From f64ebb1c1f10e8d15fcc4879d781703c86c5fb8b Mon Sep 17 00:00:00 2001
From: Michael Sevakis <jethead71@rockbox.org>
Date: Sat, 8 Sep 2007 12:20:53 +0000
Subject: Sim I/O and threading that runs more like on target. Tweakable if any
 genuine slowness imitation is required for any one of them. One point of
 concern is the sim shutdown on an OS other than Linux just because
 terminating threads in a manner other than having the do it themselves is
 kind of dirty IMHO.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14639 a1c6a512-1295-4272-9138-f99709370657
---
 uisimulator/common/io.c | 169 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 168 insertions(+), 1 deletion(-)

(limited to 'uisimulator/common')

diff --git a/uisimulator/common/io.c b/uisimulator/common/io.c
index 3f7087876a..127a1c36f1 100644
--- a/uisimulator/common/io.c
+++ b/uisimulator/common/io.c
@@ -47,7 +47,10 @@
 #define MAX_PATH 260
 
 #include <fcntl.h>
-
+#include <SDL.h>
+#include <SDL_thread.h>
+#include "thread.h"
+#include "kernel.h"
 #include "debug.h"
 #include "config.h"
 
@@ -175,6 +178,131 @@ static unsigned int rockbox2sim(int opt)
 }
 #endif
 
+/** Simulator I/O engine routines **/
+enum
+{
+    IO_QUIT = -1,
+    IO_OPEN,
+    IO_CLOSE,
+    IO_READ,
+    IO_WRITE,
+};
+
+struct sim_io
+{
+    SDL_mutex *m; /* Mutex for condition */
+    SDL_cond *c;  /* Condition for synchronizing threads */
+    SDL_Thread *t; /* The I/O thread */
+    struct mutex sim_mutex; /* Rockbox mutex */
+    volatile int cmd; /* The command to perform */
+    volatile int ready; /* I/O ready flag - 1= ready */
+    volatile int fd; /* The file to read/write */
+    void* volatile buf; /* The buffer to read/write */
+    volatile size_t count; /* Number of bytes to read/write */
+    ssize_t result; /* Result of operation */
+};
+
+static struct sim_io io;
+
+static int io_thread(void *data)
+{
+    SDL_LockMutex(io.m);
+
+    io.ready = 1; /* Indication mutex has been locked */
+
+    for (;;)
+    {
+        SDL_CondWait(io.c, io.m); /* unlock mutex and wait */
+
+        switch (io.cmd)
+        {
+        case IO_READ:
+            io.result = read(io.fd, io.buf, io.count);
+            io.ready = 1;
+            break;
+        case IO_WRITE:
+            io.result = write(io.fd, io.buf, io.count);
+            io.ready = 1;
+            break;
+        case IO_QUIT:
+            SDL_UnlockMutex(io.m);
+            return 0;
+        }
+    }
+
+    (void)data;
+}
+
+void sim_io_init(void)
+{
+    mutex_init(&io.sim_mutex);
+
+    io.ready = 0;
+
+    io.m = SDL_CreateMutex();
+    if (io.m == NULL)
+    {
+        fprintf(stderr, "Failed to create IO mutex\n");
+        exit(-1);
+    }
+
+    io.c = SDL_CreateCond();
+    if (io.c == NULL)
+    {
+        fprintf(stderr, "Failed to create IO cond\n");
+        exit(-1);
+    }
+
+    io.t = SDL_CreateThread(io_thread, NULL);
+    if (io.t == NULL)
+    {
+        fprintf(stderr, "Failed to create IO thread\n");
+        exit(-1);
+    }
+
+    /* Wait for IO thread to lock mutex */
+    while (!io.ready);
+
+    /* Wait for it to unlock */
+    SDL_LockMutex(io.m);
+    /* Free it for another thread */
+    SDL_UnlockMutex(io.m);
+}
+
+void sim_io_shutdown(void)
+{
+    SDL_LockMutex(io.m);
+
+    io.cmd = IO_QUIT;
+
+    SDL_CondSignal(io.c);
+    SDL_UnlockMutex(io.m);
+
+    SDL_WaitThread(io.t, NULL);
+
+    SDL_DestroyMutex(io.m);
+    SDL_DestroyCond(io.c);
+}
+
+static void io_trigger_and_wait(int cmd)
+{
+    /* Lock mutex before setting up new params and signaling condition */
+    SDL_LockMutex(io.m);
+
+    io.cmd = cmd;
+    io.ready = 0;
+
+    /* Get thread started */
+    SDL_CondSignal(io.c);
+
+    /* Let it run */
+    SDL_UnlockMutex(io.m);
+
+    /* Wait for IO to complete */
+    while (!io.ready)
+        yield();
+}
+
 MYDIR *sim_opendir(const char *name)
 {
     char buffer[MAX_PATH]; /* sufficiently big */
@@ -287,6 +415,45 @@ int sim_creat(const char *name)
 #endif
 }      
 
+ssize_t sim_read(int fd, void *buf, size_t count)
+{
+    ssize_t result;
+
+    mutex_lock(&io.sim_mutex);
+
+    /* Setup parameters */
+    io.fd = fd;
+    io.buf = buf;
+    io.count = count;
+
+    io_trigger_and_wait(IO_READ);
+
+    result = io.result;
+
+    mutex_unlock(&io.sim_mutex);
+
+    return result;
+}
+
+ssize_t sim_write(int fd, const void *buf, size_t count)
+{
+    ssize_t result;
+
+    mutex_lock(&io.sim_mutex);
+
+    io.fd = fd;
+    io.buf = (void*)buf;
+    io.count = count;
+
+    io_trigger_and_wait(IO_WRITE);
+
+    result = io.result;
+
+    mutex_unlock(&io.sim_mutex);
+
+    return result;
+}
+
 int sim_mkdir(const char *name)
 {
 #ifdef __PCTOOL__
-- 
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