diff options
Diffstat (limited to 'src/runtime/asm_arm.s')
| -rw-r--r-- | src/runtime/asm_arm.s | 38 |
1 files changed, 33 insertions, 5 deletions
diff --git a/src/runtime/asm_arm.s b/src/runtime/asm_arm.s index 01621245dc..cd692e51a3 100644 --- a/src/runtime/asm_arm.s +++ b/src/runtime/asm_arm.s @@ -630,6 +630,16 @@ nosave: TEXT ·cgocallback(SB),NOSPLIT,$12-12 NO_LOCAL_POINTERS + // Skip cgocallbackg, just dropm when fn is nil, and frame is the saved g. + // It is used to dropm while thread is exiting. + MOVW fn+0(FP), R1 + CMP $0, R1 + B.NE loadg + // Restore the g from frame. + MOVW frame+4(FP), g + B dropm + +loadg: // Load m and g from thread-local storage. #ifdef GOOS_openbsd BL runtime·load_g(SB) @@ -639,7 +649,8 @@ TEXT ·cgocallback(SB),NOSPLIT,$12-12 BL.NE runtime·load_g(SB) #endif - // If g is nil, Go did not create the current thread. + // If g is nil, Go did not create the current thread, + // or if this thread never called into Go on pthread platforms. // Call needm to obtain one for temporary use. // In this case, we're running on the thread stack, so there's // lots of space, but the linker doesn't know. Hide the call from @@ -653,7 +664,7 @@ TEXT ·cgocallback(SB),NOSPLIT,$12-12 needm: MOVW g, savedm-4(SP) // g is zero, so is m. - MOVW $runtime·needm(SB), R0 + MOVW $runtime·needAndBindM(SB), R0 BL (R0) // Set m->g0->sched.sp = SP, so that if a panic happens @@ -724,14 +735,31 @@ havem: MOVW savedsp-12(SP), R4 // must match frame size MOVW R4, (g_sched+gobuf_sp)(g) - // If the m on entry was nil, we called needm above to borrow an m - // for the duration of the call. Since the call is over, return it with dropm. + // If the m on entry was nil, we called needm above to borrow an m, + // 1. for the duration of the call on non-pthread platforms, + // 2. or the duration of the C thread alive on pthread platforms. + // If the m on entry wasn't nil, + // 1. the thread might be a Go thread, + // 2. or it's wasn't the first call from a C thread on pthread platforms, + // since the we skip dropm to resue the m in the first call. MOVW savedm-4(SP), R6 CMP $0, R6 - B.NE 3(PC) + B.NE done + + // Skip dropm to reuse it in the next call, when a pthread key has been created. + MOVW _cgo_pthread_key_created(SB), R6 + // It means cgo is disabled when _cgo_pthread_key_created is a nil pointer, need dropm. + CMP $0, R6 + B.EQ dropm + MOVW (R6), R6 + CMP $0, R6 + B.NE done + +dropm: MOVW $runtime·dropm(SB), R0 BL (R0) +done: // Done! RET |