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-rw-r--r--coro.c206
-rw-r--r--coro.h40
2 files changed, 159 insertions, 87 deletions
diff --git a/coro.c b/coro.c
index bc382d3..625eb3e 100644
--- a/coro.c
+++ b/coro.c
@@ -40,6 +40,8 @@
#include "coro.h"
+#include <string.h>
+
#if !defined(STACK_ADJUST_PTR)
/* IRIX is decidedly NON-unix */
# if __sgi
@@ -63,13 +65,13 @@
#if CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM
-#include <stdlib.h>
+# include <stdlib.h>
-#if CORO_SJLJ
-# include <stdio.h>
-# include <signal.h>
-# include <unistd.h>
-#endif
+# if CORO_SJLJ
+# include <stdio.h>
+# include <signal.h>
+# include <unistd.h>
+# endif
static volatile coro_func coro_init_func;
static volatile void *coro_init_arg;
@@ -77,9 +79,9 @@ static volatile coro_context *new_coro, *create_coro;
/* what we really want to detect here is wether we use a new-enough version of GAS */
/* instead, check for gcc 3, ELF and GNU/Linux and hope for the best */
-#if __GNUC__ >= 3 && __ELF__ && __linux__
-# define HAVE_CFI 1
-#endif
+# if __GNUC__ >= 3 && __ELF__ && __linux__
+# define HAVE_CFI 1
+# endif
static void
coro_init (void)
@@ -105,13 +107,13 @@ trampoline (int sig)
{
if (setjmp (((coro_context *)new_coro)->env))
{
-#if HAVE_CFI
+# if HAVE_CFI
asm (".cfi_startproc");
-#endif
+# endif
coro_init (); /* start it */
-#if HAVE_CFI
+# if HAVE_CFI
asm (".cfi_endproc");
-#endif
+# endif
}
else
trampoline_count++;
@@ -122,55 +124,68 @@ trampoline (int sig)
#endif
#if CORO_ASM
-asm (
- ".text\n"
- ".globl coro_transfer\n"
- ".type coro_transfer, @function\n"
- "coro_transfer:\n"
-#if __amd64
-# define NUM_SAVED 6
- "\tpush %rbp\n"
- "\tpush %rbx\n"
- "\tpush %r12\n"
- "\tpush %r13\n"
- "\tpush %r14\n"
- "\tpush %r15\n"
- "\tmov %rsp, (%rdi)\n"
- "\tmov (%rsi), %rsp\n"
- "\tpop %r15\n"
- "\tpop %r14\n"
- "\tpop %r13\n"
- "\tpop %r12\n"
- "\tpop %rbx\n"
- "\tpop %rbp\n"
-#elif __i386
-# define NUM_SAVED 4
- "\tpush %ebp\n"
- "\tpush %ebx\n"
- "\tpush %esi\n"
- "\tpush %edi\n"
- "\tmov %esp, (%eax)\n"
- "\tmov (%edx), %esp\n"
- "\tpop %edi\n"
- "\tpop %esi\n"
- "\tpop %ebx\n"
- "\tpop %ebp\n"
-#else
-# error unsupported architecture
-#endif
- "\tret\n"
-);
+
+ asm (
+ ".text\n"
+ ".globl coro_transfer\n"
+ ".type coro_transfer, @function\n"
+ "coro_transfer:\n"
+# if __amd64
+# define NUM_SAVED 6
+ "\tpush %rbp\n"
+ "\tpush %rbx\n"
+ "\tpush %r12\n"
+ "\tpush %r13\n"
+ "\tpush %r14\n"
+ "\tpush %r15\n"
+ "\tmov %rsp, (%rdi)\n"
+ "\tmov (%rsi), %rsp\n"
+ "\tpop %r15\n"
+ "\tpop %r14\n"
+ "\tpop %r13\n"
+ "\tpop %r12\n"
+ "\tpop %rbx\n"
+ "\tpop %rbp\n"
+# elif __i386
+# define NUM_SAVED 4
+ "\tpush %ebp\n"
+ "\tpush %ebx\n"
+ "\tpush %esi\n"
+ "\tpush %edi\n"
+ "\tmov %esp, (%eax)\n"
+ "\tmov (%edx), %esp\n"
+ "\tpop %edi\n"
+ "\tpop %esi\n"
+ "\tpop %ebx\n"
+ "\tpop %ebp\n"
+# else
+# error unsupported architecture
+# endif
+ "\tret\n"
+ );
+
#endif
#if CORO_PTHREAD
-struct coro_init_args {
+/* this mutex will be locked by the running coroutine */
+pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
+
+struct coro_init_args
+{
coro_func func;
void *arg;
coro_context *self, *main;
};
-pthread_mutex_t coro_mutex = PTHREAD_MUTEX_INITIALIZER;
+static pthread_t null_tid;
+
+/* I'd so love to cast pthread_mutex_unlock to void (*)(void *)... */
+static void
+mutex_unlock_wrapper (void *arg)
+{
+ pthread_mutex_unlock ((pthread_mutex_t *)arg);
