diff options
Diffstat (limited to 'libcr/coroutine.c')
| -rw-r--r-- | libcr/coroutine.c | 492 |
1 files changed, 316 insertions, 176 deletions
diff --git a/libcr/coroutine.c b/libcr/coroutine.c index 041b624..bf44219 100644 --- a/libcr/coroutine.c +++ b/libcr/coroutine.c @@ -1,52 +1,63 @@ /* libcr/coroutine.c - Simple embeddable coroutine implementation * - * Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com> + * Copyright (C) 2024-2025 Luke T. Shumaker <lukeshu@lukeshu.com> * SPDX-License-Identifier: AGPL-3.0-or-later */ -#include <setjmp.h> /* for setjmp(), longjmp(), jmp_buf */ #include <stdint.h> /* for uint8_t */ -#include <stdio.h> /* for printf() */ #include <stdlib.h> /* for aligned_alloc(), free() */ +#include <string.h> /* for strncpy(), memset() */ #include <libmisc/assert.h> +#include <libmisc/macro.h> + +#define LOG_NAME COROUTINE +#include <libmisc/log.h> #include <libcr/coroutine.h> +#undef COROUTINE /* Configuration **************************************************************/ #include "config.h" -#ifndef CONFIG_COROUTINE_DEFAULT_STACK_SIZE - #error config.h must define CONFIG_COROUTINE_DEFAULT_STACK_SIZE +#ifndef CONFIG_COROUTINE_NAME_LEN + #error config.h must define CONFIG_COROUTINE_NAME_LEN (non-negative integer) #endif #ifndef CONFIG_COROUTINE_NUM - #error config.h must define CONFIG_COROUTINE_NUM + #error config.h must define CONFIG_COROUTINE_NUM (non-negative integer) #endif #ifndef CONFIG_COROUTINE_MEASURE_STACK - #error config.h must define CONFIG_COROUTINE_MEASURE_STACK + #error config.h must define CONFIG_COROUTINE_MEASURE_STACK (bool) #endif #ifndef CONFIG_COROUTINE_PROTECT_STACK - #error config.h must define CONFIG_COROUTINE_PROTECT_STACK + #error config.h must define CONFIG_COROUTINE_PROTECT_STACK (bool) #endif #ifndef CONFIG_COROUTINE_DEBUG - #error config.h must define CONFIG_COROUTINE_DEBUG + #error config.h must define CONFIG_COROUTINE_DEBUG (bool) #endif #ifndef CONFIG_COROUTINE_VALGRIND - #error config.h must define CONFIG_COROUTINE_VALGRIND + #error config.h must define CONFIG_COROUTINE_VALGRIND (bool) +#endif +#ifndef CONFIG_COROUTINE_GDB + #error config.h must define CONFIG_COROUTINE_GDB (bool) #endif +/* Enforce that CONFIG_COROUTINE_NUM is greater than 1, to work around + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=118212 */ +static_assert(CONFIG_COROUTINE_NUM > 1); + +/* Implementation *************************************************************/ + #if CONFIG_COROUTINE_VALGRIND #include <valgrind/valgrind.h> #endif -/* Implementation *************************************************************/ - /* * Portability notes: * - * - It uses GCC `__attribute__`s, and the GNUC ({ ... }) statement - * exprs extension. + * - It uses GCC `gnu::` attributes, and the GNUC `({ ... })` + * statement exprs extension. * * - It has a small bit of platform-specific code in the "platform * support" section. Other than this, it should be portable to @@ -119,41 +130,19 @@ * no longer exists. */ -#define ALWAYS_INLINE inline __attribute__((always_inline)) - /* platform support ***********************************************************/ /* As part of sbc-harness, this only really needs to support ARM-32, but being * able to run it on my x86-64 GNU/Linux laptop is useful for debugging. */ #define CR_PLAT_STACK_ALIGNMENT \ - ({ __attribute__((aligned)) void fn(void) {}; __alignof__(fn); }) + ({ [[gnu::aligned]] void fn(void) {}; __alignof__(fn); }) #if 0 { /* bracket to get Emacs indentation to work how I want */ #endif /*==================================================================== - * Wrappers for setjmp()/longjmp() that do *not* save the - * interrupt mask. */ -#if __unix__ - /* On __unix__, we use POSIX real-time signals as interrupts. - * POSIX leaves it implementation-defined whether - * setjmp()/longjmp() save the signal mask; while glibc does - * not save it, let's not rely on that. */ - #define cr_plat_setjmp(env) sigsetjmp(env, 0) - #define cr_plat_longjmp(env, val) siglongjmp(env, val) -#elif __NEWLIB__ - /* newlib does not have sigsetjmp()/sigsetlongjmp(), but - * setjmp()/longjmp() do not save the interrupt mask, * so we - * can use them directly. */ - #define cr_plat_setjmp(env) setjmp(env) - #define cr_plat_longjmp(env, val) longjmp(env, val) -#else - #error unsupported platform (not __unix__, not __NEWLIB__) -#endif - -/*==================================================================== * Interrupt management routines. */ #if __unix__ #include <signal.h> /* for sig*, SIG* */ @@ -161,11 +150,26 @@ /* For a signal to be *in* the mask means that the signal is * *blocked*. */ - bool cr_is_in_intrhandler(void) { + #define _CR_SIG_SENTINEL SIGURG + #if CONFIG_COROUTINE_GDB + #define _CR_SIG_GDB SIGWINCH + #endif + +#if CONFIG_COROUTINE_VALGRIND + /* Hack around a bug in Valgrind where it runs the + * sigsuspend(tmp_sigmask)-triggered handler function with the + * original mask, not the `tmp_mask`. */ + static bool _cr_plat_in_sigsuspend = false; +#endif + + bool cr_plat_is_in_intrhandler(void) { +#if CONFIG_COROUTINE_VALGRIND + if (_cr_plat_in_sigsuspend) + return true; +#endif sigset_t cur_mask; - sigfillset(&cur_mask); sigprocmask(0, NULL, &cur_mask); - if (sigismember(&cur_mask, SIGHUP)) + if (sigismember(&cur_mask, _CR_SIG_SENTINEL)) /* Interrupts are disabled, so we cannot be in * an interrupt handler. */ return false; @@ -175,47 +179,63 @@ return false; } static inline bool _cr_plat_are_interrupts_enabled(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); sigset_t cur_mask; sigfillset(&cur_mask); sigprocmask(0, NULL, &cur_mask); - return !sigismember(&cur_mask, SIGHUP); + return !sigismember(&cur_mask, _CR_SIG_SENTINEL); } static inline void cr_plat_wait_for_interrupt(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); assert(!_cr_plat_are_interrupts_enabled()); sigset_t set; sigemptyset(&set); +#if CONFIG_COROUTINE_VALGRIND + _cr_plat_in_sigsuspend = true; +#endif sigsuspend(&set); - - sigfillset(&set); - sigprocmask(SIG_SETMASK, &set, NULL); +#if CONFIG_COROUTINE_VALGRIND + _cr_plat_in_sigsuspend = false; +#endif } bool _cr_plat_save_and_disable_interrupts(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); sigset_t all, old; sigfillset(&all); sigprocmask(SIG_SETMASK, &all, &old); - return !sigismember(&old, SIGHUP); + return !sigismember(&old, _CR_SIG_SENTINEL); } void _cr_plat_enable_interrupts(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); assert(!_cr_plat_are_interrupts_enabled()); sigset_t zero; sigemptyset(&zero); sigprocmask(SIG_SETMASK, &zero, NULL); } + #if CONFIG_COROUTINE_GDB + static void _cr_gdb_intrhandler(int LM_UNUSED(sig)) {} + #endif + static void cr_plat_init(void) { + #if CONFIG_COROUTINE_GDB + int r; + struct sigaction action = { + .sa_handler = _cr_gdb_intrhandler, + }; + r = sigaction(_CR_SIG_GDB, &action, NULL); + assert(r == 0); + #endif + } #elif __ARM_ARCH_6M__ && __ARM_EABI__ - bool cr_is_in_intrhandler(void) { + bool cr_plat_is_in_intrhandler(void) { uint32_t isr_number; asm volatile ("mrs %0, ipsr" : /* %0 */"=l"(isr_number) ); return isr_number != 0; } - static ALWAYS_INLINE bool _cr_plat_are_interrupts_enabled(void) { - assert(!cr_is_in_intrhandler()); + LM_ALWAYS_INLINE static bool _cr_plat_are_interrupts_enabled(void) { + assert(!cr_plat_is_in_intrhandler()); uint32_t primask; asm volatile ("mrs %0, PRIMASK" : /* %0 */"=l"(primask) @@ -223,8 +243,8 @@ return primask == 0; } - static ALWAYS_INLINE void cr_plat_wait_for_interrupt(void) { - assert(!cr_is_in_intrhandler()); + LM_ALWAYS_INLINE static void cr_plat_wait_for_interrupt(void) { + assert(!cr_plat_is_in_intrhandler()); assert(!