dom, "exit-task glue", exit_task_glue); + LOGPTR(dom, "from spawnee", spawnee_fn); + + // Set sp to last uintptr_t-sized cell of segment + rust_sp -= sizeof(uintptr_t); + + // NB: Darwin needs "16-byte aligned" stacks *at the point of the call + // instruction in the caller*. This means that the address at which the + // word before retpc is pushed must always be 16-byte aligned. + // + // see: "Mac OS X ABI Function Call Guide" + + + // Begin synthesizing frames. There are two: a "fully formed" + // exit-task frame at the top of the stack -- that pretends to be + // mid-execution -- and a just-starting frame beneath it that + // starts executing the first instruction of the spawnee. The + // spawnee *thinks* it was called by the exit-task frame above + // it. It wasn't; we put that fake frame in place here, but the + // illusion is enough for the spawnee to return to the exit-task + // frame when it's done, and exit. + uintptr_t *spp = (uintptr_t *)rust_sp; + + + // The exit_task_glue frame we synthesize above the frame we activate: + make_aligned_room_for_bytes(spp, 2 * sizeof(uintptr_t)); + *spp-- = (uintptr_t) 0; // closure-or-obj + *spp-- = (uintptr_t) this; // task + I(dom, spp == align_down(spp)); + *spp-- = (uintptr_t) 0x0; // output + *spp-- = (uintptr_t) 0x0; // retpc + + uintptr_t exit_task_frame_base = 0; + + I(dom, args); + make_aligned_room_for_bytes(spp, callsz - 3 * sizeof(uintptr_t)); + + // Copy args from spawner to spawnee. + uintptr_t *src = (uintptr_t *)args; + src += 1; // spawn-call output slot + src += 1; // spawn-call task slot + src += 1; // spawn-call closure-or-obj slot + + // Undo previous sp-- so we're pointing at the last word pushed. + ++spp; + + // Memcpy all but the task, output and env pointers + callsz -= (3 * sizeof(uintptr_t)); + spp = (uintptr_t*) (((uintptr_t)spp) - callsz); + memcpy(spp, src, callsz); + + // Move sp down to point to last implicit-arg cell (env). + spp--; + + // The *implicit* incoming args to the spawnee frame we're + // activating: + *spp-- = (uintptr_t) 0x0; // closure-or-obj + + // in FASTCALL mode we don't, the outptr will be in ecx and the task + // in edx, and the activate_glue will make sure to set that up. + I(dom, spp+1 == align_down(spp+1)); *spp-- = (uintptr_t) exit_task_glue; // retpc diff --git a/src/rt/rust_task.h b/src/rt/rust_task.h index 7d4ed221..9169a0b3 100644 --- a/src/rt/rust_task.h +++ b/src/rt/rust_task.h @@ -60,6 +60,14 @@ rust_task : public maybe_proxy<rust_task>, uintptr_t spawnee_fn, uintptr_t args, size_t callsz); + void start_rustboot(uintptr_t exit_task_glue, + uintptr_t spawnee_fn, + uintptr_t args, + size_t callsz); + void start_rustc(uintptr_t exit_task_glue, + uintptr_t spawnee_fn, + uintptr_t args, + size_t callsz); void grow(size_t n_frame_bytes); bool running(); bool blocked(); |