+}
static void *
trampoline (void *args_)
@@ -180,33 +195,48 @@ trampoline (void *args_)
void *arg = args->arg;
pthread_mutex_lock (&coro_mutex);
- pthread_cond_destroy (&args->self->c);
- coro_transfer (args->self, args->main);
- func (arg);
- pthread_mutex_unlock (&coro_mutex);
+
+ /* we try to be good citizens and use deferred cancellation and cleanup handlers */
+ pthread_cleanup_push (mutex_unlock_wrapper, &coro_mutex);
+ coro_transfer (args->self, args->main);
+ func (arg);
+ pthread_cleanup_pop (1);
return 0;
}
-asm("");
+void
+coro_transfer (coro_context *prev, coro_context *next)
+{
+ pthread_cond_signal (&next->cv);
+ pthread_cond_wait (&prev->cv, &coro_mutex);
+}
-void coro_transfer(coro_context *prev, coro_context *next)
+void
+coro_destroy (coro_context *ctx)
{
- pthread_cond_init (&prev->c, 0);
- pthread_cond_signal (&next->c);
- pthread_cond_wait (&prev->c, &coro_mutex);
- pthread_cond_destroy (&prev->c);
+ if (!pthread_equal (ctx->id, null_tid))
+ {
+ pthread_cancel (ctx->id);
+ pthread_mutex_unlock (&coro_mutex);
+ pthread_join (ctx->id, 0);
+ pthread_mutex_lock (&coro_mutex);
+ }
+
+ pthread_cond_destroy (&ctx->cv);
}
#endif
/* initialize a machine state */
-void coro_create (coro_context *ctx,
- coro_func coro, void *arg,
- void *sptr, long ssize)
+void
+coro_create (coro_context *ctx, coro_func coro, void *arg, void *sptr, long ssize)
{
#if CORO_UCONTEXT
+ if (!coro)
+ return;
+
getcontext (&(ctx->uc));
ctx->uc.uc_link = 0;
@@ -214,7 +244,7 @@ void coro_create (coro_context *ctx,
ctx->uc.uc_stack.ss_size = (size_t)STACK_ADJUST_SIZE (sptr,ssize);
ctx->uc.uc_stack.ss_flags = 0;
- makecontext (&(ctx->uc), (void (*)()) coro, 1, arg);
+ makecontext (&(ctx->uc), (void (*)())coro, 1, arg);
#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX || CORO_ASM
@@ -225,6 +255,9 @@ void coro_create (coro_context *ctx,
# endif
coro_context nctx;
+ if (!coro)
+ return;
+
coro_init_func = coro;
coro_init_arg = arg;
@@ -339,30 +372,39 @@ void coro_create (coro_context *ctx,
# elif CORO_PTHREAD
- pthread_t id;
- pthread_attr_t attr;
- coro_context nctx;
- struct coro_init_args args;
+ static coro_context nctx;
static int once;
if (!once)
{
- pthread_mutex_lock (&coro_mutex);
once = 1;
+
+ pthread_mutex_lock (&coro_mutex);
+ pthread_cond_init (&nctx.cv, 0);
+ null_tid = pthread_self ();
}
- args.func = coro;
- args.arg = arg;
- args.self = ctx;
- args.main = &nctx;
+ pthread_cond_init (&ctx->cv, 0);
- pthread_attr_init (&attr);
- pthread_attr_setdetachstate (&attr, PTHREAD_CREATE_DETACHED);
- pthread_attr_setstack (&attr, sptr, (size_t)ssize);
- pthread_create (&id, &attr, trampoline, &args);
+ if (coro)
+ {
+ pthread_attr_t attr;
+ struct coro_init_args args;
+
+ args.func = coro;
+ args.arg = arg;
+ args.self = ctx;
+ args.main = &nctx;
+
+ pthread_attr_init (&attr);
+ pthread_attr_setstack (&attr, sptr, (size_t)ssize);
+ pthread_attr_setscope (&attr, PTHREAD_SCOPE_PROCESS);
+ pthread_create (&ctx->id, &attr, trampoline, &args);
- pthread_cond_init (&args.self->c, 0);
- coro_transfer (args.main, args.self);
+ coro_transfer (args.main, args.self);
+ }
+ else
+ ctx->id = null_tid;
#else
# error unsupported backend
diff --git a/coro.h b/coro.h
index 3fdd555..2a907b0 100644
--- a/coro.h
+++ b/coro.h
@@ -59,6 +59,9 @@
* 2008-11-03 Use a global asm statement for CORO_ASM, idea by pippijn.
