making thread_local fiber_local #618
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| ATTR must be non-NULL and point to a valid pthread_attr. | ||
| PDP must be non-NULL. */ | ||
| -static int | ||
| +int |
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making the internal function allocate_stack() in lib pthread public and accessible by, say, fiber_create().
| @@ -534,14 +540,7 @@ namespace photon | |||
| vcpu = current->get_vcpu(); | |||
| (plock = &vcpu->runq_lock) -> foreground_lock(); | |||
| } | |||
| mutable bool update_current = false; | |||
| void set_current(thread* th) const { | |||
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There's no longer the need to set/switch the thread-local variable CURRENT as part of context switching, given that it has become a fiber-local varible.
thread/thread.cpp
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| #if defined(__x86_64__) | ||
| #if !defined(_WIN64) | ||
| asm( | ||
| DEF_ASM_FUNC(_photon_switch_context) // (void** rdi_to, void** rsi_from) | ||
| R"( | ||
| rdfsbase %rax |
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Save and restore fs register as part of context switching. It points to thread control block (TCB) and thread-local storage (TLS).
X86_64 only, for now.
| void _photon_thread_die(thread* th) { | ||
| static __attribute__((noreturn)) | ||
| void _photon_thread_stub() { | ||
| register thread* th asm("rbp"); |
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On entry rbp points to struct thread.
| size_t pstacksize; | ||
| pthread_attr_t attr; | ||
| pthread_attr_init(&attr); | ||
| allocate_stack((struct pthread_attr*)&attr, &pd, (void**)&ptr, &pstacksize); |
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We must make use of allocate_thread() in lib pthread to allocate the stack, TCB (that compatible to threading facilities) and TLS (for all modules, no matter loaded at startup time or run time).
| +#if TLS_TCB_AT_TP | ||
| + /* Reference to the TCB itself. */ | ||
| + pd->header.self = pd; | ||
| + |
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These lines are moved from pthread_create(), because fiber_create() doesn't have the definition of *pd, and can not do it outside.
| jmp *%rsi | ||
| )" | ||
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| DEF_ASM_FUNC(_photon_thread_stub) |
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_photon_thread_stub() becomes more complex and would better be implemented in C++.
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