_cr_plat_are_interrupts_enabled()); asm volatile ("wfi\n" "cpsie i\n" @@ -233,16 +253,17 @@ :::"memory"); } bool _cr_plat_save_and_disable_interrupts(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); bool were_enabled = _cr_plat_are_interrupts_enabled(); asm volatile ("cpsid i"); return were_enabled; } void _cr_plat_enable_interrupts(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); assert(!_cr_plat_are_interrupts_enabled()); asm volatile ("cpsie i"); } + static void cr_plat_init(void) {} #else #error unsupported platform (not __unix__, not __ARM_ARCH_6M__ && __ARM_EABI__) #endif @@ -253,7 +274,7 @@ #define CR_PLAT_STACK_GROWS_DOWNWARD 1 #if CONFIG_COROUTINE_MEASURE_STACK - static ALWAYS_INLINE uintptr_t cr_plat_get_sp(void) { + LM_ALWAYS_INLINE static uintptr_t cr_plat_get_sp(void) { uintptr_t sp; asm volatile ("mov %0, sp":"=r"(sp)); return sp; @@ -285,7 +306,7 @@ #define CR_PLAT_STACK_GROWS_DOWNWARD 1 #if CONFIG_COROUTINE_MEASURE_STACK - static ALWAYS_INLINE uintptr_t cr_plat_get_sp(void) { + LM_ALWAYS_INLINE static uintptr_t cr_plat_get_sp(void) { uintptr_t sp; asm volatile ("movq %%rsp, %0":"=r"(sp)); return sp; @@ -312,41 +333,75 @@ #error unsupported CPU (not __ARM_ARCH_6M__, not __x86_64__) #endif +/*==================================================================== + * Wrappers for setjmp()/longjmp() that: + * 1. Allow us to inspect the buffer. + * 2. Do *not* save the interrupt mask. + */ + #include <setjmp.h> /* for setjmp(), longjmp(), jmp_buf */ + typedef struct { + jmp_buf raw; + #if CONFIG_COROUTINE_MEASURE_STACK + /* We aught to be able to get sp out of the raw + * `jmp_buf`, but libc authors insist on jmp_buf being + * opaque, glibc going as far as to xor it with a + * secret to obfuscate it! */ + uintptr_t sp; + #endif + } cr_plat_jmp_buf; + static void _cr_plat_setjmp_pre(cr_plat_jmp_buf *env [[gnu::unused]]) { + #if CONFIG_COROUTINE_MEASURE_STACK + env->sp = cr_plat_get_sp(); + #endif + } + #if CONFIG_COROUTINE_MEASURE_STACK + static uintptr_t cr_plat_setjmp_get_sp(cr_plat_jmp_buf *env) { return env->sp; } + #endif + /* cr_plat_setjmp *NEEDS* to be a preprocessor macro rather + * than a real function, because [[gnu::returns_twice]] + * doesn't work. + * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117469 */ +#if __unix__ + /* On __unix__, we use POSIX real-time signals as interrupts. + * POSIX leaves it implementation-defined whether + * setjmp()/longjmp() save the signal mask; while glibc does + * not save it, let's not rely on that. */ + #define cr_plat_setjmp(env) ({ _cr_plat_setjmp_pre(env); sigsetjmp((env)->raw, 0); }) + [[noreturn]] static void cr_plat_longjmp(cr_plat_jmp_buf *env, int val) { siglongjmp(env->raw, val); } +#elif __NEWLIB__ + /* newlib does not have sigsetjmp()/sigsetlongjmp(), but + * setjmp()/longjmp() do not save the interrupt mask, so we + * can use them directly. */ + #define cr_plat_setjmp(env) ({ _cr_plat_setjmp_pre(env); setjmp((env)->raw); }) + [[noreturn]] static void cr_plat_longjmp(cr_plat_jmp_buf *env, int