* 2008-11-05 Hopefully fix misaligned stacks with CORO_ASM/SETJMP.
* 2008-11-07 rbp wasn't saved in CORO_ASM on x86_64.
+ * introduce coro_destroy, which is a nop except for pthreads.
+ * speed up CORO_PTHREAD. Do no longer leak threads either.
+ * coro_create now allows one to create source coro_contexts.
*/
#ifndef CORO_H
@@ -139,8 +142,14 @@ typedef struct coro_context coro_context;
* uninitialised coro_context, it expects a pointer to the entry function
* and the single pointer value that is given to it as argument.
*
- * Allocating/deallocating the stack is your own responsibility, so there is
- * no coro_destroy function.
+ * Allocating/deallocating the stack is your own responsibility.
+ *
+ * As a special case, if coro, arg, sptr and ssize are all zero,
+ * then an "empty" coro_contetx will be created that is suitable
+ * as an initial source for coro_transfer.
+ *
+ * This function is not reentrant, but putting a mutex around it
+ * will work.
*/
void coro_create (coro_context *ctx, /* an uninitialised coro_context */
coro_func coro, /* the coroutine code to be executed */
@@ -152,8 +161,22 @@ void coro_create (coro_context *ctx, /* an uninitialised coro_context */
* The following prototype defines the coroutine switching function. It is
* usually implemented as a macro, so watch out.
*
-void coro_transfer(coro_context *prev, coro_context *next);
+ * This function is thread-safe and reentrant.
*/
+#if 0
+void coro_transfer (coro_context *prev, coro_context *next);
+#endif
+
+/*
+ * The following prototype defines the coroutine destroy function. It is
+ * usually implemented as a macro, so watch out. It also serves
+ * no purpose unless you want to use the CORO_PTHREAD backend.
+ *
+ * This function is thread-safe and reentrant.
+ */
+#if 0
+void coro_destroy (coro_context *ctx);
+#endif
/*
* That was it. No other user-visible functions are implemented here.
@@ -189,6 +212,7 @@ struct coro_context {
};
# define coro_transfer(p,n) swapcontext (&((p)->uc), &((n)->uc))
+# define coro_destroy(ctx) (void *)(ctx)
#elif CORO_SJLJ || CORO_LOSER || CORO_LINUX || CORO_IRIX
@@ -208,6 +232,8 @@ struct coro_context {
# define coro_transfer(p,n) do { if (!setjmp ((p)->env)) longjmp ((n)->env, 1); } while (0)
# endif
+# define coro_destroy(ctx) (void *)(ctx)
+
#elif CORO_ASM
struct coro_context {
@@ -217,17 +243,21 @@ struct coro_context {
void __attribute__ ((__noinline__, __regparm__(2)))
coro_transfer (coro_context *prev, coro_context *next);
+# define coro_destroy(ctx) (void *)(ctx)
+
#elif CORO_PTHREAD
-#include <pthread.h>
+# include <pthread.h>
extern pthread_mutex_t coro_mutex;
struct coro_context {
- pthread_cond_t c;
+ pthread_cond_t cv;
+ pthread_t id;
};
void coro_transfer (coro_context *prev, coro_context *next);
+void coro_destroy (coro_context *ctx);
#endif
generated by cgit v1.2.3 (git 2.39.1) at 2025-10-31 19:58:25 +0000