val) { longjmp(env->raw, val); } +#else + #error unsupported platform (not __unix__, not __NEWLIB__) +#endif + #if 0 } #endif -/* preprocessor macros ********************************************************/ - -/** Return `n` rounded up to the nearest multiple of `d` */ -#define ROUND_UP(n, d) ( ( ((n)+(d)-1) / (d) ) * (d) ) -#define ARRAY_LEN(arr) (sizeof(arr)/sizeof((arr)[0])) -#define NEXT_POWER_OF_2(x) ((1ULL)<<((sizeof(unsigned long long)*8)-__builtin_clzll(x))) - /* types **********************************************************************/ -enum coroutine_state { - CR_NONE = 0, /* this slot in the table is empty */ - CR_INITIALIZING, /* running, before cr_begin() */ - CR_RUNNING, /* running, after cr_begin() */ - CR_RUNNABLE, /* not running, but runnable */ - CR_PAUSED, /* not running, and not runnable */ -}; - struct coroutine { + /* 1. state *************************************************/ volatile enum coroutine_state state; - jmp_buf env; -#if CONFIG_COROUTINE_MEASURE_STACK - /* We aught to be able to get this out of .env, but libc - * authors insist on jmp_buf being opaque, glibc going as far - * as to xor it with a secret ot obfuscate it! */ - uintptr_t sp; -#endif + + /* 2. name **************************************************/ + [[gnu::nonstring]] char name[CONFIG_COROUTINE_NAME_LEN]; + + /* 3. stack *************************************************/ + /* stack_size *includes* CR_STACK_GUARD at each end. */ size_t stack_size; + /* stack is the bottom of the CR_STACK_GUARD at the bottom of the stack. */ void *stack; #if CONFIG_COROUTINE_VALGRIND unsigned stack_id; #endif + + /* 4. env ***************************************************/ + cr_plat_jmp_buf env; }; /* constants ******************************************************************/ @@ -368,16 +423,20 @@ static const uint8_t stack_pattern[] = { }; #endif #if CONFIG_COROUTINE_PROTECT_STACK - #define STACK_GUARD_SIZE \ - ROUND_UP(sizeof(stack_pattern), CR_PLAT_STACK_ALIGNMENT) + #define CR_STACK_GUARD_SIZE \ + ((size_t)LM_ROUND_UP(sizeof(stack_pattern), CR_PLAT_STACK_ALIGNMENT)) #else - #define STACK_GUARD_SIZE 0 + #define CR_STACK_GUARD_SIZE ((size_t)0) #endif /* global variables ***********************************************************/ -static jmp_buf coroutine_add_env; -static jmp_buf coroutine_main_env; +static bool coroutine_initialized = false; +static cr_plat_jmp_buf coroutine_add_env; +static cr_plat_jmp_buf coroutine_main_env; +#if CONFIG_COROUTINE_GDB +static cr_plat_jmp_buf coroutine_gdb_env; +#endif /* * Invariants (and non-invariants): @@ -408,36 +467,46 @@ static struct { * compiler will optimize `%array_len` to &(array_len-1)`, (b) * we don't have to worry about funny wrap-around behavior * when head or tail overflow. */ - cid_t buf[NEXT_POWER_OF_2(CONFIG_COROUTINE_NUM)]; + cid_t buf[LM_NEXT_POWER_OF_2(CONFIG_COROUTINE_NUM)]; } coroutine_ringbuf = {0}; static cid_t coroutine_running = 0; +static size_t coroutine_cnt = 0; /* utility functions **********************************************************/ -#define errorf(...) printf("error: " __VA_ARGS__) -#define infof(...) printf("info: " __VA_ARGS__) -#if CONFIG_COROUTINE_DEBUG - #define debugf(...) printf("dbg: " __VA_ARGS__) -#else - #define debugf(...) -#endif - -static inline const char* coroutine_state_str(enum coroutine_state state) { - assert(state < ARRAY_LEN(coroutine_state_strs)); - return coroutine_state_strs[state]; -} - static inline void coroutine_ringbuf_push(cid_t val) { - coroutine_ringbuf.buf[coroutine_ringbuf.head++ % ARRAY_LEN(coroutine_ringbuf.buf)] = val; - assert((coroutine_ringbuf.head % ARRAY_LEN(coroutine_ringbuf.buf)) != - (coroutine_ringbuf.tail % ARRAY_LEN(coroutine_ringbuf.buf))); + coroutine_ringbuf.buf[coroutine_ringbuf.head++ % LM_ARRAY_LEN(coroutine_ringbuf.buf)] = val; + assert((coroutine_ringbuf.head % LM_ARRAY_LEN(coroutine_ringbuf.buf)) != + (coroutine_ringbuf.tail % LM_ARRAY_LEN(coroutine_ringbuf.buf))); } static inline cid_t coroutine_ringbuf_pop(void) { if (coroutine_ringbuf.tail == coroutine_ringbuf.head) return 0; - return coroutine_ringbuf.buf[coroutine_ringbuf.tail++ % ARRAY_LEN(coroutine_ringbuf.buf)]; + return coroutine_ringbuf.buf[coroutine_ringbuf.tail++ % LM_ARRAY_LEN(coroutine_ringbuf.buf)]; +} + +#if CONFIG_COROUTINE_GDB +LM_NEVER_INLINE void cr_gdb_breakpoint(void) { + /* Prevent the call from being optimized away. */ + asm (""); +} +LM_NEVER_INLINE void cr_gdb_readjmp(cr_plat_jmp_buf *env) { + if (!cr_plat_setjmp(&coroutine_gdb_env)) + cr_plat_longjmp(env, 2); } +#define cr_setjmp(env) ({ \ + int val = cr_plat_setjmp(env); \ + if (val == 2) { \ + cr_gdb_breakpoint(); \ + cr_plat_longjmp(&coroutine_gdb_env, 1); \ + } \ + val; \ + }) +#else +#define cr_setjmp(env) cr_plat_setjmp(env) +#endif +#define cr_longjmp(env) cr_plat_longjmp(env, 1) static inline void assert_cid(cid_t cid) { assert(cid > 0); @@ -446,7 +515,7 @@ static inline void assert_cid(cid_t cid) { assert(coroutine_table[cid-1].stack_size); uint8_t *stack = coroutine_table[cid-1].stack; assert(stack); - for (size_t i = 0; i < STACK_GUARD_SIZE; i++) { + for (size_t i = 0; i < CR_STACK_GUARD_SIZE; i++) { size_t j = coroutine_table[cid-1].stack_size - (i+1); assert(stack[i] == stack_pattern[i%sizeof(stack_pattern)]); assert(stack[j] == stack_pattern[j%sizeof(stack_pattern)]); @@ -463,61 +532,84 @@ static inline void assert_cid(cid_t cid) { /* coroutine_add() ************************************************************/ +LM_NEVER_INLINE +cid_t coroutine_allocate_cid(void) { + static cid_t last_created = 0; + + size_t base = last_created; + for (size_t shift = 0; shift < CONFIG_COROUTINE_NUM; shift++) { + cid_t child = ((base + shift) % CONFIG_COROUTINE_NUM) + 1; + if (coroutine_table[child-1].state == CR_NONE) { + last_created = child; + return child; + } + } + return 0; +} + cid_t coroutine_add_with_stack_size(size_t stack_size, - const char __attribute__((unused)) *name, + const char *name, cr_fn_t fn, void *args) { - static cid_t last_created = 0; cid_t parent = coroutine_running; if (parent) assert_cid_state(parent, state == CR_RUNNING); assert(stack_size); assert(fn); - debugf("coroutine_add_with_stack_size(%zu, \"%s\", %p, %p)...\n", + debugf("coroutine_add_with_stack_size(%zu, \"%s\", %p, %p)...", stack_size, name, fn, args); - cid_t child; - { - size_t base = last_created; - for (size_t shift = 0; shift < CONFIG_COROUTINE_NUM; shift++) { - child = ((base + shift) % CONFIG_COROUTINE_NUM) + 1; - if (coroutine_table[child-1].state == CR_NONE) - goto found; - } - return 0; - found: + if (!coroutine_initialized) { + cr_plat_init(); + coroutine_initialized = true; } - debugf("...child=%zu\n", child); - last_created = child; + cid_t child = coroutine_allocate_cid(); + if (!child) + return 0; + debugf("...child=%zu", child); + + /* 1. state *************************************************/ + coroutine_table[child-1].state = CR_INITIALIZING; + + /* 2. name **************************************************/ + if (name) + strncpy(coroutine_table[child-1].name, name, sizeof(coroutine_table[child-1].name)); + else + memset(coroutine_table[child-1].name, 0, sizeof(coroutine_table[child-1].name)); - coroutine_table[child-1].stack_size = stack_size; + /* 3. stack *************************************************/ + coroutine_table[child-1].stack_size = stack_size + 2*CR_STACK_GUARD_SIZE; + infof("allocing \"%s\" stack with size %zu+2*%zu=%zu", + name, stack_size, CR_STACK_GUARD_SIZE, coroutine_table[child-1].stack_size); coroutine_table[child-1].stack = - aligned_alloc(CR_PLAT_STACK_ALIGNMENT, stack_size); + aligned_alloc(CR_PLAT_STACK_ALIGNMENT, coroutine_table[child-1].stack_size); + infof("... done, stack is [0x%p,0x%p)", + coroutine_table[child-1].stack + CR_STACK_GUARD_SIZE, + coroutine_table[child-1].stack + CR_STACK_GUARD_SIZE + stack_size); #if CONFIG_COROUTINE_MEASURE_STACK || CONFIG_COROUTINE_PROTECT_STACK - for (size_t i = 0; i < stack_size; i++) + for (size_t i = 0; i < coroutine_table[child-1].stack_size; i++) ((uint8_t *)coroutine_table[child-1].stack)[i] = stack_pattern[i%sizeof(stack_pattern)]; #endif #if CONFIG_COROUTINE_VALGRIND coroutine_table[child-1].stack_id = VALGRIND_STACK_REGISTER( - coroutine_table[child-1].stack + STACK_GUARD_SIZE, - coroutine_table[child-1].stack + stack_size - STACK_GUARD_SIZE); + coroutine_table[child-1].stack + CR_STACK_GUARD_SIZE, + coroutine_table[child-1].stack + CR_STACK_GUARD_SIZE + stack_size); #endif + /* 4. env ***************************************************/ coroutine_running = child; - coroutine_table[child-1].state = CR_INITIALIZING; - if (!cr_plat_setjmp(coroutine_add_env)) { /* point=a */ + coroutine_cnt++; + if (!cr_setjmp(&coroutine_add_env)) { /* point=a */ void *stack_base = coroutine_table[child-1].stack + + CR_STACK_GUARD_SIZE #if CR_PLAT_STACK_GROWS_DOWNWARD + stack_size - - STACK_GUARD_SIZE -#else - + STACK_GUARD_SIZE #endif ; - debugf("...stack =%p\n", coroutine_table[child-1].stack); - debugf("...stack_base=%p\n", stack_base); + debugf("...stack =%p", coroutine_table[child-1].stack); + debugf("...stack_base=%p", stack_base); /* run until cr_begin() */ cr_plat_call_with_stack(stack_base, fn, args); assert_notreached("should cr_begin() instead of returning"); @@ -535,20 +627,25 @@ cid_t coroutine_add_with_stack_size(size_t stack_size, return child; } -cid_t coroutine_add(const char *name, cr_fn_t fn, void *args) { - return coroutine_add_with_stack_size( - CONFIG_COROUTINE_DEFAULT_STACK_SIZE, name, fn, args); -} - /* coroutine_main() ***********************************************************/ -__attribute__ ((noreturn)) void coroutine_main(void) { - debugf("coroutine_main()\n"); +void coroutine_main(void) { + debugf("coroutine_main()"); + if (!coroutine_initialized) { + cr_plat_init(); + coroutine_initialized = true; + } bool saved = cr_save_and_disable_interrupts(); assert(saved); - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); coroutine_running = 0; - for (;;) { +#if CONFIG_COROUTINE_GDB + /* Some pointless call to prevent cr_gdb_readjmp() from + * getting pruned out by `ld --gc-sections`. */ + if (coroutine_table[0].state != CR_NONE) + cr_gdb_readjmp(&coroutine_table[0].env); +#endif + while (coroutine_cnt) { cid_t next; while ( !((next = coroutine_ringbuf_pop())) ) { /* No coroutines are runnable, wait for an interrupt @@ -556,10 +653,10 @@ __attribute__ ((noreturn)) void coroutine_main(void) { cr_plat_wait_for_interrupt(); } - if (!cr_plat_setjmp(coroutine_main_env)) { /* point=b */ + if (!cr_setjmp(&coroutine_main_env)) { /* point=b */ coroutine_running = next; coroutine_table[coroutine_running-1].state = CR_RUNNING; - cr_plat_longjmp(coroutine_table[coroutine_running-1].env, 1); /* jump to point=c */ + cr_longjmp(&coroutine_table[coroutine_running-1].env); /* jump to point=c */ } /* This is where we jump to from cr_exit(), and from * nowhere else. */ @@ -569,21 +666,23 @@ __attribute__ ((noreturn)) void coroutine_main(void) { #endif free(coroutine_table[coroutine_running-1].stack); coroutine_table[coroutine_running-1] = (struct coroutine){0}; + coroutine_cnt--; } + coroutine_running = 0; + cr_restore_interrupts(saved); } /* cr_*() *********************************************************************/ void cr_begin(void) { - debugf("cid=%zu: cr_begin()\n", coroutine_running); + debugf("cid=%zu: cr_begin()", coroutine_running); assert_cid_state(coroutine_running, state == CR_INITIALIZING); bool saved = cr_save_and_disable_interrupts(); coroutine_table[coroutine_running-1].state = CR_RUNNABLE; coroutine_ringbuf_push(coroutine_running); - coroutine_table[coroutine_running-1].sp = cr_plat_get_sp(); - if (!cr_plat_setjmp(coroutine_table[coroutine_running-1].env)) /* point=c1 */ - cr_plat_longjmp(coroutine_add_env, 1); /* jump to point=a */ + if (!cr_setjmp(&coroutine_table[coroutine_running-1].env)) /* point=c1 */ + cr_longjmp(&coroutine_add_env); /* jump to point=a */ cr_restore_interrupts(saved); } @@ -600,17 +699,16 @@ static inline void _cr_yield() { return; } - coroutine_table[coroutine_running-1].sp = cr_plat_get_sp(); - if (!cr_plat_setjmp(coroutine_table[coroutine_running-1].env)) { /* point=c2 */ + if (!cr_setjmp(&coroutine_table[coroutine_running-1].env)) { /* point=c2 */ coroutine_running = next; coroutine_table[coroutine_running-1].state = CR_RUNNING; - cr_plat_longjmp(coroutine_table[coroutine_running-1].env, 1); /* jump to point=c */ + cr_longjmp(&coroutine_table[coroutine_running-1].env); /* jump to point=c */ } } void cr_yield(void) { - debugf("cid=%zu: cr_yield()\n", coroutine_running); - assert(!cr_is_in_intrhandler()); + debugf("cid=%zu: cr_yield()", coroutine_running); + assert(!cr_plat_is_in_intrhandler()); assert_cid_state(coroutine_running, state == CR_RUNNING); bool saved = cr_save_and_disable_interrupts(); @@ -621,8 +719,8 @@ void cr_yield(void) { } void cr_pause_and_yield(void) { - debugf("cid=%zu: cr_pause_and_yield()\n", coroutine_running); - assert(!cr_is_in_intrhandler()); + debugf("cid=%zu: cr_pause_and_yield()", coroutine_running); + assert(!cr_plat_is_in_intrhandler()); assert_cid_state(coroutine_running, state == CR_RUNNING); bool saved = cr_save_and_disable_interrupts(); @@ -631,14 +729,14 @@ void cr_pause_and_yield(void) { cr_restore_interrupts(saved); } -__attribute__ ((noreturn)) void cr_exit(void) { - debugf("cid=%zu: cr_exit()\n", coroutine_running); - assert(!cr_is_in_intrhandler()); +[[noreturn]] void cr_exit(void) { + debugf("cid=%zu: cr_exit()", coroutine_running); + assert(!cr_plat_is_in_intrhandler()); assert_cid_state(coroutine_running, state == CR_RUNNING); (void)cr_save_and_disable_interrupts(); coroutine_table[coroutine_running-1].state = CR_NONE; - cr_plat_longjmp(coroutine_main_env, 1); /* jump to point=b */ + cr_longjmp(&coroutine_main_env); /* jump to point=b */ } static void _cr_unpause(cid_t cid) { @@ -649,8 +747,8 @@ static void _cr_unpause(cid_t cid) { } void cr_unpause(cid_t cid) { - debugf("cr_unpause(%zu)\n", cid); - assert(!cr_is_in_intrhandler()); + debugf("cr_unpause(%zu)", cid); + assert(!cr_plat_is_in_intrhandler()); assert_cid_state(coroutine_running, state == CR_RUNNING); bool saved = cr_save_and_disable_interrupts(); @@ -659,42 +757,77 @@ void cr_unpause(cid_t cid) { } void cr_unpause_from_intrhandler(cid_t cid) { - debugf("cr_unpause_from_intrhandler(%zu)\n", cid); - assert(cr_is_in_intrhandler()); + debugf("cr_unpause_from_intrhandler(%zu)", cid); + assert(cr_plat_is_in_intrhandler()); _cr_unpause(cid); } cid_t cr_getcid(void) { - assert(!cr_is_in_intrhandler()); + assert(!cr_plat_is_in_intrhandler()); assert_cid_state(coroutine_running, state == CR_RUNNING); return coroutine_running; } -/* cr_cid_info() **************************************************************/ +#ifndef NDEBUG +void cr_assert_in_coroutine(void) { + assert(!cr_plat_is_in_intrhandler()); + assert_cid_state(coroutine_running, state == CR_RUNNING); +} -#if CONFIG_COROUTINE_MEASURE_STACK +void cr_assert_in_intrhandler(void) { + assert(cr_plat_is_in_intrhandler()); +} +#endif + +/* answering questions about coroutines ***************************************/ void cr_cid_info(cid_t cid, struct cr_cid_info *ret) { - assert_cid(cid); + assert(cid > 0); + assert(cid <= CONFIG_COROUTINE_NUM); assert(ret); + memset(ret, 0, sizeof(*ret)); + if (coroutine_table[cid-1].state == CR_NONE) + return; + assert_cid(cid); + + /* 1. state *************************************************/ + ret->state = coroutine_table[cid-1].state; + + /* 2. name **************************************************/ + memcpy(ret->name, coroutine_table[cid-1].name, CONFIG_COROUTINE_NAME_LEN); + + /* 3. stack *************************************************/ +#if CONFIG_COROUTINE_MEASURE_STACK + uint8_t *stack = (uint8_t *)coroutine_table[cid-1].stack; + uint8_t *stack_lo = stack + CR_STACK_GUARD_SIZE; + uint8_t *stack_hi = stack + coroutine_table[cid-1].stack_size - CR_STACK_GUARD_SIZE; + /* stack_cap */ - ret->stack_cap = coroutine_table[cid-1].stack_size - 2*STACK_GUARD_SIZE; + ret->stack_cap = stack_hi - stack_lo; /* stack_max */ ret->stack_max = ret->stack_cap; - uint8_t *stack = (uint8_t *)coroutine_table[cid-1].stack; for (;;) { size_t i = #if CR_PLAT_STACK_GROWS_DOWNWARD - STACK_GUARD_SIZE + ret->stack_cap - ret->stack_max + CR_STACK_GUARD_SIZE + ret->stack_cap - ret->stack_max #else - ret->stack_max - 1 - STACK_GUARD_SIZE + ret->stack_max - 1 - CR_STACK_GUARD_SIZE #endif ; - if (ret->stack_max == 0 || - stack[i] != stack_pattern[i%sizeof(stack_pattern)]) + if (ret->stack_max == 0) + break; + assert(stack_lo <= &stack[i] && &stack[i] < stack_hi); +#if CONFIG_COROUTINE_VALGRIND + VALGRIND_DISABLE_ERROR_REPORTING; +#endif + uint8_t v = stack[i]; +#if CONFIG_COROUTINE_VALGRIND + VALGRIND_ENABLE_ERROR_REPORTING; +#endif + if (v != stack_pattern[i%sizeof(stack_pattern)]) break; ret->stack_max--; } @@ -703,15 +836,22 @@ void cr_cid_info(cid_t cid, struct cr_cid_info *ret) { uintptr_t sp; if (cid == coroutine_running) sp = cr_plat_get_sp(); + else if (coroutine_table[cid-1].state == CR_RUNNING) + sp = cr_plat_setjmp_get_sp(&coroutine_add_env); else - sp = coroutine_table[cid-1].sp; + sp = cr_plat_setjmp_get_sp(&coroutine_table[cid-1].env); assert(sp); - uintptr_t sb = (uintptr_t)coroutine_table[cid-1].stack; #if CR_PLAT_STACK_GROWS_DOWNWARD - ret->stack_cur = (sb - STACK_GUARD_SIZE) - sp; + uintptr_t sb = (uintptr_t)stack_hi; + ret->stack_cur = sb - sp; #else - ret->stack_cur = sp - (sb + STACK_GUARD_SIZE); + uintptr_t sb = (uintptr_t)stack_lo; + ret->stack_cur = sp - sb; #endif +#endif /* CONFIG_COROUTINE_MEASURE_STACK */ } -#endif /* CONFIG_COROUTINE_MEASURE_STACK */ +const char *coroutine_state_str(enum coroutine_state state) { + assert(state < LM_ARRAY_LEN(coroutine_state_strs)); + return coroutine_state_strs[state]; +} |